зеркало из https://github.com/Azure/ARO-RP.git
Vendor
This commit is contained in:
Mikalai Radchuk
Родитель
0083f846d0
Коммит
93d2da5684
|
|
@ -529,6 +529,14 @@
|
|||
revision = "6c65a5562fc06764971b7c5d05c76c75e84bdbf7"
|
||||
version = "v1.3.2"
|
||||
|
||||
[[projects]]
|
||||
digest = "1:0bfbe13936953a98ae3cfe8ed6670d396ad81edf069a806d2f6515d7bb6950df"
|
||||
name = "github.com/google/btree"
|
||||
packages = ["."]
|
||||
pruneopts = "UT"
|
||||
revision = "4030bb1f1f0c35b30ca7009e9ebd06849dd45306"
|
||||
version = "v1.0.0"
|
||||
|
||||
[[projects]]
|
||||
digest = "1:0aeda02073125667ac6c9df50c7921cb22c08a4accdc54589c697a7e76be65c2"
|
||||
name = "github.com/google/go-cmp"
|
||||
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@ -616,6 +624,17 @@
|
|||
revision = "00bdffe0f3c77e27d2cf6f5c70232a2d3e4d9c15"
|
||||
version = "v1.7.3"
|
||||
|
||||
[[projects]]
|
||||
branch = "master"
|
||||
digest = "1:5fc0e23b254a1bd7d8d2d42fa093ba33471d08f52fe04afd3713adabb5888dc3"
|
||||
name = "github.com/gregjones/httpcache"
|
||||
packages = [
|
||||
".",
|
||||
"diskcache",
|
||||
]
|
||||
pruneopts = "UT"
|
||||
revision = "901d90724c7919163f472a9812253fb26761123d"
|
||||
|
||||
[[projects]]
|
||||
digest = "1:a1038ef593beb4771c8f0f9c26e8b00410acd800af5c6864651d9bf160ea1813"
|
||||
name = "github.com/hpcloud/tail"
|
||||
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@ -1159,6 +1178,22 @@
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|||
revision = "adf5a7427709b9deb95d29d3fa8a2bf9cfd388f1"
|
||||
version = "v1.2"
|
||||
|
||||
[[projects]]
|
||||
branch = "master"
|
||||
digest = "1:89da0f0574bc94cfd0ac8b59af67bf76cdd110d503df2721006b9f0492394333"
|
||||
name = "github.com/petar/GoLLRB"
|
||||
packages = ["llrb"]
|
||||
pruneopts = "UT"
|
||||
revision = "33fb24c13b99c46c93183c291836c573ac382536"
|
||||
|
||||
[[projects]]
|
||||
digest = "1:a8c2725121694dfbf6d552fb86fe6b46e3e7135ea05db580c28695b916162aad"
|
||||
name = "github.com/peterbourgon/diskv"
|
||||
packages = ["."]
|
||||
pruneopts = "UT"
|
||||
revision = "0be1b92a6df0e4f5cb0a5d15fb7f643d0ad93ce6"
|
||||
version = "v3.0.0"
|
||||
|
||||
[[projects]]
|
||||
digest = "1:cf31692c14422fa27c83a05292eb5cbe0fb2775972e8f1f8446a71549bd8980b"
|
||||
name = "github.com/pkg/errors"
|
||||
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@ -1732,10 +1767,11 @@
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|||
|
||||
[[projects]]
|
||||
branch = "origin-4.3-kubernetes-1.16.2"
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||||
digest = "1:121980454af2ecc796d3d5c7bf3a4e52773c5aa6b1d7e7528140f76ab70c2f5f"
|
||||
digest = "1:812e13dc35a042fcdddb85d9392e3746d86878ebe0c5f4e67fdc8700c276757f"
|
||||
name = "k8s.io/client-go"
|
||||
packages = [
|
||||
"discovery",
|
||||
"discovery/cached/disk",
|
||||
"discovery/fake",
|
||||
"dynamic",
|
||||
"kubernetes",
|
||||
|
|
@ -1970,6 +2006,7 @@
|
|||
"github.com/golang/mock/gomock",
|
||||
"github.com/golang/mock/mockgen",
|
||||
"github.com/google/go-cmp/cmp",
|
||||
"github.com/googleapis/gnostic/OpenAPIv2",
|
||||
"github.com/gorilla/mux",
|
||||
"github.com/jim-minter/go-cosmosdb/cmd/gencosmosdb",
|
||||
"github.com/jmespath/go-jmespath",
|
||||
|
|
@ -2029,6 +2066,7 @@
|
|||
"github.com/ugorji/go/codec",
|
||||
"golang.org/x/crypto/chacha20poly1305",
|
||||
"golang.org/x/crypto/ssh",
|
||||
"golang.org/x/net/context",
|
||||
"golang.org/x/sync/errgroup",
|
||||
"golang.org/x/tools/cmd/goimports",
|
||||
"golang.org/x/tools/go/ast/astutil",
|
||||
|
|
@ -2046,17 +2084,19 @@
|
|||
"k8s.io/apimachinery/pkg/util/httpstream",
|
||||
"k8s.io/apimachinery/pkg/util/httpstream/spdy",
|
||||
"k8s.io/apimachinery/pkg/util/wait",
|
||||
"k8s.io/apimachinery/pkg/version",
|
||||
"k8s.io/client-go/discovery",
|
||||
"k8s.io/client-go/discovery/cached/disk",
|
||||
"k8s.io/client-go/dynamic",
|
||||
"k8s.io/client-go/kubernetes",
|
||||
"k8s.io/client-go/kubernetes/fake",
|
||||
"k8s.io/client-go/kubernetes/scheme",
|
||||
"k8s.io/client-go/kubernetes/typed/core/v1",
|
||||
"k8s.io/client-go/rest",
|
||||
"k8s.io/client-go/testing",
|
||||
"k8s.io/client-go/tools/clientcmd",
|
||||
"k8s.io/client-go/tools/clientcmd/api/v1",
|
||||
"k8s.io/client-go/tools/metrics",
|
||||
"k8s.io/client-go/util/flowcontrol",
|
||||
"k8s.io/client-go/util/retry",
|
||||
]
|
||||
solver-name = "gps-cdcl"
|
||||
|
|
|
|||
|
|
@ -396,6 +396,15 @@
|
|||
}
|
||||
}
|
||||
},
|
||||
{
|
||||
"component": {
|
||||
"type": "git",
|
||||
"git": {
|
||||
"commitHash": "4030bb1f1f0c35b30ca7009e9ebd06849dd45306",
|
||||
"repositoryUrl": "https://github.com/google/btree/"
|
||||
}
|
||||
}
|
||||
},
|
||||
{
|
||||
"component": {
|
||||
"type": "git",
|
||||
|
|
@ -459,6 +468,15 @@
|
|||
}
|
||||
}
|
||||
},
|
||||
{
|
||||
"component": {
|
||||
"type": "git",
|
||||
"git": {
|
||||
"commitHash": "901d90724c7919163f472a9812253fb26761123d",
|
||||
"repositoryUrl": "https://github.com/gregjones/httpcache/"
|
||||
}
|
||||
}
|
||||
},
|
||||
{
|
||||
"component": {
|
||||
"type": "git",
|
||||
|
|
@ -837,6 +855,24 @@
|
|||
}
|
||||
}
|
||||
},
|
||||
{
|
||||
"component": {
|
||||
"type": "git",
|
||||
"git": {
|
||||
"commitHash": "33fb24c13b99c46c93183c291836c573ac382536",
|
||||
"repositoryUrl": "https://github.com/petar/GoLLRB/"
|
||||
}
|
||||
}
|
||||
},
|
||||
{
|
||||
"component": {
|
||||
"type": "git",
|
||||
"git": {
|
||||
"commitHash": "0be1b92a6df0e4f5cb0a5d15fb7f643d0ad93ce6",
|
||||
"repositoryUrl": "https://github.com/peterbourgon/diskv/"
|
||||
}
|
||||
}
|
||||
},
|
||||
{
|
||||
"component": {
|
||||
"type": "git",
|
||||
|
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|
|||
|
|
@ -0,0 +1 @@
|
|||
language: go
|
||||
|
|
@ -0,0 +1,202 @@
|
|||
|
||||
Apache License
|
||||
Version 2.0, January 2004
|
||||
http://www.apache.org/licenses/
|
||||
|
||||
TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
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|
@ -0,0 +1,12 @@
|
|||
# BTree implementation for Go
|
||||
|
||||
|
||||
|
||||
This package provides an in-memory B-Tree implementation for Go, useful as
|
||||
an ordered, mutable data structure.
|
||||
|
||||
The API is based off of the wonderful
|
||||
http://godoc.org/github.com/petar/GoLLRB/llrb, and is meant to allow btree to
|
||||
act as a drop-in replacement for gollrb trees.
|
||||
|
||||
See http://godoc.org/github.com/google/btree for documentation.
|
||||
|
|
@ -0,0 +1,890 @@
|
|||
// Copyright 2014 Google Inc.
|
||||
//
|
||||
// Licensed under the Apache License, Version 2.0 (the "License");
|
||||
// you may not use this file except in compliance with the License.
|
||||
// You may obtain a copy of the License at
|
||||
//
|
||||
// http://www.apache.org/licenses/LICENSE-2.0
|
||||
//
|
||||
// Unless required by applicable law or agreed to in writing, software
|
||||
// distributed under the License is distributed on an "AS IS" BASIS,
|
||||
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
// See the License for the specific language governing permissions and
|
||||
// limitations under the License.
|
||||
|
||||
// Package btree implements in-memory B-Trees of arbitrary degree.
|
||||
//
|
||||
// btree implements an in-memory B-Tree for use as an ordered data structure.
|
||||
// It is not meant for persistent storage solutions.
|
||||
//
|
||||
// It has a flatter structure than an equivalent red-black or other binary tree,
|
||||
// which in some cases yields better memory usage and/or performance.
|
||||
// See some discussion on the matter here:
|
||||
// http://google-opensource.blogspot.com/2013/01/c-containers-that-save-memory-and-time.html
|
||||
// Note, though, that this project is in no way related to the C++ B-Tree
|
||||
// implementation written about there.
|
||||
//
|
||||
// Within this tree, each node contains a slice of items and a (possibly nil)
|
||||
// slice of children. For basic numeric values or raw structs, this can cause
|
||||
// efficiency differences when compared to equivalent C++ template code that
|
||||
// stores values in arrays within the node:
|
||||
// * Due to the overhead of storing values as interfaces (each
|
||||
// value needs to be stored as the value itself, then 2 words for the
|
||||
// interface pointing to that value and its type), resulting in higher
|
||||
// memory use.
|
||||
// * Since interfaces can point to values anywhere in memory, values are
|
||||
// most likely not stored in contiguous blocks, resulting in a higher
|
||||
// number of cache misses.
|
||||
// These issues don't tend to matter, though, when working with strings or other
|
||||
// heap-allocated structures, since C++-equivalent structures also must store
|
||||
// pointers and also distribute their values across the heap.
|
||||
//
|
||||
// This implementation is designed to be a drop-in replacement to gollrb.LLRB
|
||||
// trees, (http://github.com/petar/gollrb), an excellent and probably the most
|
||||
// widely used ordered tree implementation in the Go ecosystem currently.
|
||||
// Its functions, therefore, exactly mirror those of
|
||||
// llrb.LLRB where possible. Unlike gollrb, though, we currently don't
|
||||
// support storing multiple equivalent values.
|
||||
package btree
|
||||
|
||||
import (
|
||||
"fmt"
|
||||
"io"
|
||||
"sort"
|
||||
"strings"
|
||||
"sync"
|
||||
)
|
||||
|
||||
// Item represents a single object in the tree.
|
||||
type Item interface {
|
||||
// Less tests whether the current item is less than the given argument.
|
||||
//
|
||||
// This must provide a strict weak ordering.
|
||||
// If !a.Less(b) && !b.Less(a), we treat this to mean a == b (i.e. we can only
|
||||
// hold one of either a or b in the tree).
|
||||
Less(than Item) bool
|
||||
}
|
||||
|
||||
const (
|
||||
DefaultFreeListSize = 32
|
||||
)
|
||||
|
||||
var (
|
||||
nilItems = make(items, 16)
|
||||
nilChildren = make(children, 16)
|
||||
)
|
||||
|
||||
// FreeList represents a free list of btree nodes. By default each
|
||||
// BTree has its own FreeList, but multiple BTrees can share the same
|
||||
// FreeList.
|
||||
// Two Btrees using the same freelist are safe for concurrent write access.
|
||||
type FreeList struct {
|
||||
mu sync.Mutex
|
||||
freelist []*node
|
||||
}
|
||||
|
||||
// NewFreeList creates a new free list.
|
||||
// size is the maximum size of the returned free list.
|
||||
func NewFreeList(size int) *FreeList {
|
||||
return &FreeList{freelist: make([]*node, 0, size)}
|
||||
}
|
||||
|
||||
func (f *FreeList) newNode() (n *node) {
|
||||
f.mu.Lock()
|
||||
index := len(f.freelist) - 1
|
||||
if index < 0 {
|
||||
f.mu.Unlock()
|
||||
return new(node)
|
||||
}
|
||||
n = f.freelist[index]
|
||||
f.freelist[index] = nil
|
||||
f.freelist = f.freelist[:index]
|
||||
f.mu.Unlock()
|
||||
return
|
||||
}
|
||||
|
||||
// freeNode adds the given node to the list, returning true if it was added
|
||||
// and false if it was discarded.
|
||||
func (f *FreeList) freeNode(n *node) (out bool) {
|
||||
f.mu.Lock()
|
||||
if len(f.freelist) < cap(f.freelist) {
|
||||
f.freelist = append(f.freelist, n)
|
||||
out = true
|
||||
}
|
||||
f.mu.Unlock()
|
||||
return
|
||||
}
|
||||
|
||||
// ItemIterator allows callers of Ascend* to iterate in-order over portions of
|
||||
// the tree. When this function returns false, iteration will stop and the
|
||||
// associated Ascend* function will immediately return.
|
||||
type ItemIterator func(i Item) bool
|
||||
|
||||
// New creates a new B-Tree with the given degree.
|
||||
//
|
||||
// New(2), for example, will create a 2-3-4 tree (each node contains 1-3 items
|
||||
// and 2-4 children).
|
||||
func New(degree int) *BTree {
|
||||
return NewWithFreeList(degree, NewFreeList(DefaultFreeListSize))
|
||||
}
|
||||
|
||||
// NewWithFreeList creates a new B-Tree that uses the given node free list.
|
||||
func NewWithFreeList(degree int, f *FreeList) *BTree {
|
||||
if degree <= 1 {
|
||||
panic("bad degree")
|
||||
}
|
||||
return &BTree{
|
||||
degree: degree,
|
||||
cow: ©OnWriteContext{freelist: f},
|
||||
}
|
||||
}
|
||||
|
||||
// items stores items in a node.
|
||||
type items []Item
|
||||
|
||||
// insertAt inserts a value into the given index, pushing all subsequent values
|
||||
// forward.
|
||||
func (s *items) insertAt(index int, item Item) {
|
||||
*s = append(*s, nil)
|
||||
if index < len(*s) {
|
||||
copy((*s)[index+1:], (*s)[index:])
|
||||
}
|
||||
(*s)[index] = item
|
||||
}
|
||||
|
||||
// removeAt removes a value at a given index, pulling all subsequent values
|
||||
// back.
|
||||
func (s *items) removeAt(index int) Item {
|
||||
item := (*s)[index]
|
||||
copy((*s)[index:], (*s)[index+1:])
|
||||
(*s)[len(*s)-1] = nil
|
||||
*s = (*s)[:len(*s)-1]
|
||||
return item
|
||||
}
|
||||
|
||||
// pop removes and returns the last element in the list.
|
||||
func (s *items) pop() (out Item) {
|
||||
index := len(*s) - 1
|
||||
out = (*s)[index]
|
||||
(*s)[index] = nil
|
||||
*s = (*s)[:index]
|
||||
return
|
||||
}
|
||||
|
||||
// truncate truncates this instance at index so that it contains only the
|
||||
// first index items. index must be less than or equal to length.
|
||||
func (s *items) truncate(index int) {
|
||||
var toClear items
|
||||
*s, toClear = (*s)[:index], (*s)[index:]
|
||||
for len(toClear) > 0 {
|
||||
toClear = toClear[copy(toClear, nilItems):]
|
||||
}
|
||||
}
|
||||
|
||||
// find returns the index where the given item should be inserted into this
|
||||
// list. 'found' is true if the item already exists in the list at the given
|
||||
// index.
|
||||
func (s items) find(item Item) (index int, found bool) {
|
||||
i := sort.Search(len(s), func(i int) bool {
|
||||
return item.Less(s[i])
|
||||
})
|
||||
if i > 0 && !s[i-1].Less(item) {
|
||||
return i - 1, true
|
||||
}
|
||||
return i, false
|
||||
}
|
||||
|
||||
// children stores child nodes in a node.
|
||||
type children []*node
|
||||
|
||||
// insertAt inserts a value into the given index, pushing all subsequent values
|
||||
// forward.
|
||||
func (s *children) insertAt(index int, n *node) {
|
||||
*s = append(*s, nil)
|
||||
if index < len(*s) {
|
||||
copy((*s)[index+1:], (*s)[index:])
|
||||
}
|
||||
(*s)[index] = n
|
||||
}
|
||||
|
||||
// removeAt removes a value at a given index, pulling all subsequent values
|
||||
// back.
|
||||
func (s *children) removeAt(index int) *node {
|
||||
n := (*s)[index]
|
||||
copy((*s)[index:], (*s)[index+1:])
|
||||
(*s)[len(*s)-1] = nil
|
||||
*s = (*s)[:len(*s)-1]
|
||||
return n
|
||||
}
|
||||
|
||||
// pop removes and returns the last element in the list.
|
||||
func (s *children) pop() (out *node) {
|
||||
index := len(*s) - 1
|
||||
out = (*s)[index]
|
||||
(*s)[index] = nil
|
||||
*s = (*s)[:index]
|
||||
return
|
||||
}
|
||||
|
||||
// truncate truncates this instance at index so that it contains only the
|
||||
// first index children. index must be less than or equal to length.
|
||||
func (s *children) truncate(index int) {
|
||||
var toClear children
|
||||
*s, toClear = (*s)[:index], (*s)[index:]
|
||||
for len(toClear) > 0 {
|
||||
toClear = toClear[copy(toClear, nilChildren):]
|
||||
}
|
||||
}
|
||||
|
||||
// node is an internal node in a tree.
|
||||
//
|
||||
// It must at all times maintain the invariant that either
|
||||
// * len(children) == 0, len(items) unconstrained
|
||||
// * len(children) == len(items) + 1
|
||||
type node struct {
|
||||
items items
|
||||
children children
|
||||
cow *copyOnWriteContext
|
||||
}
|
||||
|
||||
func (n *node) mutableFor(cow *copyOnWriteContext) *node {
|
||||
if n.cow == cow {
|
||||
return n
|
||||
}
|
||||
out := cow.newNode()
|
||||
if cap(out.items) >= len(n.items) {
|
||||
out.items = out.items[:len(n.items)]
|
||||
} else {
|
||||
out.items = make(items, len(n.items), cap(n.items))
|
||||
}
|
||||
copy(out.items, n.items)
|
||||
// Copy children
|
||||
if cap(out.children) >= len(n.children) {
|
||||
out.children = out.children[:len(n.children)]
|
||||
} else {
|
||||
out.children = make(children, len(n.children), cap(n.children))
|
||||
}
|
||||
copy(out.children, n.children)
|
||||
return out
|
||||
}
|
||||
|
||||
func (n *node) mutableChild(i int) *node {
|
||||
c := n.children[i].mutableFor(n.cow)
|
||||
n.children[i] = c
|
||||
return c
|
||||
}
|
||||
|
||||
// split splits the given node at the given index. The current node shrinks,
|
||||
// and this function returns the item that existed at that index and a new node
|
||||
// containing all items/children after it.
|
||||
func (n *node) split(i int) (Item, *node) {
|
||||
item := n.items[i]
|
||||
next := n.cow.newNode()
|
||||
next.items = append(next.items, n.items[i+1:]...)
|
||||
n.items.truncate(i)
|
||||
if len(n.children) > 0 {
|
||||
next.children = append(next.children, n.children[i+1:]...)
|
||||
n.children.truncate(i + 1)
|
||||
}
|
||||
return item, next
|
||||
}
|
||||
|
||||
// maybeSplitChild checks if a child should be split, and if so splits it.
|
||||
// Returns whether or not a split occurred.
|
||||
func (n *node) maybeSplitChild(i, maxItems int) bool {
|
||||
if len(n.children[i].items) < maxItems {
|
||||
return false
|
||||
}
|
||||
first := n.mutableChild(i)
|
||||
item, second := first.split(maxItems / 2)
|
||||
n.items.insertAt(i, item)
|
||||
n.children.insertAt(i+1, second)
|
||||
return true
|
||||
}
|
||||
|
||||
// insert inserts an item into the subtree rooted at this node, making sure
|
||||
// no nodes in the subtree exceed maxItems items. Should an equivalent item be
|
||||
// be found/replaced by insert, it will be returned.
|
||||
func (n *node) insert(item Item, maxItems int) Item {
|
||||
i, found := n.items.find(item)
|
||||
if found {
|
||||
out := n.items[i]
|
||||
n.items[i] = item
|
||||
return out
|
||||
}
|
||||
if len(n.children) == 0 {
|
||||
n.items.insertAt(i, item)
|
||||
return nil
|
||||
}
|
||||
if n.maybeSplitChild(i, maxItems) {
|
||||
inTree := n.items[i]
|
||||
switch {
|
||||
case item.Less(inTree):
|
||||
// no change, we want first split node
|
||||
case inTree.Less(item):
|
||||
i++ // we want second split node
|
||||
default:
|
||||
out := n.items[i]
|
||||
n.items[i] = item
|
||||
return out
|
||||
}
|
||||
}
|
||||
return n.mutableChild(i).insert(item, maxItems)
|
||||
}
|
||||
|
||||
// get finds the given key in the subtree and returns it.
|
||||
func (n *node) get(key Item) Item {
|
||||
i, found := n.items.find(key)
|
||||
if found {
|
||||
return n.items[i]
|
||||
} else if len(n.children) > 0 {
|
||||
return n.children[i].get(key)
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
// min returns the first item in the subtree.
|
||||
func min(n *node) Item {
|
||||
if n == nil {
|
||||
return nil
|
||||
}
|
||||
for len(n.children) > 0 {
|
||||
n = n.children[0]
|
||||
}
|
||||
if len(n.items) == 0 {
|
||||
return nil
|
||||
}
|
||||
return n.items[0]
|
||||
}
|
||||
|
||||
// max returns the last item in the subtree.
|
||||
func max(n *node) Item {
|
||||
if n == nil {
|
||||
return nil
|
||||
}
|
||||
for len(n.children) > 0 {
|
||||
n = n.children[len(n.children)-1]
|
||||
}
|
||||
if len(n.items) == 0 {
|
||||
return nil
|
||||
}
|
||||
return n.items[len(n.items)-1]
|
||||
}
|
||||
|
||||
// toRemove details what item to remove in a node.remove call.
|
||||
type toRemove int
|
||||
|
||||
const (
|
||||
removeItem toRemove = iota // removes the given item
|
||||
removeMin // removes smallest item in the subtree
|
||||
removeMax // removes largest item in the subtree
|
||||
)
|
||||
|
||||
// remove removes an item from the subtree rooted at this node.
|
||||
func (n *node) remove(item Item, minItems int, typ toRemove) Item {
|
||||
var i int
|
||||
var found bool
|
||||
switch typ {
|
||||
case removeMax:
|
||||
if len(n.children) == 0 {
|
||||
return n.items.pop()
|
||||
}
|
||||
i = len(n.items)
|
||||
case removeMin:
|
||||
if len(n.children) == 0 {
|
||||
return n.items.removeAt(0)
|
||||
}
|
||||
i = 0
|
||||
case removeItem:
|
||||
i, found = n.items.find(item)
|
||||
if len(n.children) == 0 {
|
||||
if found {
|
||||
return n.items.removeAt(i)
|
||||
}
|
||||
return nil
|
||||
}
|
||||
default:
|
||||
panic("invalid type")
|
||||
}
|
||||
// If we get to here, we have children.
|
||||
if len(n.children[i].items) <= minItems {
|
||||
return n.growChildAndRemove(i, item, minItems, typ)
|
||||
}
|
||||
child := n.mutableChild(i)
|
||||
// Either we had enough items to begin with, or we've done some
|
||||
// merging/stealing, because we've got enough now and we're ready to return
|
||||
// stuff.
|
||||
if found {
|
||||
// The item exists at index 'i', and the child we've selected can give us a
|
||||
// predecessor, since if we've gotten here it's got > minItems items in it.
|
||||
out := n.items[i]
|
||||
// We use our special-case 'remove' call with typ=maxItem to pull the
|
||||
// predecessor of item i (the rightmost leaf of our immediate left child)
|
||||
// and set it into where we pulled the item from.
|
||||
n.items[i] = child.remove(nil, minItems, removeMax)
|
||||
return out
|
||||
}
|
||||
// Final recursive call. Once we're here, we know that the item isn't in this
|
||||
// node and that the child is big enough to remove from.
|
||||
return child.remove(item, minItems, typ)
|
||||
}
|
||||
|
||||
// growChildAndRemove grows child 'i' to make sure it's possible to remove an
|
||||
// item from it while keeping it at minItems, then calls remove to actually
|
||||
// remove it.
|
||||
//
|
||||
// Most documentation says we have to do two sets of special casing:
|
||||
// 1) item is in this node
|
||||
// 2) item is in child
|
||||
// In both cases, we need to handle the two subcases:
|
||||
// A) node has enough values that it can spare one
|
||||
// B) node doesn't have enough values
|
||||
// For the latter, we have to check:
|
||||
// a) left sibling has node to spare
|
||||
// b) right sibling has node to spare
|
||||
// c) we must merge
|
||||
// To simplify our code here, we handle cases #1 and #2 the same:
|
||||
// If a node doesn't have enough items, we make sure it does (using a,b,c).
|
||||
// We then simply redo our remove call, and the second time (regardless of
|
||||
// whether we're in case 1 or 2), we'll have enough items and can guarantee
|
||||
// that we hit case A.
|
||||
func (n *node) growChildAndRemove(i int, item Item, minItems int, typ toRemove) Item {
|
||||
if i > 0 && len(n.children[i-1].items) > minItems {
|
||||
// Steal from left child
|
||||
child := n.mutableChild(i)
|
||||
stealFrom := n.mutableChild(i - 1)
|
||||
stolenItem := stealFrom.items.pop()
|
||||
child.items.insertAt(0, n.items[i-1])
|
||||
n.items[i-1] = stolenItem
|
||||
if len(stealFrom.children) > 0 {
|
||||
child.children.insertAt(0, stealFrom.children.pop())
|
||||
}
|
||||
} else if i < len(n.items) && len(n.children[i+1].items) > minItems {
|
||||
// steal from right child
|
||||
child := n.mutableChild(i)
|
||||
stealFrom := n.mutableChild(i + 1)
|
||||
stolenItem := stealFrom.items.removeAt(0)
|
||||
child.items = append(child.items, n.items[i])
|
||||
n.items[i] = stolenItem
|
||||
if len(stealFrom.children) > 0 {
|
||||
child.children = append(child.children, stealFrom.children.removeAt(0))
|
||||
}
|
||||
} else {
|
||||
if i >= len(n.items) {
|
||||
i--
|
||||
}
|
||||
child := n.mutableChild(i)
|
||||
// merge with right child
|
||||
mergeItem := n.items.removeAt(i)
|
||||
mergeChild := n.children.removeAt(i + 1)
|
||||
child.items = append(child.items, mergeItem)
|
||||
child.items = append(child.items, mergeChild.items...)
|
||||
child.children = append(child.children, mergeChild.children...)
|
||||
n.cow.freeNode(mergeChild)
|
||||
}
|
||||
return n.remove(item, minItems, typ)
|
||||
}
|
||||
|
||||
type direction int
|
||||
|
||||
const (
|
||||
descend = direction(-1)
|
||||
ascend = direction(+1)
|
||||
)
|
||||
|
||||
// iterate provides a simple method for iterating over elements in the tree.
|
||||
//
|
||||
// When ascending, the 'start' should be less than 'stop' and when descending,
|
||||
// the 'start' should be greater than 'stop'. Setting 'includeStart' to true
|
||||
// will force the iterator to include the first item when it equals 'start',
|
||||
// thus creating a "greaterOrEqual" or "lessThanEqual" rather than just a
|
||||
// "greaterThan" or "lessThan" queries.
|
||||
func (n *node) iterate(dir direction, start, stop Item, includeStart bool, hit bool, iter ItemIterator) (bool, bool) {
|
||||
var ok, found bool
|
||||
var index int
|
||||
switch dir {
|
||||
case ascend:
|
||||
if start != nil {
|
||||
index, _ = n.items.find(start)
|
||||
}
|
||||
for i := index; i < len(n.items); i++ {
|
||||
if len(n.children) > 0 {
|
||||
if hit, ok = n.children[i].iterate(dir, start, stop, includeStart, hit, iter); !ok {
|
||||
return hit, false
|
||||
}
|
||||
}
|
||||
if !includeStart && !hit && start != nil && !start.Less(n.items[i]) {
|
||||
hit = true
|
||||
continue
|
||||
}
|
||||
hit = true
|
||||
if stop != nil && !n.items[i].Less(stop) {
|
||||
return hit, false
|
||||
}
|
||||
if !iter(n.items[i]) {
|
||||
return hit, false
|
||||
}
|
||||
}
|
||||
if len(n.children) > 0 {
|
||||
if hit, ok = n.children[len(n.children)-1].iterate(dir, start, stop, includeStart, hit, iter); !ok {
|
||||
return hit, false
|
||||
}
|
||||
}
|
||||
case descend:
|
||||
if start != nil {
|
||||
index, found = n.items.find(start)
|
||||
if !found {
|
||||
index = index - 1
|
||||
}
|
||||
} else {
|
||||
index = len(n.items) - 1
|
||||
}
|
||||
for i := index; i >= 0; i-- {
|
||||
if start != nil && !n.items[i].Less(start) {
|
||||
if !includeStart || hit || start.Less(n.items[i]) {
|
||||
continue
|
||||
}
|
||||
}
|
||||
if len(n.children) > 0 {
|
||||
if hit, ok = n.children[i+1].iterate(dir, start, stop, includeStart, hit, iter); !ok {
|
||||
return hit, false
|
||||
}
|
||||
}
|
||||
if stop != nil && !stop.Less(n.items[i]) {
|
||||
return hit, false // continue
|
||||
}
|
||||
hit = true
|
||||
if !iter(n.items[i]) {
|
||||
return hit, false
|
||||
}
|
||||
}
|
||||
if len(n.children) > 0 {
|
||||
if hit, ok = n.children[0].iterate(dir, start, stop, includeStart, hit, iter); !ok {
|
||||
return hit, false
|
||||
}
|
||||
}
|
||||
}
|
||||
return hit, true
|
||||
}
|
||||
|
||||
// Used for testing/debugging purposes.
|
||||
func (n *node) print(w io.Writer, level int) {
|
||||
fmt.Fprintf(w, "%sNODE:%v\n", strings.Repeat(" ", level), n.items)
|
||||
for _, c := range n.children {
|
||||
c.print(w, level+1)
|
||||
}
|
||||
}
|
||||
|
||||
// BTree is an implementation of a B-Tree.
|
||||
//
|
||||
// BTree stores Item instances in an ordered structure, allowing easy insertion,
|
||||
// removal, and iteration.
|
||||
//
|
||||
// Write operations are not safe for concurrent mutation by multiple
|
||||
// goroutines, but Read operations are.
|
||||
type BTree struct {
|
||||
degree int
|
||||
length int
|
||||
root *node
|
||||
cow *copyOnWriteContext
|
||||
}
|
||||
|
||||
// copyOnWriteContext pointers determine node ownership... a tree with a write
|
||||
// context equivalent to a node's write context is allowed to modify that node.
|
||||
// A tree whose write context does not match a node's is not allowed to modify
|
||||
// it, and must create a new, writable copy (IE: it's a Clone).
|
||||
//
|
||||
// When doing any write operation, we maintain the invariant that the current
|
||||
// node's context is equal to the context of the tree that requested the write.
|
||||
// We do this by, before we descend into any node, creating a copy with the
|
||||
// correct context if the contexts don't match.
|
||||
//
|
||||
// Since the node we're currently visiting on any write has the requesting
|
||||
// tree's context, that node is modifiable in place. Children of that node may
|
||||
// not share context, but before we descend into them, we'll make a mutable
|
||||
// copy.
|
||||
type copyOnWriteContext struct {
|
||||
freelist *FreeList
|
||||
}
|
||||
|
||||
// Clone clones the btree, lazily. Clone should not be called concurrently,
|
||||
// but the original tree (t) and the new tree (t2) can be used concurrently
|
||||
// once the Clone call completes.
|
||||
//
|
||||
// The internal tree structure of b is marked read-only and shared between t and
|
||||
// t2. Writes to both t and t2 use copy-on-write logic, creating new nodes
|
||||
// whenever one of b's original nodes would have been modified. Read operations
|
||||
// should have no performance degredation. Write operations for both t and t2
|
||||
// will initially experience minor slow-downs caused by additional allocs and
|
||||
// copies due to the aforementioned copy-on-write logic, but should converge to
|
||||
// the original performance characteristics of the original tree.
|
||||
func (t *BTree) Clone() (t2 *BTree) {
|
||||
// Create two entirely new copy-on-write contexts.
|
||||
// This operation effectively creates three trees:
|
||||
// the original, shared nodes (old b.cow)
|
||||
// the new b.cow nodes
|
||||
// the new out.cow nodes
|
||||
cow1, cow2 := *t.cow, *t.cow
|
||||
out := *t
|
||||
t.cow = &cow1
|
||||
out.cow = &cow2
|
||||
return &out
|
||||
}
|
||||
|
||||
// maxItems returns the max number of items to allow per node.
|
||||
func (t *BTree) maxItems() int {
|
||||
return t.degree*2 - 1
|
||||
}
|
||||
|
||||
// minItems returns the min number of items to allow per node (ignored for the
|
||||
// root node).
|
||||
func (t *BTree) minItems() int {
|
||||
return t.degree - 1
|
||||
}
|
||||
|
||||
func (c *copyOnWriteContext) newNode() (n *node) {
|
||||
n = c.freelist.newNode()
|
||||
n.cow = c
|
||||
return
|
||||
}
|
||||
|
||||
type freeType int
|
||||
|
||||
const (
|
||||
ftFreelistFull freeType = iota // node was freed (available for GC, not stored in freelist)
|
||||
ftStored // node was stored in the freelist for later use
|
||||
ftNotOwned // node was ignored by COW, since it's owned by another one
|
||||
)
|
||||
|
||||
// freeNode frees a node within a given COW context, if it's owned by that
|
||||
// context. It returns what happened to the node (see freeType const
|
||||
// documentation).
|
||||
func (c *copyOnWriteContext) freeNode(n *node) freeType {
|
||||
if n.cow == c {
|
||||
// clear to allow GC
|
||||
n.items.truncate(0)
|
||||
n.children.truncate(0)
|
||||
n.cow = nil
|
||||
if c.freelist.freeNode(n) {
|
||||
return ftStored
|
||||
} else {
|
||||
return ftFreelistFull
|
||||
}
|
||||
} else {
|
||||
return ftNotOwned
|
||||
}
|
||||
}
|
||||
|
||||
// ReplaceOrInsert adds the given item to the tree. If an item in the tree
|
||||
// already equals the given one, it is removed from the tree and returned.
|
||||
// Otherwise, nil is returned.
|
||||
//
|
||||
// nil cannot be added to the tree (will panic).
|
||||
func (t *BTree) ReplaceOrInsert(item Item) Item {
|
||||
if item == nil {
|
||||
panic("nil item being added to BTree")
|
||||
}
|
||||
if t.root == nil {
|
||||
t.root = t.cow.newNode()
|
||||
t.root.items = append(t.root.items, item)
|
||||
t.length++
|
||||
return nil
|
||||
} else {
|
||||
t.root = t.root.mutableFor(t.cow)
|
||||
if len(t.root.items) >= t.maxItems() {
|
||||
item2, second := t.root.split(t.maxItems() / 2)
|
||||
oldroot := t.root
|
||||
t.root = t.cow.newNode()
|
||||
t.root.items = append(t.root.items, item2)
|
||||
t.root.children = append(t.root.children, oldroot, second)
|
||||
}
|
||||
}
|
||||
out := t.root.insert(item, t.maxItems())
|
||||
if out == nil {
|
||||
t.length++
|
||||
}
|
||||
return out
|
||||
}
|
||||
|
||||
// Delete removes an item equal to the passed in item from the tree, returning
|
||||
// it. If no such item exists, returns nil.
|
||||
func (t *BTree) Delete(item Item) Item {
|
||||
return t.deleteItem(item, removeItem)
|
||||
}
|
||||
|
||||
// DeleteMin removes the smallest item in the tree and returns it.
|
||||
// If no such item exists, returns nil.
|
||||
func (t *BTree) DeleteMin() Item {
|
||||
return t.deleteItem(nil, removeMin)
|
||||
}
|
||||
|
||||
// DeleteMax removes the largest item in the tree and returns it.
|
||||
// If no such item exists, returns nil.
|
||||
func (t *BTree) DeleteMax() Item {
|
||||
return t.deleteItem(nil, removeMax)
|
||||
}
|
||||
|
||||
func (t *BTree) deleteItem(item Item, typ toRemove) Item {
|
||||
if t.root == nil || len(t.root.items) == 0 {
|
||||
return nil
|
||||
}
|
||||
t.root = t.root.mutableFor(t.cow)
|
||||
out := t.root.remove(item, t.minItems(), typ)
|
||||
if len(t.root.items) == 0 && len(t.root.children) > 0 {
|
||||
oldroot := t.root
|
||||
t.root = t.root.children[0]
|
||||
t.cow.freeNode(oldroot)
|
||||
}
|
||||
if out != nil {
|
||||
t.length--
|
||||
}
|
||||
return out
|
||||
}
|
||||
|
||||
// AscendRange calls the iterator for every value in the tree within the range
|
||||
// [greaterOrEqual, lessThan), until iterator returns false.
|
||||
func (t *BTree) AscendRange(greaterOrEqual, lessThan Item, iterator ItemIterator) {
|
||||
if t.root == nil {
|
||||
return
|
||||
}
|
||||
t.root.iterate(ascend, greaterOrEqual, lessThan, true, false, iterator)
|
||||
}
|
||||
|
||||
// AscendLessThan calls the iterator for every value in the tree within the range
|
||||
// [first, pivot), until iterator returns false.
|
||||
func (t *BTree) AscendLessThan(pivot Item, iterator ItemIterator) {
|
||||
if t.root == nil {
|
||||
return
|
||||
}
|
||||
t.root.iterate(ascend, nil, pivot, false, false, iterator)
|
||||
}
|
||||
|
||||
// AscendGreaterOrEqual calls the iterator for every value in the tree within
|
||||
// the range [pivot, last], until iterator returns false.
|
||||
func (t *BTree) AscendGreaterOrEqual(pivot Item, iterator ItemIterator) {
|
||||
if t.root == nil {
|
||||
return
|
||||
}
|
||||
t.root.iterate(ascend, pivot, nil, true, false, iterator)
|
||||
}
|
||||
|
||||
// Ascend calls the iterator for every value in the tree within the range
|
||||
// [first, last], until iterator returns false.
|
||||
func (t *BTree) Ascend(iterator ItemIterator) {
|
||||
if t.root == nil {
|
||||
return
|
||||
}
|
||||
t.root.iterate(ascend, nil, nil, false, false, iterator)
|
||||
}
|
||||
|
||||
// DescendRange calls the iterator for every value in the tree within the range
|
||||
// [lessOrEqual, greaterThan), until iterator returns false.
|
||||
func (t *BTree) DescendRange(lessOrEqual, greaterThan Item, iterator ItemIterator) {
|
||||
if t.root == nil {
|
||||
return
|
||||
}
|
||||
t.root.iterate(descend, lessOrEqual, greaterThan, true, false, iterator)
|
||||
}
|
||||
|
||||
// DescendLessOrEqual calls the iterator for every value in the tree within the range
|
||||
// [pivot, first], until iterator returns false.
|
||||
func (t *BTree) DescendLessOrEqual(pivot Item, iterator ItemIterator) {
|
||||
if t.root == nil {
|
||||
return
|
||||
}
|
||||
t.root.iterate(descend, pivot, nil, true, false, iterator)
|
||||
}
|
||||
|
||||
// DescendGreaterThan calls the iterator for every value in the tree within
|
||||
// the range (pivot, last], until iterator returns false.
|
||||
func (t *BTree) DescendGreaterThan(pivot Item, iterator ItemIterator) {
|
||||
if t.root == nil {
|
||||
return
|
||||
}
|
||||
t.root.iterate(descend, nil, pivot, false, false, iterator)
|
||||
}
|
||||
|
||||
// Descend calls the iterator for every value in the tree within the range
|
||||
// [last, first], until iterator returns false.
|
||||
func (t *BTree) Descend(iterator ItemIterator) {
|
||||
if t.root == nil {
|
||||
return
|
||||
}
|
||||
t.root.iterate(descend, nil, nil, false, false, iterator)
|
||||
}
|
||||
|
||||
// Get looks for the key item in the tree, returning it. It returns nil if
|
||||
// unable to find that item.
|
||||
func (t *BTree) Get(key Item) Item {
|
||||
if t.root == nil {
|
||||
return nil
|
||||
}
|
||||
return t.root.get(key)
|
||||
}
|
||||
|
||||
// Min returns the smallest item in the tree, or nil if the tree is empty.
|
||||
func (t *BTree) Min() Item {
|
||||
return min(t.root)
|
||||
}
|
||||
|
||||
// Max returns the largest item in the tree, or nil if the tree is empty.
|
||||
func (t *BTree) Max() Item {
|
||||
return max(t.root)
|
||||
}
|
||||
|
||||
// Has returns true if the given key is in the tree.
|
||||
func (t *BTree) Has(key Item) bool {
|
||||
return t.Get(key) != nil
|
||||
}
|
||||
|
||||
// Len returns the number of items currently in the tree.
|
||||
func (t *BTree) Len() int {
|
||||
return t.length
|
||||
}
|
||||
|
||||
// Clear removes all items from the btree. If addNodesToFreelist is true,
|
||||
// t's nodes are added to its freelist as part of this call, until the freelist
|
||||
// is full. Otherwise, the root node is simply dereferenced and the subtree
|
||||
// left to Go's normal GC processes.
|
||||
//
|
||||
// This can be much faster
|
||||
// than calling Delete on all elements, because that requires finding/removing
|
||||
// each element in the tree and updating the tree accordingly. It also is
|
||||
// somewhat faster than creating a new tree to replace the old one, because
|
||||
// nodes from the old tree are reclaimed into the freelist for use by the new
|
||||
// one, instead of being lost to the garbage collector.
|
||||
//
|
||||
// This call takes:
|
||||
// O(1): when addNodesToFreelist is false, this is a single operation.
|
||||
// O(1): when the freelist is already full, it breaks out immediately
|
||||
// O(freelist size): when the freelist is empty and the nodes are all owned
|
||||
// by this tree, nodes are added to the freelist until full.
|
||||
// O(tree size): when all nodes are owned by another tree, all nodes are
|
||||
// iterated over looking for nodes to add to the freelist, and due to
|
||||
// ownership, none are.
|
||||
func (t *BTree) Clear(addNodesToFreelist bool) {
|
||||
if t.root != nil && addNodesToFreelist {
|
||||
t.root.reset(t.cow)
|
||||
}
|
||||
t.root, t.length = nil, 0
|
||||
}
|
||||
|
||||
// reset returns a subtree to the freelist. It breaks out immediately if the
|
||||
// freelist is full, since the only benefit of iterating is to fill that
|
||||
// freelist up. Returns true if parent reset call should continue.
|
||||
func (n *node) reset(c *copyOnWriteContext) bool {
|
||||
for _, child := range n.children {
|
||||
if !child.reset(c) {
|
||||
return false
|
||||
}
|
||||
}
|
||||
return c.freeNode(n) != ftFreelistFull
|
||||
}
|
||||
|
||||
// Int implements the Item interface for integers.
|
||||
type Int int
|
||||
|
||||
// Less returns true if int(a) < int(b).
|
||||
func (a Int) Less(b Item) bool {
|
||||
return a < b.(Int)
|
||||
}
|
||||
|
|
@ -0,0 +1,76 @@
|
|||
// Copyright 2014 Google Inc.
|
||||
//
|
||||
// Licensed under the Apache License, Version 2.0 (the "License");
|
||||
// you may not use this file except in compliance with the License.
|
||||
// You may obtain a copy of the License at
|
||||
//
|
||||
// http://www.apache.org/licenses/LICENSE-2.0
|
||||
//
|
||||
// Unless required by applicable law or agreed to in writing, software
|
||||
// distributed under the License is distributed on an "AS IS" BASIS,
|
||||
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
// See the License for the specific language governing permissions and
|
||||
// limitations under the License.
|
||||
|
||||
// +build ignore
|
||||
|
||||
// This binary compares memory usage between btree and gollrb.
|
||||
package main
|
||||
|
||||
import (
|
||||
"flag"
|
||||
"fmt"
|
||||
"math/rand"
|
||||
"runtime"
|
||||
"time"
|
||||
|
||||
"github.com/google/btree"
|
||||
"github.com/petar/GoLLRB/llrb"
|
||||
)
|
||||
|
||||
var (
|
||||
size = flag.Int("size", 1000000, "size of the tree to build")
|
||||
degree = flag.Int("degree", 8, "degree of btree")
|
||||
gollrb = flag.Bool("llrb", false, "use llrb instead of btree")
|
||||
)
|
||||
|
||||
func main() {
|
||||
flag.Parse()
|
||||
vals := rand.Perm(*size)
|
||||
var t, v interface{}
|
||||
v = vals
|
||||
var stats runtime.MemStats
|
||||
for i := 0; i < 10; i++ {
|
||||
runtime.GC()
|
||||
}
|
||||
fmt.Println("-------- BEFORE ----------")
|
||||
runtime.ReadMemStats(&stats)
|
||||
fmt.Printf("%+v\n", stats)
|
||||
start := time.Now()
|
||||
if *gollrb {
|
||||
tr := llrb.New()
|
||||
for _, v := range vals {
|
||||
tr.ReplaceOrInsert(llrb.Int(v))
|
||||
}
|
||||
t = tr // keep it around
|
||||
} else {
|
||||
tr := btree.New(*degree)
|
||||
for _, v := range vals {
|
||||
tr.ReplaceOrInsert(btree.Int(v))
|
||||
}
|
||||
t = tr // keep it around
|
||||
}
|
||||
fmt.Printf("%v inserts in %v\n", *size, time.Since(start))
|
||||
fmt.Println("-------- AFTER ----------")
|
||||
runtime.ReadMemStats(&stats)
|
||||
fmt.Printf("%+v\n", stats)
|
||||
for i := 0; i < 10; i++ {
|
||||
runtime.GC()
|
||||
}
|
||||
fmt.Println("-------- AFTER GC ----------")
|
||||
runtime.ReadMemStats(&stats)
|
||||
fmt.Printf("%+v\n", stats)
|
||||
if t == v {
|
||||
fmt.Println("to make sure vals and tree aren't GC'd")
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,18 @@
|
|||
sudo: false
|
||||
language: go
|
||||
matrix:
|
||||
allow_failures:
|
||||
- go: master
|
||||
fast_finish: true
|
||||
include:
|
||||
- go: 1.10.x
|
||||
- go: 1.11.x
|
||||
env: GOFMT=1
|
||||
- go: master
|
||||
install:
|
||||
- # Do nothing. This is needed to prevent default install action "go get -t -v ./..." from happening here (we want it to happen inside script step).
|
||||
script:
|
||||
- go get -t -v ./...
|
||||
- if test -n "${GOFMT}"; then gofmt -w -s . && git diff --exit-code; fi
|
||||
- go tool vet .
|
||||
- go test -v -race ./...
|
||||
|
|
@ -0,0 +1,7 @@
|
|||
Copyright © 2012 Greg Jones (greg.jones@gmail.com)
|
||||
|
||||
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
|
||||
|
||||
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
|
||||
|
||||
THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
|
||||
|
|
@ -0,0 +1,29 @@
|
|||
httpcache
|
||||
=========
|
||||
|
||||
[](https://travis-ci.org/gregjones/httpcache) [](https://godoc.org/github.com/gregjones/httpcache)
|
||||
|
||||
Package httpcache provides a http.RoundTripper implementation that works as a mostly [RFC 7234](https://tools.ietf.org/html/rfc7234) compliant cache for http responses.
|
||||
|
||||
It is only suitable for use as a 'private' cache (i.e. for a web-browser or an API-client and not for a shared proxy).
|
||||
|
||||
This project isn't actively maintained; it works for what I, and seemingly others, want to do with it, and I consider it "done". That said, if you find any issues, please open a Pull Request and I will try to review it. Any changes now that change the public API won't be considered.
|
||||
|
||||
Cache Backends
|
||||
--------------
|
||||
|
||||
- The built-in 'memory' cache stores responses in an in-memory map.
|
||||
- [`github.com/gregjones/httpcache/diskcache`](https://github.com/gregjones/httpcache/tree/master/diskcache) provides a filesystem-backed cache using the [diskv](https://github.com/peterbourgon/diskv) library.
|
||||
- [`github.com/gregjones/httpcache/memcache`](https://github.com/gregjones/httpcache/tree/master/memcache) provides memcache implementations, for both App Engine and 'normal' memcache servers.
|
||||
- [`sourcegraph.com/sourcegraph/s3cache`](https://sourcegraph.com/github.com/sourcegraph/s3cache) uses Amazon S3 for storage.
|
||||
- [`github.com/gregjones/httpcache/leveldbcache`](https://github.com/gregjones/httpcache/tree/master/leveldbcache) provides a filesystem-backed cache using [leveldb](https://github.com/syndtr/goleveldb/leveldb).
|
||||
- [`github.com/die-net/lrucache`](https://github.com/die-net/lrucache) provides an in-memory cache that will evict least-recently used entries.
|
||||
- [`github.com/die-net/lrucache/twotier`](https://github.com/die-net/lrucache/tree/master/twotier) allows caches to be combined, for example to use lrucache above with a persistent disk-cache.
|
||||
- [`github.com/birkelund/boltdbcache`](https://github.com/birkelund/boltdbcache) provides a BoltDB implementation (based on the [bbolt](https://github.com/coreos/bbolt) fork).
|
||||
|
||||
If you implement any other backend and wish it to be linked here, please send a PR editing this file.
|
||||
|
||||
License
|
||||
-------
|
||||
|
||||
- [MIT License](LICENSE.txt)
|
||||
61
vendor/github.com/gregjones/httpcache/diskcache/diskcache.go
сгенерированный
поставляемый
Normal file
61
vendor/github.com/gregjones/httpcache/diskcache/diskcache.go
сгенерированный
поставляемый
Normal file
|
|
@ -0,0 +1,61 @@
|
|||
// Package diskcache provides an implementation of httpcache.Cache that uses the diskv package
|
||||
// to supplement an in-memory map with persistent storage
|
||||
//
|
||||
package diskcache
|
||||
|
||||
import (
|
||||
"bytes"
|
||||
"crypto/md5"
|
||||
"encoding/hex"
|
||||
"github.com/peterbourgon/diskv"
|
||||
"io"
|
||||
)
|
||||
|
||||
// Cache is an implementation of httpcache.Cache that supplements the in-memory map with persistent storage
|
||||
type Cache struct {
|
||||
d *diskv.Diskv
|
||||
}
|
||||
|
||||
// Get returns the response corresponding to key if present
|
||||
func (c *Cache) Get(key string) (resp []byte, ok bool) {
|
||||
key = keyToFilename(key)
|
||||
resp, err := c.d.Read(key)
|
||||
if err != nil {
|
||||
return []byte{}, false
|
||||
}
|
||||
return resp, true
|
||||
}
|
||||
|
||||
// Set saves a response to the cache as key
|
||||
func (c *Cache) Set(key string, resp []byte) {
|
||||
key = keyToFilename(key)
|
||||
c.d.WriteStream(key, bytes.NewReader(resp), true)
|
||||
}
|
||||
|
||||
// Delete removes the response with key from the cache
|
||||
func (c *Cache) Delete(key string) {
|
||||
key = keyToFilename(key)
|
||||
c.d.Erase(key)
|
||||
}
|
||||
|
||||
func keyToFilename(key string) string {
|
||||
h := md5.New()
|
||||
io.WriteString(h, key)
|
||||
return hex.EncodeToString(h.Sum(nil))
|
||||
}
|
||||
|
||||
// New returns a new Cache that will store files in basePath
|
||||
func New(basePath string) *Cache {
|
||||
return &Cache{
|
||||
d: diskv.New(diskv.Options{
|
||||
BasePath: basePath,
|
||||
CacheSizeMax: 100 * 1024 * 1024, // 100MB
|
||||
}),
|
||||
}
|
||||
}
|
||||
|
||||
// NewWithDiskv returns a new Cache using the provided Diskv as underlying
|
||||
// storage.
|
||||
func NewWithDiskv(d *diskv.Diskv) *Cache {
|
||||
return &Cache{d}
|
||||
}
|
||||
|
|
@ -0,0 +1,551 @@
|
|||
// Package httpcache provides a http.RoundTripper implementation that works as a
|
||||
// mostly RFC-compliant cache for http responses.
|
||||
//
|
||||
// It is only suitable for use as a 'private' cache (i.e. for a web-browser or an API-client
|
||||
// and not for a shared proxy).
|
||||
//
|
||||
package httpcache
|
||||
|
||||
import (
|
||||
"bufio"
|
||||
"bytes"
|
||||
"errors"
|
||||
"io"
|
||||
"io/ioutil"
|
||||
"net/http"
|
||||
"net/http/httputil"
|
||||
"strings"
|
||||
"sync"
|
||||
"time"
|
||||
)
|
||||
|
||||
const (
|
||||
stale = iota
|
||||
fresh
|
||||
transparent
|
||||
// XFromCache is the header added to responses that are returned from the cache
|
||||
XFromCache = "X-From-Cache"
|
||||
)
|
||||
|
||||
// A Cache interface is used by the Transport to store and retrieve responses.
|
||||
type Cache interface {
|
||||
// Get returns the []byte representation of a cached response and a bool
|
||||
// set to true if the value isn't empty
|
||||
Get(key string) (responseBytes []byte, ok bool)
|
||||
// Set stores the []byte representation of a response against a key
|
||||
Set(key string, responseBytes []byte)
|
||||
// Delete removes the value associated with the key
|
||||
Delete(key string)
|
||||
}
|
||||
|
||||
// cacheKey returns the cache key for req.
|
||||
func cacheKey(req *http.Request) string {
|
||||
if req.Method == http.MethodGet {
|
||||
return req.URL.String()
|
||||
} else {
|
||||
return req.Method + " " + req.URL.String()
|
||||
}
|
||||
}
|
||||
|
||||
// CachedResponse returns the cached http.Response for req if present, and nil
|
||||
// otherwise.
|
||||
func CachedResponse(c Cache, req *http.Request) (resp *http.Response, err error) {
|
||||
cachedVal, ok := c.Get(cacheKey(req))
|
||||
if !ok {
|
||||
return
|
||||
}
|
||||
|
||||
b := bytes.NewBuffer(cachedVal)
|
||||
return http.ReadResponse(bufio.NewReader(b), req)
|
||||
}
|
||||
|
||||
// MemoryCache is an implemtation of Cache that stores responses in an in-memory map.
|
||||
type MemoryCache struct {
|
||||
mu sync.RWMutex
|
||||
items map[string][]byte
|
||||
}
|
||||
|
||||
// Get returns the []byte representation of the response and true if present, false if not
|
||||
func (c *MemoryCache) Get(key string) (resp []byte, ok bool) {
|
||||
c.mu.RLock()
|
||||
resp, ok = c.items[key]
|
||||
c.mu.RUnlock()
|
||||
return resp, ok
|
||||
}
|
||||
|
||||
// Set saves response resp to the cache with key
|
||||
func (c *MemoryCache) Set(key string, resp []byte) {
|
||||
c.mu.Lock()
|
||||
c.items[key] = resp
|
||||
c.mu.Unlock()
|
||||
}
|
||||
|
||||
// Delete removes key from the cache
|
||||
func (c *MemoryCache) Delete(key string) {
|
||||
c.mu.Lock()
|
||||
delete(c.items, key)
|
||||
c.mu.Unlock()
|
||||
}
|
||||
|
||||
// NewMemoryCache returns a new Cache that will store items in an in-memory map
|
||||
func NewMemoryCache() *MemoryCache {
|
||||
c := &MemoryCache{items: map[string][]byte{}}
|
||||
return c
|
||||
}
|
||||
|
||||
// Transport is an implementation of http.RoundTripper that will return values from a cache
|
||||
// where possible (avoiding a network request) and will additionally add validators (etag/if-modified-since)
|
||||
// to repeated requests allowing servers to return 304 / Not Modified
|
||||
type Transport struct {
|
||||
// The RoundTripper interface actually used to make requests
|
||||
// If nil, http.DefaultTransport is used
|
||||
Transport http.RoundTripper
|
||||
Cache Cache
|
||||
// If true, responses returned from the cache will be given an extra header, X-From-Cache
|
||||
MarkCachedResponses bool
|
||||
}
|
||||
|
||||
// NewTransport returns a new Transport with the
|
||||
// provided Cache implementation and MarkCachedResponses set to true
|
||||
func NewTransport(c Cache) *Transport {
|
||||
return &Transport{Cache: c, MarkCachedResponses: true}
|
||||
}
|
||||
|
||||
// Client returns an *http.Client that caches responses.
|
||||
func (t *Transport) Client() *http.Client {
|
||||
return &http.Client{Transport: t}
|
||||
}
|
||||
|
||||
// varyMatches will return false unless all of the cached values for the headers listed in Vary
|
||||
// match the new request
|
||||
func varyMatches(cachedResp *http.Response, req *http.Request) bool {
|
||||
for _, header := range headerAllCommaSepValues(cachedResp.Header, "vary") {
|
||||
header = http.CanonicalHeaderKey(header)
|
||||
if header != "" && req.Header.Get(header) != cachedResp.Header.Get("X-Varied-"+header) {
|
||||
return false
|
||||
}
|
||||
}
|
||||
return true
|
||||
}
|
||||
|
||||
// RoundTrip takes a Request and returns a Response
|
||||
//
|
||||
// If there is a fresh Response already in cache, then it will be returned without connecting to
|
||||
// the server.
|
||||
//
|
||||
// If there is a stale Response, then any validators it contains will be set on the new request
|
||||
// to give the server a chance to respond with NotModified. If this happens, then the cached Response
|
||||
// will be returned.
|
||||
func (t *Transport) RoundTrip(req *http.Request) (resp *http.Response, err error) {
|
||||
cacheKey := cacheKey(req)
|
||||
cacheable := (req.Method == "GET" || req.Method == "HEAD") && req.Header.Get("range") == ""
|
||||
var cachedResp *http.Response
|
||||
if cacheable {
|
||||
cachedResp, err = CachedResponse(t.Cache, req)
|
||||
} else {
|
||||
// Need to invalidate an existing value
|
||||
t.Cache.Delete(cacheKey)
|
||||
}
|
||||
|
||||
transport := t.Transport
|
||||
if transport == nil {
|
||||
transport = http.DefaultTransport
|
||||
}
|
||||
|
||||
if cacheable && cachedResp != nil && err == nil {
|
||||
if t.MarkCachedResponses {
|
||||
cachedResp.Header.Set(XFromCache, "1")
|
||||
}
|
||||
|
||||
if varyMatches(cachedResp, req) {
|
||||
// Can only use cached value if the new request doesn't Vary significantly
|
||||
freshness := getFreshness(cachedResp.Header, req.Header)
|
||||
if freshness == fresh {
|
||||
return cachedResp, nil
|
||||
}
|
||||
|
||||
if freshness == stale {
|
||||
var req2 *http.Request
|
||||
// Add validators if caller hasn't already done so
|
||||
etag := cachedResp.Header.Get("etag")
|
||||
if etag != "" && req.Header.Get("etag") == "" {
|
||||
req2 = cloneRequest(req)
|
||||
req2.Header.Set("if-none-match", etag)
|
||||
}
|
||||
lastModified := cachedResp.Header.Get("last-modified")
|
||||
if lastModified != "" && req.Header.Get("last-modified") == "" {
|
||||
if req2 == nil {
|
||||
req2 = cloneRequest(req)
|
||||
}
|
||||
req2.Header.Set("if-modified-since", lastModified)
|
||||
}
|
||||
if req2 != nil {
|
||||
req = req2
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
resp, err = transport.RoundTrip(req)
|
||||
if err == nil && req.Method == "GET" && resp.StatusCode == http.StatusNotModified {
|
||||
// Replace the 304 response with the one from cache, but update with some new headers
|
||||
endToEndHeaders := getEndToEndHeaders(resp.Header)
|
||||
for _, header := range endToEndHeaders {
|
||||
cachedResp.Header[header] = resp.Header[header]
|
||||
}
|
||||
resp = cachedResp
|
||||
} else if (err != nil || (cachedResp != nil && resp.StatusCode >= 500)) &&
|
||||
req.Method == "GET" && canStaleOnError(cachedResp.Header, req.Header) {
|
||||
// In case of transport failure and stale-if-error activated, returns cached content
|
||||
// when available
|
||||
return cachedResp, nil
|
||||
} else {
|
||||
if err != nil || resp.StatusCode != http.StatusOK {
|
||||
t.Cache.Delete(cacheKey)
|
||||
}
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
}
|
||||
} else {
|
||||
reqCacheControl := parseCacheControl(req.Header)
|
||||
if _, ok := reqCacheControl["only-if-cached"]; ok {
|
||||
resp = newGatewayTimeoutResponse(req)
|
||||
} else {
|
||||
resp, err = transport.RoundTrip(req)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
if cacheable && canStore(parseCacheControl(req.Header), parseCacheControl(resp.Header)) {
|
||||
for _, varyKey := range headerAllCommaSepValues(resp.Header, "vary") {
|
||||
varyKey = http.CanonicalHeaderKey(varyKey)
|
||||
fakeHeader := "X-Varied-" + varyKey
|
||||
reqValue := req.Header.Get(varyKey)
|
||||
if reqValue != "" {
|
||||
resp.Header.Set(fakeHeader, reqValue)
|
||||
}
|
||||
}
|
||||
switch req.Method {
|
||||
case "GET":
|
||||
// Delay caching until EOF is reached.
|
||||
resp.Body = &cachingReadCloser{
|
||||
R: resp.Body,
|
||||
OnEOF: func(r io.Reader) {
|
||||
resp := *resp
|
||||
resp.Body = ioutil.NopCloser(r)
|
||||
respBytes, err := httputil.DumpResponse(&resp, true)
|
||||
if err == nil {
|
||||
t.Cache.Set(cacheKey, respBytes)
|
||||
}
|
||||
},
|
||||
}
|
||||
default:
|
||||
respBytes, err := httputil.DumpResponse(resp, true)
|
||||
if err == nil {
|
||||
t.Cache.Set(cacheKey, respBytes)
|
||||
}
|
||||
}
|
||||
} else {
|
||||
t.Cache.Delete(cacheKey)
|
||||
}
|
||||
return resp, nil
|
||||
}
|
||||
|
||||
// ErrNoDateHeader indicates that the HTTP headers contained no Date header.
|
||||
var ErrNoDateHeader = errors.New("no Date header")
|
||||
|
||||
// Date parses and returns the value of the Date header.
|
||||
func Date(respHeaders http.Header) (date time.Time, err error) {
|
||||
dateHeader := respHeaders.Get("date")
|
||||
if dateHeader == "" {
|
||||
err = ErrNoDateHeader
|
||||
return
|
||||
}
|
||||
|
||||
return time.Parse(time.RFC1123, dateHeader)
|
||||
}
|
||||
|
||||
type realClock struct{}
|
||||
|
||||
func (c *realClock) since(d time.Time) time.Duration {
|
||||
return time.Since(d)
|
||||
}
|
||||
|
||||
type timer interface {
|
||||
since(d time.Time) time.Duration
|
||||
}
|
||||
|
||||
var clock timer = &realClock{}
|
||||
|
||||
// getFreshness will return one of fresh/stale/transparent based on the cache-control
|
||||
// values of the request and the response
|
||||
//
|
||||
// fresh indicates the response can be returned
|
||||
// stale indicates that the response needs validating before it is returned
|
||||
// transparent indicates the response should not be used to fulfil the request
|
||||
//
|
||||
// Because this is only a private cache, 'public' and 'private' in cache-control aren't
|
||||
// signficant. Similarly, smax-age isn't used.
|
||||
func getFreshness(respHeaders, reqHeaders http.Header) (freshness int) {
|
||||
respCacheControl := parseCacheControl(respHeaders)
|
||||
reqCacheControl := parseCacheControl(reqHeaders)
|
||||
if _, ok := reqCacheControl["no-cache"]; ok {
|
||||
return transparent
|
||||
}
|
||||
if _, ok := respCacheControl["no-cache"]; ok {
|
||||
return stale
|
||||
}
|
||||
if _, ok := reqCacheControl["only-if-cached"]; ok {
|
||||
return fresh
|
||||
}
|
||||
|
||||
date, err := Date(respHeaders)
|
||||
if err != nil {
|
||||
return stale
|
||||
}
|
||||
currentAge := clock.since(date)
|
||||
|
||||
var lifetime time.Duration
|
||||
var zeroDuration time.Duration
|
||||
|
||||
// If a response includes both an Expires header and a max-age directive,
|
||||
// the max-age directive overrides the Expires header, even if the Expires header is more restrictive.
|
||||
if maxAge, ok := respCacheControl["max-age"]; ok {
|
||||
lifetime, err = time.ParseDuration(maxAge + "s")
|
||||
if err != nil {
|
||||
lifetime = zeroDuration
|
||||
}
|
||||
} else {
|
||||
expiresHeader := respHeaders.Get("Expires")
|
||||
if expiresHeader != "" {
|
||||
expires, err := time.Parse(time.RFC1123, expiresHeader)
|
||||
if err != nil {
|
||||
lifetime = zeroDuration
|
||||
} else {
|
||||
lifetime = expires.Sub(date)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
if maxAge, ok := reqCacheControl["max-age"]; ok {
|
||||
// the client is willing to accept a response whose age is no greater than the specified time in seconds
|
||||
lifetime, err = time.ParseDuration(maxAge + "s")
|
||||
if err != nil {
|
||||
lifetime = zeroDuration
|
||||
}
|
||||
}
|
||||
if minfresh, ok := reqCacheControl["min-fresh"]; ok {
|
||||
// the client wants a response that will still be fresh for at least the specified number of seconds.
|
||||
minfreshDuration, err := time.ParseDuration(minfresh + "s")
|
||||
if err == nil {
|
||||
currentAge = time.Duration(currentAge + minfreshDuration)
|
||||
}
|
||||
}
|
||||
|
||||
if maxstale, ok := reqCacheControl["max-stale"]; ok {
|
||||
// Indicates that the client is willing to accept a response that has exceeded its expiration time.
|
||||
// If max-stale is assigned a value, then the client is willing to accept a response that has exceeded
|
||||
// its expiration time by no more than the specified number of seconds.
|
||||
// If no value is assigned to max-stale, then the client is willing to accept a stale response of any age.
|
||||
//
|
||||
// Responses served only because of a max-stale value are supposed to have a Warning header added to them,
|
||||
// but that seems like a hassle, and is it actually useful? If so, then there needs to be a different
|
||||
// return-value available here.
|
||||
if maxstale == "" {
|
||||
return fresh
|
||||
}
|
||||
maxstaleDuration, err := time.ParseDuration(maxstale + "s")
|
||||
if err == nil {
|
||||
currentAge = time.Duration(currentAge - maxstaleDuration)
|
||||
}
|
||||
}
|
||||
|
||||
if lifetime > currentAge {
|
||||
return fresh
|
||||
}
|
||||
|
||||
return stale
|
||||
}
|
||||
|
||||
// Returns true if either the request or the response includes the stale-if-error
|
||||
// cache control extension: https://tools.ietf.org/html/rfc5861
|
||||
func canStaleOnError(respHeaders, reqHeaders http.Header) bool {
|
||||
respCacheControl := parseCacheControl(respHeaders)
|
||||
reqCacheControl := parseCacheControl(reqHeaders)
|
||||
|
||||
var err error
|
||||
lifetime := time.Duration(-1)
|
||||
|
||||
if staleMaxAge, ok := respCacheControl["stale-if-error"]; ok {
|
||||
if staleMaxAge != "" {
|
||||
lifetime, err = time.ParseDuration(staleMaxAge + "s")
|
||||
if err != nil {
|
||||
return false
|
||||
}
|
||||
} else {
|
||||
return true
|
||||
}
|
||||
}
|
||||
if staleMaxAge, ok := reqCacheControl["stale-if-error"]; ok {
|
||||
if staleMaxAge != "" {
|
||||
lifetime, err = time.ParseDuration(staleMaxAge + "s")
|
||||
if err != nil {
|
||||
return false
|
||||
}
|
||||
} else {
|
||||
return true
|
||||
}
|
||||
}
|
||||
|
||||
if lifetime >= 0 {
|
||||
date, err := Date(respHeaders)
|
||||
if err != nil {
|
||||
return false
|
||||
}
|
||||
currentAge := clock.since(date)
|
||||
if lifetime > currentAge {
|
||||
return true
|
||||
}
|
||||
}
|
||||
|
||||
return false
|
||||
}
|
||||
|
||||
func getEndToEndHeaders(respHeaders http.Header) []string {
|
||||
// These headers are always hop-by-hop
|
||||
hopByHopHeaders := map[string]struct{}{
|
||||
"Connection": {},
|
||||
"Keep-Alive": {},
|
||||
"Proxy-Authenticate": {},
|
||||
"Proxy-Authorization": {},
|
||||
"Te": {},
|
||||
"Trailers": {},
|
||||
"Transfer-Encoding": {},
|
||||
"Upgrade": {},
|
||||
}
|
||||
|
||||
for _, extra := range strings.Split(respHeaders.Get("connection"), ",") {
|
||||
// any header listed in connection, if present, is also considered hop-by-hop
|
||||
if strings.Trim(extra, " ") != "" {
|
||||
hopByHopHeaders[http.CanonicalHeaderKey(extra)] = struct{}{}
|
||||
}
|
||||
}
|
||||
endToEndHeaders := []string{}
|
||||
for respHeader := range respHeaders {
|
||||
if _, ok := hopByHopHeaders[respHeader]; !ok {
|
||||
endToEndHeaders = append(endToEndHeaders, respHeader)
|
||||
}
|
||||
}
|
||||
return endToEndHeaders
|
||||
}
|
||||
|
||||
func canStore(reqCacheControl, respCacheControl cacheControl) (canStore bool) {
|
||||
if _, ok := respCacheControl["no-store"]; ok {
|
||||
return false
|
||||
}
|
||||
if _, ok := reqCacheControl["no-store"]; ok {
|
||||
return false
|
||||
}
|
||||
return true
|
||||
}
|
||||
|
||||
func newGatewayTimeoutResponse(req *http.Request) *http.Response {
|
||||
var braw bytes.Buffer
|
||||
braw.WriteString("HTTP/1.1 504 Gateway Timeout\r\n\r\n")
|
||||
resp, err := http.ReadResponse(bufio.NewReader(&braw), req)
|
||||
if err != nil {
|
||||
panic(err)
|
||||
}
|
||||
return resp
|
||||
}
|
||||
|
||||
// cloneRequest returns a clone of the provided *http.Request.
|
||||
// The clone is a shallow copy of the struct and its Header map.
|
||||
// (This function copyright goauth2 authors: https://code.google.com/p/goauth2)
|
||||
func cloneRequest(r *http.Request) *http.Request {
|
||||
// shallow copy of the struct
|
||||
r2 := new(http.Request)
|
||||
*r2 = *r
|
||||
// deep copy of the Header
|
||||
r2.Header = make(http.Header)
|
||||
for k, s := range r.Header {
|
||||
r2.Header[k] = s
|
||||
}
|
||||
return r2
|
||||
}
|
||||
|
||||
type cacheControl map[string]string
|
||||
|
||||
func parseCacheControl(headers http.Header) cacheControl {
|
||||
cc := cacheControl{}
|
||||
ccHeader := headers.Get("Cache-Control")
|
||||
for _, part := range strings.Split(ccHeader, ",") {
|
||||
part = strings.Trim(part, " ")
|
||||
if part == "" {
|
||||
continue
|
||||
}
|
||||
if strings.ContainsRune(part, '=') {
|
||||
keyval := strings.Split(part, "=")
|
||||
cc[strings.Trim(keyval[0], " ")] = strings.Trim(keyval[1], ",")
|
||||
} else {
|
||||
cc[part] = ""
|
||||
}
|
||||
}
|
||||
return cc
|
||||
}
|
||||
|
||||
// headerAllCommaSepValues returns all comma-separated values (each
|
||||
// with whitespace trimmed) for header name in headers. According to
|
||||
// Section 4.2 of the HTTP/1.1 spec
|
||||
// (http://www.w3.org/Protocols/rfc2616/rfc2616-sec4.html#sec4.2),
|
||||
// values from multiple occurrences of a header should be concatenated, if
|
||||
// the header's value is a comma-separated list.
|
||||
func headerAllCommaSepValues(headers http.Header, name string) []string {
|
||||
var vals []string
|
||||
for _, val := range headers[http.CanonicalHeaderKey(name)] {
|
||||
fields := strings.Split(val, ",")
|
||||
for i, f := range fields {
|
||||
fields[i] = strings.TrimSpace(f)
|
||||
}
|
||||
vals = append(vals, fields...)
|
||||
}
|
||||
return vals
|
||||
}
|
||||
|
||||
// cachingReadCloser is a wrapper around ReadCloser R that calls OnEOF
|
||||
// handler with a full copy of the content read from R when EOF is
|
||||
// reached.
|
||||
type cachingReadCloser struct {
|
||||
// Underlying ReadCloser.
|
||||
R io.ReadCloser
|
||||
// OnEOF is called with a copy of the content of R when EOF is reached.
|
||||
OnEOF func(io.Reader)
|
||||
|
||||
buf bytes.Buffer // buf stores a copy of the content of R.
|
||||
}
|
||||
|
||||
// Read reads the next len(p) bytes from R or until R is drained. The
|
||||
// return value n is the number of bytes read. If R has no data to
|
||||
// return, err is io.EOF and OnEOF is called with a full copy of what
|
||||
// has been read so far.
|
||||
func (r *cachingReadCloser) Read(p []byte) (n int, err error) {
|
||||
n, err = r.R.Read(p)
|
||||
r.buf.Write(p[:n])
|
||||
if err == io.EOF {
|
||||
r.OnEOF(bytes.NewReader(r.buf.Bytes()))
|
||||
}
|
||||
return n, err
|
||||
}
|
||||
|
||||
func (r *cachingReadCloser) Close() error {
|
||||
return r.R.Close()
|
||||
}
|
||||
|
||||
// NewMemoryCacheTransport returns a new Transport using the in-memory cache implementation
|
||||
func NewMemoryCacheTransport() *Transport {
|
||||
c := NewMemoryCache()
|
||||
t := NewTransport(c)
|
||||
return t
|
||||
}
|
||||
|
|
@ -0,0 +1,4 @@
|
|||
Petar Maymounkov <petar@5ttt.org>
|
||||
Vadim Vygonets <vadik@vygo.net>
|
||||
Ian Smith <iansmith@acm.org>
|
||||
Martin Bruse
|
||||
|
|
@ -0,0 +1,27 @@
|
|||
Copyright (c) 2010, Petar Maymounkov
|
||||
All rights reserved.
|
||||
|
||||
Redistribution and use in source and binary forms, with or without modification,
|
||||
are permitted provided that the following conditions are met:
|
||||
|
||||
(*) Redistributions of source code must retain the above copyright notice, this list
|
||||
of conditions and the following disclaimer.
|
||||
|
||||
(*) Redistributions in binary form must reproduce the above copyright notice, this
|
||||
list of conditions and the following disclaimer in the documentation and/or
|
||||
other materials provided with the distribution.
|
||||
|
||||
(*) Neither the name of Petar Maymounkov nor the names of its contributors may be
|
||||
used to endorse or promote products derived from this software without specific
|
||||
prior written permission.
|
||||
|
||||
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
|
||||
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
|
||||
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
||||
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
|
||||
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
|
||||
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
||||
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
|
||||
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
||||
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
||||
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
||||
|
|
@ -0,0 +1,39 @@
|
|||
// Copyright 2010 Petar Maymounkov. All rights reserved.
|
||||
// Use of this source code is governed by a BSD-style
|
||||
// license that can be found in the LICENSE file.
|
||||
|
||||
package llrb
|
||||
|
||||
import "math"
|
||||
|
||||
// avgVar maintains the average and variance of a stream of numbers
|
||||
// in a space-efficient manner.
|
||||
type avgVar struct {
|
||||
count int64
|
||||
sum, sumsq float64
|
||||
}
|
||||
|
||||
func (av *avgVar) Init() {
|
||||
av.count = 0
|
||||
av.sum = 0.0
|
||||
av.sumsq = 0.0
|
||||
}
|
||||
|
||||
func (av *avgVar) Add(sample float64) {
|
||||
av.count++
|
||||
av.sum += sample
|
||||
av.sumsq += sample * sample
|
||||
}
|
||||
|
||||
func (av *avgVar) GetCount() int64 { return av.count }
|
||||
|
||||
func (av *avgVar) GetAvg() float64 { return av.sum / float64(av.count) }
|
||||
|
||||
func (av *avgVar) GetTotal() float64 { return av.sum }
|
||||
|
||||
func (av *avgVar) GetVar() float64 {
|
||||
a := av.GetAvg()
|
||||
return av.sumsq/float64(av.count) - a*a
|
||||
}
|
||||
|
||||
func (av *avgVar) GetStdDev() float64 { return math.Sqrt(av.GetVar()) }
|
||||
|
|
@ -0,0 +1,95 @@
|
|||
package llrb
|
||||
|
||||
type ItemIterator func(i Item) bool
|
||||
|
||||
//func (t *Tree) Ascend(iterator ItemIterator) {
|
||||
// t.AscendGreaterOrEqual(Inf(-1), iterator)
|
||||
//}
|
||||
|
||||
func (t *LLRB) AscendRange(greaterOrEqual, lessThan Item, iterator ItemIterator) {
|
||||
t.ascendRange(t.root, greaterOrEqual, lessThan, iterator)
|
||||
}
|
||||
|
||||
func (t *LLRB) ascendRange(h *Node, inf, sup Item, iterator ItemIterator) bool {
|
||||
if h == nil {
|
||||
return true
|
||||
}
|
||||
if !less(h.Item, sup) {
|
||||
return t.ascendRange(h.Left, inf, sup, iterator)
|
||||
}
|
||||
if less(h.Item, inf) {
|
||||
return t.ascendRange(h.Right, inf, sup, iterator)
|
||||
}
|
||||
|
||||
if !t.ascendRange(h.Left, inf, sup, iterator) {
|
||||
return false
|
||||
}
|
||||
if !iterator(h.Item) {
|
||||
return false
|
||||
}
|
||||
return t.ascendRange(h.Right, inf, sup, iterator)
|
||||
}
|
||||
|
||||
// AscendGreaterOrEqual will call iterator once for each element greater or equal to
|
||||
// pivot in ascending order. It will stop whenever the iterator returns false.
|
||||
func (t *LLRB) AscendGreaterOrEqual(pivot Item, iterator ItemIterator) {
|
||||
t.ascendGreaterOrEqual(t.root, pivot, iterator)
|
||||
}
|
||||
|
||||
func (t *LLRB) ascendGreaterOrEqual(h *Node, pivot Item, iterator ItemIterator) bool {
|
||||
if h == nil {
|
||||
return true
|
||||
}
|
||||
if !less(h.Item, pivot) {
|
||||
if !t.ascendGreaterOrEqual(h.Left, pivot, iterator) {
|
||||
return false
|
||||
}
|
||||
if !iterator(h.Item) {
|
||||
return false
|
||||
}
|
||||
}
|
||||
return t.ascendGreaterOrEqual(h.Right, pivot, iterator)
|
||||
}
|
||||
|
||||
// AscendLessThan will call iterator once for each element lower than
|
||||
// pivot in ascending order. It will stop whenever the iterator returns false.
|
||||
func (t *LLRB) AscendLessThan(pivot Item, iterator ItemIterator) {
|
||||
t.ascendLessThan(t.root, pivot, iterator)
|
||||
}
|
||||
|
||||
func (t *LLRB) ascendLessThan(h *Node, pivot Item, iterator ItemIterator) bool {
|
||||
if h == nil {
|
||||
return true
|
||||
}
|
||||
if !t.ascendLessThan(h.Left, pivot, iterator) {
|
||||
return false
|
||||
}
|
||||
if less(h.Item, pivot) {
|
||||
if !iterator(h.Item) {
|
||||
return false
|
||||
}
|
||||
return t.ascendLessThan(h.Right, pivot, iterator)
|
||||
}
|
||||
return true
|
||||
}
|
||||
|
||||
// DescendLessOrEqual will call iterator once for each element less than the
|
||||
// pivot in descending order. It will stop whenever the iterator returns false.
|
||||
func (t *LLRB) DescendLessOrEqual(pivot Item, iterator ItemIterator) {
|
||||
t.descendLessOrEqual(t.root, pivot, iterator)
|
||||
}
|
||||
|
||||
func (t *LLRB) descendLessOrEqual(h *Node, pivot Item, iterator ItemIterator) bool {
|
||||
if h == nil {
|
||||
return true
|
||||
}
|
||||
if less(h.Item, pivot) || !less(pivot, h.Item) {
|
||||
if !t.descendLessOrEqual(h.Right, pivot, iterator) {
|
||||
return false
|
||||
}
|
||||
if !iterator(h.Item) {
|
||||
return false
|
||||
}
|
||||
}
|
||||
return t.descendLessOrEqual(h.Left, pivot, iterator)
|
||||
}
|
||||
|
|
@ -0,0 +1,46 @@
|
|||
// Copyright 2010 Petar Maymounkov. All rights reserved.
|
||||
// Use of this source code is governed by a BSD-style
|
||||
// license that can be found in the LICENSE file.
|
||||
|
||||
package llrb
|
||||
|
||||
// GetHeight returns an item in the tree with key @key, and it's height in the tree
|
||||
func (t *LLRB) GetHeight(key Item) (result Item, depth int) {
|
||||
return t.getHeight(t.root, key)
|
||||
}
|
||||
|
||||
func (t *LLRB) getHeight(h *Node, item Item) (Item, int) {
|
||||
if h == nil {
|
||||
return nil, 0
|
||||
}
|
||||
if less(item, h.Item) {
|
||||
result, depth := t.getHeight(h.Left, item)
|
||||
return result, depth + 1
|
||||
}
|
||||
if less(h.Item, item) {
|
||||
result, depth := t.getHeight(h.Right, item)
|
||||
return result, depth + 1
|
||||
}
|
||||
return h.Item, 0
|
||||
}
|
||||
|
||||
// HeightStats returns the average and standard deviation of the height
|
||||
// of elements in the tree
|
||||
func (t *LLRB) HeightStats() (avg, stddev float64) {
|
||||
av := &avgVar{}
|
||||
heightStats(t.root, 0, av)
|
||||
return av.GetAvg(), av.GetStdDev()
|
||||
}
|
||||
|
||||
func heightStats(h *Node, d int, av *avgVar) {
|
||||
if h == nil {
|
||||
return
|
||||
}
|
||||
av.Add(float64(d))
|
||||
if h.Left != nil {
|
||||
heightStats(h.Left, d+1, av)
|
||||
}
|
||||
if h.Right != nil {
|
||||
heightStats(h.Right, d+1, av)
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,456 @@
|
|||
// Copyright 2010 Petar Maymounkov. All rights reserved.
|
||||
// Use of this source code is governed by a BSD-style
|
||||
// license that can be found in the LICENSE file.
|
||||
|
||||
// A Left-Leaning Red-Black (LLRB) implementation of 2-3 balanced binary search trees,
|
||||
// based on the following work:
|
||||
//
|
||||
// http://www.cs.princeton.edu/~rs/talks/LLRB/08Penn.pdf
|
||||
// http://www.cs.princeton.edu/~rs/talks/LLRB/LLRB.pdf
|
||||
// http://www.cs.princeton.edu/~rs/talks/LLRB/Java/RedBlackBST.java
|
||||
//
|
||||
// 2-3 trees (and the run-time equivalent 2-3-4 trees) are the de facto standard BST
|
||||
// algoritms found in implementations of Python, Java, and other libraries. The LLRB
|
||||
// implementation of 2-3 trees is a recent improvement on the traditional implementation,
|
||||
// observed and documented by Robert Sedgewick.
|
||||
//
|
||||
package llrb
|
||||
|
||||
// Tree is a Left-Leaning Red-Black (LLRB) implementation of 2-3 trees
|
||||
type LLRB struct {
|
||||
count int
|
||||
root *Node
|
||||
}
|
||||
|
||||
type Node struct {
|
||||
Item
|
||||
Left, Right *Node // Pointers to left and right child nodes
|
||||
Black bool // If set, the color of the link (incoming from the parent) is black
|
||||
// In the LLRB, new nodes are always red, hence the zero-value for node
|
||||
}
|
||||
|
||||
type Item interface {
|
||||
Less(than Item) bool
|
||||
}
|
||||
|
||||
//
|
||||
func less(x, y Item) bool {
|
||||
if x == pinf {
|
||||
return false
|
||||
}
|
||||
if x == ninf {
|
||||
return true
|
||||
}
|
||||
return x.Less(y)
|
||||
}
|
||||
|
||||
// Inf returns an Item that is "bigger than" any other item, if sign is positive.
|
||||
// Otherwise it returns an Item that is "smaller than" any other item.
|
||||
func Inf(sign int) Item {
|
||||
if sign == 0 {
|
||||
panic("sign")
|
||||
}
|
||||
if sign > 0 {
|
||||
return pinf
|
||||
}
|
||||
return ninf
|
||||
}
|
||||
|
||||
var (
|
||||
ninf = nInf{}
|
||||
pinf = pInf{}
|
||||
)
|
||||
|
||||
type nInf struct{}
|
||||
|
||||
func (nInf) Less(Item) bool {
|
||||
return true
|
||||
}
|
||||
|
||||
type pInf struct{}
|
||||
|
||||
func (pInf) Less(Item) bool {
|
||||
return false
|
||||
}
|
||||
|
||||
// New allocates a new tree
|
||||
func New() *LLRB {
|
||||
return &LLRB{}
|
||||
}
|
||||
|
||||
// SetRoot sets the root node of the tree.
|
||||
// It is intended to be used by functions that deserialize the tree.
|
||||
func (t *LLRB) SetRoot(r *Node) {
|
||||
t.root = r
|
||||
}
|
||||
|
||||
// Root returns the root node of the tree.
|
||||
// It is intended to be used by functions that serialize the tree.
|
||||
func (t *LLRB) Root() *Node {
|
||||
return t.root
|
||||
}
|
||||
|
||||
// Len returns the number of nodes in the tree.
|
||||
func (t *LLRB) Len() int { return t.count }
|
||||
|
||||
// Has returns true if the tree contains an element whose order is the same as that of key.
|
||||
func (t *LLRB) Has(key Item) bool {
|
||||
return t.Get(key) != nil
|
||||
}
|
||||
|
||||
// Get retrieves an element from the tree whose order is the same as that of key.
|
||||
func (t *LLRB) Get(key Item) Item {
|
||||
h := t.root
|
||||
for h != nil {
|
||||
switch {
|
||||
case less(key, h.Item):
|
||||
h = h.Left
|
||||
case less(h.Item, key):
|
||||
h = h.Right
|
||||
default:
|
||||
return h.Item
|
||||
}
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
// Min returns the minimum element in the tree.
|
||||
func (t *LLRB) Min() Item {
|
||||
h := t.root
|
||||
if h == nil {
|
||||
return nil
|
||||
}
|
||||
for h.Left != nil {
|
||||
h = h.Left
|
||||
}
|
||||
return h.Item
|
||||
}
|
||||
|
||||
// Max returns the maximum element in the tree.
|
||||
func (t *LLRB) Max() Item {
|
||||
h := t.root
|
||||
if h == nil {
|
||||
return nil
|
||||
}
|
||||
for h.Right != nil {
|
||||
h = h.Right
|
||||
}
|
||||
return h.Item
|
||||
}
|
||||
|
||||
func (t *LLRB) ReplaceOrInsertBulk(items ...Item) {
|
||||
for _, i := range items {
|
||||
t.ReplaceOrInsert(i)
|
||||
}
|
||||
}
|
||||
|
||||
func (t *LLRB) InsertNoReplaceBulk(items ...Item) {
|
||||
for _, i := range items {
|
||||
t.InsertNoReplace(i)
|
||||
}
|
||||
}
|
||||
|
||||
// ReplaceOrInsert inserts item into the tree. If an existing
|
||||
// element has the same order, it is removed from the tree and returned.
|
||||
func (t *LLRB) ReplaceOrInsert(item Item) Item {
|
||||
if item == nil {
|
||||
panic("inserting nil item")
|
||||
}
|
||||
var replaced Item
|
||||
t.root, replaced = t.replaceOrInsert(t.root, item)
|
||||
t.root.Black = true
|
||||
if replaced == nil {
|
||||
t.count++
|
||||
}
|
||||
return replaced
|
||||
}
|
||||
|
||||
func (t *LLRB) replaceOrInsert(h *Node, item Item) (*Node, Item) {
|
||||
if h == nil {
|
||||
return newNode(item), nil
|
||||
}
|
||||
|
||||
h = walkDownRot23(h)
|
||||
|
||||
var replaced Item
|
||||
if less(item, h.Item) { // BUG
|
||||
h.Left, replaced = t.replaceOrInsert(h.Left, item)
|
||||
} else if less(h.Item, item) {
|
||||
h.Right, replaced = t.replaceOrInsert(h.Right, item)
|
||||
} else {
|
||||
replaced, h.Item = h.Item, item
|
||||
}
|
||||
|
||||
h = walkUpRot23(h)
|
||||
|
||||
return h, replaced
|
||||
}
|
||||
|
||||
// InsertNoReplace inserts item into the tree. If an existing
|
||||
// element has the same order, both elements remain in the tree.
|
||||
func (t *LLRB) InsertNoReplace(item Item) {
|
||||
if item == nil {
|
||||
panic("inserting nil item")
|
||||
}
|
||||
t.root = t.insertNoReplace(t.root, item)
|
||||
t.root.Black = true
|
||||
t.count++
|
||||
}
|
||||
|
||||
func (t *LLRB) insertNoReplace(h *Node, item Item) *Node {
|
||||
if h == nil {
|
||||
return newNode(item)
|
||||
}
|
||||
|
||||
h = walkDownRot23(h)
|
||||
|
||||
if less(item, h.Item) {
|
||||
h.Left = t.insertNoReplace(h.Left, item)
|
||||
} else {
|
||||
h.Right = t.insertNoReplace(h.Right, item)
|
||||
}
|
||||
|
||||
return walkUpRot23(h)
|
||||
}
|
||||
|
||||
// Rotation driver routines for 2-3 algorithm
|
||||
|
||||
func walkDownRot23(h *Node) *Node { return h }
|
||||
|
||||
func walkUpRot23(h *Node) *Node {
|
||||
if isRed(h.Right) && !isRed(h.Left) {
|
||||
h = rotateLeft(h)
|
||||
}
|
||||
|
||||
if isRed(h.Left) && isRed(h.Left.Left) {
|
||||
h = rotateRight(h)
|
||||
}
|
||||
|
||||
if isRed(h.Left) && isRed(h.Right) {
|
||||
flip(h)
|
||||
}
|
||||
|
||||
return h
|
||||
}
|
||||
|
||||
// Rotation driver routines for 2-3-4 algorithm
|
||||
|
||||
func walkDownRot234(h *Node) *Node {
|
||||
if isRed(h.Left) && isRed(h.Right) {
|
||||
flip(h)
|
||||
}
|
||||
|
||||
return h
|
||||
}
|
||||
|
||||
func walkUpRot234(h *Node) *Node {
|
||||
if isRed(h.Right) && !isRed(h.Left) {
|
||||
h = rotateLeft(h)
|
||||
}
|
||||
|
||||
if isRed(h.Left) && isRed(h.Left.Left) {
|
||||
h = rotateRight(h)
|
||||
}
|
||||
|
||||
return h
|
||||
}
|
||||
|
||||
// DeleteMin deletes the minimum element in the tree and returns the
|
||||
// deleted item or nil otherwise.
|
||||
func (t *LLRB) DeleteMin() Item {
|
||||
var deleted Item
|
||||
t.root, deleted = deleteMin(t.root)
|
||||
if t.root != nil {
|
||||
t.root.Black = true
|
||||
}
|
||||
if deleted != nil {
|
||||
t.count--
|
||||
}
|
||||
return deleted
|
||||
}
|
||||
|
||||
// deleteMin code for LLRB 2-3 trees
|
||||
func deleteMin(h *Node) (*Node, Item) {
|
||||
if h == nil {
|
||||
return nil, nil
|
||||
}
|
||||
if h.Left == nil {
|
||||
return nil, h.Item
|
||||
}
|
||||
|
||||
if !isRed(h.Left) && !isRed(h.Left.Left) {
|
||||
h = moveRedLeft(h)
|
||||
}
|
||||
|
||||
var deleted Item
|
||||
h.Left, deleted = deleteMin(h.Left)
|
||||
|
||||
return fixUp(h), deleted
|
||||
}
|
||||
|
||||
// DeleteMax deletes the maximum element in the tree and returns
|
||||
// the deleted item or nil otherwise
|
||||
func (t *LLRB) DeleteMax() Item {
|
||||
var deleted Item
|
||||
t.root, deleted = deleteMax(t.root)
|
||||
if t.root != nil {
|
||||
t.root.Black = true
|
||||
}
|
||||
if deleted != nil {
|
||||
t.count--
|
||||
}
|
||||
return deleted
|
||||
}
|
||||
|
||||
func deleteMax(h *Node) (*Node, Item) {
|
||||
if h == nil {
|
||||
return nil, nil
|
||||
}
|
||||
if isRed(h.Left) {
|
||||
h = rotateRight(h)
|
||||
}
|
||||
if h.Right == nil {
|
||||
return nil, h.Item
|
||||
}
|
||||
if !isRed(h.Right) && !isRed(h.Right.Left) {
|
||||
h = moveRedRight(h)
|
||||
}
|
||||
var deleted Item
|
||||
h.Right, deleted = deleteMax(h.Right)
|
||||
|
||||
return fixUp(h), deleted
|
||||
}
|
||||
|
||||
// Delete deletes an item from the tree whose key equals key.
|
||||
// The deleted item is return, otherwise nil is returned.
|
||||
func (t *LLRB) Delete(key Item) Item {
|
||||
var deleted Item
|
||||
t.root, deleted = t.delete(t.root, key)
|
||||
if t.root != nil {
|
||||
t.root.Black = true
|
||||
}
|
||||
if deleted != nil {
|
||||
t.count--
|
||||
}
|
||||
return deleted
|
||||
}
|
||||
|
||||
func (t *LLRB) delete(h *Node, item Item) (*Node, Item) {
|
||||
var deleted Item
|
||||
if h == nil {
|
||||
return nil, nil
|
||||
}
|
||||
if less(item, h.Item) {
|
||||
if h.Left == nil { // item not present. Nothing to delete
|
||||
return h, nil
|
||||
}
|
||||
if !isRed(h.Left) && !isRed(h.Left.Left) {
|
||||
h = moveRedLeft(h)
|
||||
}
|
||||
h.Left, deleted = t.delete(h.Left, item)
|
||||
} else {
|
||||
if isRed(h.Left) {
|
||||
h = rotateRight(h)
|
||||
}
|
||||
// If @item equals @h.Item and no right children at @h
|
||||
if !less(h.Item, item) && h.Right == nil {
|
||||
return nil, h.Item
|
||||
}
|
||||
// PETAR: Added 'h.Right != nil' below
|
||||
if h.Right != nil && !isRed(h.Right) && !isRed(h.Right.Left) {
|
||||
h = moveRedRight(h)
|
||||
}
|
||||
// If @item equals @h.Item, and (from above) 'h.Right != nil'
|
||||
if !less(h.Item, item) {
|
||||
var subDeleted Item
|
||||
h.Right, subDeleted = deleteMin(h.Right)
|
||||
if subDeleted == nil {
|
||||
panic("logic")
|
||||
}
|
||||
deleted, h.Item = h.Item, subDeleted
|
||||
} else { // Else, @item is bigger than @h.Item
|
||||
h.Right, deleted = t.delete(h.Right, item)
|
||||
}
|
||||
}
|
||||
|
||||
return fixUp(h), deleted
|
||||
}
|
||||
|
||||
// Internal node manipulation routines
|
||||
|
||||
func newNode(item Item) *Node { return &Node{Item: item} }
|
||||
|
||||
func isRed(h *Node) bool {
|
||||
if h == nil {
|
||||
return false
|
||||
}
|
||||
return !h.Black
|
||||
}
|
||||
|
||||
func rotateLeft(h *Node) *Node {
|
||||
x := h.Right
|
||||
if x.Black {
|
||||
panic("rotating a black link")
|
||||
}
|
||||
h.Right = x.Left
|
||||
x.Left = h
|
||||
x.Black = h.Black
|
||||
h.Black = false
|
||||
return x
|
||||
}
|
||||
|
||||
func rotateRight(h *Node) *Node {
|
||||
x := h.Left
|
||||
if x.Black {
|
||||
panic("rotating a black link")
|
||||
}
|
||||
h.Left = x.Right
|
||||
x.Right = h
|
||||
x.Black = h.Black
|
||||
h.Black = false
|
||||
return x
|
||||
}
|
||||
|
||||
// REQUIRE: Left and Right children must be present
|
||||
func flip(h *Node) {
|
||||
h.Black = !h.Black
|
||||
h.Left.Black = !h.Left.Black
|
||||
h.Right.Black = !h.Right.Black
|
||||
}
|
||||
|
||||
// REQUIRE: Left and Right children must be present
|
||||
func moveRedLeft(h *Node) *Node {
|
||||
flip(h)
|
||||
if isRed(h.Right.Left) {
|
||||
h.Right = rotateRight(h.Right)
|
||||
h = rotateLeft(h)
|
||||
flip(h)
|
||||
}
|
||||
return h
|
||||
}
|
||||
|
||||
// REQUIRE: Left and Right children must be present
|
||||
func moveRedRight(h *Node) *Node {
|
||||
flip(h)
|
||||
if isRed(h.Left.Left) {
|
||||
h = rotateRight(h)
|
||||
flip(h)
|
||||
}
|
||||
return h
|
||||
}
|
||||
|
||||
func fixUp(h *Node) *Node {
|
||||
if isRed(h.Right) {
|
||||
h = rotateLeft(h)
|
||||
}
|
||||
|
||||
if isRed(h.Left) && isRed(h.Left.Left) {
|
||||
h = rotateRight(h)
|
||||
}
|
||||
|
||||
if isRed(h.Left) && isRed(h.Right) {
|
||||
flip(h)
|
||||
}
|
||||
|
||||
return h
|
||||
}
|
||||
|
|
@ -0,0 +1,17 @@
|
|||
// Copyright 2010 Petar Maymounkov. All rights reserved.
|
||||
// Use of this source code is governed by a BSD-style
|
||||
// license that can be found in the LICENSE file.
|
||||
|
||||
package llrb
|
||||
|
||||
type Int int
|
||||
|
||||
func (x Int) Less(than Item) bool {
|
||||
return x < than.(Int)
|
||||
}
|
||||
|
||||
type String string
|
||||
|
||||
func (x String) Less(than Item) bool {
|
||||
return x < than.(String)
|
||||
}
|
||||
|
|
@ -0,0 +1,19 @@
|
|||
Copyright (c) 2011-2012 Peter Bourgon
|
||||
|
||||
Permission is hereby granted, free of charge, to any person obtaining a copy
|
||||
of this software and associated documentation files (the "Software"), to deal
|
||||
in the Software without restriction, including without limitation the rights
|
||||
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
||||
copies of the Software, and to permit persons to whom the Software is
|
||||
furnished to do so, subject to the following conditions:
|
||||
|
||||
The above copyright notice and this permission notice shall be included in
|
||||
all copies or substantial portions of the Software.
|
||||
|
||||
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
||||
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
||||
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
||||
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
||||
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
||||
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
||||
THE SOFTWARE.
|
||||
|
|
@ -0,0 +1,191 @@
|
|||
# What is diskv?
|
||||
|
||||
Diskv (disk-vee) is a simple, persistent key-value store written in the Go
|
||||
language. It starts with an incredibly simple API for storing arbitrary data on
|
||||
a filesystem by key, and builds several layers of performance-enhancing
|
||||
abstraction on top. The end result is a conceptually simple, but highly
|
||||
performant, disk-backed storage system.
|
||||
|
||||
[![Build Status][1]][2]
|
||||
|
||||
[1]: https://drone.io/github.com/peterbourgon/diskv/status.png
|
||||
[2]: https://drone.io/github.com/peterbourgon/diskv/latest
|
||||
|
||||
|
||||
# Installing
|
||||
|
||||
Install [Go 1][3], either [from source][4] or [with a prepackaged binary][5].
|
||||
Then,
|
||||
|
||||
```bash
|
||||
$ go get github.com/peterbourgon/diskv
|
||||
```
|
||||
|
||||
[3]: http://golang.org
|
||||
[4]: http://golang.org/doc/install/source
|
||||
[5]: http://golang.org/doc/install
|
||||
|
||||
|
||||
# Usage
|
||||
|
||||
```go
|
||||
package main
|
||||
|
||||
import (
|
||||
"fmt"
|
||||
"github.com/peterbourgon/diskv"
|
||||
)
|
||||
|
||||
func main() {
|
||||
// Simplest transform function: put all the data files into the base dir.
|
||||
flatTransform := func(s string) []string { return []string{} }
|
||||
|
||||
// Initialize a new diskv store, rooted at "my-data-dir", with a 1MB cache.
|
||||
d := diskv.New(diskv.Options{
|
||||
BasePath: "my-data-dir",
|
||||
Transform: flatTransform,
|
||||
CacheSizeMax: 1024 * 1024,
|
||||
})
|
||||
|
||||
// Write three bytes to the key "alpha".
|
||||
key := "alpha"
|
||||
d.Write(key, []byte{'1', '2', '3'})
|
||||
|
||||
// Read the value back out of the store.
|
||||
value, _ := d.Read(key)
|
||||
fmt.Printf("%v\n", value)
|
||||
|
||||
// Erase the key+value from the store (and the disk).
|
||||
d.Erase(key)
|
||||
}
|
||||
```
|
||||
|
||||
More complex examples can be found in the "examples" subdirectory.
|
||||
|
||||
|
||||
# Theory
|
||||
|
||||
## Basic idea
|
||||
|
||||
At its core, diskv is a map of a key (`string`) to arbitrary data (`[]byte`).
|
||||
The data is written to a single file on disk, with the same name as the key.
|
||||
The key determines where that file will be stored, via a user-provided
|
||||
`TransformFunc`, which takes a key and returns a slice (`[]string`)
|
||||
corresponding to a path list where the key file will be stored. The simplest
|
||||
TransformFunc,
|
||||
|
||||
```go
|
||||
func SimpleTransform (key string) []string {
|
||||
return []string{}
|
||||
}
|
||||
```
|
||||
|
||||
will place all keys in the same, base directory. The design is inspired by
|
||||
[Redis diskstore][6]; a TransformFunc which emulates the default diskstore
|
||||
behavior is available in the content-addressable-storage example.
|
||||
|
||||
[6]: http://groups.google.com/group/redis-db/browse_thread/thread/d444bc786689bde9?pli=1
|
||||
|
||||
**Note** that your TransformFunc should ensure that one valid key doesn't
|
||||
transform to a subset of another valid key. That is, it shouldn't be possible
|
||||
to construct valid keys that resolve to directory names. As a concrete example,
|
||||
if your TransformFunc splits on every 3 characters, then
|
||||
|
||||
```go
|
||||
d.Write("abcabc", val) // OK: written to <base>/abc/abc/abcabc
|
||||
d.Write("abc", val) // Error: attempted write to <base>/abc/abc, but it's a directory
|
||||
```
|
||||
|
||||
This will be addressed in an upcoming version of diskv.
|
||||
|
||||
Probably the most important design principle behind diskv is that your data is
|
||||
always flatly available on the disk. diskv will never do anything that would
|
||||
prevent you from accessing, copying, backing up, or otherwise interacting with
|
||||
your data via common UNIX commandline tools.
|
||||
|
||||
## Advanced path transformation
|
||||
|
||||
If you need more control over the file name written to disk or if you want to support
|
||||
slashes in your key name or special characters in the keys, you can use the
|
||||
AdvancedTransform property. You must supply a function that returns
|
||||
a special PathKey structure, which is a breakdown of a path and a file name. Strings
|
||||
returned must be clean of any slashes or special characters:
|
||||
|
||||
```go
|
||||
func AdvancedTransformExample(key string) *diskv.PathKey {
|
||||
path := strings.Split(key, "/")
|
||||
last := len(path) - 1
|
||||
return &diskv.PathKey{
|
||||
Path: path[:last],
|
||||
FileName: path[last] + ".txt",
|
||||
}
|
||||
}
|
||||
|
||||
// If you provide an AdvancedTransform, you must also provide its
|
||||
// inverse:
|
||||
|
||||
func InverseTransformExample(pathKey *diskv.PathKey) (key string) {
|
||||
txt := pathKey.FileName[len(pathKey.FileName)-4:]
|
||||
if txt != ".txt" {
|
||||
panic("Invalid file found in storage folder!")
|
||||
}
|
||||
return strings.Join(pathKey.Path, "/") + pathKey.FileName[:len(pathKey.FileName)-4]
|
||||
}
|
||||
|
||||
func main() {
|
||||
d := diskv.New(diskv.Options{
|
||||
BasePath: "my-data-dir",
|
||||
AdvancedTransform: AdvancedTransformExample,
|
||||
InverseTransform: InverseTransformExample,
|
||||
CacheSizeMax: 1024 * 1024,
|
||||
})
|
||||
// Write some text to the key "alpha/beta/gamma".
|
||||
key := "alpha/beta/gamma"
|
||||
d.WriteString(key, "¡Hola!") // will be stored in "<basedir>/alpha/beta/gamma.txt"
|
||||
fmt.Println(d.ReadString("alpha/beta/gamma"))
|
||||
}
|
||||
```
|
||||
|
||||
|
||||
## Adding a cache
|
||||
|
||||
An in-memory caching layer is provided by combining the BasicStore
|
||||
functionality with a simple map structure, and keeping it up-to-date as
|
||||
appropriate. Since the map structure in Go is not threadsafe, it's combined
|
||||
with a RWMutex to provide safe concurrent access.
|
||||
|
||||
## Adding order
|
||||
|
||||
diskv is a key-value store and therefore inherently unordered. An ordering
|
||||
system can be injected into the store by passing something which satisfies the
|
||||
diskv.Index interface. (A default implementation, using Google's
|
||||
[btree][7] package, is provided.) Basically, diskv keeps an ordered (by a
|
||||
user-provided Less function) index of the keys, which can be queried.
|
||||
|
||||
[7]: https://github.com/google/btree
|
||||
|
||||
## Adding compression
|
||||
|
||||
Something which implements the diskv.Compression interface may be passed
|
||||
during store creation, so that all Writes and Reads are filtered through
|
||||
a compression/decompression pipeline. Several default implementations,
|
||||
using stdlib compression algorithms, are provided. Note that data is cached
|
||||
compressed; the cost of decompression is borne with each Read.
|
||||
|
||||
## Streaming
|
||||
|
||||
diskv also now provides ReadStream and WriteStream methods, to allow very large
|
||||
data to be handled efficiently.
|
||||
|
||||
|
||||
# Future plans
|
||||
|
||||
* Needs plenty of robust testing: huge datasets, etc...
|
||||
* More thorough benchmarking
|
||||
* Your suggestions for use-cases I haven't thought of
|
||||
|
||||
|
||||
# Credits and contributions
|
||||
|
||||
Original idea, design and implementation: [Peter Bourgon](https://github.com/peterbourgon)
|
||||
Other collaborations: [Javier Peletier](https://github.com/jpeletier) ([Epic Labs](https://www.epiclabs.io))
|
||||
|
|
@ -0,0 +1,64 @@
|
|||
package diskv
|
||||
|
||||
import (
|
||||
"compress/flate"
|
||||
"compress/gzip"
|
||||
"compress/zlib"
|
||||
"io"
|
||||
)
|
||||
|
||||
// Compression is an interface that Diskv uses to implement compression of
|
||||
// data. Writer takes a destination io.Writer and returns a WriteCloser that
|
||||
// compresses all data written through it. Reader takes a source io.Reader and
|
||||
// returns a ReadCloser that decompresses all data read through it. You may
|
||||
// define these methods on your own type, or use one of the NewCompression
|
||||
// helpers.
|
||||
type Compression interface {
|
||||
Writer(dst io.Writer) (io.WriteCloser, error)
|
||||
Reader(src io.Reader) (io.ReadCloser, error)
|
||||
}
|
||||
|
||||
// NewGzipCompression returns a Gzip-based Compression.
|
||||
func NewGzipCompression() Compression {
|
||||
return NewGzipCompressionLevel(flate.DefaultCompression)
|
||||
}
|
||||
|
||||
// NewGzipCompressionLevel returns a Gzip-based Compression with the given level.
|
||||
func NewGzipCompressionLevel(level int) Compression {
|
||||
return &genericCompression{
|
||||
wf: func(w io.Writer) (io.WriteCloser, error) { return gzip.NewWriterLevel(w, level) },
|
||||
rf: func(r io.Reader) (io.ReadCloser, error) { return gzip.NewReader(r) },
|
||||
}
|
||||
}
|
||||
|
||||
// NewZlibCompression returns a Zlib-based Compression.
|
||||
func NewZlibCompression() Compression {
|
||||
return NewZlibCompressionLevel(flate.DefaultCompression)
|
||||
}
|
||||
|
||||
// NewZlibCompressionLevel returns a Zlib-based Compression with the given level.
|
||||
func NewZlibCompressionLevel(level int) Compression {
|
||||
return NewZlibCompressionLevelDict(level, nil)
|
||||
}
|
||||
|
||||
// NewZlibCompressionLevelDict returns a Zlib-based Compression with the given
|
||||
// level, based on the given dictionary.
|
||||
func NewZlibCompressionLevelDict(level int, dict []byte) Compression {
|
||||
return &genericCompression{
|
||||
func(w io.Writer) (io.WriteCloser, error) { return zlib.NewWriterLevelDict(w, level, dict) },
|
||||
func(r io.Reader) (io.ReadCloser, error) { return zlib.NewReaderDict(r, dict) },
|
||||
}
|
||||
}
|
||||
|
||||
type genericCompression struct {
|
||||
wf func(w io.Writer) (io.WriteCloser, error)
|
||||
rf func(r io.Reader) (io.ReadCloser, error)
|
||||
}
|
||||
|
||||
func (g *genericCompression) Writer(dst io.Writer) (io.WriteCloser, error) {
|
||||
return g.wf(dst)
|
||||
}
|
||||
|
||||
func (g *genericCompression) Reader(src io.Reader) (io.ReadCloser, error) {
|
||||
return g.rf(src)
|
||||
}
|
||||
|
|
@ -0,0 +1,726 @@
|
|||
// Diskv (disk-vee) is a simple, persistent, key-value store.
|
||||
// It stores all data flatly on the filesystem.
|
||||
|
||||
package diskv
|
||||
|
||||
import (
|
||||
"bytes"
|
||||
"errors"
|
||||
"fmt"
|
||||
"io"
|
||||
"io/ioutil"
|
||||
"os"
|
||||
"path/filepath"
|
||||
"strings"
|
||||
"sync"
|
||||
"syscall"
|
||||
)
|
||||
|
||||
const (
|
||||
defaultBasePath = "diskv"
|
||||
defaultFilePerm os.FileMode = 0666
|
||||
defaultPathPerm os.FileMode = 0777
|
||||
)
|
||||
|
||||
// PathKey represents a string key that has been transformed to
|
||||
// a directory and file name where the content will eventually
|
||||
// be stored
|
||||
type PathKey struct {
|
||||
Path []string
|
||||
FileName string
|
||||
originalKey string
|
||||
}
|
||||
|
||||
var (
|
||||
defaultAdvancedTransform = func(s string) *PathKey { return &PathKey{Path: []string{}, FileName: s} }
|
||||
defaultInverseTransform = func(pathKey *PathKey) string { return pathKey.FileName }
|
||||
errCanceled = errors.New("canceled")
|
||||
errEmptyKey = errors.New("empty key")
|
||||
errBadKey = errors.New("bad key")
|
||||
errImportDirectory = errors.New("can't import a directory")
|
||||
)
|
||||
|
||||
// TransformFunction transforms a key into a slice of strings, with each
|
||||
// element in the slice representing a directory in the file path where the
|
||||
// key's entry will eventually be stored.
|
||||
//
|
||||
// For example, if TransformFunc transforms "abcdef" to ["ab", "cde", "f"],
|
||||
// the final location of the data file will be <basedir>/ab/cde/f/abcdef
|
||||
type TransformFunction func(s string) []string
|
||||
|
||||
// AdvancedTransformFunction transforms a key into a PathKey.
|
||||
//
|
||||
// A PathKey contains a slice of strings, where each element in the slice
|
||||
// represents a directory in the file path where the key's entry will eventually
|
||||
// be stored, as well as the filename.
|
||||
//
|
||||
// For example, if AdvancedTransformFunc transforms "abcdef/file.txt" to the
|
||||
// PathKey {Path: ["ab", "cde", "f"], FileName: "file.txt"}, the final location
|
||||
// of the data file will be <basedir>/ab/cde/f/file.txt.
|
||||
//
|
||||
// You must provide an InverseTransformFunction if you use an
|
||||
// AdvancedTransformFunction.
|
||||
type AdvancedTransformFunction func(s string) *PathKey
|
||||
|
||||
// InverseTransformFunction takes a PathKey and converts it back to a Diskv key.
|
||||
// In effect, it's the opposite of an AdvancedTransformFunction.
|
||||
type InverseTransformFunction func(pathKey *PathKey) string
|
||||
|
||||
// Options define a set of properties that dictate Diskv behavior.
|
||||
// All values are optional.
|
||||
type Options struct {
|
||||
BasePath string
|
||||
Transform TransformFunction
|
||||
AdvancedTransform AdvancedTransformFunction
|
||||
InverseTransform InverseTransformFunction
|
||||
CacheSizeMax uint64 // bytes
|
||||
PathPerm os.FileMode
|
||||
FilePerm os.FileMode
|
||||
// If TempDir is set, it will enable filesystem atomic writes by
|
||||
// writing temporary files to that location before being moved
|
||||
// to BasePath.
|
||||
// Note that TempDir MUST be on the same device/partition as
|
||||
// BasePath.
|
||||
TempDir string
|
||||
|
||||
Index Index
|
||||
IndexLess LessFunction
|
||||
|
||||
Compression Compression
|
||||
}
|
||||
|
||||
// Diskv implements the Diskv interface. You shouldn't construct Diskv
|
||||
// structures directly; instead, use the New constructor.
|
||||
type Diskv struct {
|
||||
Options
|
||||
mu sync.RWMutex
|
||||
cache map[string][]byte
|
||||
cacheSize uint64
|
||||
}
|
||||
|
||||
// New returns an initialized Diskv structure, ready to use.
|
||||
// If the path identified by baseDir already contains data,
|
||||
// it will be accessible, but not yet cached.
|
||||
func New(o Options) *Diskv {
|
||||
if o.BasePath == "" {
|
||||
o.BasePath = defaultBasePath
|
||||
}
|
||||
|
||||
if o.AdvancedTransform == nil {
|
||||
if o.Transform == nil {
|
||||
o.AdvancedTransform = defaultAdvancedTransform
|
||||
} else {
|
||||
o.AdvancedTransform = convertToAdvancedTransform(o.Transform)
|
||||
}
|
||||
if o.InverseTransform == nil {
|
||||
o.InverseTransform = defaultInverseTransform
|
||||
}
|
||||
} else {
|
||||
if o.InverseTransform == nil {
|
||||
panic("You must provide an InverseTransform function in advanced mode")
|
||||
}
|
||||
}
|
||||
|
||||
if o.PathPerm == 0 {
|
||||
o.PathPerm = defaultPathPerm
|
||||
}
|
||||
if o.FilePerm == 0 {
|
||||
o.FilePerm = defaultFilePerm
|
||||
}
|
||||
|
||||
d := &Diskv{
|
||||
Options: o,
|
||||
cache: map[string][]byte{},
|
||||
cacheSize: 0,
|
||||
}
|
||||
|
||||
if d.Index != nil && d.IndexLess != nil {
|
||||
d.Index.Initialize(d.IndexLess, d.Keys(nil))
|
||||
}
|
||||
|
||||
return d
|
||||
}
|
||||
|
||||
// convertToAdvancedTransform takes a classic Transform function and
|
||||
// converts it to the new AdvancedTransform
|
||||
func convertToAdvancedTransform(oldFunc func(s string) []string) AdvancedTransformFunction {
|
||||
return func(s string) *PathKey {
|
||||
return &PathKey{Path: oldFunc(s), FileName: s}
|
||||
}
|
||||
}
|
||||
|
||||
// Write synchronously writes the key-value pair to disk, making it immediately
|
||||
// available for reads. Write relies on the filesystem to perform an eventual
|
||||
// sync to physical media. If you need stronger guarantees, see WriteStream.
|
||||
func (d *Diskv) Write(key string, val []byte) error {
|
||||
return d.WriteStream(key, bytes.NewReader(val), false)
|
||||
}
|
||||
|
||||
// WriteString writes a string key-value pair to disk
|
||||
func (d *Diskv) WriteString(key string, val string) error {
|
||||
return d.Write(key, []byte(val))
|
||||
}
|
||||
|
||||
func (d *Diskv) transform(key string) (pathKey *PathKey) {
|
||||
pathKey = d.AdvancedTransform(key)
|
||||
pathKey.originalKey = key
|
||||
return pathKey
|
||||
}
|
||||
|
||||
// WriteStream writes the data represented by the io.Reader to the disk, under
|
||||
// the provided key. If sync is true, WriteStream performs an explicit sync on
|
||||
// the file as soon as it's written.
|
||||
//
|
||||
// bytes.Buffer provides io.Reader semantics for basic data types.
|
||||
func (d *Diskv) WriteStream(key string, r io.Reader, sync bool) error {
|
||||
if len(key) <= 0 {
|
||||
return errEmptyKey
|
||||
}
|
||||
|
||||
pathKey := d.transform(key)
|
||||
|
||||
// Ensure keys cannot evaluate to paths that would not exist
|
||||
for _, pathPart := range pathKey.Path {
|
||||
if strings.ContainsRune(pathPart, os.PathSeparator) {
|
||||
return errBadKey
|
||||
}
|
||||
}
|
||||
|
||||
if strings.ContainsRune(pathKey.FileName, os.PathSeparator) {
|
||||
return errBadKey
|
||||
}
|
||||
|
||||
d.mu.Lock()
|
||||
defer d.mu.Unlock()
|
||||
|
||||
return d.writeStreamWithLock(pathKey, r, sync)
|
||||
}
|
||||
|
||||
// createKeyFileWithLock either creates the key file directly, or
|
||||
// creates a temporary file in TempDir if it is set.
|
||||
func (d *Diskv) createKeyFileWithLock(pathKey *PathKey) (*os.File, error) {
|
||||
if d.TempDir != "" {
|
||||
if err := os.MkdirAll(d.TempDir, d.PathPerm); err != nil {
|
||||
return nil, fmt.Errorf("temp mkdir: %s", err)
|
||||
}
|
||||
f, err := ioutil.TempFile(d.TempDir, "")
|
||||
if err != nil {
|
||||
return nil, fmt.Errorf("temp file: %s", err)
|
||||
}
|
||||
|
||||
if err := f.Chmod(d.FilePerm); err != nil {
|
||||
f.Close() // error deliberately ignored
|
||||
os.Remove(f.Name()) // error deliberately ignored
|
||||
return nil, fmt.Errorf("chmod: %s", err)
|
||||
}
|
||||
return f, nil
|
||||
}
|
||||
|
||||
mode := os.O_WRONLY | os.O_CREATE | os.O_TRUNC // overwrite if exists
|
||||
f, err := os.OpenFile(d.completeFilename(pathKey), mode, d.FilePerm)
|
||||
if err != nil {
|
||||
return nil, fmt.Errorf("open file: %s", err)
|
||||
}
|
||||
return f, nil
|
||||
}
|
||||
|
||||
// writeStream does no input validation checking.
|
||||
func (d *Diskv) writeStreamWithLock(pathKey *PathKey, r io.Reader, sync bool) error {
|
||||
if err := d.ensurePathWithLock(pathKey); err != nil {
|
||||
return fmt.Errorf("ensure path: %s", err)
|
||||
}
|
||||
|
||||
f, err := d.createKeyFileWithLock(pathKey)
|
||||
if err != nil {
|
||||
return fmt.Errorf("create key file: %s", err)
|
||||
}
|
||||
|
||||
wc := io.WriteCloser(&nopWriteCloser{f})
|
||||
if d.Compression != nil {
|
||||
wc, err = d.Compression.Writer(f)
|
||||
if err != nil {
|
||||
f.Close() // error deliberately ignored
|
||||
os.Remove(f.Name()) // error deliberately ignored
|
||||
return fmt.Errorf("compression writer: %s", err)
|
||||
}
|
||||
}
|
||||
|
||||
if _, err := io.Copy(wc, r); err != nil {
|
||||
f.Close() // error deliberately ignored
|
||||
os.Remove(f.Name()) // error deliberately ignored
|
||||
return fmt.Errorf("i/o copy: %s", err)
|
||||
}
|
||||
|
||||
if err := wc.Close(); err != nil {
|
||||
f.Close() // error deliberately ignored
|
||||
os.Remove(f.Name()) // error deliberately ignored
|
||||
return fmt.Errorf("compression close: %s", err)
|
||||
}
|
||||
|
||||
if sync {
|
||||
if err := f.Sync(); err != nil {
|
||||
f.Close() // error deliberately ignored
|
||||
os.Remove(f.Name()) // error deliberately ignored
|
||||
return fmt.Errorf("file sync: %s", err)
|
||||
}
|
||||
}
|
||||
|
||||
if err := f.Close(); err != nil {
|
||||
return fmt.Errorf("file close: %s", err)
|
||||
}
|
||||
|
||||
fullPath := d.completeFilename(pathKey)
|
||||
if f.Name() != fullPath {
|
||||
if err := os.Rename(f.Name(), fullPath); err != nil {
|
||||
os.Remove(f.Name()) // error deliberately ignored
|
||||
return fmt.Errorf("rename: %s", err)
|
||||
}
|
||||
}
|
||||
|
||||
if d.Index != nil {
|
||||
d.Index.Insert(pathKey.originalKey)
|
||||
}
|
||||
|
||||
d.bustCacheWithLock(pathKey.originalKey) // cache only on read
|
||||
|
||||
return nil
|
||||
}
|
||||
|
||||
// Import imports the source file into diskv under the destination key. If the
|
||||
// destination key already exists, it's overwritten. If move is true, the
|
||||
// source file is removed after a successful import.
|
||||
func (d *Diskv) Import(srcFilename, dstKey string, move bool) (err error) {
|
||||
if dstKey == "" {
|
||||
return errEmptyKey
|
||||
}
|
||||
|
||||
if fi, err := os.Stat(srcFilename); err != nil {
|
||||
return err
|
||||
} else if fi.IsDir() {
|
||||
return errImportDirectory
|
||||
}
|
||||
|
||||
dstPathKey := d.transform(dstKey)
|
||||
|
||||
d.mu.Lock()
|
||||
defer d.mu.Unlock()
|
||||
|
||||
if err := d.ensurePathWithLock(dstPathKey); err != nil {
|
||||
return fmt.Errorf("ensure path: %s", err)
|
||||
}
|
||||
|
||||
if move {
|
||||
if err := syscall.Rename(srcFilename, d.completeFilename(dstPathKey)); err == nil {
|
||||
d.bustCacheWithLock(dstPathKey.originalKey)
|
||||
return nil
|
||||
} else if err != syscall.EXDEV {
|
||||
// If it failed due to being on a different device, fall back to copying
|
||||
return err
|
||||
}
|
||||
}
|
||||
|
||||
f, err := os.Open(srcFilename)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
defer f.Close()
|
||||
err = d.writeStreamWithLock(dstPathKey, f, false)
|
||||
if err == nil && move {
|
||||
err = os.Remove(srcFilename)
|
||||
}
|
||||
return err
|
||||
}
|
||||
|
||||
// Read reads the key and returns the value.
|
||||
// If the key is available in the cache, Read won't touch the disk.
|
||||
// If the key is not in the cache, Read will have the side-effect of
|
||||
// lazily caching the value.
|
||||
func (d *Diskv) Read(key string) ([]byte, error) {
|
||||
rc, err := d.ReadStream(key, false)
|
||||
if err != nil {
|
||||
return []byte{}, err
|
||||
}
|
||||
defer rc.Close()
|
||||
return ioutil.ReadAll(rc)
|
||||
}
|
||||
|
||||
// ReadString reads the key and returns a string value
|
||||
// In case of error, an empty string is returned
|
||||
func (d *Diskv) ReadString(key string) string {
|
||||
value, _ := d.Read(key)
|
||||
return string(value)
|
||||
}
|
||||
|
||||
// ReadStream reads the key and returns the value (data) as an io.ReadCloser.
|
||||
// If the value is cached from a previous read, and direct is false,
|
||||
// ReadStream will use the cached value. Otherwise, it will return a handle to
|
||||
// the file on disk, and cache the data on read.
|
||||
//
|
||||
// If direct is true, ReadStream will lazily delete any cached value for the
|
||||
// key, and return a direct handle to the file on disk.
|
||||
//
|
||||
// If compression is enabled, ReadStream taps into the io.Reader stream prior
|
||||
// to decompression, and caches the compressed data.
|
||||
func (d *Diskv) ReadStream(key string, direct bool) (io.ReadCloser, error) {
|
||||
|
||||
pathKey := d.transform(key)
|
||||
d.mu.RLock()
|
||||
defer d.mu.RUnlock()
|
||||
|
||||
if val, ok := d.cache[key]; ok {
|
||||
if !direct {
|
||||
buf := bytes.NewReader(val)
|
||||
if d.Compression != nil {
|
||||
return d.Compression.Reader(buf)
|
||||
}
|
||||
return ioutil.NopCloser(buf), nil
|
||||
}
|
||||
|
||||
go func() {
|
||||
d.mu.Lock()
|
||||
defer d.mu.Unlock()
|
||||
d.uncacheWithLock(key, uint64(len(val)))
|
||||
}()
|
||||
}
|
||||
|
||||
return d.readWithRLock(pathKey)
|
||||
}
|
||||
|
||||
// read ignores the cache, and returns an io.ReadCloser representing the
|
||||
// decompressed data for the given key, streamed from the disk. Clients should
|
||||
// acquire a read lock on the Diskv and check the cache themselves before
|
||||
// calling read.
|
||||
func (d *Diskv) readWithRLock(pathKey *PathKey) (io.ReadCloser, error) {
|
||||
filename := d.completeFilename(pathKey)
|
||||
|
||||
fi, err := os.Stat(filename)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
if fi.IsDir() {
|
||||
return nil, os.ErrNotExist
|
||||
}
|
||||
|
||||
f, err := os.Open(filename)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
var r io.Reader
|
||||
if d.CacheSizeMax > 0 {
|
||||
r = newSiphon(f, d, pathKey.originalKey)
|
||||
} else {
|
||||
r = &closingReader{f}
|
||||
}
|
||||
|
||||
var rc = io.ReadCloser(ioutil.NopCloser(r))
|
||||
if d.Compression != nil {
|
||||
rc, err = d.Compression.Reader(r)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
}
|
||||
|
||||
return rc, nil
|
||||
}
|
||||
|
||||
// closingReader provides a Reader that automatically closes the
|
||||
// embedded ReadCloser when it reaches EOF
|
||||
type closingReader struct {
|
||||
rc io.ReadCloser
|
||||
}
|
||||
|
||||
func (cr closingReader) Read(p []byte) (int, error) {
|
||||
n, err := cr.rc.Read(p)
|
||||
if err == io.EOF {
|
||||
if closeErr := cr.rc.Close(); closeErr != nil {
|
||||
return n, closeErr // close must succeed for Read to succeed
|
||||
}
|
||||
}
|
||||
return n, err
|
||||
}
|
||||
|
||||
// siphon is like a TeeReader: it copies all data read through it to an
|
||||
// internal buffer, and moves that buffer to the cache at EOF.
|
||||
type siphon struct {
|
||||
f *os.File
|
||||
d *Diskv
|
||||
key string
|
||||
buf *bytes.Buffer
|
||||
}
|
||||
|
||||
// newSiphon constructs a siphoning reader that represents the passed file.
|
||||
// When a successful series of reads ends in an EOF, the siphon will write
|
||||
// the buffered data to Diskv's cache under the given key.
|
||||
func newSiphon(f *os.File, d *Diskv, key string) io.Reader {
|
||||
return &siphon{
|
||||
f: f,
|
||||
d: d,
|
||||
key: key,
|
||||
buf: &bytes.Buffer{},
|
||||
}
|
||||
}
|
||||
|
||||
// Read implements the io.Reader interface for siphon.
|
||||
func (s *siphon) Read(p []byte) (int, error) {
|
||||
n, err := s.f.Read(p)
|
||||
|
||||
if err == nil {
|
||||
return s.buf.Write(p[0:n]) // Write must succeed for Read to succeed
|
||||
}
|
||||
|
||||
if err == io.EOF {
|
||||
s.d.cacheWithoutLock(s.key, s.buf.Bytes()) // cache may fail
|
||||
if closeErr := s.f.Close(); closeErr != nil {
|
||||
return n, closeErr // close must succeed for Read to succeed
|
||||
}
|
||||
return n, err
|
||||
}
|
||||
|
||||
return n, err
|
||||
}
|
||||
|
||||
// Erase synchronously erases the given key from the disk and the cache.
|
||||
func (d *Diskv) Erase(key string) error {
|
||||
pathKey := d.transform(key)
|
||||
d.mu.Lock()
|
||||
defer d.mu.Unlock()
|
||||
|
||||
d.bustCacheWithLock(key)
|
||||
|
||||
// erase from index
|
||||
if d.Index != nil {
|
||||
d.Index.Delete(key)
|
||||
}
|
||||
|
||||
// erase from disk
|
||||
filename := d.completeFilename(pathKey)
|
||||
if s, err := os.Stat(filename); err == nil {
|
||||
if s.IsDir() {
|
||||
return errBadKey
|
||||
}
|
||||
if err = os.Remove(filename); err != nil {
|
||||
return err
|
||||
}
|
||||
} else {
|
||||
// Return err as-is so caller can do os.IsNotExist(err).
|
||||
return err
|
||||
}
|
||||
|
||||
// clean up and return
|
||||
d.pruneDirsWithLock(key)
|
||||
return nil
|
||||
}
|
||||
|
||||
// EraseAll will delete all of the data from the store, both in the cache and on
|
||||
// the disk. Note that EraseAll doesn't distinguish diskv-related data from non-
|
||||
// diskv-related data. Care should be taken to always specify a diskv base
|
||||
// directory that is exclusively for diskv data.
|
||||
func (d *Diskv) EraseAll() error {
|
||||
d.mu.Lock()
|
||||
defer d.mu.Unlock()
|
||||
d.cache = make(map[string][]byte)
|
||||
d.cacheSize = 0
|
||||
if d.TempDir != "" {
|
||||
os.RemoveAll(d.TempDir) // errors ignored
|
||||
}
|
||||
return os.RemoveAll(d.BasePath)
|
||||
}
|
||||
|
||||
// Has returns true if the given key exists.
|
||||
func (d *Diskv) Has(key string) bool {
|
||||
pathKey := d.transform(key)
|
||||
d.mu.Lock()
|
||||
defer d.mu.Unlock()
|
||||
|
||||
if _, ok := d.cache[key]; ok {
|
||||
return true
|
||||
}
|
||||
|
||||
filename := d.completeFilename(pathKey)
|
||||
s, err := os.Stat(filename)
|
||||
if err != nil {
|
||||
return false
|
||||
}
|
||||
if s.IsDir() {
|
||||
return false
|
||||
}
|
||||
|
||||
return true
|
||||
}
|
||||
|
||||
// Keys returns a channel that will yield every key accessible by the store,
|
||||
// in undefined order. If a cancel channel is provided, closing it will
|
||||
// terminate and close the keys channel.
|
||||
func (d *Diskv) Keys(cancel <-chan struct{}) <-chan string {
|
||||
return d.KeysPrefix("", cancel)
|
||||
}
|
||||
|
||||
// KeysPrefix returns a channel that will yield every key accessible by the
|
||||
// store with the given prefix, in undefined order. If a cancel channel is
|
||||
// provided, closing it will terminate and close the keys channel. If the
|
||||
// provided prefix is the empty string, all keys will be yielded.
|
||||
func (d *Diskv) KeysPrefix(prefix string, cancel <-chan struct{}) <-chan string {
|
||||
var prepath string
|
||||
if prefix == "" {
|
||||
prepath = d.BasePath
|
||||
} else {
|
||||
prefixKey := d.transform(prefix)
|
||||
prepath = d.pathFor(prefixKey)
|
||||
}
|
||||
c := make(chan string)
|
||||
go func() {
|
||||
filepath.Walk(prepath, d.walker(c, prefix, cancel))
|
||||
close(c)
|
||||
}()
|
||||
return c
|
||||
}
|
||||
|
||||
// walker returns a function which satisfies the filepath.WalkFunc interface.
|
||||
// It sends every non-directory file entry down the channel c.
|
||||
func (d *Diskv) walker(c chan<- string, prefix string, cancel <-chan struct{}) filepath.WalkFunc {
|
||||
return func(path string, info os.FileInfo, err error) error {
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
relPath, _ := filepath.Rel(d.BasePath, path)
|
||||
dir, file := filepath.Split(relPath)
|
||||
pathSplit := strings.Split(dir, string(filepath.Separator))
|
||||
pathSplit = pathSplit[:len(pathSplit)-1]
|
||||
|
||||
pathKey := &PathKey{
|
||||
Path: pathSplit,
|
||||
FileName: file,
|
||||
}
|
||||
|
||||
key := d.InverseTransform(pathKey)
|
||||
|
||||
if info.IsDir() || !strings.HasPrefix(key, prefix) {
|
||||
return nil // "pass"
|
||||
}
|
||||
|
||||
select {
|
||||
case c <- key:
|
||||
case <-cancel:
|
||||
return errCanceled
|
||||
}
|
||||
|
||||
return nil
|
||||
}
|
||||
}
|
||||
|
||||
// pathFor returns the absolute path for location on the filesystem where the
|
||||
// data for the given key will be stored.
|
||||
func (d *Diskv) pathFor(pathKey *PathKey) string {
|
||||
return filepath.Join(d.BasePath, filepath.Join(pathKey.Path...))
|
||||
}
|
||||
|
||||
// ensurePathWithLock is a helper function that generates all necessary
|
||||
// directories on the filesystem for the given key.
|
||||
func (d *Diskv) ensurePathWithLock(pathKey *PathKey) error {
|
||||
return os.MkdirAll(d.pathFor(pathKey), d.PathPerm)
|
||||
}
|
||||
|
||||
// completeFilename returns the absolute path to the file for the given key.
|
||||
func (d *Diskv) completeFilename(pathKey *PathKey) string {
|
||||
return filepath.Join(d.pathFor(pathKey), pathKey.FileName)
|
||||
}
|
||||
|
||||
// cacheWithLock attempts to cache the given key-value pair in the store's
|
||||
// cache. It can fail if the value is larger than the cache's maximum size.
|
||||
func (d *Diskv) cacheWithLock(key string, val []byte) error {
|
||||
valueSize := uint64(len(val))
|
||||
if err := d.ensureCacheSpaceWithLock(valueSize); err != nil {
|
||||
return fmt.Errorf("%s; not caching", err)
|
||||
}
|
||||
|
||||
// be very strict about memory guarantees
|
||||
if (d.cacheSize + valueSize) > d.CacheSizeMax {
|
||||
panic(fmt.Sprintf("failed to make room for value (%d/%d)", valueSize, d.CacheSizeMax))
|
||||
}
|
||||
|
||||
d.cache[key] = val
|
||||
d.cacheSize += valueSize
|
||||
return nil
|
||||
}
|
||||
|
||||
// cacheWithoutLock acquires the store's (write) mutex and calls cacheWithLock.
|
||||
func (d *Diskv) cacheWithoutLock(key string, val []byte) error {
|
||||
d.mu.Lock()
|
||||
defer d.mu.Unlock()
|
||||
return d.cacheWithLock(key, val)
|
||||
}
|
||||
|
||||
func (d *Diskv) bustCacheWithLock(key string) {
|
||||
if val, ok := d.cache[key]; ok {
|
||||
d.uncacheWithLock(key, uint64(len(val)))
|
||||
}
|
||||
}
|
||||
|
||||
func (d *Diskv) uncacheWithLock(key string, sz uint64) {
|
||||
d.cacheSize -= sz
|
||||
delete(d.cache, key)
|
||||
}
|
||||
|
||||
// pruneDirsWithLock deletes empty directories in the path walk leading to the
|
||||
// key k. Typically this function is called after an Erase is made.
|
||||
func (d *Diskv) pruneDirsWithLock(key string) error {
|
||||
pathlist := d.transform(key).Path
|
||||
for i := range pathlist {
|
||||
dir := filepath.Join(d.BasePath, filepath.Join(pathlist[:len(pathlist)-i]...))
|
||||
|
||||
// thanks to Steven Blenkinsop for this snippet
|
||||
switch fi, err := os.Stat(dir); true {
|
||||
case err != nil:
|
||||
return err
|
||||
case !fi.IsDir():
|
||||
panic(fmt.Sprintf("corrupt dirstate at %s", dir))
|
||||
}
|
||||
|
||||
nlinks, err := filepath.Glob(filepath.Join(dir, "*"))
|
||||
if err != nil {
|
||||
return err
|
||||
} else if len(nlinks) > 0 {
|
||||
return nil // has subdirs -- do not prune
|
||||
}
|
||||
if err = os.Remove(dir); err != nil {
|
||||
return err
|
||||
}
|
||||
}
|
||||
|
||||
return nil
|
||||
}
|
||||
|
||||
// ensureCacheSpaceWithLock deletes entries from the cache in arbitrary order
|
||||
// until the cache has at least valueSize bytes available.
|
||||
func (d *Diskv) ensureCacheSpaceWithLock(valueSize uint64) error {
|
||||
if valueSize > d.CacheSizeMax {
|
||||
return fmt.Errorf("value size (%d bytes) too large for cache (%d bytes)", valueSize, d.CacheSizeMax)
|
||||
}
|
||||
|
||||
safe := func() bool { return (d.cacheSize + valueSize) <= d.CacheSizeMax }
|
||||
|
||||
for key, val := range d.cache {
|
||||
if safe() {
|
||||
break
|
||||
}
|
||||
|
||||
d.uncacheWithLock(key, uint64(len(val)))
|
||||
}
|
||||
|
||||
if !safe() {
|
||||
panic(fmt.Sprintf("%d bytes still won't fit in the cache! (max %d bytes)", valueSize, d.CacheSizeMax))
|
||||
}
|
||||
|
||||
return nil
|
||||
}
|
||||
|
||||
// nopWriteCloser wraps an io.Writer and provides a no-op Close method to
|
||||
// satisfy the io.WriteCloser interface.
|
||||
type nopWriteCloser struct {
|
||||
io.Writer
|
||||
}
|
||||
|
||||
func (wc *nopWriteCloser) Write(p []byte) (int, error) { return wc.Writer.Write(p) }
|
||||
func (wc *nopWriteCloser) Close() error { return nil }
|
||||
|
|
@ -0,0 +1,5 @@
|
|||
module github.com/peterbourgon/diskv/v3
|
||||
|
||||
go 1.12
|
||||
|
||||
require github.com/google/btree v1.0.0
|
||||
|
|
@ -0,0 +1,2 @@
|
|||
github.com/google/btree v1.0.0 h1:0udJVsspx3VBr5FwtLhQQtuAsVc79tTq0ocGIPAU6qo=
|
||||
github.com/google/btree v1.0.0/go.mod h1:lNA+9X1NB3Zf8V7Ke586lFgjr2dZNuvo3lPJSGZ5JPQ=
|
||||
|
|
@ -0,0 +1,115 @@
|
|||
package diskv
|
||||
|
||||
import (
|
||||
"sync"
|
||||
|
||||
"github.com/google/btree"
|
||||
)
|
||||
|
||||
// Index is a generic interface for things that can
|
||||
// provide an ordered list of keys.
|
||||
type Index interface {
|
||||
Initialize(less LessFunction, keys <-chan string)
|
||||
Insert(key string)
|
||||
Delete(key string)
|
||||
Keys(from string, n int) []string
|
||||
}
|
||||
|
||||
// LessFunction is used to initialize an Index of keys in a specific order.
|
||||
type LessFunction func(string, string) bool
|
||||
|
||||
// btreeString is a custom data type that satisfies the BTree Less interface,
|
||||
// making the strings it wraps sortable by the BTree package.
|
||||
type btreeString struct {
|
||||
s string
|
||||
l LessFunction
|
||||
}
|
||||
|
||||
// Less satisfies the BTree.Less interface using the btreeString's LessFunction.
|
||||
func (s btreeString) Less(i btree.Item) bool {
|
||||
return s.l(s.s, i.(btreeString).s)
|
||||
}
|
||||
|
||||
// BTreeIndex is an implementation of the Index interface using google/btree.
|
||||
type BTreeIndex struct {
|
||||
sync.RWMutex
|
||||
LessFunction
|
||||
*btree.BTree
|
||||
}
|
||||
|
||||
// Initialize populates the BTree tree with data from the keys channel,
|
||||
// according to the passed less function. It's destructive to the BTreeIndex.
|
||||
func (i *BTreeIndex) Initialize(less LessFunction, keys <-chan string) {
|
||||
i.Lock()
|
||||
defer i.Unlock()
|
||||
i.LessFunction = less
|
||||
i.BTree = rebuild(less, keys)
|
||||
}
|
||||
|
||||
// Insert inserts the given key (only) into the BTree tree.
|
||||
func (i *BTreeIndex) Insert(key string) {
|
||||
i.Lock()
|
||||
defer i.Unlock()
|
||||
if i.BTree == nil || i.LessFunction == nil {
|
||||
panic("uninitialized index")
|
||||
}
|
||||
i.BTree.ReplaceOrInsert(btreeString{s: key, l: i.LessFunction})
|
||||
}
|
||||
|
||||
// Delete removes the given key (only) from the BTree tree.
|
||||
func (i *BTreeIndex) Delete(key string) {
|
||||
i.Lock()
|
||||
defer i.Unlock()
|
||||
if i.BTree == nil || i.LessFunction == nil {
|
||||
panic("uninitialized index")
|
||||
}
|
||||
i.BTree.Delete(btreeString{s: key, l: i.LessFunction})
|
||||
}
|
||||
|
||||
// Keys yields a maximum of n keys in order. If the passed 'from' key is empty,
|
||||
// Keys will return the first n keys. If the passed 'from' key is non-empty, the
|
||||
// first key in the returned slice will be the key that immediately follows the
|
||||
// passed key, in key order.
|
||||
func (i *BTreeIndex) Keys(from string, n int) []string {
|
||||
i.RLock()
|
||||
defer i.RUnlock()
|
||||
|
||||
if i.BTree == nil || i.LessFunction == nil {
|
||||
panic("uninitialized index")
|
||||
}
|
||||
|
||||
if i.BTree.Len() <= 0 {
|
||||
return []string{}
|
||||
}
|
||||
|
||||
btreeFrom := btreeString{s: from, l: i.LessFunction}
|
||||
skipFirst := true
|
||||
if len(from) <= 0 || !i.BTree.Has(btreeFrom) {
|
||||
// no such key, so fabricate an always-smallest item
|
||||
btreeFrom = btreeString{s: "", l: func(string, string) bool { return true }}
|
||||
skipFirst = false
|
||||
}
|
||||
|
||||
keys := []string{}
|
||||
iterator := func(i btree.Item) bool {
|
||||
keys = append(keys, i.(btreeString).s)
|
||||
return len(keys) < n
|
||||
}
|
||||
i.BTree.AscendGreaterOrEqual(btreeFrom, iterator)
|
||||
|
||||
if skipFirst && len(keys) > 0 {
|
||||
keys = keys[1:]
|
||||
}
|
||||
|
||||
return keys
|
||||
}
|
||||
|
||||
// rebuildIndex does the work of regenerating the index
|
||||
// with the given keys.
|
||||
func rebuild(less LessFunction, keys <-chan string) *btree.BTree {
|
||||
tree := btree.New(2)
|
||||
for key := range keys {
|
||||
tree.ReplaceOrInsert(btreeString{s: key, l: less})
|
||||
}
|
||||
return tree
|
||||
}
|
||||
300
vendor/k8s.io/client-go/discovery/cached/disk/cached_discovery.go
сгенерированный
поставляемый
Normal file
300
vendor/k8s.io/client-go/discovery/cached/disk/cached_discovery.go
сгенерированный
поставляемый
Normal file
|
|
@ -0,0 +1,300 @@
|
|||
/*
|
||||
Copyright 2016 The Kubernetes Authors.
|
||||
|
||||
Licensed under the Apache License, Version 2.0 (the "License");
|
||||
you may not use this file except in compliance with the License.
|
||||
You may obtain a copy of the License at
|
||||
|
||||
http://www.apache.org/licenses/LICENSE-2.0
|
||||
|
||||
Unless required by applicable law or agreed to in writing, software
|
||||
distributed under the License is distributed on an "AS IS" BASIS,
|
||||
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
See the License for the specific language governing permissions and
|
||||
limitations under the License.
|
||||
*/
|
||||
|
||||
package disk
|
||||
|
||||
import (
|
||||
"errors"
|
||||
"io/ioutil"
|
||||
"net/http"
|
||||
"os"
|
||||
"path/filepath"
|
||||
"sync"
|
||||
"time"
|
||||
|
||||
openapi_v2 "github.com/googleapis/gnostic/OpenAPIv2"
|
||||
"k8s.io/klog"
|
||||
|
||||
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
|
||||
"k8s.io/apimachinery/pkg/runtime"
|
||||
"k8s.io/apimachinery/pkg/version"
|
||||
"k8s.io/client-go/discovery"
|
||||
"k8s.io/client-go/kubernetes/scheme"
|
||||
restclient "k8s.io/client-go/rest"
|
||||
)
|
||||
|
||||
// CachedDiscoveryClient implements the functions that discovery server-supported API groups,
|
||||
// versions and resources.
|
||||
type CachedDiscoveryClient struct {
|
||||
delegate discovery.DiscoveryInterface
|
||||
|
||||
// cacheDirectory is the directory where discovery docs are held. It must be unique per host:port combination to work well.
|
||||
cacheDirectory string
|
||||
|
||||
// ttl is how long the cache should be considered valid
|
||||
ttl time.Duration
|
||||
|
||||
// mutex protects the variables below
|
||||
mutex sync.Mutex
|
||||
|
||||
// ourFiles are all filenames of cache files created by this process
|
||||
ourFiles map[string]struct{}
|
||||
// invalidated is true if all cache files should be ignored that are not ours (e.g. after Invalidate() was called)
|
||||
invalidated bool
|
||||
// fresh is true if all used cache files were ours
|
||||
fresh bool
|
||||
}
|
||||
|
||||
var _ discovery.CachedDiscoveryInterface = &CachedDiscoveryClient{}
|
||||
|
||||
// ServerResourcesForGroupVersion returns the supported resources for a group and version.
|
||||
func (d *CachedDiscoveryClient) ServerResourcesForGroupVersion(groupVersion string) (*metav1.APIResourceList, error) {
|
||||
filename := filepath.Join(d.cacheDirectory, groupVersion, "serverresources.json")
|
||||
cachedBytes, err := d.getCachedFile(filename)
|
||||
// don't fail on errors, we either don't have a file or won't be able to run the cached check. Either way we can fallback.
|
||||
if err == nil {
|
||||
cachedResources := &metav1.APIResourceList{}
|
||||
if err := runtime.DecodeInto(scheme.Codecs.UniversalDecoder(), cachedBytes, cachedResources); err == nil {
|
||||
klog.V(10).Infof("returning cached discovery info from %v", filename)
|
||||
return cachedResources, nil
|
||||
}
|
||||
}
|
||||
|
||||
liveResources, err := d.delegate.ServerResourcesForGroupVersion(groupVersion)
|
||||
if err != nil {
|
||||
klog.V(3).Infof("skipped caching discovery info due to %v", err)
|
||||
return liveResources, err
|
||||
}
|
||||
if liveResources == nil || len(liveResources.APIResources) == 0 {
|
||||
klog.V(3).Infof("skipped caching discovery info, no resources found")
|
||||
return liveResources, err
|
||||
}
|
||||
|
||||
if err := d.writeCachedFile(filename, liveResources); err != nil {
|
||||
klog.V(1).Infof("failed to write cache to %v due to %v", filename, err)
|
||||
}
|
||||
|
||||
return liveResources, nil
|
||||
}
|
||||
|
||||
// ServerResources returns the supported resources for all groups and versions.
|
||||
// Deprecated: use ServerGroupsAndResources instead.
|
||||
func (d *CachedDiscoveryClient) ServerResources() ([]*metav1.APIResourceList, error) {
|
||||
_, rs, err := discovery.ServerGroupsAndResources(d)
|
||||
return rs, err
|
||||
}
|
||||
|
||||
// ServerGroupsAndResources returns the supported groups and resources for all groups and versions.
|
||||
func (d *CachedDiscoveryClient) ServerGroupsAndResources() ([]*metav1.APIGroup, []*metav1.APIResourceList, error) {
|
||||
return discovery.ServerGroupsAndResources(d)
|
||||
}
|
||||
|
||||
// ServerGroups returns the supported groups, with information like supported versions and the
|
||||
// preferred version.
|
||||
func (d *CachedDiscoveryClient) ServerGroups() (*metav1.APIGroupList, error) {
|
||||
filename := filepath.Join(d.cacheDirectory, "servergroups.json")
|
||||
cachedBytes, err := d.getCachedFile(filename)
|
||||
// don't fail on errors, we either don't have a file or won't be able to run the cached check. Either way we can fallback.
|
||||
if err == nil {
|
||||
cachedGroups := &metav1.APIGroupList{}
|
||||
if err := runtime.DecodeInto(scheme.Codecs.UniversalDecoder(), cachedBytes, cachedGroups); err == nil {
|
||||
klog.V(10).Infof("returning cached discovery info from %v", filename)
|
||||
return cachedGroups, nil
|
||||
}
|
||||
}
|
||||
|
||||
liveGroups, err := d.delegate.ServerGroups()
|
||||
if err != nil {
|
||||
klog.V(3).Infof("skipped caching discovery info due to %v", err)
|
||||
return liveGroups, err
|
||||
}
|
||||
if liveGroups == nil || len(liveGroups.Groups) == 0 {
|
||||
klog.V(3).Infof("skipped caching discovery info, no groups found")
|
||||
return liveGroups, err
|
||||
}
|
||||
|
||||
if err := d.writeCachedFile(filename, liveGroups); err != nil {
|
||||
klog.V(1).Infof("failed to write cache to %v due to %v", filename, err)
|
||||
}
|
||||
|
||||
return liveGroups, nil
|
||||
}
|
||||
|
||||
func (d *CachedDiscoveryClient) getCachedFile(filename string) ([]byte, error) {
|
||||
// after invalidation ignore cache files not created by this process
|
||||
d.mutex.Lock()
|
||||
_, ourFile := d.ourFiles[filename]
|
||||
if d.invalidated && !ourFile {
|
||||
d.mutex.Unlock()
|
||||
return nil, errors.New("cache invalidated")
|
||||
}
|
||||
d.mutex.Unlock()
|
||||
|
||||
file, err := os.Open(filename)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
defer file.Close()
|
||||
|
||||
fileInfo, err := file.Stat()
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
if time.Now().After(fileInfo.ModTime().Add(d.ttl)) {
|
||||
return nil, errors.New("cache expired")
|
||||
}
|
||||
|
||||
// the cache is present and its valid. Try to read and use it.
|
||||
cachedBytes, err := ioutil.ReadAll(file)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
d.mutex.Lock()
|
||||
defer d.mutex.Unlock()
|
||||
d.fresh = d.fresh && ourFile
|
||||
|
||||
return cachedBytes, nil
|
||||
}
|
||||
|
||||
func (d *CachedDiscoveryClient) writeCachedFile(filename string, obj runtime.Object) error {
|
||||
if err := os.MkdirAll(filepath.Dir(filename), 0750); err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
bytes, err := runtime.Encode(scheme.Codecs.LegacyCodec(), obj)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
f, err := ioutil.TempFile(filepath.Dir(filename), filepath.Base(filename)+".")
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
defer os.Remove(f.Name())
|
||||
_, err = f.Write(bytes)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
err = os.Chmod(f.Name(), 0660)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
name := f.Name()
|
||||
err = f.Close()
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
// atomic rename
|
||||
d.mutex.Lock()
|
||||
defer d.mutex.Unlock()
|
||||
err = os.Rename(name, filename)
|
||||
if err == nil {
|
||||
d.ourFiles[filename] = struct{}{}
|
||||
}
|
||||
return err
|
||||
}
|
||||
|
||||
// RESTClient returns a RESTClient that is used to communicate with API server
|
||||
// by this client implementation.
|
||||
func (d *CachedDiscoveryClient) RESTClient() restclient.Interface {
|
||||
return d.delegate.RESTClient()
|
||||
}
|
||||
|
||||
// ServerPreferredResources returns the supported resources with the version preferred by the
|
||||
// server.
|
||||
func (d *CachedDiscoveryClient) ServerPreferredResources() ([]*metav1.APIResourceList, error) {
|
||||
return discovery.ServerPreferredResources(d)
|
||||
}
|
||||
|
||||
// ServerPreferredNamespacedResources returns the supported namespaced resources with the
|
||||
// version preferred by the server.
|
||||
func (d *CachedDiscoveryClient) ServerPreferredNamespacedResources() ([]*metav1.APIResourceList, error) {
|
||||
return discovery.ServerPreferredNamespacedResources(d)
|
||||
}
|
||||
|
||||
// ServerVersion retrieves and parses the server's version (git version).
|
||||
func (d *CachedDiscoveryClient) ServerVersion() (*version.Info, error) {
|
||||
return d.delegate.ServerVersion()
|
||||
}
|
||||
|
||||
// OpenAPISchema retrieves and parses the swagger API schema the server supports.
|
||||
func (d *CachedDiscoveryClient) OpenAPISchema() (*openapi_v2.Document, error) {
|
||||
return d.delegate.OpenAPISchema()
|
||||
}
|
||||
|
||||
// Fresh is supposed to tell the caller whether or not to retry if the cache
|
||||
// fails to find something (false = retry, true = no need to retry).
|
||||
func (d *CachedDiscoveryClient) Fresh() bool {
|
||||
d.mutex.Lock()
|
||||
defer d.mutex.Unlock()
|
||||
|
||||
return d.fresh
|
||||
}
|
||||
|
||||
// Invalidate enforces that no cached data is used in the future that is older than the current time.
|
||||
func (d *CachedDiscoveryClient) Invalidate() {
|
||||
d.mutex.Lock()
|
||||
defer d.mutex.Unlock()
|
||||
|
||||
d.ourFiles = map[string]struct{}{}
|
||||
d.fresh = true
|
||||
d.invalidated = true
|
||||
}
|
||||
|
||||
// NewCachedDiscoveryClientForConfig creates a new DiscoveryClient for the given config, and wraps
|
||||
// the created client in a CachedDiscoveryClient. The provided configuration is updated with a
|
||||
// custom transport that understands cache responses.
|
||||
// We receive two distinct cache directories for now, in order to preserve old behavior
|
||||
// which makes use of the --cache-dir flag value for storing cache data from the CacheRoundTripper,
|
||||
// and makes use of the hardcoded destination (~/.kube/cache/discovery/...) for storing
|
||||
// CachedDiscoveryClient cache data. If httpCacheDir is empty, the restconfig's transport will not
|
||||
// be updated with a roundtripper that understands cache responses.
|
||||
// If discoveryCacheDir is empty, cached server resource data will be looked up in the current directory.
|
||||
// TODO(juanvallejo): the value of "--cache-dir" should be honored. Consolidate discoveryCacheDir with httpCacheDir
|
||||
// so that server resources and http-cache data are stored in the same location, provided via config flags.
|
||||
func NewCachedDiscoveryClientForConfig(config *restclient.Config, discoveryCacheDir, httpCacheDir string, ttl time.Duration) (*CachedDiscoveryClient, error) {
|
||||
if len(httpCacheDir) > 0 {
|
||||
// update the given restconfig with a custom roundtripper that
|
||||
// understands how to handle cache responses.
|
||||
config = restclient.CopyConfig(config)
|
||||
config.Wrap(func(rt http.RoundTripper) http.RoundTripper {
|
||||
return newCacheRoundTripper(httpCacheDir, rt)
|
||||
})
|
||||
}
|
||||
|
||||
discoveryClient, err := discovery.NewDiscoveryClientForConfig(config)
|
||||
if err != nil {
|
||||
return nil, err
|
||||
}
|
||||
|
||||
return newCachedDiscoveryClient(discoveryClient, discoveryCacheDir, ttl), nil
|
||||
}
|
||||
|
||||
// NewCachedDiscoveryClient creates a new DiscoveryClient. cacheDirectory is the directory where discovery docs are held. It must be unique per host:port combination to work well.
|
||||
func newCachedDiscoveryClient(delegate discovery.DiscoveryInterface, cacheDirectory string, ttl time.Duration) *CachedDiscoveryClient {
|
||||
return &CachedDiscoveryClient{
|
||||
delegate: delegate,
|
||||
cacheDirectory: cacheDirectory,
|
||||
ttl: ttl,
|
||||
ourFiles: map[string]struct{}{},
|
||||
fresh: true,
|
||||
}
|
||||
}
|
||||
65
vendor/k8s.io/client-go/discovery/cached/disk/round_tripper.go
сгенерированный
поставляемый
Normal file
65
vendor/k8s.io/client-go/discovery/cached/disk/round_tripper.go
сгенерированный
поставляемый
Normal file
|
|
@ -0,0 +1,65 @@
|
|||
/*
|
||||
Copyright 2017 The Kubernetes Authors.
|
||||
|
||||
Licensed under the Apache License, Version 2.0 (the "License");
|
||||
you may not use this file except in compliance with the License.
|
||||
You may obtain a copy of the License at
|
||||
|
||||
http://www.apache.org/licenses/LICENSE-2.0
|
||||
|
||||
Unless required by applicable law or agreed to in writing, software
|
||||
distributed under the License is distributed on an "AS IS" BASIS,
|
||||
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
See the License for the specific language governing permissions and
|
||||
limitations under the License.
|
||||
*/
|
||||
|
||||
package disk
|
||||
|
||||
import (
|
||||
"net/http"
|
||||
"os"
|
||||
"path/filepath"
|
||||
|
||||
"github.com/gregjones/httpcache"
|
||||
"github.com/gregjones/httpcache/diskcache"
|
||||
"github.com/peterbourgon/diskv"
|
||||
"k8s.io/klog"
|
||||
)
|
||||
|
||||
type cacheRoundTripper struct {
|
||||
rt *httpcache.Transport
|
||||
}
|
||||
|
||||
// newCacheRoundTripper creates a roundtripper that reads the ETag on
|
||||
// response headers and send the If-None-Match header on subsequent
|
||||
// corresponding requests.
|
||||
func newCacheRoundTripper(cacheDir string, rt http.RoundTripper) http.RoundTripper {
|
||||
d := diskv.New(diskv.Options{
|
||||
PathPerm: os.FileMode(0750),
|
||||
FilePerm: os.FileMode(0660),
|
||||
BasePath: cacheDir,
|
||||
TempDir: filepath.Join(cacheDir, ".diskv-temp"),
|
||||
})
|
||||
t := httpcache.NewTransport(diskcache.NewWithDiskv(d))
|
||||
t.Transport = rt
|
||||
|
||||
return &cacheRoundTripper{rt: t}
|
||||
}
|
||||
|
||||
func (rt *cacheRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
|
||||
return rt.rt.RoundTrip(req)
|
||||
}
|
||||
|
||||
func (rt *cacheRoundTripper) CancelRequest(req *http.Request) {
|
||||
type canceler interface {
|
||||
CancelRequest(*http.Request)
|
||||
}
|
||||
if cr, ok := rt.rt.Transport.(canceler); ok {
|
||||
cr.CancelRequest(req)
|
||||
} else {
|
||||
klog.Errorf("CancelRequest not implemented by %T", rt.rt.Transport)
|
||||
}
|
||||
}
|
||||
|
||||
func (rt *cacheRoundTripper) WrappedRoundTripper() http.RoundTripper { return rt.rt.Transport }
|
||||
Загрузка…
Ссылка в новой задаче