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move the DeltaTree implementation out of line, remove debugging printfs etc. 

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@49591 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2008-04-12 22:00:40 +00:00
Родитель 77257889f5
Коммит 8100d74951
3 изменённых файлов: 429 добавлений и 379 удалений
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4
clang.xcodeproj/project.pbxproj
Просмотреть файл

@ -171,6 +171,7 @@
DEF2F0100C6CFED5000C4259 /* SemaChecking.cpp in Sources */ = {isa = PBXBuildFile; fileRef = DEF2F00F0C6CFED5000C4259 /* SemaChecking.cpp */; };
DEF7D9F70C9C8B1A0001F598 /* Rewriter.h in CopyFiles */ = {isa = PBXBuildFile; fileRef = DEF7D9F60C9C8B1A0001F598 /* Rewriter.h */; };
DEF7D9F90C9C8B1D0001F598 /* Rewriter.cpp in Sources */ = {isa = PBXBuildFile; fileRef = DEF7D9F80C9C8B1D0001F598 /* Rewriter.cpp */; };
DEFFECA70DB1546600B4E7C3 /* DeltaTree.cpp in Sources */ = {isa = PBXBuildFile; fileRef = DEFFECA60DB1546600B4E7C3 /* DeltaTree.cpp */; };
F0226FD20C18084500141F42 /* TextDiagnosticPrinter.cpp in Sources */ = {isa = PBXBuildFile; fileRef = F0226FD00C18084500141F42 /* TextDiagnosticPrinter.cpp */; };
F0226FD30C18084500141F42 /* TextDiagnosticPrinter.h in CopyFiles */ = {isa = PBXBuildFile; fileRef = F0226FD10C18084500141F42 /* TextDiagnosticPrinter.h */; };
/* End PBXBuildFile section */
@ -458,6 +459,7 @@
DEF7D9F60C9C8B1A0001F598 /* Rewriter.h */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.c.h; name = Rewriter.h; path = clang/Rewrite/Rewriter.h; sourceTree = "<group>"; };
DEF7D9F80C9C8B1D0001F598 /* Rewriter.cpp */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.cpp.cpp; name = Rewriter.cpp; path = lib/Rewrite/Rewriter.cpp; sourceTree = "<group>"; };
DEFFECA30DB093D100B4E7C3 /* DeltaTree.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = DeltaTree.h; path = clang/Rewrite/DeltaTree.h; sourceTree = "<group>"; };
DEFFECA60DB1546600B4E7C3 /* DeltaTree.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = DeltaTree.cpp; path = lib/Rewrite/DeltaTree.cpp; sourceTree = "<group>"; };
F0226FD00C18084500141F42 /* TextDiagnosticPrinter.cpp */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.cpp.cpp; name = TextDiagnosticPrinter.cpp; path = Driver/TextDiagnosticPrinter.cpp; sourceTree = "<group>"; };
F0226FD10C18084500141F42 /* TextDiagnosticPrinter.h */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.c.h; name = TextDiagnosticPrinter.h; path = Driver/TextDiagnosticPrinter.h; sourceTree = "<group>"; };
/* End PBXFileReference section */
@ -902,6 +904,7 @@
DEF7D9F50C9C8B0C0001F598 /* Rewrite */ = {
isa = PBXGroup;
children = (
DEFFECA60DB1546600B4E7C3 /* DeltaTree.cpp */,
72D16C1E0D9975C400E6DA4A /* HTMLRewrite.cpp */,
DEF7D9F80C9C8B1D0001F598 /* Rewriter.cpp */,
);
@ -1061,6 +1064,7 @@
DECAB0950DA684C500E13CCB /* CGObjCEtoile.cpp in Sources */,
35EF67700DAD1D2C00B19414 /* SemaDeclCXX.cpp in Sources */,
352712510DAFE54700C76352 /* IdentifierResolver.cpp in Sources */,
DEFFECA70DB1546600B4E7C3 /* DeltaTree.cpp in Sources */,
);
runOnlyForDeploymentPostprocessing = 0;
};

386
include/clang/Rewrite/DeltaTree.h
Просмотреть файл

@ -14,269 +14,7 @@
#ifndef CLANG_REWRITE_DELTATREE_H
#define CLANG_REWRITE_DELTATREE_H
#include "llvm/Support/Casting.h"
namespace clang {
using llvm::cast;
using llvm::dyn_cast;
class DeltaTreeInteriorNode;
/// SourceDelta - As code in the original input buffer is added and deleted,
/// SourceDelta records are used to keep track of how the input SourceLocation
/// object is mapped into the output buffer.
struct SourceDelta {
unsigned FileLoc;
int Delta;
static SourceDelta get(unsigned Loc, int D) {
SourceDelta Delta;
Delta.FileLoc = Loc;
Delta.Delta = D;
return Delta;
}
};
/// The DeltaTree class is a multiway search tree (BTree) structure with some
/// fancy features. B-Trees are are generally more memory and cache efficient
/// than binary trees, because they store multiple keys/values in each node.
///
/// DeltaTree implements a key/value mapping from FileIndex to Delta, allowing
/// fast lookup by FileIndex. However, an added (important) bonus is that it
/// can also efficiently tell us the full accumulated delta for a specific
/// file offset as well, without traversing the whole tree.
///
/// The nodes of the tree are made up of instances of two classes:
/// DeltaTreeNode and DeltaTreeInteriorNode. The later subclasses the
/// former and adds children pointers. Each node knows the full delta of all
/// entries (recursively) contained inside of it, which allows us to get the
/// full delta implied by a whole subtree in constant time.
/// DeltaTreeNode - The common part of all nodes.
///
class DeltaTreeNode {
friend class DeltaTreeInteriorNode;
/// WidthFactor - This controls the number of K/V slots held in the BTree:
/// how wide it is. Each level of the BTree is guaranteed to have at least
/// WidthFactor-1 K/V pairs (unless the whole tree is less full than that)
/// and may have at most 2*WidthFactor-1 K/V pairs.
enum { WidthFactor = 8 };
/// Values - This tracks the SourceDelta's currently in this node.
///
SourceDelta Values[2*WidthFactor-1];
/// NumValuesUsed - This tracks the number of values this node currently
/// holds.
unsigned char NumValuesUsed;
/// IsLeaf - This is true if this is a leaf of the btree. If false, this is
/// an interior node, and is actually an instance of DeltaTreeInteriorNode.
bool IsLeaf;
/// FullDelta - This is the full delta of all the values in this node and
/// all children nodes.
int FullDelta;
public:
DeltaTreeNode(bool isLeaf = true)
: NumValuesUsed(0), IsLeaf(isLeaf), FullDelta(0) {}
bool isLeaf() const { return IsLeaf; }
int getFullDelta() const { return FullDelta; }
bool isFull() const { return NumValuesUsed == 2*WidthFactor-1; }
unsigned getNumValuesUsed() const { return NumValuesUsed; }
const SourceDelta &getValue(unsigned i) const {
assert(i < NumValuesUsed && "Invalid value #");
return Values[i];
}
SourceDelta &getValue(unsigned i) {
assert(i < NumValuesUsed && "Invalid value #");
return Values[i];
}
/// AddDeltaNonFull - Add a delta to this tree and/or it's children, knowing
/// that this node is not currently full.
void AddDeltaNonFull(unsigned FileIndex, int Delta);
/// RecomputeFullDeltaLocally - Recompute the FullDelta field by doing a
/// local walk over our contained deltas.
void RecomputeFullDeltaLocally();
void Destroy();
static inline bool classof(const DeltaTreeNode *) { return true; }
};
/// DeltaTreeInteriorNode - When isLeaf = false, a node has child pointers.
/// This class tracks them.
class DeltaTreeInteriorNode : public DeltaTreeNode {
DeltaTreeNode *Children[2*WidthFactor];
~DeltaTreeInteriorNode() {
for (unsigned i = 0, e = NumValuesUsed+1; i != e; ++i)
Children[i]->Destroy();
}
friend class DeltaTreeNode;
public:
DeltaTreeInteriorNode() : DeltaTreeNode(false /*nonleaf*/) {}
DeltaTreeInteriorNode(DeltaTreeNode *FirstChild)
: DeltaTreeNode(false /*nonleaf*/) {
FullDelta = FirstChild->FullDelta;
Children[0] = FirstChild;
}
const DeltaTreeNode *getChild(unsigned i) const {
assert(i < getNumValuesUsed()+1 && "Invalid child");
return Children[i];
}
DeltaTreeNode *getChild(unsigned i) {
assert(i < getNumValuesUsed()+1 && "Invalid child");
return Children[i];
}
static inline bool classof(const DeltaTreeInteriorNode *) { return true; }
static inline bool classof(const DeltaTreeNode *N) { return !N->isLeaf(); }
private:
void SplitChild(unsigned ChildNo);
};
/// Destroy - A 'virtual' destructor.
inline void DeltaTreeNode::Destroy() {
if (isLeaf())
delete this;
else
delete cast<DeltaTreeInteriorNode>(this);
}
/// RecomputeFullDeltaLocally - Recompute the FullDelta field by doing a
/// local walk over our contained deltas.
inline void DeltaTreeNode::RecomputeFullDeltaLocally() {
int NewFullDelta = 0;
for (unsigned i = 0, e = getNumValuesUsed(); i != e; ++i)
NewFullDelta += Values[i].Delta;
if (DeltaTreeInteriorNode *IN = dyn_cast<DeltaTreeInteriorNode>(this))
for (unsigned i = 0, e = getNumValuesUsed()+1; i != e; ++i)
NewFullDelta += IN->getChild(i)->getFullDelta();
FullDelta = NewFullDelta;
}
/// AddDeltaNonFull - Add a delta to this tree and/or it's children, knowing
/// that this node is not currently full.
inline void DeltaTreeNode::AddDeltaNonFull(unsigned FileIndex, int Delta) {
assert(!isFull() && "AddDeltaNonFull on a full tree?");
// Maintain full delta for this node.
FullDelta += Delta;
// Find the insertion point, the first delta whose index is >= FileIndex.
unsigned i = 0, e = getNumValuesUsed();
while (i != e && FileIndex > getValue(i).FileLoc)
++i;
// If we found an a record for exactly this file index, just merge this
// value into the preexisting record and finish early.
if (i != e && getValue(i).FileLoc == FileIndex) {
// NOTE: Delta could drop to zero here. This means that the next delta
// entry is useless and could be removed. Supporting erases is
// significantly more complex though, so we just leave an entry with
// Delta=0 in the tree.
Values[i].Delta += Delta;
return;
}
if (DeltaTreeInteriorNode *IN = dyn_cast<DeltaTreeInteriorNode>(this)) {
// Insertion into an interior node propagates the value down to a child.
DeltaTreeNode *Child = IN->getChild(i);
// If the child tree is full, split it, pulling an element up into our
// node.
if (Child->isFull()) {
IN->SplitChild(i);
SourceDelta &MedianVal = getValue(i);
// If the median value we pulled up is exactly our insert position, add
// the delta and return.
if (MedianVal.FileLoc == FileIndex) {
MedianVal.Delta += Delta;
return;
}
// If the median value pulled up is less than our current search point,
// include those deltas and search down the RHS now.
if (MedianVal.FileLoc < FileIndex)
Child = IN->getChild(i+1);
}
Child->AddDeltaNonFull(FileIndex, Delta);
} else {
// For an insertion into a non-full leaf node, just insert the value in
// its sorted position. This requires moving later values over.
if (i != e)
memmove(&Values[i+1], &Values[i], sizeof(Values[0])*(e-i));
Values[i] = SourceDelta::get(FileIndex, Delta);
++NumValuesUsed;
}
}
/// SplitChild - At this point, we know that the current node is not full and
/// that the specified child of this node is. Split the child in half at its
/// median, propagating one value up into us. Child may be either an interior
/// or leaf node.
inline void DeltaTreeInteriorNode::SplitChild(unsigned ChildNo) {
//printf("SplitChild: %p %d\n", (void*)this, ChildNo);
DeltaTreeNode *Child = getChild(ChildNo);
assert(!isFull() && Child->isFull() && "Inconsistent constraints");
// Since the child is full, it contains 2*WidthFactor-1 values. We move
// the first 'WidthFactor-1' values to the LHS child (which we leave in the
// original child), propagate one value up into us, and move the last
// 'WidthFactor-1' values into thew RHS child.
// Create the new child node.
DeltaTreeNode *NewNode;
if (DeltaTreeInteriorNode *CIN = dyn_cast<DeltaTreeInteriorNode>(Child)) {
// If the child is an interior node, also move over 'WidthFactor' grand
// children into the new node.
NewNode = new DeltaTreeInteriorNode();
memcpy(&((DeltaTreeInteriorNode*)NewNode)->Children[0],
&CIN->Children[WidthFactor],
WidthFactor*sizeof(CIN->Children[0]));
} else {
// Just create the child node.
NewNode = new DeltaTreeNode();
}
// Move over the last 'WidthFactor-1' values from Child to NewNode.
memcpy(&NewNode->Values[0], &Child->Values[WidthFactor],
(WidthFactor-1)*sizeof(Child->Values[0]));
// Decrease the number of values in the two children.
NewNode->NumValuesUsed = Child->NumValuesUsed = WidthFactor-1;
// Recompute the two children's full delta. Our delta hasn't changed, but
// their delta has.
NewNode->RecomputeFullDeltaLocally();
Child->RecomputeFullDeltaLocally();
// Now that we have two nodes and a new element, insert the median value
// into ourself by moving all the later values/children down, then inserting
// the new one.
if (getNumValuesUsed() != ChildNo)
memmove(&Children[ChildNo+2], &Children[ChildNo+1],
(getNumValuesUsed()-ChildNo)*sizeof(Children[0]));
Children[ChildNo+1] = NewNode;
if (getNumValuesUsed() != ChildNo)
memmove(&Values[ChildNo+1], &Values[ChildNo],
(getNumValuesUsed()-ChildNo)*sizeof(Values[0]));
Values[ChildNo] = Child->Values[WidthFactor-1];
++NumValuesUsed;
}
/// DeltaTree - a multiway search tree (BTree) structure with some fancy
/// features. B-Trees are are generally more memory and cache efficient than
@ -286,133 +24,25 @@ namespace clang {
/// efficiently tell us the full accumulated delta for a specific file offset
/// as well, without traversing the whole tree.
class DeltaTree {
DeltaTreeNode *Root;
void *Root; // "DeltaTreeNode *"
void operator=(const DeltaTree&); // DO NOT IMPLEMENT
public:
DeltaTree() {
Root = new DeltaTreeNode();
}
DeltaTree(const DeltaTree &RHS) {
// Currently we only support copying when the RHS is empty.
assert(RHS.empty() && "Can only copy empty tree");
Root = new DeltaTreeNode();
}
DeltaTree();
~DeltaTree() {
Root->Destroy();
}
bool empty() const {
return Root->getNumValuesUsed() == 0;
}
// Note: Currently we only support copying when the RHS is empty.
DeltaTree(const DeltaTree &RHS);
~DeltaTree();
/// getDeltaAt - Return the accumulated delta at the specified file offset.
/// This includes all insertions or delections that occurred *before* the
/// specified file index.
int getDeltaAt(unsigned FileIndex) const {
const DeltaTreeNode *Node = Root;
int Result = 0;
// Walk down the tree.
while (1) {
// For all nodes, include any local deltas before the specified file
// index by summing them up directly. Keep track of how many were
// included.
unsigned NumValsGreater = 0;
for (unsigned e = Node->getNumValuesUsed(); NumValsGreater != e;
++NumValsGreater) {
const SourceDelta &Val = Node->getValue(NumValsGreater);
if (Val.FileLoc >= FileIndex)
break;
Result += Val.Delta;
}
// If we have an interior node, include information about children and
// recurse. Otherwise, if we have a leaf, we're done.
const DeltaTreeInteriorNode *IN = dyn_cast<DeltaTreeInteriorNode>(Node);
if (!IN) return Result;
// Include any children to the left of the values we skipped, all of
// their deltas should be included as well.
for (unsigned i = 0; i != NumValsGreater; ++i)
Result += IN->getChild(i)->getFullDelta();
// If we found exactly the value we were looking for, break off the
// search early. There is no need to search the RHS of the value for
// partial results.
if (NumValsGreater != Node->getNumValuesUsed() &&
Node->getValue(NumValsGreater).FileLoc == FileIndex)
return Result;
// Otherwise, traverse down the tree. The selected subtree may be
// partially included in the range.
Node = IN->getChild(NumValsGreater);
}
// NOT REACHED.
}
int getDeltaAt(unsigned FileIndex) const;
/// AddDelta - When a change is made that shifts around the text buffer,
/// this method is used to record that info. It inserts a delta of 'Delta'
/// into the current DeltaTree at offset FileIndex.
void AddDelta(unsigned FileIndex, int Delta) {
assert(Delta && "Adding a noop?");
//printf("Add: %d %d\n", FileIndex, Delta);
//if (FileIndex == 9251)
//printf("Here\n");
// If the root is full, create a new dummy (non-empty) interior node that
// points to it, allowing the old root to be split.
if (Root->isFull())
Root = new DeltaTreeInteriorNode(Root);
Root->AddDeltaNonFull(FileIndex, Delta);
//VerifyTree(Root);
}
void VerifyTree(const DeltaTreeNode *N) const {
const DeltaTreeInteriorNode *IN = dyn_cast<DeltaTreeInteriorNode>(N);
if (IN == 0) {
// Verify leaves, just ensure that FullDelta matches up and the elements
// are in proper order.
int FullDelta = 0;
for (unsigned i = 0, e = N->getNumValuesUsed(); i != e; ++i) {
if (i)
assert(N->getValue(i-1).FileLoc < N->getValue(i).FileLoc);
FullDelta += N->getValue(i).Delta;
}
assert(FullDelta == N->getFullDelta());
return;
}
// Verify interior nodes: Ensure that FullDelta matches up and the
// elements are in proper order and the children are in proper order.
int FullDelta = 0;
for (unsigned i = 0, e = IN->getNumValuesUsed(); i != e; ++i) {
const SourceDelta &IVal = N->getValue(i);
const DeltaTreeNode *IChild = IN->getChild(i);
if (i)
assert(IN->getValue(i-1).FileLoc < IVal.FileLoc);
FullDelta += IVal.Delta;
FullDelta += IChild->getFullDelta();
// The largest value in child #i should be smaller than FileLoc.
assert(IChild->getValue(IChild->getNumValuesUsed()-1).FileLoc <
IVal.FileLoc);
// The smallest value in child #i+1 should be larger than FileLoc.
assert(IN->getChild(i+1)->getValue(0).FileLoc > IVal.FileLoc);
VerifyTree(IChild);
}
FullDelta += IN->getChild(IN->getNumValuesUsed())->getFullDelta();
assert(FullDelta == N->getFullDelta());
}
void AddDelta(unsigned FileIndex, int Delta);
};
} // end namespace llvm
} // end namespace clang
#endif

416
lib/Rewrite/DeltaTree.cpp Normal file
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@ -0,0 +1,416 @@
//===--- DeltaTree.cpp - B-Tree for Rewrite Delta tracking ----------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the DeltaTree and related classes.
//
//===----------------------------------------------------------------------===//
#include "clang/Rewrite/DeltaTree.h"
#include "llvm/Support/Casting.h"
#include <cstring>
using namespace clang;
using llvm::cast;
using llvm::dyn_cast;
namespace {
struct SourceDelta;
class DeltaTreeNode;
class DeltaTreeInteriorNode;
}
/// The DeltaTree class is a multiway search tree (BTree) structure with some
/// fancy features. B-Trees are are generally more memory and cache efficient
/// than binary trees, because they store multiple keys/values in each node.
///
/// DeltaTree implements a key/value mapping from FileIndex to Delta, allowing
/// fast lookup by FileIndex. However, an added (important) bonus is that it
/// can also efficiently tell us the full accumulated delta for a specific
/// file offset as well, without traversing the whole tree.
///
/// The nodes of the tree are made up of instances of two classes:
/// DeltaTreeNode and DeltaTreeInteriorNode. The later subclasses the
/// former and adds children pointers. Each node knows the full delta of all
/// entries (recursively) contained inside of it, which allows us to get the
/// full delta implied by a whole subtree in constant time.
namespace {
/// SourceDelta - As code in the original input buffer is added and deleted,
/// SourceDelta records are used to keep track of how the input SourceLocation
/// object is mapped into the output buffer.
struct SourceDelta {
unsigned FileLoc;
int Delta;
static SourceDelta get(unsigned Loc, int D) {
SourceDelta Delta;
Delta.FileLoc = Loc;
Delta.Delta = D;
return Delta;
}
};
} // end anonymous namespace
namespace {
/// DeltaTreeNode - The common part of all nodes.
///
class DeltaTreeNode {
friend class DeltaTreeInteriorNode;
/// WidthFactor - This controls the number of K/V slots held in the BTree:
/// how wide it is. Each level of the BTree is guaranteed to have at least
/// WidthFactor-1 K/V pairs (unless the whole tree is less full than that)
/// and may have at most 2*WidthFactor-1 K/V pairs.
enum { WidthFactor = 8 };
/// Values - This tracks the SourceDelta's currently in this node.
///
SourceDelta Values[2*WidthFactor-1];
/// NumValuesUsed - This tracks the number of values this node currently
/// holds.
unsigned char NumValuesUsed;
/// IsLeaf - This is true if this is a leaf of the btree. If false, this is
/// an interior node, and is actually an instance of DeltaTreeInteriorNode.
bool IsLeaf;
/// FullDelta - This is the full delta of all the values in this node and
/// all children nodes.
int FullDelta;
public:
DeltaTreeNode(bool isLeaf = true)
: NumValuesUsed(0), IsLeaf(isLeaf), FullDelta(0) {}
bool isLeaf() const { return IsLeaf; }
int getFullDelta() const { return FullDelta; }
bool isFull() const { return NumValuesUsed == 2*WidthFactor-1; }
unsigned getNumValuesUsed() const { return NumValuesUsed; }
const SourceDelta &getValue(unsigned i) const {
assert(i < NumValuesUsed && "Invalid value #");
return Values[i];
}
SourceDelta &getValue(unsigned i) {
assert(i < NumValuesUsed && "Invalid value #");
return Values[i];
}
/// AddDeltaNonFull - Add a delta to this tree and/or it's children, knowing
/// that this node is not currently full.
void AddDeltaNonFull(unsigned FileIndex, int Delta);
/// RecomputeFullDeltaLocally - Recompute the FullDelta field by doing a
/// local walk over our contained deltas.
void RecomputeFullDeltaLocally();
void Destroy();
static inline bool classof(const DeltaTreeNode *) { return true; }
};
} // end anonymous namespace
namespace {
/// DeltaTreeInteriorNode - When isLeaf = false, a node has child pointers.
/// This class tracks them.
class DeltaTreeInteriorNode : public DeltaTreeNode {
DeltaTreeNode *Children[2*WidthFactor];
~DeltaTreeInteriorNode() {
for (unsigned i = 0, e = NumValuesUsed+1; i != e; ++i)
Children[i]->Destroy();
}
friend class DeltaTreeNode;
public:
DeltaTreeInteriorNode() : DeltaTreeNode(false /*nonleaf*/) {}
DeltaTreeInteriorNode(DeltaTreeNode *FirstChild)
: DeltaTreeNode(false /*nonleaf*/) {
FullDelta = FirstChild->FullDelta;
Children[0] = FirstChild;
}
const DeltaTreeNode *getChild(unsigned i) const {
assert(i < getNumValuesUsed()+1 && "Invalid child");
return Children[i];
}
DeltaTreeNode *getChild(unsigned i) {
assert(i < getNumValuesUsed()+1 && "Invalid child");
return Children[i];
}
static inline bool classof(const DeltaTreeInteriorNode *) { return true; }
static inline bool classof(const DeltaTreeNode *N) { return !N->isLeaf(); }
private:
void SplitChild(unsigned ChildNo);
};
}
/// Destroy - A 'virtual' destructor.
void DeltaTreeNode::Destroy() {
if (isLeaf())
delete this;
else
delete cast<DeltaTreeInteriorNode>(this);
}
/// RecomputeFullDeltaLocally - Recompute the FullDelta field by doing a
/// local walk over our contained deltas.
void DeltaTreeNode::RecomputeFullDeltaLocally() {
int NewFullDelta = 0;
for (unsigned i = 0, e = getNumValuesUsed(); i != e; ++i)
NewFullDelta += Values[i].Delta;
if (DeltaTreeInteriorNode *IN = dyn_cast<DeltaTreeInteriorNode>(this))
for (unsigned i = 0, e = getNumValuesUsed()+1; i != e; ++i)
NewFullDelta += IN->getChild(i)->getFullDelta();
FullDelta = NewFullDelta;
}
/// AddDeltaNonFull - Add a delta to this tree and/or it's children, knowing
/// that this node is not currently full.
void DeltaTreeNode::AddDeltaNonFull(unsigned FileIndex, int Delta) {
assert(!isFull() && "AddDeltaNonFull on a full tree?");
// Maintain full delta for this node.
FullDelta += Delta;
// Find the insertion point, the first delta whose index is >= FileIndex.
unsigned i = 0, e = getNumValuesUsed();
while (i != e && FileIndex > getValue(i).FileLoc)
++i;
// If we found an a record for exactly this file index, just merge this
// value into the preexisting record and finish early.
if (i != e && getValue(i).FileLoc == FileIndex) {
// NOTE: Delta could drop to zero here. This means that the next delta
// entry is useless and could be removed. Supporting erases is
// significantly more complex though, so we just leave an entry with
// Delta=0 in the tree.
Values[i].Delta += Delta;
return;
}
if (DeltaTreeInteriorNode *IN = dyn_cast<DeltaTreeInteriorNode>(this)) {
// Insertion into an interior node propagates the value down to a child.
DeltaTreeNode *Child = IN->getChild(i);
// If the child tree is full, split it, pulling an element up into our
// node.
if (Child->isFull()) {
IN->SplitChild(i);
SourceDelta &MedianVal = getValue(i);
// If the median value we pulled up is exactly our insert position, add
// the delta and return.
if (MedianVal.FileLoc == FileIndex) {
MedianVal.Delta += Delta;
return;
}
// If the median value pulled up is less than our current search point,
// include those deltas and search down the RHS now.
if (MedianVal.FileLoc < FileIndex)
Child = IN->getChild(i+1);
}
Child->AddDeltaNonFull(FileIndex, Delta);
} else {
// For an insertion into a non-full leaf node, just insert the value in
// its sorted position. This requires moving later values over.
if (i != e)
memmove(&Values[i+1], &Values[i], sizeof(Values[0])*(e-i));
Values[i] = SourceDelta::get(FileIndex, Delta);
++NumValuesUsed;
}
}
/// SplitChild - At this point, we know that the current node is not full and
/// that the specified child of this node is. Split the child in half at its
/// median, propagating one value up into us. Child may be either an interior
/// or leaf node.
void DeltaTreeInteriorNode::SplitChild(unsigned ChildNo) {
DeltaTreeNode *Child = getChild(ChildNo);
assert(!isFull() && Child->isFull() && "Inconsistent constraints");
// Since the child is full, it contains 2*WidthFactor-1 values. We move
// the first 'WidthFactor-1' values to the LHS child (which we leave in the
// original child), propagate one value up into us, and move the last
// 'WidthFactor-1' values into thew RHS child.
// Create the new child node.
DeltaTreeNode *NewNode;
if (DeltaTreeInteriorNode *CIN = dyn_cast<DeltaTreeInteriorNode>(Child)) {
// If the child is an interior node, also move over 'WidthFactor' grand
// children into the new node.
NewNode = new DeltaTreeInteriorNode();
memcpy(&((DeltaTreeInteriorNode*)NewNode)->Children[0],
&CIN->Children[WidthFactor],
WidthFactor*sizeof(CIN->Children[0]));
} else {
// Just create the child node.
NewNode = new DeltaTreeNode();
}
// Move over the last 'WidthFactor-1' values from Child to NewNode.
memcpy(&NewNode->Values[0], &Child->Values[WidthFactor],
(WidthFactor-1)*sizeof(Child->Values[0]));
// Decrease the number of values in the two children.
NewNode->NumValuesUsed = Child->NumValuesUsed = WidthFactor-1;
// Recompute the two children's full delta. Our delta hasn't changed, but
// their delta has.
NewNode->RecomputeFullDeltaLocally();
Child->RecomputeFullDeltaLocally();
// Now that we have two nodes and a new element, insert the median value
// into ourself by moving all the later values/children down, then inserting
// the new one.
if (getNumValuesUsed() != ChildNo)
memmove(&Children[ChildNo+2], &Children[ChildNo+1],
(getNumValuesUsed()-ChildNo)*sizeof(Children[0]));
Children[ChildNo+1] = NewNode;
if (getNumValuesUsed() != ChildNo)
memmove(&Values[ChildNo+1], &Values[ChildNo],
(getNumValuesUsed()-ChildNo)*sizeof(Values[0]));
Values[ChildNo] = Child->Values[WidthFactor-1];
++NumValuesUsed;
}
//===----------------------------------------------------------------------===//
// DeltaTree Implementation
//===----------------------------------------------------------------------===//
/// VerifyTree - Walk the btree performing assertions on various properties to
/// verify consistency. This is useful for debugging new changes to the tree.
static void VerifyTree(const DeltaTreeNode *N) {
const DeltaTreeInteriorNode *IN = dyn_cast<DeltaTreeInteriorNode>(N);
if (IN == 0) {
// Verify leaves, just ensure that FullDelta matches up and the elements
// are in proper order.
int FullDelta = 0;
for (unsigned i = 0, e = N->getNumValuesUsed(); i != e; ++i) {
if (i)
assert(N->getValue(i-1).FileLoc < N->getValue(i).FileLoc);
FullDelta += N->getValue(i).Delta;
}
assert(FullDelta == N->getFullDelta());
return;
}
// Verify interior nodes: Ensure that FullDelta matches up and the
// elements are in proper order and the children are in proper order.
int FullDelta = 0;
for (unsigned i = 0, e = IN->getNumValuesUsed(); i != e; ++i) {
const SourceDelta &IVal = N->getValue(i);
const DeltaTreeNode *IChild = IN->getChild(i);
if (i)
assert(IN->getValue(i-1).FileLoc < IVal.FileLoc);
FullDelta += IVal.Delta;
FullDelta += IChild->getFullDelta();
// The largest value in child #i should be smaller than FileLoc.
assert(IChild->getValue(IChild->getNumValuesUsed()-1).FileLoc <
IVal.FileLoc);
// The smallest value in child #i+1 should be larger than FileLoc.
assert(IN->getChild(i+1)->getValue(0).FileLoc > IVal.FileLoc);
VerifyTree(IChild);
}
FullDelta += IN->getChild(IN->getNumValuesUsed())->getFullDelta();
assert(FullDelta == N->getFullDelta());
}
static DeltaTreeNode *getRoot(void *Root) {
return (DeltaTreeNode*)Root;
}
DeltaTree::DeltaTree() {
Root = new DeltaTreeNode();
}
DeltaTree::DeltaTree(const DeltaTree &RHS) {
// Currently we only support copying when the RHS is empty.
assert(getRoot(RHS.Root)->getNumValuesUsed() == 0 &&
"Can only copy empty tree");
Root = new DeltaTreeNode();
}
DeltaTree::~DeltaTree() {
getRoot(Root)->Destroy();
}
/// getDeltaAt - Return the accumulated delta at the specified file offset.
/// This includes all insertions or delections that occurred *before* the
/// specified file index.
int DeltaTree::getDeltaAt(unsigned FileIndex) const {
const DeltaTreeNode *Node = getRoot(Root);
int Result = 0;
// Walk down the tree.
while (1) {
// For all nodes, include any local deltas before the specified file
// index by summing them up directly. Keep track of how many were
// included.
unsigned NumValsGreater = 0;
for (unsigned e = Node->getNumValuesUsed(); NumValsGreater != e;
++NumValsGreater) {
const SourceDelta &Val = Node->getValue(NumValsGreater);
if (Val.FileLoc >= FileIndex)
break;
Result += Val.Delta;
}
// If we have an interior node, include information about children and
// recurse. Otherwise, if we have a leaf, we're done.
const DeltaTreeInteriorNode *IN = dyn_cast<DeltaTreeInteriorNode>(Node);
if (!IN) return Result;
// Include any children to the left of the values we skipped, all of
// their deltas should be included as well.
for (unsigned i = 0; i != NumValsGreater; ++i)
Result += IN->getChild(i)->getFullDelta();
// If we found exactly the value we were looking for, break off the
// search early. There is no need to search the RHS of the value for
// partial results.
if (NumValsGreater != Node->getNumValuesUsed() &&
Node->getValue(NumValsGreater).FileLoc == FileIndex)
return Result;
// Otherwise, traverse down the tree. The selected subtree may be
// partially included in the range.
Node = IN->getChild(NumValsGreater);
}
// NOT REACHED.
}
/// AddDelta - When a change is made that shifts around the text buffer,
/// this method is used to record that info. It inserts a delta of 'Delta'
/// into the current DeltaTree at offset FileIndex.
void DeltaTree::AddDelta(unsigned FileIndex, int Delta) {
assert(Delta && "Adding a noop?");
// If the root is full, create a new dummy (non-empty) interior node that
// points to it, allowing the old root to be split.
if (getRoot(Root)->isFull())
Root = new DeltaTreeInteriorNode(getRoot(Root));
getRoot(Root)->AddDeltaNonFull(FileIndex, Delta);
//VerifyTree(Root);
}