зеркало из https://github.com/golang/build.git
60 строки
1.5 KiB
Go
60 строки
1.5 KiB
Go
// Copyright 2016 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package devapp
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import (
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"bytes"
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"compress/gzip"
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"encoding/gob"
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"golang.org/x/net/context"
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)
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// Cache is a datastore entity type that contains serialized data for dashboards.
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type Cache struct {
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// Value contains a gzipped gob'd serialization of the object
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// to be cached. It must be []byte to avail ourselves of the
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// datastore's 1 MB size limit.
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Value []byte `datastore:"value,noindex"`
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}
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func unpackCache(cache *Cache, data interface{}) error {
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if len(cache.Value) > 0 {
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gzr, err := gzip.NewReader(bytes.NewReader(cache.Value))
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if err != nil {
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return err
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}
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defer gzr.Close()
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if err := gob.NewDecoder(gzr).Decode(data); err != nil {
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return err
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}
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}
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return nil
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}
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func loadCache(ctx context.Context, name string, data interface{}) error {
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cache, err := getCache(ctx, name)
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if err != nil {
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return err
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}
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return unpackCache(cache, data)
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}
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func writeCache(ctx context.Context, name string, data interface{}) error {
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var cache Cache
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var cacheout bytes.Buffer
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cachegz := gzip.NewWriter(&cacheout)
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e := gob.NewEncoder(cachegz)
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if err := e.Encode(data); err != nil {
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return err
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}
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if err := cachegz.Close(); err != nil {
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return err
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}
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cache.Value = cacheout.Bytes()
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logger.Infof(ctx, "Cache %q update finished; writing %d bytes", name, cacheout.Len())
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return putCache(ctx, name, &cache)
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}
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