62 lines
1.4 KiB
Go
62 lines
1.4 KiB
Go
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// Package diskcache provides an implementation of httpcache.Cache that uses the diskv package
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// to supplement an in-memory map with persistent storage
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//
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package diskcache
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import (
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"bytes"
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"crypto/md5"
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"encoding/hex"
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"github.com/peterbourgon/diskv"
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"io"
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)
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// Cache is an implementation of httpcache.Cache that supplements the in-memory map with persistent storage
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type Cache struct {
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d *diskv.Diskv
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}
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// Get returns the response corresponding to key if present
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func (c *Cache) Get(key string) (resp []byte, ok bool) {
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key = keyToFilename(key)
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resp, err := c.d.Read(key)
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if err != nil {
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return []byte{}, false
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}
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return resp, true
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}
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// Set saves a response to the cache as key
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func (c *Cache) Set(key string, resp []byte) {
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key = keyToFilename(key)
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c.d.WriteStream(key, bytes.NewReader(resp), true)
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}
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// Delete removes the response with key from the cache
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func (c *Cache) Delete(key string) {
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key = keyToFilename(key)
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c.d.Erase(key)
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}
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func keyToFilename(key string) string {
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h := md5.New()
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io.WriteString(h, key)
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return hex.EncodeToString(h.Sum(nil))
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}
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// New returns a new Cache that will store files in basePath
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func New(basePath string) *Cache {
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return &Cache{
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d: diskv.New(diskv.Options{
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BasePath: basePath,
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CacheSizeMax: 100 * 1024 * 1024, // 100MB
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}),
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}
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}
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// NewWithDiskv returns a new Cache using the provided Diskv as underlying
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// storage.
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func NewWithDiskv(d *diskv.Diskv) *Cache {
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return &Cache{d}
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}
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