64 lines
1.3 KiB
Go
64 lines
1.3 KiB
Go
package dirivcache
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import (
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"sync"
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"time"
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)
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// Single-entry DirIV cache. Stores the directory IV and the encrypted
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// path.
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type DirIVCache struct {
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// Directory the DirIV belongs to
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dir string
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// Time the entry expires.
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// The cached entry my become out-of-date if the ciphertext directory is
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// modifed behind the back of gocryptfs. Having an expiry time limits the
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// inconstency to one second, like attr_timeout does for the kernel
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// getattr cache.
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expiry time.Time
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// The DirIV
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iv []byte
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// Ecrypted version of "dir"
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cDir string
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// Invalidated?
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cleared bool
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sync.RWMutex
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}
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// lookup - fetch entry for "dir" from the cache
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func (c *DirIVCache) Lookup(dir string) ([]byte, string) {
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c.RLock()
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defer c.RUnlock()
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if c.cleared || c.dir != dir {
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return nil, ""
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}
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if time.Since(c.expiry) > 0 {
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c.cleared = true
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return nil, ""
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}
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return c.iv, c.cDir
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}
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// store - write entry for "dir" into the cache
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func (c *DirIVCache) Store(dir string, iv []byte, cDir string) {
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c.Lock()
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defer c.Unlock()
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c.cleared = false
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c.iv = iv
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c.dir = dir
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c.cDir = cDir
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// Set expiry time one second into the future
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c.expiry = time.Now().Add(1 * time.Second)
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}
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// Clear ... clear the cache.
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// Exported because it is called from fusefrontend when directories are
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// renamed or deleted.
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func (c *DirIVCache) Clear() {
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c.Lock()
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defer c.Unlock()
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c.cleared = true
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}
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