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package mount |
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|
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import ( |
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"os" |
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"path/filepath" |
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"sync" |
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) |
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|
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/* BlobCache provides persistent storage for downloaded blobs. |
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* Uses ~/.cache/larc/blobs/{prefix}/{hash} structure. |
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* Thread-safe for concurrent access. */ |
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|
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type BlobCache struct { |
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dir string |
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mu sync.RWMutex |
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} |
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|
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// NewBlobCache creates a cache in ~/.cache/larc/blobs |
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func NewBlobCache() (*BlobCache, error) { |
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home, err := os.UserHomeDir() |
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if err != nil { |
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return nil, err |
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} |
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|
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dir := filepath.Join(home, ".cache", "larc", "blobs") |
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if err := os.MkdirAll(dir, 0755); err != nil { |
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return nil, err |
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} |
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|
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return &BlobCache{dir: dir}, nil |
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} |
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|
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// NewBlobCacheAt creates a cache at a specific path |
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func NewBlobCacheAt(dir string) (*BlobCache, error) { |
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if err := os.MkdirAll(dir, 0755); err != nil { |
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return nil, err |
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} |
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return &BlobCache{dir: dir}, nil |
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} |
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|
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func (c *BlobCache) path(hash string) string { |
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if len(hash) < 2 { |
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return filepath.Join(c.dir, hash) |
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} |
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return filepath.Join(c.dir, hash[:2], hash) |
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} |
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|
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// Get retrieves blob from cache, returns nil if not found |
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func (c *BlobCache) Get(hash string) ([]byte, bool) { |
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c.mu.RLock() |
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defer c.mu.RUnlock() |
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|
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data, err := os.ReadFile(c.path(hash)) |
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if err != nil { |
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return nil, false |
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} |
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return data, true |
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} |
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|
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// Put stores blob in cache |
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func (c *BlobCache) Put(hash string, data []byte) error { |
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c.mu.Lock() |
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defer c.mu.Unlock() |
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|
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p := c.path(hash) |
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if err := os.MkdirAll(filepath.Dir(p), 0755); err != nil { |
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return err |
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} |
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return os.WriteFile(p, data, 0644) |
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} |
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|
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// Exists checks if blob is cached |
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func (c *BlobCache) Exists(hash string) bool { |
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c.mu.RLock() |
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defer c.mu.RUnlock() |
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|
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_, err := os.Stat(c.path(hash)) |
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return err == nil |
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} |
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|
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// Dir returns cache directory path |
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func (c *BlobCache) Dir() string { |
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return c.dir |
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} |
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|