Method PutStream

cmd/cache-proxy/cache.go:229–282

PutStream stores data from r under key without buffering the whole body in memory. It writes to a temp file and atomically renames it into place, so a truncated or failed copy never becomes a servable entry. Returns the number of bytes stored. This is the streaming counterpart to Put and is what kee

(key string, r io.Reader)

}

type openCacheDirectory func(string) (cacheDirectory, error)

func openDirectory(path string) (cacheDirectory, error) {
	return os.Open(path)
}

type cacheEntry struct {
	key                  string
	size                 int64
	lastAccess           time.Time
	lastPersistedRecency time.Time
	evictionInFlight     bool
}

// NewDiskCache creates a cache backed by the given directory.
// maxPercent is the percentage of filesystem capacity to use (e.g. 80).
func NewDiskCache(dir string, maxPercent int, options ...DiskCacheOptions) (*DiskCache, error) {
	if err := os.MkdirAll(dir, 0750); err != nil {
		return nil, fmt.Errorf("create cache dir: %w", err)
	}

	dc := &DiskCache{
		dir: dir,
		// Startup must account for committed files before applying a byte
		// ceiling, so scans initially load without byte pruning.
		maxBytes:          math.MaxInt64,
		maxEntries:        defaultCacheMaxEntries,
		hardMaxEntries:    int(cacheMetadataEntryLimit),
		maxPercent:        maxPercent,
		blockSize:         defaultCacheBlockSizeBytes,
		space:             statfsDiskSpace,
		order:             list.New(),
		index:             make(map[string]*list.Element),
		renameFile:        os.Rename,
		removeFile:        os.Remove,
		openScanDirectory: openDirectory,
		recencyNow:        time.Now,
		recencyInterval:   defaultRecencyGranularity,
	}
	var option DiskCacheOptions
	if len(options) > 0 {
		option = options[0]
		if option.MaxEntries > 0 {
			dc.maxEntries = option.MaxEntries
		}
		if option.BlockSizeBytes > 0 {
			dc.blockSize = option.BlockSizeBytes
		}
		if option.CapacityProvider != nil {
			dc.space = option.CapacityProvider
		}
		if option.openScanDirectory != nil {
			dc.openScanDirectory = option.openScanDirectory
		}
		if option.removeFile != nil {
			dc.removeFile = option.removeFile
		}