blobcache

README

blobcache

A fork of Go's internal build cache but for blobs rather than actions.

Documentation

Index

• type Cache
  • func NewCache(logger *zap.Logger, dir string, newHash func() hash.Hash, hashSize int64, ...) (*Cache, error)
  • func (c *Cache) Get(id ID) (file io.ReadSeekCloser, entry Entry, err error)
  • func (c *Cache) Put(file io.ReadSeeker) (ID, int64, error)
  • func (c *Cache) Size() (int64, error)
  • func (c *Cache) Trim(maxBytes int64) error
• type Entry
• type ID
• type KeyedCache
  • func NewKeyedCache(logger *zap.Logger, dir string, newHash func() hash.Hash, hashSize int64, ...) (*KeyedCache, error)
  • func (c *KeyedCache) Get(key string) (file io.ReadSeekCloser, entry KeyedEntry, err error)
  • func (c *KeyedCache) Put(key string, file io.ReadSeeker) (ID, int64, error)
  • func (c *KeyedCache) Size() (int64, error)
  • func (c *KeyedCache) Trim(maxBytes int64) error
• type KeyedEntry

Types

type Cache

type Cache struct {
	// contains filtered or unexported fields
}

Cache is a cache that stores blobs by a hash of their contents.

func NewCache

func NewCache(logger *zap.Logger, dir string, newHash func() hash.Hash, hashSize int64, now func() time.Time) (*Cache, error)

NewCache opens and returns the cache in the given directory.

It is safe for multiple processes on a single machine to use the same cache directory in a local file system simultaneously. They will coordinate using operating system file locks and may duplicate effort but will not corrupt the cache.

However, it is NOT safe for multiple processes on different machines to share a cache directory (for example, if the directory were stored in a network file system). File locking is notoriously unreliable in network file systems and may not suffice to protect the cache.

func (*Cache) Get

func (c *Cache) Get(id ID) (file io.ReadSeekCloser, entry Entry, err error)

Get looks up the ID in the cache and returns a reader if found.

func (*Cache) Put

func (c *Cache) Put(file io.ReadSeeker) (ID, int64, error)

Put stores the given file in the cache. It may read file twice. The content of file must not change between the two passes.

func (*Cache) Size

func (c *Cache) Size() (int64, error)

Size returns the total size of the cache in bytes.

func (*Cache) Trim

func (c *Cache) Trim(maxBytes int64) error

Trim removes old cache entries that are likely not to be reused.

type Entry

type Entry struct {
	Size int64
	Time time.Time
}

type ID

type ID []byte

type KeyedCache

type KeyedCache struct {
	// contains filtered or unexported fields
}

KeyedCache is a cache that stores blobs by a key.

func NewKeyedCache

func NewKeyedCache(logger *zap.Logger, dir string, newHash func() hash.Hash, hashSize int64, now func() time.Time) (*KeyedCache, error)

func (*KeyedCache) Get

func (c *KeyedCache) Get(key string) (file io.ReadSeekCloser, entry KeyedEntry, err error)

Get looks up the ID in the cache and returns a reader if found.

func (*KeyedCache) Put

func (c *KeyedCache) Put(key string, file io.ReadSeeker) (ID, int64, error)

Put stores the given output in the cache as the output for the action ID. It may read file twice. The content of file must not change between the two passes.

func (*KeyedCache) Size

func (c *KeyedCache) Size() (int64, error)

Size returns the total size of the cache in bytes.

func (*KeyedCache) Trim

func (c *KeyedCache) Trim(maxBytes int64) error

Trim removes old cache entries that are likely not to be reused.

type KeyedEntry

type KeyedEntry struct {
	OutputID ID
	Size     int64
	Time     time.Time
}