luci: Index | Files

package cache

import ""

Package cache implements both in-memory and on-disk caching.


Package Files

cache.go doc.go lru.go


var ErrInvalidHash = errors.New("invalid hash")

ErrInvalidHash indicates invalid hash is specified.

type Cache Uses

type Cache struct {
    // contains filtered or unexported fields

Cache is a cache of objects holding content in disk.

All implementations must be thread-safe.

func New Uses

func New(policies Policies, path string, h crypto.Hash) (*Cache, error)

New creates a disk based cache.

It may return both a valid Cache and an error if it failed to load the previous cache metadata. It is safe to ignore this error. This creates cache directory if it doesn't exist.

func (*Cache) Add Uses

func (d *Cache) Add(digest isolated.HexDigest, src io.Reader) error

Add reads data from src and stores it in cache.

func (*Cache) AddFileWithoutValidation Uses

func (d *Cache) AddFileWithoutValidation(digest isolated.HexDigest, src string) error

AddFileWithoutValidation adds src as cache entry with hardlink. But this doesn't do any content validation.

TODO(tikuta): make one function and control the behavior by option?

func (d *Cache) AddWithHardlink(digest isolated.HexDigest, src io.Reader, dest string, perm os.FileMode) error

AddWithHardlink reads data from src and stores it in cache and hardlink file. This is to avoid file removal by shrink in Add().

func (*Cache) Close Uses

func (d *Cache) Close() error

Close closes the Cache, writes the cache status file to cache dir.

func (*Cache) Evict Uses

func (d *Cache) Evict(digest isolated.HexDigest)

Evict removes item from cache if it's there.

func (*Cache) GetAdded Uses

func (d *Cache) GetAdded() []int64

GetAdded returns a list of file size added to cache.

func (*Cache) GetUsed Uses

func (d *Cache) GetUsed() []int64

GetUsed returns a list of file size used from cache.

func (d *Cache) Hardlink(digest isolated.HexDigest, dest string, perm os.FileMode) error

Hardlink ensures file at |dest| has the same content as cached |digest|.

Note that the behavior when dest already exists is undefined. It will work on all POSIX and may or may not fail on Windows depending on the implementation used. Do not rely on this behavior.

func (*Cache) Keys Uses

func (d *Cache) Keys() isolated.HexDigests

Keys returns the list of all cached digests in LRU order.

func (*Cache) Read Uses

func (d *Cache) Read(digest isolated.HexDigest) (io.ReadCloser, error)

Read returns contents of the cached item.

func (*Cache) TotalSize Uses

func (d *Cache) TotalSize() units.Size

TotalSize returns the size of the contents maintained in the LRU cache.

func (*Cache) Touch Uses

func (d *Cache) Touch(digest isolated.HexDigest) bool

Touch updates the LRU position of an item to ensure it is kept in the cache.

Returns true if item is in cache.

type Policies Uses

type Policies struct {
    // MaxSize trims if the cache gets larger than this value. If 0, the cache is
    // effectively a leak.
    MaxSize units.Size
    // MaxItems is the maximum number of items to keep in the cache. If 0, do not
    // enforce a limit.
    MaxItems int
    // MinFreeSpace trims if disk free space becomes lower than this value.
    // Only makes sense when using disk based cache.
    MinFreeSpace units.Size

Policies is the policies to use on a cache to limit it's footprint.

It's a cache, not a leak.

func (*Policies) AddFlags Uses

func (p *Policies) AddFlags(f *flag.FlagSet)

AddFlags adds flags for cache policy parameters.

func (*Policies) IsDefault Uses

func (p *Policies) IsDefault() bool

IsDefault returns whether some flags are set or not.

Package cache imports 16 packages (graph) and is imported by 6 packages. Updated 2020-11-26. Refresh now. Tools for package owners.