Documentation
¶
Overview ¶
Package cache implements a build artifact cache.
Index ¶
- Constants
- Variables
- func DefaultDir() string
- func FileHash(file string) ([HashSize]byte, error)
- func SetFileHash(file string, sum [HashSize]byte)
- type ActionID
- type Cache
- func (c *Cache) FuzzDir() string
- func (c *Cache) Get(id ActionID) (Entry, error)
- func (c *Cache) GetBytes(id ActionID) ([]byte, Entry, error)
- func (c *Cache) GetFile(id ActionID) (file string, entry Entry, err error)
- func (c *Cache) OutputFile(out OutputID) string
- func (c *Cache) Put(id ActionID, file io.ReadSeeker) (OutputID, int64, error)
- func (c *Cache) PutBytes(id ActionID, data []byte) error
- func (c *Cache) PutNoVerify(id ActionID, file io.ReadSeeker) (OutputID, int64, error)
- func (c *Cache) Trim()
- type Entry
- type Hash
- type OutputID
Constants ¶
const HashSize = 32
HashSize is the number of bytes in a hash.
Variables ¶
var DebugTest = false
DebugTest is set when GODEBUG=gocachetest=1 is in the environment.
Functions ¶
func DefaultDir ¶
func DefaultDir() string
DefaultDir returns the effective GOCACHE setting. It returns "off" if the cache is disabled.
func FileHash ¶
FileHash returns the hash of the named file. It caches repeated lookups for a given file, and the cache entry for a file can be initialized using SetFileHash. The hash used by FileHash is not the same as the hash used by NewHash.
func SetFileHash ¶
SetFileHash sets the hash returned by FileHash for file.
Types ¶
type ActionID ¶
An ActionID is a cache action key, the hash of a complete description of a repeatable computation (command line, environment variables, input file contents, executable contents).
type Cache ¶
type Cache struct {
// contains filtered or unexported fields
}
A Cache is a package cache, backed by a file system directory tree.
func Default ¶
func Default() *Cache
Default returns the default cache to use, or nil if no cache should be used.
func Open ¶
Open 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) FuzzDir ¶
FuzzDir returns a subdirectory within the cache for storing fuzzing data. The subdirectory may not exist.
This directory is managed by the internal/fuzz package. Files in this directory aren't removed by the 'go clean -cache' command or by Trim. They may be removed with 'go clean -fuzzcache'.
TODO(#48526): make Trim remove unused files from this directory.
func (*Cache) Get ¶
Get looks up the action ID in the cache, returning the corresponding output ID and file size, if any. Note that finding an output ID does not guarantee that the saved file for that output ID is still available.
func (*Cache) GetBytes ¶
GetBytes looks up the action ID in the cache and returns the corresponding output bytes. GetBytes should only be used for data that can be expected to fit in memory.
func (*Cache) GetFile ¶
GetFile looks up the action ID in the cache and returns the name of the corresponding data file.
func (*Cache) OutputFile ¶
OutputFile returns the name of the cache file storing output with the given OutputID.
func (*Cache) Put ¶
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 (*Cache) PutBytes ¶
PutBytes stores the given bytes in the cache as the output for the action ID.
func (*Cache) PutNoVerify ¶
PutNoVerify is like Put but disables the verify check when GODEBUG=goverifycache=1 is set. It is meant for data that is OK to cache but that we expect to vary slightly from run to run, like test output containing times and the like.
type Hash ¶
type Hash struct {
// contains filtered or unexported fields
}
A Hash provides access to the canonical hash function used to index the cache. The current implementation uses salted SHA256, but clients must not assume this.
func NewHash ¶
NewHash returns a new Hash. The caller is expected to Write data to it and then call Sum.
Source Files