tarsum

Documentation

Index

• Variables
• func VersionLabelForChecksum(checksum string) string
• type BuilderContext
• type FileInfoSumInterface
• type FileInfoSums
  • func (fis FileInfoSums) GetAllFile(name string) FileInfoSums
  • func (fis FileInfoSums) GetDuplicatePaths() (dups FileInfoSums)
  • func (fis FileInfoSums) GetFile(name string) FileInfoSumInterface
  • func (fis FileInfoSums) Len() int
  • func (fis FileInfoSums) SortByNames()
  • func (fis FileInfoSums) SortByPos()
  • func (fis FileInfoSums) SortBySums()
  • func (fis FileInfoSums) Swap(i, j int)
• type THash
  • func NewTHash(name string, h func() hash.Hash) THash
• type TarSum
  • func NewTarSum(r io.Reader, dc bool, v Version) (TarSum, error)
  • func NewTarSumForLabel(r io.Reader, disableCompression bool, label string) (TarSum, error)
  • func NewTarSumHash(r io.Reader, dc bool, v Version, tHash THash) (TarSum, error)
• type Version
  • func GetVersionFromTarsum(tarsum string) (Version, error)
  • func GetVersions() []Version
  • func (tsv Version) String() string

Variables

var (
	ErrNotVersion            = errors.New("string does not include a TarSum Version")
	ErrVersionNotImplemented = errors.New("TarSum Version is not yet implemented")
)

Errors that may be returned by functions in this package

var DefaultTHash = NewTHash("sha256", sha256.New)

TarSum default is "sha256"

Functions

func VersionLabelForChecksum

func VersionLabelForChecksum(checksum string) string

VersionLabelForChecksum returns the label for the given tarsum checksum, i.e., everything before the first `+` character in the string or an empty string if no label separator is found.

Types

type BuilderContext

type BuilderContext interface {
	TarSum
	Remove(string)
}

This interface extends TarSum by adding the Remove method. In general there was concern about adding this method to TarSum itself so instead it is being added just to "BuilderContext" which will then only be used during the .dockerignore file processing - see builder/evaluator.go

type FileInfoSumInterface

type FileInfoSumInterface interface {
	// File name
	Name() string
	// Checksum of this particular file and its headers
	Sum() string
	// Position of file in the tar
	Pos() int64
}

This info will be accessed through interface so the actual name and sum cannot be medled with

type FileInfoSums

type FileInfoSums []FileInfoSumInterface

func (FileInfoSums) GetAllFile

func (fis FileInfoSums) GetAllFile(name string) FileInfoSums

GetAllFile returns a FileInfoSums with all matching names

func (FileInfoSums) GetDuplicatePaths

func (fis FileInfoSums) GetDuplicatePaths() (dups FileInfoSums)

func (FileInfoSums) GetFile

func (fis FileInfoSums) GetFile(name string) FileInfoSumInterface

GetFile returns the first FileInfoSumInterface with a matching name

func (FileInfoSums) Len

func (fis FileInfoSums) Len() int

func (FileInfoSums) SortByNames

func (fis FileInfoSums) SortByNames()

func (FileInfoSums) SortByPos

func (fis FileInfoSums) SortByPos()

func (FileInfoSums) SortBySums

func (fis FileInfoSums) SortBySums()

func (FileInfoSums) Swap

func (fis FileInfoSums) Swap(i, j int)

type THash

type THash interface {
	Hash() hash.Hash
	Name() string
}

A hash.Hash type generator and its name

func NewTHash

func NewTHash(name string, h func() hash.Hash) THash

Convenience method for creating a THash

type TarSum

type TarSum interface {
	io.Reader
	GetSums() FileInfoSums
	Sum([]byte) string
	Version() Version
	Hash() THash
}

TarSum is the generic interface for calculating fixed time checksums of a tar archive

func NewTarSum

func NewTarSum(r io.Reader, dc bool, v Version) (TarSum, error)

NewTarSum creates a new interface for calculating a fixed time checksum of a tar archive.

This is used for calculating checksums of layers of an image, in some cases including the byte payload of the image's json metadata as well, and for calculating the checksums for buildcache.

func NewTarSumForLabel

func NewTarSumForLabel(r io.Reader, disableCompression bool, label string) (TarSum, error)

Create a new TarSum using the provided TarSum version+hash label.

func NewTarSumHash

func NewTarSumHash(r io.Reader, dc bool, v Version, tHash THash) (TarSum, error)

Create a new TarSum, providing a THash to use rather than the DefaultTHash

type Version

type Version int

versioning of the TarSum algorithm based on the prefix of the hash used i.e. "tarsum+sha256:e58fcf7418d4390dec8e8fb69d88c06ec07039d651fedd3aa72af9972e7d046b"

const (
	Version0 Version = iota
	Version1
	// NOTE: this variable will be either the latest or an unsettled next-version of the TarSum calculation
	VersionDev
)

Prefix of "tarsum"

func GetVersionFromTarsum

func GetVersionFromTarsum(tarsum string) (Version, error)

GetVersionFromTarsum returns the Version from the provided string

func GetVersions

func GetVersions() []Version

Get a list of all known tarsum Version

func (Version) String

func (tsv Version) String() string