metadata

Documentation

Index

• func TestReader(t *testing.T, factory ReaderFactory)
• type Attr
• type Decompressor
• type File
• type MeasureLatencyHook
• type Option
  • func WithDecompressors(decompressors ...Decompressor) Option
  • func WithTOCOffset(tocOffset int64) Option
  • func WithTelemetry(telemetry *Telemetry) Option
• type Options
• type Reader
• type ReaderFactory
• type Store
• type Telemetry
• type TestableReader

Functions

func TestReader

func TestReader(t *testing.T, factory ReaderFactory)

TestReader tests Reader returns correct file metadata.

Types

type Attr

type Attr struct {
	// Size, for regular files, is the logical size of the file.
	Size int64

	// ModTime is the modification time of the node.
	ModTime time.Time

	// LinkName, for symlinks, is the link target.
	LinkName string

	// Mode is the permission and mode bits.
	Mode os.FileMode

	// UID is the user ID of the owner.
	UID int

	// GID is the group ID of the owner.
	GID int

	// DevMajor is the major device number for device.
	DevMajor int

	// DevMinor is the major device number for device.
	DevMinor int

	// Xattrs are the extended attribute for the node.
	Xattrs map[string][]byte

	// NumLink is the number of names pointing to this node.
	NumLink int
}

Attr reprensents the attributes of a node.

type Decompressor

type Decompressor interface {
	estargz.Decompressor

	// DecompressTOC decompresses the passed blob and returns a reader of TOC JSON.
	DecompressTOC(io.Reader) (tocJSON io.ReadCloser, err error)
}

type File

type File interface {
	ChunkEntryForOffset(offset int64) (off int64, size int64, dgst string, ok bool)
	ReadAt(p []byte, off int64) (n int, err error)
}

type MeasureLatencyHook

type MeasureLatencyHook func(time.Time)

A func which takes start time and records the diff

type Option

type Option func(o *Options) error

Option is an option to configure the behaviour of reader.

func WithDecompressors

func WithDecompressors(decompressors ...Decompressor) Option

WithDecompressors option specifies decompressors to use. Default is gzip-based decompressor.

func WithTOCOffset

func WithTOCOffset(tocOffset int64) Option

WithTOCOffset option specifies the offset of TOC

func WithTelemetry

func WithTelemetry(telemetry *Telemetry) Option

WithTelemetry option specifies the telemetry hooks

type Options

type Options struct {
	TOCOffset     int64
	Telemetry     *Telemetry
	Decompressors []Decompressor
}

type Reader

type Reader interface {
	RootID() uint32
	TOCDigest() digest.Digest

	GetOffset(id uint32) (offset int64, err error)
	GetAttr(id uint32) (attr Attr, err error)
	GetChild(pid uint32, base string) (id uint32, attr Attr, err error)
	ForeachChild(id uint32, f func(name string, id uint32, mode os.FileMode) bool) error
	OpenFile(id uint32) (File, error)

	Clone(sr *io.SectionReader) (Reader, error)
	Close() error
}

Reader provides access to file metadata of a blob.

type ReaderFactory

type ReaderFactory func(sr *io.SectionReader, opts ...Option) (r TestableReader, err error)

type Store

type Store func(sr *io.SectionReader, opts ...Option) (Reader, error)

Store reads the provided eStargz blob and creates a metadata reader.

type Telemetry

type Telemetry struct {
	GetFooterLatency      MeasureLatencyHook // measure time to get stargz footer (in milliseconds)
	GetTocLatency         MeasureLatencyHook // measure time to GET TOC JSON (in milliseconds)
	DeserializeTocLatency MeasureLatencyHook // measure time to deserialize TOC JSON (in milliseconds)
}

A struct which defines telemetry hooks. By implementing these hooks you should be able to record the latency metrics of the respective steps of estargz open operation.

type TestableReader

type TestableReader interface {
	Reader
	NumOfNodes() (i int, _ error)
}