package compressor

import "github.com/containers/storage/pkg/chunked/compressor"

Package rollsum implements rolling checksums similar to apenwarr's bup, which is similar to librsync.

The bup project is at https://github.com/apenwarr/bup and its splitting in particular is at https://github.com/apenwarr/bup/blob/master/lib/bup/bupsplit.c

Index ¶

• Constants
• func ZstdCompressor(r io.Writer, metadata map[string]string, level *int) (io.WriteCloser, error)
• type RollSum
• func NewRollSum() *RollSum
• func (rs *RollSum) Bits() int
• func (rs *RollSum) Digest() uint32
• func (rs *RollSum) OnSplit() bool
• func (rs *RollSum) OnSplitWithBits(n uint32) bool
• func (rs *RollSum) Roll(ch byte)

Constants ¶

const (
	RollsumBits = 16
)

Functions ¶

func ZstdCompressor ¶

func ZstdCompressor(r io.Writer, metadata map[string]string, level *int) (io.WriteCloser, error)

ZstdCompressor is a CompressorFunc for the zstd compression algorithm.

Types ¶

type RollSum ¶

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

func NewRollSum ¶

func NewRollSum() *RollSum

func (*RollSum) Bits ¶

func (rs *RollSum) Bits() int

func (*RollSum) Digest ¶

func (rs *RollSum) Digest() uint32

func (*RollSum) OnSplit ¶

func (rs *RollSum) OnSplit() bool

OnSplit reports whether at least 13 consecutive trailing bits of the current checksum are set the same way.

func (*RollSum) OnSplitWithBits ¶

func (rs *RollSum) OnSplitWithBits(n uint32) bool

OnSplitWithBits reports whether at least n consecutive trailing bits of the current checksum are set the same way.

func (*RollSum) Roll ¶

func (rs *RollSum) Roll(ch byte)

Roll adds ch to the rolling sum.

Source Files ¶

compressor.go rollsum.go