cchash

README

cchash

Package cchash provides a concurrent hasher for implementers of io.ReaderAt with a known size, such as os.File.

Documentation

Overview

Package cchash provides a concurrent hasher for implementers of io.ReaderAt with a known size, such as os.File.

Index

• type HashFactory
• type Interface
  • func New(r io.ReaderAt, size int64, factory HashFactory, opts ...Option) Interface
• type Option
  • func ChunkSize(s int64) Option

Types

type HashFactory

type HashFactory func() hash.Hash

HashFactory should return a new and usable hash.Hash upon each call.

type Interface

type Interface interface {
	// Hash computes the hash of the bytes read from the source io.ReaderAt.
	Hash() error

	// Sum appends the current hash to b and returns the resulting slice.
	// It does not change the underlying hash state.
	Sum(b []byte) []byte

	// Hash computes the hash of the bytes read from the source io.ReaderAt.
	Size() int
}

Interface represents a type that can concurrently compute a hash.

func New

func New(r io.ReaderAt, size int64, factory HashFactory, opts ...Option) Interface

New creates a new concurrent hasher that will hash the bytes read from the io.ReaderAt with the provided total size.

type Option

type Option func(c Interface)

Option configures a concurrent hasher.

func ChunkSize

func ChunkSize(s int64) Option

ChunkSize configures the size of the logical chunks that the input will be split into. A goroutine will be spawned for each chunk so TotalSize / ChunkSize is equivalent to the maximum concurrency.