gitea/modules/packages/hashed_buffer.go

82 lines
2.0 KiB
Go

// Copyright 2021 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package packages
import (
"io"
"code.gitea.io/gitea/modules/util/filebuffer"
)
// HashedSizeReader provide methods to read, sum hashes and a Size method
type HashedSizeReader interface {
io.Reader
HashSummer
Size() int64
}
// HashedBuffer is buffer which calculates multiple checksums
type HashedBuffer struct {
*filebuffer.FileBackedBuffer
hash *MultiHasher
combinedWriter io.Writer
}
const DefaultMemorySize = 32 * 1024 * 1024
// NewHashedBuffer creates a hashed buffer with the default memory size
func NewHashedBuffer() (*HashedBuffer, error) {
return NewHashedBufferWithSize(DefaultMemorySize)
}
// NewHashedBuffer creates a hashed buffer with a specific memory size
func NewHashedBufferWithSize(maxMemorySize int) (*HashedBuffer, error) {
b, err := filebuffer.New(maxMemorySize)
if err != nil {
return nil, err
}
hash := NewMultiHasher()
combinedWriter := io.MultiWriter(b, hash)
return &HashedBuffer{
b,
hash,
combinedWriter,
}, nil
}
// CreateHashedBufferFromReader creates a hashed buffer with the default memory size and copies the provided reader data into it.
func CreateHashedBufferFromReader(r io.Reader) (*HashedBuffer, error) {
return CreateHashedBufferFromReaderWithSize(r, DefaultMemorySize)
}
// CreateHashedBufferFromReaderWithSize creates a hashed buffer and copies the provided reader data into it.
func CreateHashedBufferFromReaderWithSize(r io.Reader, maxMemorySize int) (*HashedBuffer, error) {
b, err := NewHashedBufferWithSize(maxMemorySize)
if err != nil {
return nil, err
}
_, err = io.Copy(b, r)
if err != nil {
return nil, err
}
return b, nil
}
// Write implements io.Writer
func (b *HashedBuffer) Write(p []byte) (int, error) {
return b.combinedWriter.Write(p)
}
// Sums gets the MD5, SHA1, SHA256 and SHA512 checksums of the data
func (b *HashedBuffer) Sums() (hashMD5, hashSHA1, hashSHA256, hashSHA512 []byte) {
return b.hash.Sums()
}