245 lines
6.5 KiB
Go
245 lines
6.5 KiB
Go
/*
|
|
* Minio Cloud Storage, (C) 2016 Minio, Inc.
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*/
|
|
|
|
package main
|
|
|
|
import (
|
|
"bytes"
|
|
"errors"
|
|
"hash"
|
|
"io"
|
|
|
|
"github.com/klauspost/reedsolomon"
|
|
"github.com/minio/blake2b-simd"
|
|
)
|
|
|
|
// newHashWriters - inititialize a slice of hashes for the disk count.
|
|
func newHashWriters(diskCount int) []hash.Hash {
|
|
hashWriters := make([]hash.Hash, diskCount)
|
|
for index := range hashWriters {
|
|
hashWriters[index] = newHash("blake2b")
|
|
}
|
|
return hashWriters
|
|
}
|
|
|
|
// newHash - gives you a newly allocated hash depending on the input algorithm.
|
|
func newHash(algo string) hash.Hash {
|
|
switch algo {
|
|
case "blake2b":
|
|
return blake2b.New512()
|
|
// Add new hashes here.
|
|
default:
|
|
// Default to blake2b.
|
|
return blake2b.New512()
|
|
}
|
|
}
|
|
|
|
// hashSum calculates the hash of the entire path and returns.
|
|
func hashSum(disk StorageAPI, volume, path string, writer hash.Hash) ([]byte, error) {
|
|
// Allocate staging buffer of 128KiB for copyBuffer.
|
|
buf := make([]byte, readSizeV1)
|
|
|
|
// Copy entire buffer to writer.
|
|
if err := copyBuffer(writer, disk, volume, path, buf); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
// Return the final hash sum.
|
|
return writer.Sum(nil), nil
|
|
}
|
|
|
|
// getDataBlockLen - get length of data blocks from encoded blocks.
|
|
func getDataBlockLen(enBlocks [][]byte, dataBlocks int) int {
|
|
size := 0
|
|
// Figure out the data block length.
|
|
for _, block := range enBlocks[:dataBlocks] {
|
|
size += len(block)
|
|
}
|
|
return size
|
|
}
|
|
|
|
// Writes all the data blocks from encoded blocks until requested
|
|
// outSize length. Provides a way to skip bytes until the offset.
|
|
func writeDataBlocks(dst io.Writer, enBlocks [][]byte, dataBlocks int, outOffset int64, outSize int64) (int64, error) {
|
|
// Offset and out size cannot be negative.
|
|
if outOffset < 0 || outSize < 0 {
|
|
return 0, errUnexpected
|
|
}
|
|
|
|
// Do we have enough blocks?
|
|
if len(enBlocks) < dataBlocks {
|
|
return 0, reedsolomon.ErrTooFewShards
|
|
}
|
|
|
|
// Do we have enough data?
|
|
if int64(getDataBlockLen(enBlocks, dataBlocks)) < outSize {
|
|
return 0, reedsolomon.ErrShortData
|
|
}
|
|
|
|
// Counter to decrement total left to write.
|
|
write := outSize
|
|
|
|
// Counter to increment total written.
|
|
totalWritten := int64(0)
|
|
|
|
// Write all data blocks to dst.
|
|
for _, block := range enBlocks[:dataBlocks] {
|
|
// Skip blocks until we have reached our offset.
|
|
if outOffset >= int64(len(block)) {
|
|
// Decrement offset.
|
|
outOffset -= int64(len(block))
|
|
continue
|
|
} else {
|
|
// Skip until offset.
|
|
block = block[outOffset:]
|
|
|
|
// Reset the offset for next iteration to read everything
|
|
// from subsequent blocks.
|
|
outOffset = 0
|
|
}
|
|
// We have written all the blocks, write the last remaining block.
|
|
if write < int64(len(block)) {
|
|
n, err := io.Copy(dst, bytes.NewReader(block[:write]))
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
totalWritten += n
|
|
break
|
|
}
|
|
// Copy the block.
|
|
n, err := io.Copy(dst, bytes.NewReader(block))
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
|
|
// Decrement output size.
|
|
write -= n
|
|
|
|
// Increment written.
|
|
totalWritten += n
|
|
}
|
|
|
|
// Success.
|
|
return totalWritten, nil
|
|
}
|
|
|
|
// getBlockInfo - find start/end block and bytes to skip for given offset, length and block size.
|
|
func getBlockInfo(offset, length, blockSize int64) (startBlock, endBlock, bytesToSkip int64) {
|
|
// Calculate start block for given offset and how many bytes to skip to get the offset.
|
|
startBlock = offset / blockSize
|
|
bytesToSkip = offset % blockSize
|
|
endBlock = length / blockSize
|
|
return
|
|
}
|
|
|
|
// calculate the blockSize based on input length and total number of
|
|
// data blocks.
|
|
func getEncodedBlockLen(inputLen int64, dataBlocks int) (curEncBlockSize int64) {
|
|
curEncBlockSize = (inputLen + int64(dataBlocks) - 1) / int64(dataBlocks)
|
|
return curEncBlockSize
|
|
}
|
|
|
|
// copyN - copies from disk, volume, path to input writer until length
|
|
// is reached at volume, path or an error occurs. A success copyN returns
|
|
// err == nil, not err == EOF. Additionally offset can be provided to start
|
|
// the read at. copyN returns io.EOF if there aren't enough data to be read.
|
|
func copyN(writer io.Writer, disk StorageAPI, volume string, path string, offset int64, length int64) (err error) {
|
|
// Use staging buffer to read up to length.
|
|
bufSize := int64(readSizeV1)
|
|
if length > 0 && bufSize > length {
|
|
bufSize = length
|
|
}
|
|
buf := make([]byte, int(bufSize))
|
|
|
|
// Read into writer until length.
|
|
for length > 0 {
|
|
curLength := bufSize
|
|
if length < bufSize {
|
|
curLength = length
|
|
}
|
|
nr, er := disk.ReadFile(volume, path, offset, buf[:curLength])
|
|
if nr > 0 {
|
|
nw, ew := writer.Write(buf[0:nr])
|
|
if nw > 0 {
|
|
// Decrement the length.
|
|
length -= int64(nw)
|
|
|
|
// Progress the offset.
|
|
offset += int64(nw)
|
|
}
|
|
if ew != nil {
|
|
err = ew
|
|
break
|
|
}
|
|
if nr != int64(nw) {
|
|
err = io.ErrShortWrite
|
|
break
|
|
}
|
|
}
|
|
if er == io.EOF || er == io.ErrUnexpectedEOF {
|
|
break
|
|
}
|
|
if er != nil {
|
|
err = er
|
|
break
|
|
}
|
|
}
|
|
|
|
// Success.
|
|
return err
|
|
}
|
|
|
|
// copyBuffer - copies from disk, volume, path to input writer until either EOF
|
|
// is reached at volume, path or an error occurs. A success copyBuffer returns
|
|
// err == nil, not err == EOF. Because copyBuffer is defined to read from path
|
|
// until EOF. It does not treat an EOF from ReadFile an error to be reported.
|
|
// Additionally copyBuffer stages through the provided buffer; otherwise if it
|
|
// has zero length, returns error.
|
|
func copyBuffer(writer io.Writer, disk StorageAPI, volume string, path string, buf []byte) error {
|
|
// Error condition of zero length buffer.
|
|
if buf != nil && len(buf) == 0 {
|
|
return errors.New("empty buffer in readBuffer")
|
|
}
|
|
|
|
// Starting offset for Reading the file.
|
|
startOffset := int64(0)
|
|
|
|
// Read until io.EOF.
|
|
for {
|
|
n, err := disk.ReadFile(volume, path, startOffset, buf)
|
|
if n > 0 {
|
|
var m int
|
|
m, err = writer.Write(buf[:n])
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if int64(m) != n {
|
|
return io.ErrShortWrite
|
|
}
|
|
}
|
|
if err != nil {
|
|
if err == io.EOF || err == io.ErrUnexpectedEOF {
|
|
break
|
|
}
|
|
return err
|
|
}
|
|
// Progress the offset.
|
|
startOffset += n
|
|
}
|
|
|
|
// Success.
|
|
return nil
|
|
}
|