128 lines
3.1 KiB
Go
128 lines
3.1 KiB
Go
/*
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Copyright 2021 Alibaba Group Holding Limited.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package filestream
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import (
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"fmt"
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"io"
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"os"
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"path/filepath"
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)
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const (
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FallocateArchFileName = "fallocatetest"
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FALLOC_FL_KEEP_SIZE = 0x01
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FALLOC_FL_PUNCH_HOLE = 0x02
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)
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func IsFallocateSupported(fp string) bool {
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archFilepath := filepath.Join(filepath.Dir(fp), FallocateArchFileName)
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file, err := os.OpenFile(archFilepath, os.O_CREATE|os.O_TRUNC|os.O_RDWR, 0644)
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if err != nil {
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fmt.Println(err)
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return false
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}
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defer func() {
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file.Close()
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os.Remove(archFilepath)
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}()
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err = Fallocate(int(file.Fd()), FALLOC_FL_KEEP_SIZE|FALLOC_FL_PUNCH_HOLE, 0, 1)
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if err != nil {
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return false
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}
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return true
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}
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type File struct {
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Filepath string
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LastSeek uint64
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OsFile *os.File
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FallocateSupported bool
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}
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func NewFile(filepath string) *File {
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return &File{
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Filepath: filepath,
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}
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}
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func (f *File) Open() (err error) {
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f.OsFile, err = os.OpenFile(f.Filepath, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0644)
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return
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}
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func (f *File) Write(buf []byte, len uint64) (err error) {
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f.LastSeek = 0
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_, err = f.OsFile.Write(buf[:len])
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return
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}
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func (f *File) CurOffset() (int64, error) {
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pos, err := f.OsFile.Seek(0, io.SeekCurrent)
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return pos, err
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}
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func (f *File) Close() {
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if f.OsFile != nil {
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if f.LastSeek > 0 {
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_, err := f.OsFile.Seek(-1, io.SeekCurrent)
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if err == nil {
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f.OsFile.Write([]byte{0})
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}
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}
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f.LastSeek = 0
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f.OsFile.Close()
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}
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}
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func (f *File) WriteSparse(sparseMap []SparseChunk, data []byte) error {
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var index uint32 = 0
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for _, sparseChunk := range sparseMap {
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fOffset, err := f.CurOffset()
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if err != nil {
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return fmt.Errorf("failed to get cur offset %s", err.Error())
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}
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_, err = f.OsFile.Seek(int64(sparseChunk.skip), io.SeekCurrent)
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if err != nil {
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return fmt.Errorf("failed to get cur offset %s", err.Error())
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}
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if sparseChunk.len > 0 {
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_, err = f.OsFile.Write(data[index : index+sparseChunk.len])
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index += sparseChunk.len
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if err != nil {
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return fmt.Errorf("failed to writedata %s", err.Error())
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}
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}
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if f.FallocateSupported && sparseChunk.skip > 0 {
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ferr := Fallocate(int(f.OsFile.Fd()), FALLOC_FL_KEEP_SIZE|FALLOC_FL_PUNCH_HOLE, fOffset, int64(sparseChunk.skip))
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if ferr != nil {
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fmt.Printf("ferr %s , fOffset %d skip %d\n", ferr.Error(), fOffset, sparseChunk.skip)
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}
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}
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if err != nil {
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return fmt.Errorf("failed to write sparse data %s", err.Error())
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}
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}
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f.LastSeek = 0
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if len(sparseMap) > 0 {
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if sparseMap[len(sparseMap)-1].len == 0 {
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f.LastSeek = uint64(sparseMap[len(sparseMap)-1].skip)
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}
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}
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return nil
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}
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