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// Copyright © 2015 Steve Francia <spf@spf13.com>.
// Copyright 2013 tsuru authors. All rights reserved.
//
// 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 mem
import (
"bytes"
"errors"
"io"
"os"
"path/filepath"
"sync"
"sync/atomic"
)
import "time"
const FilePathSeparator = string(filepath.Separator)
type File struct {
// atomic requires 64-bit alignment for struct field access
at int64
readDirCount int64
closed bool
readOnly bool
fileData *FileData
}
func NewFileHandle(data *FileData) *File {
return &File{fileData: data}
}
func NewReadOnlyFileHandle(data *FileData) *File {
return &File{fileData: data, readOnly: true}
}
func (f File) Data() *FileData {
return f.fileData
}
type FileData struct {
sync.Mutex
name string
data []byte
memDir Dir
dir bool
mode os.FileMode
modtime time.Time
}
func (d *FileData) Name() string {
d.Lock()
defer d.Unlock()
return d.name
}
func CreateFile(name string) *FileData {
return &FileData{name: name, mode: os.ModeTemporary, modtime: time.Now()}
}
func CreateDir(name string) *FileData {
return &FileData{name: name, memDir: &DirMap{}, dir: true}
}
func ChangeFileName(f *FileData, newname string) {
f.Lock()
f.name = newname
f.Unlock()
}
func SetMode(f *FileData, mode os.FileMode) {
f.Lock()
f.mode = mode
f.Unlock()
}
func SetModTime(f *FileData, mtime time.Time) {
f.Lock()
setModTime(f, mtime)
f.Unlock()
}
func setModTime(f *FileData, mtime time.Time) {
f.modtime = mtime
}
func GetFileInfo(f *FileData) *FileInfo {
return &FileInfo{f}
}
func (f *File) Open() error {
atomic.StoreInt64(&f.at, 0)
atomic.StoreInt64(&f.readDirCount, 0)
f.fileData.Lock()
f.closed = false
f.fileData.Unlock()
return nil
}
func (f *File) Close() error {
f.fileData.Lock()
f.closed = true
if !f.readOnly {
setModTime(f.fileData, time.Now())
}
f.fileData.Unlock()
return nil
}
func (f *File) Name() string {
return f.fileData.Name()
}
func (f *File) Stat() (os.FileInfo, error) {
return &FileInfo{f.fileData}, nil
}
func (f *File) Sync() error {
return nil
}
func (f *File) Readdir(count int) (res []os.FileInfo, err error) {
var outLength int64
f.fileData.Lock()
files := f.fileData.memDir.Files()[f.readDirCount:]
if count > 0 {
if len(files) < count {
outLength = int64(len(files))
} else {
outLength = int64(count)
}
if len(files) == 0 {
err = io.EOF
}
} else {
outLength = int64(len(files))
}
f.readDirCount += outLength
f.fileData.Unlock()
res = make([]os.FileInfo, outLength)
for i := range res {
res[i] = &FileInfo{files[i]}
}
return res, err
}
func (f *File) Readdirnames(n int) (names []string, err error) {
fi, err := f.Readdir(n)
names = make([]string, len(fi))
for i, f := range fi {
_, names[i] = filepath.Split(f.Name())
}
return names, err
}
func (f *File) Read(b []byte) (n int, err error) {
f.fileData.Lock()
defer f.fileData.Unlock()
if f.closed == true {
return 0, ErrFileClosed
}
if len(b) > 0 && int(f.at) == len(f.fileData.data) {
return 0, io.EOF
}
if len(f.fileData.data)-int(f.at) >= len(b) {
n = len(b)
} else {
n = len(f.fileData.data) - int(f.at)
}
copy(b, f.fileData.data[f.at:f.at+int64(n)])
atomic.AddInt64(&f.at, int64(n))
return
}
func (f *File) ReadAt(b []byte, off int64) (n int, err error) {
atomic.StoreInt64(&f.at, off)
return f.Read(b)
}
func (f *File) Truncate(size int64) error {
if f.closed == true {
return ErrFileClosed
}
if f.readOnly {
return &os.PathError{Op: "truncate", Path: f.fileData.name, Err: errors.New("file handle is read only")}
}
if size < 0 {
return ErrOutOfRange
}
if size > int64(len(f.fileData.data)) {
diff := size - int64(len(f.fileData.data))
f.fileData.data = append(f.fileData.data, bytes.Repeat([]byte{00}, int(diff))...)
} else {
f.fileData.data = f.fileData.data[0:size]
}
setModTime(f.fileData, time.Now())
return nil
}
func (f *File) Seek(offset int64, whence int) (int64, error) {
if f.closed == true {
return 0, ErrFileClosed
}
switch whence {
case 0:
atomic.StoreInt64(&f.at, offset)
case 1:
atomic.AddInt64(&f.at, int64(offset))
case 2:
atomic.StoreInt64(&f.at, int64(len(f.fileData.data))+offset)
}
return f.at, nil
}
func (f *File) Write(b []byte) (n int, err error) {
if f.readOnly {
return 0, &os.PathError{Op: "write", Path: f.fileData.name, Err: errors.New("file handle is read only")}
}
n = len(b)
cur := atomic.LoadInt64(&f.at)
f.fileData.Lock()
defer f.fileData.Unlock()
diff := cur - int64(len(f.fileData.data))
var tail []byte
if n+int(cur) < len(f.fileData.data) {
tail = f.fileData.data[n+int(cur):]
}
if diff > 0 {
f.fileData.data = append(bytes.Repeat([]byte{00}, int(diff)), b...)
f.fileData.data = append(f.fileData.data, tail...)
} else {
f.fileData.data = append(f.fileData.data[:cur], b...)
f.fileData.data = append(f.fileData.data, tail...)
}
setModTime(f.fileData, time.Now())
atomic.StoreInt64(&f.at, int64(len(f.fileData.data)))
return
}
func (f *File) WriteAt(b []byte, off int64) (n int, err error) {
atomic.StoreInt64(&f.at, off)
return f.Write(b)
}
func (f *File) WriteString(s string) (ret int, err error) {
return f.Write([]byte(s))
}
func (f *File) Info() *FileInfo {
return &FileInfo{f.fileData}
}
type FileInfo struct {
*FileData
}
// Implements os.FileInfo
func (s *FileInfo) Name() string {
s.Lock()
_, name := filepath.Split(s.name)
s.Unlock()
return name
}
func (s *FileInfo) Mode() os.FileMode {
s.Lock()
defer s.Unlock()
return s.mode
}
func (s *FileInfo) ModTime() time.Time {
s.Lock()
defer s.Unlock()
return s.modtime
}
func (s *FileInfo) IsDir() bool {
s.Lock()
defer s.Unlock()
return s.dir
}
func (s *FileInfo) Sys() interface{} { return nil }
func (s *FileInfo) Size() int64 {
if s.IsDir() {
return int64(42)
}
s.Lock()
defer s.Unlock()
return int64(len(s.data))
}
var (
ErrFileClosed = errors.New("File is closed")
ErrOutOfRange = errors.New("Out of range")
ErrTooLarge = errors.New("Too large")
ErrFileNotFound = os.ErrNotExist
ErrFileExists = os.ErrExist
ErrDestinationExists = os.ErrExist
)
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