// Copyright © 2014 Steve Francia <spf@spf13.com>.
//
// 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 afero
import (
"fmt"
"log"
"os"
"path/filepath"
"strings"
"sync"
"time"
"github.com/spf13/afero/mem"
)
type MemMapFs struct {
mu sync.RWMutex
data map[string]*mem.FileData
init sync.Once
}
func NewMemMapFs() Fs {
return &MemMapFs{}
}
func (m *MemMapFs) getData() map[string]*mem.FileData {
m.init.Do(func() {
m.data = make(map[string]*mem.FileData)
// Root should always exist, right?
// TODO: what about windows?
m.data[FilePathSeparator] = mem.CreateDir(FilePathSeparator)
})
return m.data
}
func (*MemMapFs) Name() string { return "MemMapFS" }
func (m *MemMapFs) Create(name string) (File, error) {
name = normalizePath(name)
m.mu.Lock()
file := mem.CreateFile(name)
m.getData()[name] = file
m.registerWithParent(file)
m.mu.Unlock()
return mem.NewFileHandle(file), nil
}
func (m *MemMapFs) unRegisterWithParent(fileName string) error {
f, err := m.lockfreeOpen(fileName)
if err != nil {
return err
}
parent := m.findParent(f)
if parent == nil {
log.Panic("parent of ", f.Name(), " is nil")
}
parent.Lock()
mem.RemoveFromMemDir(parent, f)
parent.Unlock()
return nil
}
func (m *MemMapFs) findParent(f *mem.FileData) *mem.FileData {
pdir, _ := filepath.Split(f.Name())
pdir = filepath.Clean(pdir)
pfile, err := m.lockfreeOpen(pdir)
if err != nil {
return nil
}
return pfile
}
func (m *MemMapFs) registerWithParent(f *mem.FileData) {
if f == nil {
return
}
parent := m.findParent(f)
if parent == nil {
pdir := filepath.Dir(filepath.Clean(f.Name()))
err := m.lockfreeMkdir(pdir, 0777)
if err != nil {
//log.Println("Mkdir error:", err)
return
}
parent, err = m.lockfreeOpen(pdir)
if err != nil {
//log.Println("Open after Mkdir error:", err)
return
}
}
parent.Lock()
mem.InitializeDir(parent)
mem.AddToMemDir(parent, f)
parent.Unlock()
}
func (m *MemMapFs) lockfreeMkdir(name string, perm os.FileMode) error {
name = normalizePath(name)
x, ok := m.getData()[name]
if ok {
// Only return ErrFileExists if it's a file, not a directory.
i := mem.FileInfo{FileData: x}
if !i.IsDir() {
return ErrFileExists
}
} else {
item := mem.CreateDir(name)
m.getData()[name] = item
m.registerWithParent(item)
}
return nil
}
func (m *MemMapFs) Mkdir(name string, perm os.FileMode) error {
name = normalizePath(name)
m.mu.RLock()
_, ok := m.getData()[name]
m.mu.RUnlock()
if ok {
return &os.PathError{Op: "mkdir", Path: name, Err: ErrFileExists}
}
m.mu.Lock()
item := mem.CreateDir(name)
m.getData()[name] = item
m.registerWithParent(item)
m.mu.Unlock()
m.Chmod(name, perm|os.ModeDir)
return nil
}
func (m *MemMapFs) MkdirAll(path string, perm os.FileMode) error {
err := m.Mkdir(path, perm)
if err != nil {
if err.(*os.PathError).Err == ErrFileExists {
return nil
}
return err
}
return nil
}
// Handle some relative paths
func normalizePath(path string) string {
path = filepath.Clean(path)
switch path {
case ".":
return FilePathSeparator
case "..":
return FilePathSeparator
default:
return path
}
}
func (m *MemMapFs) Open(name string) (File, error) {
f, err := m.open(name)
if f != nil {
return mem.NewReadOnlyFileHandle(f), err
}
return nil, err
}
func (m *MemMapFs) openWrite(name string) (File, error) {
f, err := m.open(name)
if f != nil {
return mem.NewFileHandle(f), err
}
return nil, err
}
func (m *MemMapFs) open(name string) (*mem.FileData, error) {
name = normalizePath(name)
m.mu.RLock()
f, ok := m.getData()[name]
m.mu.RUnlock()
if !ok {
return nil, &os.PathError{Op: "open", Path: name, Err: ErrFileNotFound}
}
return f, nil
}
func (m *MemMapFs) lockfreeOpen(name string) (*mem.FileData, error) {
name = normalizePath(name)
f, ok := m.getData()[name]
if ok {
return f, nil
} else {
return nil, ErrFileNotFound
}
}
func (m *MemMapFs) OpenFile(name string, flag int, perm os.FileMode) (File, error) {
chmod := false
file, err := m.openWrite(name)
if os.IsNotExist(err) && (flag&os.O_CREATE > 0) {
file, err = m.Create(name)
chmod = true
}
if err != nil {
return nil, err
}
if flag == os.O_RDONLY {
file = mem.NewReadOnlyFileHandle(file.(*mem.File).Data())
}
if flag&os.O_APPEND > 0 {
_, err = file.Seek(0, os.SEEK_END)
if err != nil {
file.Close()
return nil, err
}
}
if flag&os.O_TRUNC > 0 && flag&(os.O_RDWR|os.O_WRONLY) > 0 {
err = file.Truncate(0)
if err != nil {
file.Close()
return nil, err
}
}
if chmod {
m.Chmod(name, perm)
}
return file, nil
}
func (m *MemMapFs) Remove(name string) error {
name = normalizePath(name)
m.mu.Lock()
defer m.mu.Unlock()
if _, ok := m.getData()[name]; ok {
err := m.unRegisterWithParent(name)
if err != nil {
return &os.PathError{Op: "remove", Path: name, Err: err}
}
delete(m.getData(), name)
} else {
return &os.PathError{Op: "remove", Path: name, Err: os.ErrNotExist}
}
return nil
}
func (m *MemMapFs) RemoveAll(path string) error {
path = normalizePath(path)
m.mu.Lock()
m.unRegisterWithParent(path)
m.mu.Unlock()
m.mu.RLock()
defer m.mu.RUnlock()
for p, _ := range m.getData() {
if strings.HasPrefix(p, path) {
m.mu.RUnlock()
m.mu.Lock()
delete(m.getData(), p)
m.mu.Unlock()
m.mu.RLock()
}
}
return nil
}
func (m *MemMapFs) Rename(oldname, newname string) error {
oldname = normalizePath(oldname)
newname = normalizePath(newname)
if oldname == newname {
return nil
}
m.mu.RLock()
defer m.mu.RUnlock()
if _, ok := m.getData()[oldname]; ok {
m.mu.RUnlock()
m.mu.Lock()
m.unRegisterWithParent(oldname)
fileData := m.getData()[oldname]
delete(m.getData(), oldname)
mem.ChangeFileName(fileData, newname)
m.getData()[newname] = fileData
m.registerWithParent(fileData)
m.mu.Unlock()
m.mu.RLock()
} else {
return &os.PathError{Op: "rename", Path: oldname, Err: ErrFileNotFound}
}
return nil
}
func (m *MemMapFs) Stat(name string) (os.FileInfo, error) {
f, err := m.Open(name)
if err != nil {
return nil, err
}
fi := mem.GetFileInfo(f.(*mem.File).Data())
return fi, nil
}
func (m *MemMapFs) Chmod(name string, mode os.FileMode) error {
name = normalizePath(name)
m.mu.RLock()
f, ok := m.getData()[name]
m.mu.RUnlock()
if !ok {
return &os.PathError{Op: "chmod", Path: name, Err: ErrFileNotFound}
}
m.mu.Lock()
mem.SetMode(f, mode)
m.mu.Unlock()
return nil
}
func (m *MemMapFs) Chtimes(name string, atime time.Time, mtime time.Time) error {
name = normalizePath(name)
m.mu.RLock()
f, ok := m.getData()[name]
m.mu.RUnlock()
if !ok {
return &os.PathError{Op: "chtimes", Path: name, Err: ErrFileNotFound}
}
m.mu.Lock()
mem.SetModTime(f, mtime)
m.mu.Unlock()
return nil
}
func (m *MemMapFs) List() {
for _, x := range m.data {
y := mem.FileInfo{FileData: x}
fmt.Println(x.Name(), y.Size())
}
}
// func debugMemMapList(fs Fs) {
// if x, ok := fs.(*MemMapFs); ok {
// x.List()
// }
// }
