distribution/storagedriver/filesystem/driver.go

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package filesystem
import (
"io"
"io/ioutil"
"os"
"path"
"github.com/docker/docker-registry/storagedriver"
"github.com/docker/docker-registry/storagedriver/factory"
)
const driverName = "filesystem"
const defaultRootDirectory = "/tmp/registry/storage"
func init() {
factory.Register(driverName, &filesystemDriverFactory{})
}
// filesystemDriverFactory implements the factory.StorageDriverFactory interface
type filesystemDriverFactory struct{}
func (factory *filesystemDriverFactory) Create(parameters map[string]string) (storagedriver.StorageDriver, error) {
return FromParameters(parameters), nil
}
// Driver is a storagedriver.StorageDriver implementation backed by a local
// filesystem. All provided paths will be subpaths of the RootDirectory
type Driver struct {
rootDirectory string
}
// FromParameters constructs a new Driver with a given parameters map
// Optional Parameters:
// - rootdirectory
func FromParameters(parameters map[string]string) *Driver {
var rootDirectory = defaultRootDirectory
if parameters != nil {
rootDir, ok := parameters["rootdirectory"]
if ok {
rootDirectory = rootDir
}
}
return New(rootDirectory)
}
// New constructs a new Driver with a given rootDirectory
func New(rootDirectory string) *Driver {
return &Driver{rootDirectory}
}
// subPath returns the absolute path of a key within the Driver's storage
func (d *Driver) subPath(subPath string) string {
return path.Join(d.rootDirectory, subPath)
}
// Implement the storagedriver.StorageDriver interface
// GetContent retrieves the content stored at "path" as a []byte.
func (d *Driver) GetContent(path string) ([]byte, error) {
contents, err := ioutil.ReadFile(d.subPath(path))
if err != nil {
return nil, storagedriver.PathNotFoundError{Path: path}
}
return contents, nil
}
// PutContent stores the []byte content at a location designated by "path".
func (d *Driver) PutContent(subPath string, contents []byte) error {
fullPath := d.subPath(subPath)
parentDir := path.Dir(fullPath)
err := os.MkdirAll(parentDir, 0755)
if err != nil {
return err
}
err = ioutil.WriteFile(fullPath, contents, 0644)
return err
}
// ReadStream retrieves an io.ReadCloser for the content stored at "path" with a
// given byte offset.
func (d *Driver) ReadStream(path string, offset uint64) (io.ReadCloser, error) {
file, err := os.OpenFile(d.subPath(path), os.O_RDONLY, 0644)
if err != nil {
return nil, storagedriver.PathNotFoundError{Path: path}
}
seekPos, err := file.Seek(int64(offset), os.SEEK_SET)
if err != nil {
file.Close()
return nil, err
} else if seekPos < int64(offset) {
file.Close()
return nil, storagedriver.InvalidOffsetError{Path: path, Offset: offset}
}
return file, nil
}
// WriteStream stores the contents of the provided io.ReadCloser at a location
// designated by the given path.
func (d *Driver) WriteStream(subPath string, offset, size uint64, reader io.ReadCloser) error {
defer reader.Close()
resumableOffset, err := d.CurrentSize(subPath)
if _, pathNotFound := err.(storagedriver.PathNotFoundError); err != nil && !pathNotFound {
return err
}
if offset > resumableOffset {
return storagedriver.InvalidOffsetError{Path: subPath, Offset: offset}
}
fullPath := d.subPath(subPath)
parentDir := path.Dir(fullPath)
err = os.MkdirAll(parentDir, 0755)
if err != nil {
return err
}
var file *os.File
if offset == 0 {
file, err = os.Create(fullPath)
} else {
file, err = os.OpenFile(fullPath, os.O_WRONLY|os.O_APPEND, 0)
}
if err != nil {
return err
}
defer file.Close()
buf := make([]byte, 32*1024)
for {
bytesRead, er := reader.Read(buf)
if bytesRead > 0 {
bytesWritten, ew := file.WriteAt(buf[0:bytesRead], int64(offset))
if bytesWritten > 0 {
offset += uint64(bytesWritten)
}
if ew != nil {
err = ew
break
}
if bytesRead != bytesWritten {
err = io.ErrShortWrite
break
}
}
if er == io.EOF {
break
}
if er != nil {
err = er
break
}
}
return err
}
// CurrentSize retrieves the curernt size in bytes of the object at the given
// path.
func (d *Driver) CurrentSize(subPath string) (uint64, error) {
fullPath := d.subPath(subPath)
fileInfo, err := os.Stat(fullPath)
if err != nil && !os.IsNotExist(err) {
return 0, err
} else if err != nil {
return 0, storagedriver.PathNotFoundError{Path: subPath}
}
return uint64(fileInfo.Size()), nil
}
// List returns a list of the objects that are direct descendants of the given
// path.
func (d *Driver) List(subPath string) ([]string, error) {
if subPath[len(subPath)-1] != '/' {
subPath += "/"
}
fullPath := d.subPath(subPath)
dir, err := os.Open(fullPath)
if err != nil {
return nil, err
}
fileNames, err := dir.Readdirnames(0)
if err != nil {
return nil, err
}
keys := make([]string, 0, len(fileNames))
for _, fileName := range fileNames {
keys = append(keys, path.Join(subPath, fileName))
}
return keys, nil
}
// Move moves an object stored at sourcePath to destPath, removing the original
// object.
func (d *Driver) Move(sourcePath string, destPath string) error {
source := d.subPath(sourcePath)
dest := d.subPath(destPath)
if _, err := os.Stat(source); os.IsNotExist(err) {
return storagedriver.PathNotFoundError{Path: sourcePath}
}
err := os.Rename(source, dest)
return err
}
// Delete recursively deletes all objects stored at "path" and its subpaths.
func (d *Driver) Delete(subPath string) error {
fullPath := d.subPath(subPath)
_, err := os.Stat(fullPath)
if err != nil && !os.IsNotExist(err) {
return err
} else if err != nil {
return storagedriver.PathNotFoundError{Path: subPath}
}
err = os.RemoveAll(fullPath)
return err
}