distribution/storagedriver/filesystem/driver.go
Stephen J Day d703a86a64 Add checks for ReadStream offset boundary conditions
Several checks for ReadStream with offset around boundary conditions were
missing. The new checks ensure negative offsets are detected and io.EOF is
returned properly when trying to read past the end of a file. The filesystem
and inmemory driver have been updated accordingly.

An outline of missing checks for List are also part of this commit. Action will
be taken here based on discussion in issue #819.
2014-12-05 11:46:41 -08:00

262 lines
6.5 KiB
Go

package filesystem
import (
"bytes"
"fmt"
"io"
"io/ioutil"
"os"
"path"
"time"
"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}
}
// Implement the storagedriver.StorageDriver interface
// GetContent retrieves the content stored at "path" as a []byte.
func (d *Driver) GetContent(path string) ([]byte, error) {
rc, err := d.ReadStream(path, 0)
if err != nil {
return nil, err
}
defer rc.Close()
p, err := ioutil.ReadAll(rc)
if err != nil {
return nil, err
}
return p, nil
}
// PutContent stores the []byte content at a location designated by "path".
func (d *Driver) PutContent(subPath string, contents []byte) error {
if _, err := d.WriteStream(subPath, 0, bytes.NewReader(contents)); err != nil {
return err
}
return os.Truncate(d.fullPath(subPath), int64(len(contents)))
}
// ReadStream retrieves an io.ReadCloser for the content stored at "path" with a
// given byte offset.
func (d *Driver) ReadStream(path string, offset int64) (io.ReadCloser, error) {
if offset < 0 {
return nil, storagedriver.InvalidOffsetError{Path: path, Offset: offset}
}
file, err := os.OpenFile(d.fullPath(path), os.O_RDONLY, 0644)
if err != nil {
if os.IsNotExist(err) {
return nil, storagedriver.PathNotFoundError{Path: path}
}
return nil, err
}
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.Reader at a location
// designated by the given path.
func (d *Driver) WriteStream(subPath string, offset int64, reader io.Reader) (nn int64, err error) {
if offset < 0 {
return 0, storagedriver.InvalidOffsetError{Path: subPath, Offset: offset}
}
// TODO(stevvooe): This needs to be a requirement.
// if !path.IsAbs(subPath) {
// return fmt.Errorf("absolute path required: %q", subPath)
// }
fullPath := d.fullPath(subPath)
parentDir := path.Dir(fullPath)
if err := os.MkdirAll(parentDir, 0755); err != nil {
return 0, err
}
fp, err := os.OpenFile(fullPath, os.O_WRONLY|os.O_CREATE, 0644)
if err != nil {
// TODO(stevvooe): A few missing conditions in storage driver:
// 1. What if the path is already a directory?
// 2. Should number 1 be exposed explicitly in storagedriver?
// 2. Can this path not exist, even if we create above?
return 0, err
}
defer fp.Close()
nn, err = fp.Seek(offset, os.SEEK_SET)
if err != nil {
return 0, err
}
if nn != offset {
return 0, fmt.Errorf("bad seek to %v, expected %v in fp=%v", offset, nn, fp)
}
return io.Copy(fp, reader)
}
// Stat retrieves the FileInfo for the given path, including the current size
// in bytes and the creation time.
func (d *Driver) Stat(subPath string) (storagedriver.FileInfo, error) {
fullPath := d.fullPath(subPath)
fi, err := os.Stat(fullPath)
if err != nil {
if os.IsNotExist(err) {
return nil, storagedriver.PathNotFoundError{Path: subPath}
}
return nil, err
}
return fileInfo{
path: subPath,
FileInfo: fi,
}, 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.fullPath(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.fullPath(sourcePath)
dest := d.fullPath(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.fullPath(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
}
// fullPath returns the absolute path of a key within the Driver's storage.
func (d *Driver) fullPath(subPath string) string {
return path.Join(d.rootDirectory, subPath)
}
type fileInfo struct {
os.FileInfo
path string
}
var _ storagedriver.FileInfo = fileInfo{}
// Path provides the full path of the target of this file info.
func (fi fileInfo) Path() string {
return fi.path
}
// Size returns current length in bytes of the file. The return value can
// be used to write to the end of the file at path. The value is
// meaningless if IsDir returns true.
func (fi fileInfo) Size() int64 {
if fi.IsDir() {
return 0
}
return fi.FileInfo.Size()
}
// ModTime returns the modification time for the file. For backends that
// don't have a modification time, the creation time should be returned.
func (fi fileInfo) ModTime() time.Time {
return fi.FileInfo.ModTime()
}
// IsDir returns true if the path is a directory.
func (fi fileInfo) IsDir() bool {
return fi.FileInfo.IsDir()
}