mirror of https://github.com/perkeep/perkeep.git
152 lines
3.8 KiB
Go
152 lines
3.8 KiB
Go
/*
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Copyright 2011 Google Inc.
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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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/*
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Package localdisk registers the "filesystem" blobserver storage type,
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storing blobs in a forest of sharded directories at the specified root.
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Example low-level config:
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"/storage/": {
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"handler": "storage-filesystem",
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"handlerArgs": {
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"path": "/var/camlistore/blobs"
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}
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},
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*/
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package localdisk
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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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"sync"
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"camlistore.org/pkg/blob"
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"camlistore.org/pkg/blobserver"
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"camlistore.org/pkg/blobserver/local"
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"camlistore.org/pkg/jsonconfig"
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"camlistore.org/pkg/osutil"
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"camlistore.org/pkg/types"
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)
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// DiskStorage implements the blobserver.Storage interface using the
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// local filesystem.
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type DiskStorage struct {
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root string
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// dirLockMu must be held for writing when deleting an empty directory
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// and for read when receiving blobs.
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dirLockMu *sync.RWMutex
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// gen will be nil if partition != ""
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gen *local.Generationer
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}
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func (ds *DiskStorage) String() string {
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return fmt.Sprintf("\"filesystem\" file-per-blob at %s", ds.root)
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}
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// IsDir reports whether root is a localdisk (file-per-blob) storage directory.
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func IsDir(root string) (bool, error) {
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if osutil.DirExists(filepath.Join(root, blob.RefFromString("").HashName())) {
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return true, nil
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}
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return false, nil
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}
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// New returns a new local disk storage implementation at the provided
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// root directory, which must already exist.
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func New(root string) (*DiskStorage, error) {
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// Local disk.
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fi, err := os.Stat(root)
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if os.IsNotExist(err) {
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return nil, fmt.Errorf("Storage root %q doesn't exist", root)
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}
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if err != nil {
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return nil, fmt.Errorf("Failed to stat directory %q: %v", root, err)
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}
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if !fi.IsDir() {
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return nil, fmt.Errorf("Storage root %q exists but is not a directory.", root)
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}
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ds := &DiskStorage{
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root: root,
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dirLockMu: new(sync.RWMutex),
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gen: local.NewGenerationer(root),
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}
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if err := ds.migrate3to2(); err != nil {
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return nil, fmt.Errorf("Error updating localdisk format: %v", err)
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}
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if _, _, err := ds.StorageGeneration(); err != nil {
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return nil, fmt.Errorf("Error initialization generation for %q: %v", root, err)
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}
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return ds, nil
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}
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func newFromConfig(_ blobserver.Loader, config jsonconfig.Obj) (storage blobserver.Storage, err error) {
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path := config.RequiredString("path")
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if err := config.Validate(); err != nil {
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return nil, err
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}
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return New(path)
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}
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func init() {
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blobserver.RegisterStorageConstructor("filesystem", blobserver.StorageConstructor(newFromConfig))
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}
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func (ds *DiskStorage) tryRemoveDir(dir string) {
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ds.dirLockMu.Lock()
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defer ds.dirLockMu.Unlock()
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os.Remove(dir) // ignore error
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}
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func (ds *DiskStorage) Fetch(blob blob.Ref) (io.ReadCloser, uint32, error) {
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fileName := ds.blobPath(blob)
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stat, err := os.Stat(fileName)
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if os.IsNotExist(err) {
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return nil, 0, os.ErrNotExist
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}
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size := types.U32(stat.Size())
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file, err := os.Open(fileName)
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if err != nil {
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if os.IsNotExist(err) {
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err = os.ErrNotExist
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}
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return nil, 0, err
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}
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return file, size, nil
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}
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func (ds *DiskStorage) RemoveBlobs(blobs []blob.Ref) error {
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for _, blob := range blobs {
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fileName := ds.blobPath(blob)
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err := os.Remove(fileName)
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switch {
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case err == nil:
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continue
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case os.IsNotExist(err):
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// deleting already-deleted file; harmless.
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continue
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default:
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return err
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}
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}
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return nil
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}
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