mirror of https://github.com/perkeep/perkeep.git
139 lines
3.4 KiB
Go
139 lines
3.4 KiB
Go
// +build linux darwin
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/*
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Copyright 2013 The Camlistore Authors
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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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package fs
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import (
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"encoding/base64"
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"log"
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"strings"
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"sync"
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"camlistore.org/pkg/blob"
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"camlistore.org/pkg/schema"
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"camlistore.org/pkg/search"
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"bazil.org/fuse"
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)
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// xattrPrefix is the permanode attribute prefix used for record
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// extended attributes.
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const xattrPrefix = "xattr:"
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// xattr provides common support for extended attributes for various
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// file and directory implementations (fuse.Node) within the FUSE services.
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type xattr struct {
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typeName string // for logging
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fs *CamliFileSystem
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permanode blob.Ref
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// mu guards xattrs. Both mu and the xattrs map are provided by the
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// fuse.Node when the struct is created.
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mu *sync.Mutex
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// This is a pointer to the particular fuse.Node's location of its
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// xattr map so that it can be initialized commonly when the fuse.Node
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// calls xattr.load(*search.DescribedPermanode)
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xattrs *map[string][]byte
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}
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// load is invoked after the creation of a fuse.Node that may contain extended
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// attributes. This creates the node's xattr map as well as fills it with any
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// extended attributes found in the permanode's claims.
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func (x *xattr) load(p *search.DescribedPermanode) {
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x.mu.Lock()
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defer x.mu.Unlock()
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*x.xattrs = map[string][]byte{}
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for k, v := range p.Attr {
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if strings.HasPrefix(k, xattrPrefix) {
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name := k[len(xattrPrefix):]
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val, err := base64.StdEncoding.DecodeString(v[0])
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if err != nil {
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log.Printf("Base64 decoding error on attribute %v: %v", name, err)
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continue
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}
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(*x.xattrs)[name] = val
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}
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}
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}
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func (x *xattr) set(req *fuse.SetxattrRequest) error {
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log.Printf("%s.setxattr(%q) -> %q", x.typeName, req.Name, req.Xattr)
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claim := schema.NewSetAttributeClaim(x.permanode, xattrPrefix+req.Name,
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base64.StdEncoding.EncodeToString(req.Xattr))
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_, err := x.fs.client.UploadAndSignBlob(claim)
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if err != nil {
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log.Printf("Error setting xattr: %v", err)
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return fuse.EIO
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}
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val := make([]byte, len(req.Xattr))
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copy(val, req.Xattr)
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x.mu.Lock()
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(*x.xattrs)[req.Name] = val
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x.mu.Unlock()
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return nil
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}
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func (x *xattr) remove(req *fuse.RemovexattrRequest) error {
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log.Printf("%s.Removexattr(%q)", x.typeName, req.Name)
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claim := schema.NewDelAttributeClaim(x.permanode, xattrPrefix+req.Name, "")
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_, err := x.fs.client.UploadAndSignBlob(claim)
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if err != nil {
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log.Printf("Error removing xattr: %v", err)
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return fuse.EIO
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}
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x.mu.Lock()
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delete(*x.xattrs, req.Name)
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x.mu.Unlock()
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return nil
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}
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func (x *xattr) get(req *fuse.GetxattrRequest, res *fuse.GetxattrResponse) error {
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x.mu.Lock()
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defer x.mu.Unlock()
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val, found := (*x.xattrs)[req.Name]
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if !found {
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return fuse.ErrNoXattr
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}
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res.Xattr = val
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return nil
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}
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func (x *xattr) list(req *fuse.ListxattrRequest, res *fuse.ListxattrResponse) error {
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x.mu.Lock()
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defer x.mu.Unlock()
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for k := range *x.xattrs {
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res.Xattr = append(res.Xattr, k...)
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res.Xattr = append(res.Xattr, '\x00')
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}
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return nil
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}
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