diff options
Diffstat (limited to 'vendor/github.com/mattermost/rsc/appfs/server/app.go')
| -rw-r--r-- | vendor/github.com/mattermost/rsc/appfs/server/app.go | 982 |
1 files changed, 0 insertions, 982 deletions
diff --git a/vendor/github.com/mattermost/rsc/appfs/server/app.go b/vendor/github.com/mattermost/rsc/appfs/server/app.go deleted file mode 100644 index 9486eac41..000000000 --- a/vendor/github.com/mattermost/rsc/appfs/server/app.go +++ /dev/null @@ -1,982 +0,0 @@ -// Copyright 2012 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -// Package server implements an appfs server backed by the -// App Engine datastore. -package server - -import ( - "bytes" - "crypto/sha1" - "encoding/base64" - "encoding/json" - "errors" - "fmt" - "io/ioutil" - "net/http" - "path" - "strconv" - "strings" - "time" - - "appengine" - "appengine/datastore" - "appengine/memcache" - "appengine/user" - - "github.com/mattermost/rsc/appfs/fs" - "github.com/mattermost/rsc/appfs/proto" -) - -const pwFile = "/.password" -var chatty = false - -func init() { - handle(proto.ReadURL, (*request).read) - handle(proto.WriteURL, (*request).write) - handle(proto.StatURL, (*request).stat) - handle(proto.MkfsURL, (*request).mkfs) - handle(proto.CreateURL, (*request).create) - handle(proto.RemoveURL, (*request).remove) -} - -type request struct { - w http.ResponseWriter - req *http.Request - c appengine.Context - name string - mname string - key *datastore.Key -} - -func auth(r *request) bool { - hdr := r.req.Header.Get("Authorization") - if !strings.HasPrefix(hdr, "Basic ") { - return false - } - data, err := base64.StdEncoding.DecodeString(hdr[6:]) - if err != nil { - return false - } - i := bytes.IndexByte(data, ':') - if i < 0 { - return false - } - user, passwd := string(data[:i]), string(data[i+1:]) - - _, data, err = read(r.c, pwFile) - if err != nil { - r.c.Errorf("reading %s: %v", pwFile, err) - if _, err := mkfs(r.c); err != nil { - r.c.Errorf("creating fs: %v", err) - } - _, data, err = read(r.c, pwFile) - if err != nil { - r.c.Errorf("reading %s again: %v", pwFile, err) - return false - } - } - - lines := strings.Split(string(data), "\n") - for _, line := range lines { - if strings.HasPrefix(line, "#") { - continue - } - f := strings.Fields(line) - if len(f) < 3 { - continue - } - if f[0] == user { - return hash(f[1]+passwd) == f[2] - } - } - return false -} - -func hash(s string) string { - h := sha1.New() - h.Write([]byte(s)) - return fmt.Sprintf("%x", h.Sum(nil)) -} - -func handle(prefix string, f func(*request)) { - http.HandleFunc(prefix, func(w http.ResponseWriter, req *http.Request) { - c := appengine.NewContext(req) - r := &request{ - w: w, - req: req, - c: c, - } - - if strings.HasSuffix(prefix, "/") { - r.name, r.mname, r.key = mangle(c, req.URL.Path[len(prefix)-1:]) - } else { - req.URL.Path = "/" - } - defer func() { - if err := recover(); err != nil { - w.WriteHeader(http.StatusConflict) - fmt.Fprintf(w, "%s\n", err) - } - }() - - if !auth(r) { - w.Header().Set("WWW-Authenticate", "Basic realm=\"appfs\"") - http.Error(w, "Need auth", http.StatusUnauthorized) - return - } - - f(r) - }) -} - -func mangle(c appengine.Context, name string) (string, string, *datastore.Key) { - name = path.Clean("/" + name) - n := strings.Count(name, "/") - if name == "/" { - n = 0 - } - mname := fmt.Sprintf("%d%s", n, name) - root := datastore.NewKey(c, "RootKey", "v2:", 0, nil) - key := datastore.NewKey(c, "FileInfo", mname, 0, root) - return name, mname, key -} - -type FileInfo struct { - Path string // mangled path - Name string - Qid int64 // assigned unique id number - Seq int64 // modification sequence number in file tree - ModTime time.Time - Size int64 - IsDir bool -} - -type FileData struct { - Data []byte -} - -func stat(c appengine.Context, name string) (*FileInfo, error) { - var fi FileInfo - name, _, key := mangle(c, name) - c.Infof("DATASTORE Stat %q", name) - err := datastore.Get(c, key, &fi) - if err != nil { - return nil, err - } - return &fi, nil -} - -func (r *request) saveStat(fi *FileInfo) { - jfi, err := json.Marshal(&fi) - if err != nil { - panic(err) - } - r.w.Header().Set("X-Appfs-Stat", string(jfi)) -} - -func (r *request) tx(f func(c appengine.Context) error) { - err := datastore.RunInTransaction(r.c, f, &datastore.TransactionOptions{XG: true}) - if err != nil { - panic(err) - } -} - -func (r *request) stat() { - var fi *FileInfo - r.tx(func(c appengine.Context) error { - fi1, err := stat(c, r.name) - if err != nil { - return err - } - fi = fi1 - return nil - }) - - jfi, err := json.Marshal(&fi) - if err != nil { - panic(err) - } - r.w.Write(jfi) -} - -func read(c appengine.Context, name string) (fi *FileInfo, data []byte, err error) { - name, _, _ = mangle(c, name) - fi1, err := stat(c, name) - if err != nil { - return nil, nil, err - } - if fi1.IsDir { - dt, err := readdir(c, name) - if err != nil { - return nil, nil, err - } - fi = fi1 - data = dt - return fi, data, nil - } - - root := datastore.NewKey(c, "RootKey", "v2:", 0, nil) - dkey := datastore.NewKey(c, "FileData", "", fi1.Qid, root) - var fd FileData - c.Infof("DATASTORE Read %q", name) - if err := datastore.Get(c, dkey, &fd); err != nil { - return nil, nil, err - } - fi = fi1 - data = fd.Data - return fi, data, nil -} - -func (r *request) read() { - var ( - fi *FileInfo - data []byte - ) - r.tx(func(c appengine.Context) error { - var err error - fi, data, err = read(r.c, r.name) - return err - }) - r.saveStat(fi) - r.w.Write(data) -} - -func readdir(c appengine.Context, name string) ([]byte, error) { - name, _, _ = mangle(c, name) - var buf bytes.Buffer - - n := strings.Count(name, "/") - if name == "/" { - name = "" - n = 0 - } - root := datastore.NewKey(c, "RootKey", "v2:", 0, nil) - first := fmt.Sprintf("%d%s/", n+1, name) - limit := fmt.Sprintf("%d%s0", n+1, name) - c.Infof("DATASTORE ReadDir %q", name) - q := datastore.NewQuery("FileInfo"). - Filter("Path >=", first). - Filter("Path <", limit). - Ancestor(root) - enc := json.NewEncoder(&buf) - it := q.Run(c) - var fi FileInfo - var pfi proto.FileInfo - for { - fi = FileInfo{} - _, err := it.Next(&fi) - if err != nil { - if err == datastore.Done { - break - } - return nil, err - } - pfi = proto.FileInfo{ - Name: fi.Name, - ModTime: fi.ModTime, - Size: fi.Size, - IsDir: fi.IsDir, - } - if err := enc.Encode(&pfi); err != nil { - return nil, err - } - } - - return buf.Bytes(), nil -} - -func readdirRaw(c appengine.Context, name string) ([]proto.FileInfo, error) { - name, _, _ = mangle(c, name) - n := strings.Count(name, "/") - if name == "/" { - name = "" - n = 0 - } - root := datastore.NewKey(c, "RootKey", "v2:", 0, nil) - first := fmt.Sprintf("%d%s/", n+1, name) - limit := fmt.Sprintf("%d%s0", n+1, name) - c.Infof("DATASTORE ReadDir %q", name) - q := datastore.NewQuery("FileInfo"). - Filter("Path >=", first). - Filter("Path <", limit). - Ancestor(root) - it := q.Run(c) - var fi FileInfo - var pfi proto.FileInfo - var out []proto.FileInfo - for { - fi = FileInfo{} - _, err := it.Next(&fi) - if err != nil { - if err == datastore.Done { - break - } - return nil, err - } - pfi = proto.FileInfo{ - Name: fi.Name, - ModTime: fi.ModTime, - Size: fi.Size, - IsDir: fi.IsDir, - } - out = append(out, pfi) - } -println("READDIR", name, len(out)) - return out, nil -} - - -var initPasswd = `# Password file -# This file controls access to the server. -# The format is lines of space-separated fields: -# user salt pwhash -# The pwhash is the SHA1 of the salt string concatenated with the password. - -# user=dummy password=dummy (replace with your own entries) -dummy 12345 faa863c7d3d41893f80165c704b714d5e31bdd3b -` - -func (r *request) mkfs() { - var fi *FileInfo - r.tx(func(c appengine.Context) error { - var err error - fi, err = mkfs(c) - return err - }) - r.saveStat(fi) -} - -func mkfs(c appengine.Context) (fi *FileInfo, err error) { - fi1, err := stat(c, "/") - if err == nil { - return fi1, nil - } - - // Root needs to be created. - // Probably root key does too. - root := datastore.NewKey(c, "RootKey", "v2:", 0, nil) - _, err = datastore.Put(c, root, &struct{}{}) - if err != nil { - return nil, fmt.Errorf("mkfs put root: %s", err) - } - - // Entry for /. - _, mpath, key := mangle(c, "/") - fi3 := FileInfo{ - Path: mpath, - Name: "/", - Seq: 2, // 2, not 1, because we're going to write password file with #2 - Qid: 1, - ModTime: time.Now(), - Size: 0, - IsDir: true, - } - _, err = datastore.Put(c, key, &fi3) - if err != nil { - return nil, fmt.Errorf("mkfs put /: %s", err) - } - - /* - * Would like to use this code but App Engine apparently - * does not let Get observe the effect of a Put in the same - * transaction. What planet does that make sense on? - * Instead, we have to execute just the datastore writes that this - * sequence would. - * - _, err = create(c, pwFile, false) - if err != nil { - return nil, fmt.Errorf("mkfs create .password: %s", err) - } - _, err = write(c, pwFile, []byte(initPasswd)) - if err != nil { - return nil, fmt.Errorf("mkfs write .password: %s", err) - } - * - */ - - { - name, mname, key := mangle(c, pwFile) - - // Create data object. - dataKey := int64(2) - root := datastore.NewKey(c, "RootKey", "v2:", 0, nil) - dkey := datastore.NewKey(c, "FileData", "", dataKey, root) - _, err := datastore.Put(c, dkey, &FileData{[]byte(initPasswd)}) - if err != nil { - return nil, err - } - - // Create new directory entry. - _, elem := path.Split(name) - fi1 = &FileInfo{ - Path: mname, - Name: elem, - Qid: 2, - Seq: 2, - ModTime: time.Now(), - Size: int64(len(initPasswd)), - IsDir: false, - } - if _, err := datastore.Put(c, key, fi1); err != nil { - return nil, err - } - } - - return &fi3, nil -} - -func (r *request) write() { - data, err := ioutil.ReadAll(r.req.Body) - if err != nil { - panic(err) - } - - var fi *FileInfo - var seq int64 - r.tx(func(c appengine.Context) error { - var err error - fi, seq, err = write(r.c, r.name, data) - return err - }) - updateCacheTime(r.c, seq) - r.saveStat(fi) -} - -func write(c appengine.Context, name string, data []byte) (*FileInfo, int64, error) { - name, _, key := mangle(c, name) - - // Check that file exists and is not a directory. - fi1, err := stat(c, name) - if err != nil { - return nil, 0, err - } - if fi1.IsDir { - return nil, 0, fmt.Errorf("cannot write to directory") - } - - // Fetch and increment root sequence number. - rfi, err := stat(c, "/") - if err != nil { - return nil, 0, err - } - rfi.Seq++ - - // Write data. - root := datastore.NewKey(c, "RootKey", "v2:", 0, nil) - dkey := datastore.NewKey(c, "FileData", "", fi1.Qid, root) - fd := &FileData{data} - if _, err := datastore.Put(c, dkey, fd); err != nil { - return nil, 0, err - } - - // Update directory entry. - fi1.Seq = rfi.Seq - fi1.Size = int64(len(data)) - fi1.ModTime = time.Now() - if _, err := datastore.Put(c, key, fi1); err != nil { - return nil, 0, err - } - - // Update sequence numbers all the way to the root. - if err := updateSeq(c, name, rfi.Seq, 1); err != nil { - return nil, 0, err - } - - return fi1, rfi.Seq, nil -} - -func updateSeq(c appengine.Context, name string, seq int64, skip int) error { - p := path.Clean(name) - for i := 0; ; i++ { - if i >= skip { - _, _, key := mangle(c, p) - var fi FileInfo - if err := datastore.Get(c, key, &fi); err != nil { - return err - } - fi.Seq = seq - if _, err := datastore.Put(c, key, &fi); err != nil { - return err - } - } - if p == "/" { - break - } - p, _ = path.Split(p) - p = path.Clean(p) - } - return nil -} - -func (r *request) remove() { - panic("remove not implemented") -} - -func (r *request) create() { - var fi *FileInfo - var seq int64 - isDir := r.req.FormValue("dir") == "1" - r.tx(func(c appengine.Context) error { - var err error - fi, seq, err = create(r.c, r.name, isDir, nil) - return err - }) - updateCacheTime(r.c, seq) - r.saveStat(fi) -} - -func create(c appengine.Context, name string, isDir bool, data []byte) (*FileInfo, int64, error) { - name, mname, key := mangle(c, name) - - // File must not exist. - fi1, err := stat(c, name) - if err == nil { - return nil, 0, fmt.Errorf("file already exists") - } - if err != datastore.ErrNoSuchEntity { - return nil, 0, err - } - - // Parent must exist and be a directory. - p, _ := path.Split(name) - fi2, err := stat(c, p) - if err != nil { - if err == datastore.ErrNoSuchEntity { - return nil, 0, fmt.Errorf("parent directory %q does not exist", p) - } - return nil, 0, err - } - if !fi2.IsDir { - return nil, 0, fmt.Errorf("parent %q is not a directory", p) - } - - // Fetch and increment root sequence number. - rfi, err := stat(c, "/") - if err != nil { - return nil, 0, err - } - rfi.Seq++ - - var dataKey int64 - // Create data object. - if !isDir { - dataKey = rfi.Seq - root := datastore.NewKey(c, "RootKey", "v2:", 0, nil) - dkey := datastore.NewKey(c, "FileData", "", dataKey, root) - _, err := datastore.Put(c, dkey, &FileData{data}) - if err != nil { - return nil, 0, err - } - } - - // Create new directory entry. - _, elem := path.Split(name) - fi1 = &FileInfo{ - Path: mname, - Name: elem, - Qid: rfi.Seq, - Seq: rfi.Seq, - ModTime: time.Now(), - Size: int64(len(data)), - IsDir: isDir, - } - if _, err := datastore.Put(c, key, fi1); err != nil { - return nil, 0, err - } - - // Update sequence numbers all the way to root, - // but skip entry we just wrote. - if err := updateSeq(c, name, rfi.Seq, 1); err != nil { - return nil, 0, err - } - - return fi1, rfi.Seq, nil -} - -// Implementation of fs.AppEngine. - -func init() { - fs.Register(ae{}) -} - -type ae struct{} - -func tx(c interface{}, f func(c appengine.Context) error) error { - return datastore.RunInTransaction(c.(appengine.Context), f, &datastore.TransactionOptions{XG: true}) -} - -func (ae) NewContext(req *http.Request) interface{} { - return appengine.NewContext(req) -} - -func (ae) User(ctxt interface{}) string { - c := ctxt.(appengine.Context) - u := user.Current(c) - if u == nil { - return "?" - } - return u.String() -} - -type cacheKey struct { - t int64 - name string -} - -func (ae) CacheRead(ctxt interface{}, name, path string) (key interface{}, data []byte, found bool) { - c := ctxt.(appengine.Context) - t, data, _, err := cacheRead(c, "cache", name, path) - return &cacheKey{t, name}, data, err == nil -} - -func (ae) CacheWrite(ctxt, key interface{}, data []byte) { - c := ctxt.(appengine.Context) - k := key.(*cacheKey) - cacheWrite(c, k.t, "cache", k.name, data) -} - -func (ae ae) Read(ctxt interface{}, name string) (data []byte, pfi *proto.FileInfo, err error) { - c := ctxt.(appengine.Context) - name = path.Clean("/"+name) - if chatty { - c.Infof("AE Read %s", name) - } - _, data, pfi, err = cacheRead(c, "data", name, name) - if err != nil { - err = fmt.Errorf("Read %q: %v", name, err) - } - return -} - -func (ae) Write(ctxt interface{}, path string, data []byte) error { - var seq int64 - err := tx(ctxt, func(c appengine.Context) error { - _, err := stat(c, path) - if err != nil { - _, seq, err = create(c, path, false, data) - } else { - _, seq, err = write(c, path, data) - } - return err - }) - if seq != 0 { - updateCacheTime(ctxt.(appengine.Context), seq) - } - if err != nil { - err = fmt.Errorf("Write %q: %v", path, err) - } - return err -} - -func (ae) Remove(ctxt interface{}, path string) error { - return fmt.Errorf("remove not implemented") -} - -func (ae) Mkdir(ctxt interface{}, path string) error { - var seq int64 - err := tx(ctxt, func(c appengine.Context) error { - var err error - _, seq, err = create(c, path, true, nil) - return err - }) - if seq != 0 { - updateCacheTime(ctxt.(appengine.Context), seq) - } - if err != nil { - err = fmt.Errorf("Mkdir %q: %v", path, err) - } - return err -} - -func (ae) Criticalf(ctxt interface{}, format string, args ...interface{}) { - ctxt.(appengine.Context).Criticalf(format, args...) -} - -type readDirCacheEntry struct { - Dir []proto.FileInfo - Error string -} - -func (ae) ReadDir(ctxt interface{}, name string) (dir []proto.FileInfo, err error) { - c := ctxt.(appengine.Context) - name = path.Clean("/"+name) - t, data, _, err := cacheRead(c, "dir", name, name) - if err == nil { - var e readDirCacheEntry - if err := json.Unmarshal(data, &e); err == nil { - if chatty { - c.Infof("cached ReadDir %q", name) - } - if e.Error != "" { - return nil, errors.New(e.Error) - } - return e.Dir, nil - } - c.Criticalf("unmarshal cached dir %q: %v", name) - } - err = tx(ctxt, func(c appengine.Context) error { - var err error - dir, err = readdirRaw(c, name) - return err - }) - var e readDirCacheEntry - e.Dir = dir - if err != nil { - err = fmt.Errorf("ReadDir %q: %v", name, err) - e.Error = err.Error() - } - if data, err := json.Marshal(&e); err != nil { - c.Criticalf("json marshal cached dir: %v", err) - } else { - c.Criticalf("caching dir %q@%d %d bytes", name, t, len(data)) - cacheWrite(c, t, "dir", name, data) - } - return -} - -// Caching of file system data. -// -// The cache stores entries under keys of the form time,space,name, -// where time is the time at which the entry is valid for, space is a name -// space identifier, and name is an arbitrary name. -// -// A key of the form t,mtime,path maps to an integer value giving the -// modification time of the named path at root time t. -// The special key 0,mtime,/ is an integer giving the current time at the root. -// -// A key of the form t,data,path maps to the content of path at time t. -// -// Thus, a read from path should first obtain the root time, -// then obtain the modification time for the path at that root time -// then obtain the data for that path. -// t1 = get(0,mtime,/) -// t2 = get(t1,mtime,path) -// data = get(t2,data,path) -// -// The API allows clients to cache their own data too, with expiry tied to -// the modification time of a particular path (file or directory). To look -// up one of those, we use: -// t1 = get(0,mtime,/) -// t2 = get(t1,mtime,path) -// data = get(t2,clientdata,name) -// -// To store data in the cache, the t1, t2 should be determined before reading -// from datastore. Then the data should be saved under t2. This ensures -// that if a datastore update happens after the read but before the cache write, -// we'll be writing to an entry that will no longer be used (t2). - -const rootMemcacheKey = "0,mtime,/" - -func updateCacheTime(c appengine.Context, seq int64) { - const key = rootMemcacheKey - bseq := []byte(strconv.FormatInt(seq, 10)) - for tries := 0; tries < 10; tries++ { - item, err := memcache.Get(c, key) - if err != nil { - c.Infof("memcache.Get %q: %v", key, err) - err = memcache.Add(c, &memcache.Item{Key: key, Value: bseq}) - if err == nil { - c.Infof("memcache.Add %q %q ok", key, bseq) - return - } - c.Infof("memcache.Add %q %q: %v", key, bseq, err) - } - v, err := strconv.ParseInt(string(item.Value), 10, 64) - if err != nil { - c.Criticalf("memcache.Get %q = %q (%v)", key, item.Value, err) - return - } - if v >= seq { - return - } - item.Value = bseq - err = memcache.CompareAndSwap(c, item) - if err == nil { - c.Infof("memcache.CAS %q %d->%d ok", key, v, seq) - return - } - c.Infof("memcache.CAS %q %d->%d: %v", key, v, seq, err) - } - c.Criticalf("repeatedly failed to update root key") -} - -func cacheTime(c appengine.Context) (t int64, err error) { - const key = rootMemcacheKey - item, err := memcache.Get(c, key) - if err == nil { - v, err := strconv.ParseInt(string(item.Value), 10, 64) - if err == nil { - if chatty { - c.Infof("cacheTime %q = %v", key, v) - } - return v, nil - } - c.Criticalf("memcache.Get %q = %q (%v) - deleting", key, item.Value, err) - memcache.Delete(c, key) - } - fi, err := stat(c, "/") - if err != nil { - c.Criticalf("stat /: %v", err) - return 0, err - } - updateCacheTime(c, fi.Seq) - return fi.Seq, nil -} - -func cachePathTime(c appengine.Context, path string) (t int64, err error) { - t, err = cacheTime(c) - if err != nil { - return 0, err - } - - key := fmt.Sprintf("%d,mtime,%s", t, path) - item, err := memcache.Get(c, key) - if err == nil { - v, err := strconv.ParseInt(string(item.Value), 10, 64) - if err == nil { - if chatty { - c.Infof("cachePathTime %q = %v", key, v) - } - return v, nil - } - c.Criticalf("memcache.Get %q = %q (%v) - deleting", key, item.Value, err) - memcache.Delete(c, key) - } - - var seq int64 - if fi, err := stat(c, path); err == nil { - seq = fi.Seq - } - - c.Infof("cachePathTime save %q = %v", key, seq) - item = &memcache.Item{Key: key, Value: []byte(strconv.FormatInt(seq, 10))} - if err := memcache.Set(c, item); err != nil { - c.Criticalf("memcache.Set %q %q: %v", key, item.Value, err) - } - return seq, nil -} - -type statCacheEntry struct { - FileInfo *proto.FileInfo - Error string -} - -func cacheRead(c appengine.Context, kind, name, path string) (mtime int64, data []byte, pfi *proto.FileInfo, err error) { - for tries := 0; tries < 10; tries++ { - t, err := cachePathTime(c, path) - if err != nil { - return 0, nil, nil, err - } - - key := fmt.Sprintf("%d,%s,%s", t, kind, name) - item, err := memcache.Get(c, key) - var data []byte - if item != nil { - data = item.Value - } - if err != nil { - c.Infof("memcache miss %q %v", key, err) - } else if chatty { - c.Infof("memcache hit %q (%d bytes)", key, len(data)) - } - if kind != "data" { - // Not a file; whatever memcache says is all we have. - return t, data, nil, err - } - - // Load stat from cache (includes negative entry). - statkey := fmt.Sprintf("%d,stat,%s", t, name) - var st statCacheEntry - _, err = memcache.JSON.Get(c, statkey, &st) - if err == nil { - if st.Error != "" { - if chatty { - c.Infof("memcache hit stat error %q %q", statkey, st.Error) - } - err = errors.New(st.Error) - } else { - if chatty { - c.Infof("memcache hit stat %q", statkey) - } - } - if err != nil || data != nil { - return t, data, st.FileInfo, err - } - } - - // Need stat, or maybe stat+data. - var fi *FileInfo - if data != nil { - c.Infof("stat %q", name) - fi, err = stat(c, name) - if err == nil && fi.Seq != t { - c.Criticalf("loaded %s but found stat %d", key, fi.Seq) - continue - } - } else { - c.Infof("read %q", name) - fi, data, err = read(c, name) - if err == nil && fi.Seq != t { - c.Infof("loaded %s but found read %d", key, fi.Seq) - t = fi.Seq - key = fmt.Sprintf("%d,data,%s", t, name) - statkey = fmt.Sprintf("%d,stat,%s", t, name) - } - - // Save data to memcache. - if err == nil { - if true || chatty { - c.Infof("save data in memcache %q", key) - } - item := &memcache.Item{Key: key, Value: data} - if err := memcache.Set(c, item); err != nil { - c.Criticalf("failed to cache %s: %v", key, err) - } - } - } - - // Cache stat, including error. - st = statCacheEntry{} - if fi != nil { - st.FileInfo = &proto.FileInfo{ - Name: fi.Name, - ModTime: fi.ModTime, - Size: fi.Size, - IsDir: fi.IsDir, - } - } - if err != nil { - st.Error = err.Error() - // If this is a deadline exceeded, do not cache. - if strings.Contains(st.Error, "Canceled") || strings.Contains(st.Error, "Deadline") { - return t, data, st.FileInfo, err - } - } - if chatty { - c.Infof("save stat in memcache %q", statkey) - } - if err := memcache.JSON.Set(c, &memcache.Item{Key: statkey, Object: &st}); err != nil { - c.Criticalf("failed to cache %s: %v", statkey, err) - } - - // Done! - return t, data, st.FileInfo, err - } - - c.Criticalf("failed repeatedly in cacheRead") - return 0, nil, nil, errors.New("cacheRead loop failed") -} - -func cacheWrite(c appengine.Context, t int64, kind, name string, data []byte) error { - mkey := fmt.Sprintf("%d,%s,%s", t, kind, name) - if true || chatty { - c.Infof("cacheWrite %s %d bytes", mkey, len(data)) - } - err := memcache.Set(c, &memcache.Item{Key: mkey, Value: data}) - if err != nil { - c.Criticalf("cacheWrite memcache.Set %q: %v", mkey, err) - } - return err -} |