Add missing file from 83a0f2b47c

Change-Id: I8e9b905276bf1e48a378fd88b38884bb9767a5b6

clients/go/camput/flatcache.go

@@ -0,0 +1,125 @@
+/*
+Copyright 2011 Google Inc.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package main
+
+import (
+	"gob"
+	"log"
+	"os"
+	"path/filepath"
+	"reflect"
+	"sync"
+
+	"camli/client"
+	"camli/osutil"
+)
+
+type fileInfoPutRes struct {
+	Fi os.FileInfo
+	Pr client.PutResult
+}
+
+// FlatCache is an ugly hack, until leveldb-go is ready
+// (http://code.google.com/p/leveldb-go/)
+type FlatCache struct {
+	mu sync.Mutex
+	filename string
+	m        map[string]fileInfoPutRes
+	dirty    map[string]fileInfoPutRes
+}
+
+func NewFlatCache() *FlatCache {
+	filename := filepath.Join(osutil.CacheDir(), "camput.cache")
+	fc := &FlatCache{
+		filename: filename,
+		m:        make(map[string]fileInfoPutRes),
+		dirty: make(map[string]fileInfoPutRes),
+	}
+
+	if f, err := os.Open(filename); err == nil {
+		defer f.Close()
+		d := gob.NewDecoder(f)
+		for {
+			var key string
+			var val fileInfoPutRes
+			if d.Decode(&key) != nil || d.Decode(&val) != nil {
+				break
+			}
+			val.Pr.Skipped = true
+			fc.m[key] = val
+		}
+	}
+	return fc
+}
+
+var _ UploadCache = (*FlatCache)(nil)
+
+var ErrCacheMiss = os.NewError("not in cache")
+
+// filename may be relative.
+// returns ErrCacheMiss on miss
+func cacheKey(pwd, filename string) string {
+	return pwd + "\x00" + filename
+}
+
+func (c *FlatCache) CachedPutResult(pwd, filename string, fi *os.FileInfo) (*client.PutResult, os.Error) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	val, ok := c.m[cacheKey(pwd, filename)]
+	if !ok {
+		return nil, ErrCacheMiss
+	}
+	if !reflect.DeepEqual(val.Fi, fi) {
+		return nil, ErrCacheMiss
+	}
+	pr := val.Pr
+	return &pr, nil
+}
+
+func (c *FlatCache) AddCachedPutResult(pwd, filename string, fi *os.FileInfo, pr *client.PutResult) {
+	c.mu.Lock()
+        defer c.mu.Unlock()
+	key := cacheKey(pwd, filename)
+
+	vprintf("Adding to stat cache %q: %v", filename, pr)
+
+	c.dirty[key] = fileInfoPutRes{*fi, *pr}
+	c.m[key] = fileInfoPutRes{*fi, *pr}
+}
+
+func (c *FlatCache) Save() {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	f, err := os.OpenFile(c.filename, os.O_WRONLY|os.O_CREATE|os.O_APPEND, 0600)
+	if err != nil {
+		log.Fatalf("FlatCache OpenFile: %v", err)
+	}
+	defer f.Close()
+	e := gob.NewEncoder(f)
+	write := func(v interface{}) {
+		if err := e.Encode(v); err != nil {
+			panic("Encode: " + err.String())
+		}
+	}
+	for k, v := range c.dirty {
+		write(k)
+		write(v)
+	}
+	c.dirty = make(map[string]fileInfoPutRes)
+}