generic index: untested stat support.

Change-Id: Idff5ff19d7b18ef6581c6c8bc344230470c468ef

lib/go/camli/index/enumstat.go

@@ -17,6 +17,7 @@ limitations under the License.
 package index
 
 import (
+	"fmt"
 	"os"
 	"strconv"
 	"strings"
@@ -44,6 +45,20 @@ func (ix *Index) EnumerateBlobs(dest chan<- blobref.SizedBlobRef, after string,
 }
 
 func (ix *Index) StatBlobs(dest chan<- blobref.SizedBlobRef, blobs []*blobref.BlobRef, waitSeconds int) os.Error {
-	panic("TODO")
+	for _, br := range blobs {
+		key := "have:" + br.String()
+		v, err := ix.s.Get(key)
+		if err == ErrNotFound {
+			continue
+		}
+		if err != nil {
+			return fmt.Errorf("error looking up key %q: %v", key, err)
+		}
+		size, err := strconv.Atoi64(v)
+		if err != nil {
+			return fmt.Errorf("invalid size for key %q = %q", key, v)
+		}
+		dest <- blobref.SizedBlobRef{br, size}
+	}
 	return nil
 }

lib/go/camli/index/index.go

@@ -25,7 +25,13 @@ import (
 	"camli/search"
 )
 
+var ErrNotFound = os.NewError("index: key not found")
+
 type IndexStorage interface {
+	// Get gets the value for the given key. It returns ErrNotFound if the DB
+	// does not contain the key.
+	Get(key string) (string, os.Error)
+
 	Set(key, value string) os.Error
 	Delete(key string) os.Error
 

lib/go/camli/index/memindex.go

@@ -53,6 +53,16 @@ func (s stringIterator) Value() string {
 	return string(s.Iterator.Value())
 }
 
+func (mk *memKeys) Get(key string) (string, os.Error) {
+	mk.mu.Lock()
+	defer mk.mu.Unlock()
+	k, err := mk.db.Get([]byte(key))
+	if err == db.ErrNotFound {
+		return "", ErrNotFound
+	}
+	return string(k), err
+}
+
 func (mk *memKeys) Find(key string) Iterator {
 	mk.mu.Lock()
 	defer mk.mu.Unlock()