Start of making canLongPoll configurable for App Engine to set it to false, for now.

Change-Id: Ib4d7a306276a7292e7d8a8838c3b026d38b5fb6b

lib/go/camli/blobserver/handlers/stat.go

@@ -117,7 +117,11 @@ func handleStat(conn http.ResponseWriter, req *http.Request, storage blobserver.
 
 	configer, _ := storage.(blobserver.Configer)
 	ret := commonUploadResponse(configer, req)
+	if configer != nil {
+		ret["canLongPoll"] = true
+	} else {
+		ret["canLongPoll"] = configer.Config().CanLongPoll
+	}
 	ret["stat"] = statRes
-	ret["canLongPoll"] = true
 	httputil.ReturnJson(conn, ret)
 }

lib/go/camli/blobserver/interface.go

@@ -39,8 +39,8 @@ type BlobStatter interface {
 	// waitSeconds is the max time to wait for the blobs to exist,
 	// or 0 for no delay.
 	StatBlobs(dest chan<- blobref.SizedBlobRef,
-	blobs []*blobref.BlobRef,
-	waitSeconds int) os.Error
+		blobs []*blobref.BlobRef,
+		waitSeconds int) os.Error
 }
 
 type StatReceiver interface {
@@ -75,9 +75,9 @@ type BlobEnumerator interface {
 	// after and waitSeconds can't be used together. One must be
 	// its zero value.
 	EnumerateBlobs(dest chan<- blobref.SizedBlobRef,
-	after string,
-	limit uint,
-	waitSeconds int) os.Error
+		after string,
+		limit uint,
+		waitSeconds int) os.Error
 }
 
 // Cache is the minimal interface expected of a blob cache.
@@ -95,6 +95,7 @@ type BlobReceiveConfiger interface {
 type Config struct {
 	Writable, Readable bool
 	IsQueue            bool // supports deletes
+	CanLongPoll        bool
 
 	// the "http://host:port" and optional path (but without trailing slash) to have "/camli/*" appended
 	URLBase string

lib/go/camli/serverconfig/serverconfig.go

@@ -118,13 +118,17 @@ func makeCamliHandler(prefix, baseURL string, storage blobserver.Storage) http.H
 	}
 	baseURL = strings.TrimRight(baseURL, "/")
 
+	canLongPoll := true
+	// TODO(bradfitz): set to false if this is App Engine, or provide some way to disable
+
 	storageConfig := &storageAndConfig{
 		storage,
 		&blobserver.Config{
-			Writable: true,
-			Readable: true,
-			IsQueue:  false,
-			URLBase:  baseURL + prefix[:len(prefix)-1],
+			Writable:    true,
+			Readable:    true,
+			IsQueue:     false,
+			URLBase:     baseURL + prefix[:len(prefix)-1],
+			CanLongPoll: canLongPoll,
 		},
 	}
 	return http.HandlerFunc(func(conn http.ResponseWriter, req *http.Request) {