LogDog: Add collector service implementation.

common/gcloud/gcps/pubsub.go

Index: common/gcloud/gcps/pubsub.go
diff --git a/common/gcloud/gcps/pubsub.go b/common/gcloud/gcps/pubsub.go
index 1e713b0cc04fce8481c25d922705ab108751c1f5..bb92b6620cf6bd5b51df87f5d0e962c43d9bccc5 100644
--- a/common/gcloud/gcps/pubsub.go
+++ b/common/gcloud/gcps/pubsub.go
@@ -5,6 +5,7 @@
 package gcps
 
 import (
+	"golang.org/x/net/context"
 	"google.golang.org/cloud/pubsub"
 )
 
@@ -28,18 +29,18 @@ var (
 // encountered error was transient.
 type PubSub interface {
 	// TopicExists tests if a given Topic exists.
-	TopicExists(Topic) (bool, error)
+	TopicExists(context.Context, Topic) (bool, error)

[dnj (Google), 2016/01/21 04:36:24]

All methods take context.Context now. This is because we may want to cancel them
on a per-call basis (e.g., cancel the Pull, do not cancel the Ack). Previously
the only way to do this was two separate instances! This is more natural.

 
 	// SubscriptionExists tests if a given Subscription exists.
-	SubExists(Subscription) (bool, error)
+	SubExists(context.Context, Subscription) (bool, error)
 
 	// Publish publishes a batch of Pub/Sub messages.
-	Publish(Topic, ...*pubsub.Message) ([]string, error)
+	Publish(context.Context, Topic, ...*pubsub.Message) ([]string, error)
 
 	// Pull pulls messages from the subscription. It returns up the requested
 	// number of messages.
-	Pull(Subscription, int) ([]*pubsub.Message, error)
+	Pull(context.Context, Subscription, int) ([]*pubsub.Message, error)
 
 	// Ack acknowledges one or more Pub/Sub message ACK IDs.
-	Ack(Subscription, ...string) error
+	Ack(context.Context, Subscription, ...string) error
 }