Documentation
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Index ¶
Constants ¶
const ( // MaxPublishRequestBytes is the maximum size of a single publish request in // bytes, as determined by the PubSub service. // // See: https://cloud.google.com/pubsub/publisher MaxPublishRequestBytes = 1e7 // MaxPublishRequestCount is the maximum PubSub batch size. MaxPublishRequestCount = pubsub.MaxPublishRequestCount // MaxProjectMessagesPerSecond is the maximum number of requests per second, // across the entire project. MaxProjectMessagesPerSecond = 10000 // MaxACKDeadline is the maximum acknowledgement deadline that can be applied // to a leased subscription Message. MaxACKDeadline = 600 * time.Second )
Cloud PubSub quota is documented here: https://cloud.google.com/pubsub/quotas
Variables ¶
var ( // PublisherScopes is the set of OAuth2 scopes needed for a publisher to // publish messages. PublisherScopes = []string{ pubsub.ScopePubSub, } // SubscriberScopes is the set of OAuth2 scopes needed for a subscriber to // pull and acknowledge messages. SubscriberScopes = []string{ pubsub.ScopePubSub, } )
Functions ¶
This section is empty.
Types ¶
type ClientFactory ¶
type ClientFactory interface {
// Client returns the Pub/Sub publisher client to use.
// Client will be closed when this UnbufferedPublisher is closed.
Client(context.Context) (*vkit.PublisherClient, error)
// RecreateClient is called if any publish calls fail.
// This is used to tell the underlying service to maybe generate a new client.
RecreateClient()
}
ClientFactory is passed into an UnbufferedPublisher to create or reset a client.
type Publisher ¶
type Publisher interface {
Publish(c context.Context, msgs ...*pubsub.Message) ([]string, error)
Close() error
}
Publisher is a generic interface to something that can publish Pub/Sub messages.
A Publisher should be Closed when finished with it.
type Subscription ¶
type Subscription string
Subscription is a Pub/Sub subscription name.
func NewSubscription ¶
func NewSubscription(project, name string) Subscription
NewSubscription generates a new Subscritpion for a given project and subscription name.
func (*Subscription) Set ¶
func (s *Subscription) Set(value string) error
Set implements flag.Value.
func (Subscription) Split ¶
func (s Subscription) Split() (p, n string)
Split returns the Subscription's project component. If no project is defined (malformed), an empty string will be returned.
func (Subscription) SplitErr ¶
func (s Subscription) SplitErr() (p, n string, err error)
SplitErr returns the Subscription's project and name components.
func (*Subscription) String ¶
func (s *Subscription) String() string
func (Subscription) Validate ¶
func (s Subscription) Validate() error
Validate returns an error if the subscription name is invalid.
type Topic ¶
type Topic string
Topic is a fully-qualified Pub/Sub project/topic name.
func (Topic) Split ¶
Split returns the Topic's project component. If no project is defined (malformed), an empty string will be returned.
type UnbufferedPublisher ¶
type UnbufferedPublisher struct {
// AECtx is the AppEngine context used to create a pubsub client.
AECtx context.Context
// Topic is the name of the Topic to publish to.
Topic Topic
// ClientFactory produces a client for the publisher. This is called on each
// and every publish request. If a publish request fails, then RecreateClient is called.
ClientFactory ClientFactory
// CallOpts are arbitrary call options that will be passed to the Publish
// call.
CallOpts []gax.CallOption
}
UnbufferedPublisher directly instantiates a Pub/Sub client and publishes a message to it.
The standard Pub/Sub library has several issues, especially when used from AppEngine:
- It uses an empty Context, discarding AppEngine context.
- It uses a buffer, which expects a lifecycle beyond that of a simple AppEngine Request.
func (*UnbufferedPublisher) Close ¶
func (up *UnbufferedPublisher) Close() error
Close closes the UnbufferedPublisher, notably its Client.
Source Files