pubsub/apiv1/publisher_client.go - gocloud - Git at Google

 // Copyright 2018 Google LLC
 //
 // 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
 //
 //     https://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.

 // AUTO-GENERATED CODE. DO NOT EDIT.

 package pubsub

 import (
 	"math"
 	"time"

 	"cloud.google.com/go/iam"
 	"cloud.google.com/go/internal/version"
 	"github.com/golang/protobuf/proto"
 	gax "github.com/googleapis/gax-go"
 	"golang.org/x/net/context"
 	"google.golang.org/api/iterator"
 	"google.golang.org/api/option"
 	"google.golang.org/api/transport"
 	pubsubpb "google.golang.org/genproto/googleapis/pubsub/v1"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/metadata"
 )

 // PublisherCallOptions contains the retry settings for each method of PublisherClient.
 type PublisherCallOptions struct {
 	CreateTopic            []gax.CallOption
 	UpdateTopic            []gax.CallOption
 	Publish                []gax.CallOption
 	GetTopic               []gax.CallOption
 	ListTopics             []gax.CallOption
 	ListTopicSubscriptions []gax.CallOption
 	DeleteTopic            []gax.CallOption
 }

 func defaultPublisherClientOptions() []option.ClientOption {
 	return []option.ClientOption{
 		option.WithEndpoint("pubsub.googleapis.com:443"),
 		option.WithScopes(DefaultAuthScopes()...),
 	}
 }

 func defaultPublisherCallOptions() *PublisherCallOptions {
 	retry := map[[2]string][]gax.CallOption{
 		{"default", "idempotent"}: {
 			gax.WithRetry(func() gax.Retryer {
 				return gax.OnCodes([]codes.Code{
 					codes.DeadlineExceeded,
 					codes.Unavailable,
 				}, gax.Backoff{
 					Initial:    100 * time.Millisecond,
 					Max:        60000 * time.Millisecond,
 					Multiplier: 1.3,
 				})
 			}),
 		},
 		{"messaging", "one_plus_delivery"}: {
 			gax.WithRetry(func() gax.Retryer {
 				return gax.OnCodes([]codes.Code{
 					codes.Aborted,
 					codes.Canceled,
 					codes.DeadlineExceeded,
 					codes.Internal,
 					codes.ResourceExhausted,
 					codes.Unavailable,
 					codes.Unknown,
 				}, gax.Backoff{
 					Initial:    100 * time.Millisecond,
 					Max:        60000 * time.Millisecond,
 					Multiplier: 1.3,
 				})
 			}),
 		},
 	}
 	return &PublisherCallOptions{
 		CreateTopic:            retry[[2]string{"default", "idempotent"}],
 		UpdateTopic:            retry[[2]string{"default", "idempotent"}],
 		Publish:                retry[[2]string{"messaging", "one_plus_delivery"}],
 		GetTopic:               retry[[2]string{"default", "idempotent"}],
 		ListTopics:             retry[[2]string{"default", "idempotent"}],
 		ListTopicSubscriptions: retry[[2]string{"default", "idempotent"}],
 		DeleteTopic:            retry[[2]string{"default", "idempotent"}],
 	}
 }

 // PublisherClient is a client for interacting with Google Cloud Pub/Sub API.
 //
 // Methods, except Close, may be called concurrently. However, fields must not be modified concurrently with method calls.
 type PublisherClient struct {
 	// The connection to the service.
 	conn *grpc.ClientConn

 	// The gRPC API client.
 	publisherClient pubsubpb.PublisherClient

 	// The call options for this service.
 	CallOptions *PublisherCallOptions

 	// The x-goog-* metadata to be sent with each request.
 	xGoogMetadata metadata.MD
 }

 // NewPublisherClient creates a new publisher client.
 //
 // The service that an application uses to manipulate topics, and to send
 // messages to a topic.
 func NewPublisherClient(ctx context.Context, opts ...option.ClientOption) (*PublisherClient, error) {
 	conn, err := transport.DialGRPC(ctx, append(defaultPublisherClientOptions(), opts...)...)
 	if err != nil {
 		return nil, err
 	}
 	c := &PublisherClient{
 		conn:        conn,
 		CallOptions: defaultPublisherCallOptions(),

 		publisherClient: pubsubpb.NewPublisherClient(conn),
 	}
 	c.SetGoogleClientInfo()
 	return c, nil
 }

 // Connection returns the client's connection to the API service.
 func (c *PublisherClient) Connection() *grpc.ClientConn {
 	return c.conn
 }

 // Close closes the connection to the API service. The user should invoke this when
 // the client is no longer required.
 func (c *PublisherClient) Close() error {
 	return c.conn.Close()
 }

 // SetGoogleClientInfo sets the name and version of the application in
 // the `x-goog-api-client` header passed on each request. Intended for
 // use by Google-written clients.
 func (c *PublisherClient) SetGoogleClientInfo(keyval ...string) {
 	kv := append([]string{"gl-go", version.Go()}, keyval...)
 	kv = append(kv, "gapic", version.Repo, "gax", gax.Version, "grpc", grpc.Version)
 	c.xGoogMetadata = metadata.Pairs("x-goog-api-client", gax.XGoogHeader(kv...))
 }

 func (c *PublisherClient) SubscriptionIAM(subscription *pubsubpb.Subscription) *iam.Handle {
 	return iam.InternalNewHandle(c.Connection(), subscription.Name)
 }

 func (c *PublisherClient) TopicIAM(topic *pubsubpb.Topic) *iam.Handle {
 	return iam.InternalNewHandle(c.Connection(), topic.Name)
 }

 // CreateTopic creates the given topic with the given name. See the
 // <a href="/pubsub/docs/admin#resource_names"> resource name rules</a>.
 func (c *PublisherClient) CreateTopic(ctx context.Context, req *pubsubpb.Topic, opts ...gax.CallOption) (*pubsubpb.Topic, error) {
 	ctx = insertMetadata(ctx, c.xGoogMetadata)
 	opts = append(c.CallOptions.CreateTopic[0:len(c.CallOptions.CreateTopic):len(c.CallOptions.CreateTopic)], opts...)
 	var resp *pubsubpb.Topic
 	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
 		var err error
 		resp, err = c.publisherClient.CreateTopic(ctx, req, settings.GRPC...)
 		return err
 	}, opts...)
 	if err != nil {
 		return nil, err
 	}
 	return resp, nil
 }

 // UpdateTopic updates an existing topic. Note that certain properties of a
 // topic are not modifiable.
 func (c *PublisherClient) UpdateTopic(ctx context.Context, req *pubsubpb.UpdateTopicRequest, opts ...gax.CallOption) (*pubsubpb.Topic, error) {
 	ctx = insertMetadata(ctx, c.xGoogMetadata)
 	opts = append(c.CallOptions.UpdateTopic[0:len(c.CallOptions.UpdateTopic):len(c.CallOptions.UpdateTopic)], opts...)
 	var resp *pubsubpb.Topic
 	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
 		var err error
 		resp, err = c.publisherClient.UpdateTopic(ctx, req, settings.GRPC...)
 		return err
 	}, opts...)
 	if err != nil {
 		return nil, err
 	}
 	return resp, nil
 }

 // Publish adds one or more messages to the topic. Returns NOT_FOUND if the topic
 // does not exist. The message payload must not be empty; it must contain
 // either a non-empty data field, or at least one attribute.
 func (c *PublisherClient) Publish(ctx context.Context, req *pubsubpb.PublishRequest, opts ...gax.CallOption) (*pubsubpb.PublishResponse, error) {
 	ctx = insertMetadata(ctx, c.xGoogMetadata)
 	opts = append(c.CallOptions.Publish[0:len(c.CallOptions.Publish):len(c.CallOptions.Publish)], opts...)
 	var resp *pubsubpb.PublishResponse
 	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
 		var err error
 		resp, err = c.publisherClient.Publish(ctx, req, settings.GRPC...)
 		return err
 	}, opts...)
 	if err != nil {
 		return nil, err
 	}
 	return resp, nil
 }

 // GetTopic gets the configuration of a topic.
 func (c *PublisherClient) GetTopic(ctx context.Context, req *pubsubpb.GetTopicRequest, opts ...gax.CallOption) (*pubsubpb.Topic, error) {
 	ctx = insertMetadata(ctx, c.xGoogMetadata)
 	opts = append(c.CallOptions.GetTopic[0:len(c.CallOptions.GetTopic):len(c.CallOptions.GetTopic)], opts...)
 	var resp *pubsubpb.Topic
 	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
 		var err error
 		resp, err = c.publisherClient.GetTopic(ctx, req, settings.GRPC...)
 		return err
 	}, opts...)
 	if err != nil {
 		return nil, err
 	}
 	return resp, nil
 }

 // ListTopics lists matching topics.
 func (c *PublisherClient) ListTopics(ctx context.Context, req *pubsubpb.ListTopicsRequest, opts ...gax.CallOption) *TopicIterator {
 	ctx = insertMetadata(ctx, c.xGoogMetadata)
 	opts = append(c.CallOptions.ListTopics[0:len(c.CallOptions.ListTopics):len(c.CallOptions.ListTopics)], opts...)
 	it := &TopicIterator{}
 	req = proto.Clone(req).(*pubsubpb.ListTopicsRequest)
 	it.InternalFetch = func(pageSize int, pageToken string) ([]*pubsubpb.Topic, string, error) {
 		var resp *pubsubpb.ListTopicsResponse
 		req.PageToken = pageToken
 		if pageSize > math.MaxInt32 {
 			req.PageSize = math.MaxInt32
 		} else {
 			req.PageSize = int32(pageSize)
 		}
 		err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
 			var err error
 			resp, err = c.publisherClient.ListTopics(ctx, req, settings.GRPC...)
 			return err
 		}, opts...)
 		if err != nil {
 			return nil, "", err
 		}
 		return resp.Topics, resp.NextPageToken, nil
 	}
 	fetch := func(pageSize int, pageToken string) (string, error) {
 		items, nextPageToken, err := it.InternalFetch(pageSize, pageToken)
 		if err != nil {
 			return "", err
 		}
 		it.items = append(it.items, items...)
 		return nextPageToken, nil
 	}
 	it.pageInfo, it.nextFunc = iterator.NewPageInfo(fetch, it.bufLen, it.takeBuf)
 	it.pageInfo.MaxSize = int(req.PageSize)
 	return it
 }

 // ListTopicSubscriptions lists the names of the subscriptions on this topic.
 func (c *PublisherClient) ListTopicSubscriptions(ctx context.Context, req *pubsubpb.ListTopicSubscriptionsRequest, opts ...gax.CallOption) *StringIterator {
 	ctx = insertMetadata(ctx, c.xGoogMetadata)
 	opts = append(c.CallOptions.ListTopicSubscriptions[0:len(c.CallOptions.ListTopicSubscriptions):len(c.CallOptions.ListTopicSubscriptions)], opts...)
 	it := &StringIterator{}
 	req = proto.Clone(req).(*pubsubpb.ListTopicSubscriptionsRequest)
 	it.InternalFetch = func(pageSize int, pageToken string) ([]string, string, error) {
 		var resp *pubsubpb.ListTopicSubscriptionsResponse
 		req.PageToken = pageToken
 		if pageSize > math.MaxInt32 {
 			req.PageSize = math.MaxInt32
 		} else {
 			req.PageSize = int32(pageSize)
 		}
 		err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
 			var err error
 			resp, err = c.publisherClient.ListTopicSubscriptions(ctx, req, settings.GRPC...)
 			return err
 		}, opts...)
 		if err != nil {
 			return nil, "", err
 		}
 		return resp.Subscriptions, resp.NextPageToken, nil
 	}
 	fetch := func(pageSize int, pageToken string) (string, error) {
 		items, nextPageToken, err := it.InternalFetch(pageSize, pageToken)
 		if err != nil {
 			return "", err
 		}
 		it.items = append(it.items, items...)
 		return nextPageToken, nil
 	}
 	it.pageInfo, it.nextFunc = iterator.NewPageInfo(fetch, it.bufLen, it.takeBuf)
 	it.pageInfo.MaxSize = int(req.PageSize)
 	return it
 }

 // DeleteTopic deletes the topic with the given name. Returns NOT_FOUND if the topic
 // does not exist. After a topic is deleted, a new topic may be created with
 // the same name; this is an entirely new topic with none of the old
 // configuration or subscriptions. Existing subscriptions to this topic are
 // not deleted, but their topic field is set to _deleted-topic_.
 func (c *PublisherClient) DeleteTopic(ctx context.Context, req *pubsubpb.DeleteTopicRequest, opts ...gax.CallOption) error {
 	ctx = insertMetadata(ctx, c.xGoogMetadata)
 	opts = append(c.CallOptions.DeleteTopic[0:len(c.CallOptions.DeleteTopic):len(c.CallOptions.DeleteTopic)], opts...)
 	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
 		var err error
 		_, err = c.publisherClient.DeleteTopic(ctx, req, settings.GRPC...)
 		return err
 	}, opts...)
 	return err
 }

 // StringIterator manages a stream of string.
 type StringIterator struct {
 	items    []string
 	pageInfo *iterator.PageInfo
 	nextFunc func() error

 	// InternalFetch is for use by the Google Cloud Libraries only.
 	// It is not part of the stable interface of this package.
 	//
 	// InternalFetch returns results from a single call to the underlying RPC.
 	// The number of results is no greater than pageSize.
 	// If there are no more results, nextPageToken is empty and err is nil.
 	InternalFetch func(pageSize int, pageToken string) (results []string, nextPageToken string, err error)
 }

 // PageInfo supports pagination. See the google.golang.org/api/iterator package for details.
 func (it *StringIterator) PageInfo() *iterator.PageInfo {
 	return it.pageInfo
 }

 // Next returns the next result. Its second return value is iterator.Done if there are no more
 // results. Once Next returns Done, all subsequent calls will return Done.
 func (it *StringIterator) Next() (string, error) {
 	var item string
 	if err := it.nextFunc(); err != nil {
 		return item, err
 	}
 	item = it.items[0]
 	it.items = it.items[1:]
 	return item, nil
 }

 func (it *StringIterator) bufLen() int {
 	return len(it.items)
 }

 func (it *StringIterator) takeBuf() interface{} {
 	b := it.items
 	it.items = nil
 	return b
 }

 // TopicIterator manages a stream of *pubsubpb.Topic.
 type TopicIterator struct {
 	items    []*pubsubpb.Topic
 	pageInfo *iterator.PageInfo
 	nextFunc func() error

 	// InternalFetch is for use by the Google Cloud Libraries only.
 	// It is not part of the stable interface of this package.
 	//
 	// InternalFetch returns results from a single call to the underlying RPC.
 	// The number of results is no greater than pageSize.
 	// If there are no more results, nextPageToken is empty and err is nil.
 	InternalFetch func(pageSize int, pageToken string) (results []*pubsubpb.Topic, nextPageToken string, err error)
 }

 // PageInfo supports pagination. See the google.golang.org/api/iterator package for details.
 func (it *TopicIterator) PageInfo() *iterator.PageInfo {
 	return it.pageInfo
 }

 // Next returns the next result. Its second return value is iterator.Done if there are no more
 // results. Once Next returns Done, all subsequent calls will return Done.
 func (it *TopicIterator) Next() (*pubsubpb.Topic, error) {
 	var item *pubsubpb.Topic
 	if err := it.nextFunc(); err != nil {
 		return item, err
 	}
 	item = it.items[0]
 	it.items = it.items[1:]
 	return item, nil
 }

 func (it *TopicIterator) bufLen() int {
 	return len(it.items)
 }

 func (it *TopicIterator) takeBuf() interface{} {
 	b := it.items
 	it.items = nil
 	return b
 }
	// Copyright 2018 Google LLC
	//
	// 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
	//
	// https://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.

	// AUTO-GENERATED CODE. DO NOT EDIT.

	package pubsub

	import (
	"math"
	"time"

	"cloud.google.com/go/iam"
	"cloud.google.com/go/internal/version"
	"github.com/golang/protobuf/proto"
	gax "github.com/googleapis/gax-go"
	"golang.org/x/net/context"
	"google.golang.org/api/iterator"
	"google.golang.org/api/option"
	"google.golang.org/api/transport"
	pubsubpb "google.golang.org/genproto/googleapis/pubsub/v1"
	"google.golang.org/grpc"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/metadata"
	)

	// PublisherCallOptions contains the retry settings for each method of PublisherClient.
	type PublisherCallOptions struct {
	CreateTopic []gax.CallOption
	UpdateTopic []gax.CallOption
	Publish []gax.CallOption
	GetTopic []gax.CallOption
	ListTopics []gax.CallOption
	ListTopicSubscriptions []gax.CallOption
	DeleteTopic []gax.CallOption
	}

	func defaultPublisherClientOptions() []option.ClientOption {
	return []option.ClientOption{
	option.WithEndpoint("pubsub.googleapis.com:443"),
	option.WithScopes(DefaultAuthScopes()...),
	}
	}

	func defaultPublisherCallOptions() *PublisherCallOptions {
	retry := map[[2]string][]gax.CallOption{
	{"default", "idempotent"}: {
	gax.WithRetry(func() gax.Retryer {
	return gax.OnCodes([]codes.Code{
	codes.DeadlineExceeded,
	codes.Unavailable,
	}, gax.Backoff{
	Initial: 100 * time.Millisecond,
	Max: 60000 * time.Millisecond,
	Multiplier: 1.3,
	})
	}),
	},
	{"messaging", "one_plus_delivery"}: {
	gax.WithRetry(func() gax.Retryer {
	return gax.OnCodes([]codes.Code{
	codes.Aborted,
	codes.Canceled,
	codes.DeadlineExceeded,
	codes.Internal,
	codes.ResourceExhausted,
	codes.Unavailable,
	codes.Unknown,
	}, gax.Backoff{
	Initial: 100 * time.Millisecond,
	Max: 60000 * time.Millisecond,
	Multiplier: 1.3,
	})
	}),
	},
	}
	return &PublisherCallOptions{
	CreateTopic: retry[[2]string{"default", "idempotent"}],
	UpdateTopic: retry[[2]string{"default", "idempotent"}],
	Publish: retry[[2]string{"messaging", "one_plus_delivery"}],
	GetTopic: retry[[2]string{"default", "idempotent"}],
	ListTopics: retry[[2]string{"default", "idempotent"}],
	ListTopicSubscriptions: retry[[2]string{"default", "idempotent"}],
	DeleteTopic: retry[[2]string{"default", "idempotent"}],
	}
	}

	// PublisherClient is a client for interacting with Google Cloud Pub/Sub API.
	//
	// Methods, except Close, may be called concurrently. However, fields must not be modified concurrently with method calls.
	type PublisherClient struct {
	// The connection to the service.
	conn *grpc.ClientConn

	// The gRPC API client.
	publisherClient pubsubpb.PublisherClient

	// The call options for this service.
	CallOptions *PublisherCallOptions

	// The x-goog-* metadata to be sent with each request.
	xGoogMetadata metadata.MD
	}

	// NewPublisherClient creates a new publisher client.
	//
	// The service that an application uses to manipulate topics, and to send
	// messages to a topic.
	func NewPublisherClient(ctx context.Context, opts ...option.ClientOption) (*PublisherClient, error) {
	conn, err := transport.DialGRPC(ctx, append(defaultPublisherClientOptions(), opts...)...)
	if err != nil {
	return nil, err
	}
	c := &PublisherClient{
	conn: conn,
	CallOptions: defaultPublisherCallOptions(),

	publisherClient: pubsubpb.NewPublisherClient(conn),
	}
	c.SetGoogleClientInfo()
	return c, nil
	}

	// Connection returns the client's connection to the API service.
	func (c PublisherClient) Connection() grpc.ClientConn {
	return c.conn
	}

	// Close closes the connection to the API service. The user should invoke this when
	// the client is no longer required.
	func (c *PublisherClient) Close() error {
	return c.conn.Close()
	}

	// SetGoogleClientInfo sets the name and version of the application in
	// the `x-goog-api-client` header passed on each request. Intended for
	// use by Google-written clients.
	func (c *PublisherClient) SetGoogleClientInfo(keyval ...string) {
	kv := append([]string{"gl-go", version.Go()}, keyval...)
	kv = append(kv, "gapic", version.Repo, "gax", gax.Version, "grpc", grpc.Version)
	c.xGoogMetadata = metadata.Pairs("x-goog-api-client", gax.XGoogHeader(kv...))
	}

	func (c PublisherClient) SubscriptionIAM(subscription pubsubpb.Subscription) *iam.Handle {
	return iam.InternalNewHandle(c.Connection(), subscription.Name)
	}

	func (c PublisherClient) TopicIAM(topic pubsubpb.Topic) *iam.Handle {
	return iam.InternalNewHandle(c.Connection(), topic.Name)
	}

	// CreateTopic creates the given topic with the given name. See the
	// <a href="/pubsub/docs/admin#resource_names"> resource name rules</a>.
	func (c PublisherClient) CreateTopic(ctx context.Context, req pubsubpb.Topic, opts ...gax.CallOption) (*pubsubpb.Topic, error) {
	ctx = insertMetadata(ctx, c.xGoogMetadata)
	opts = append(c.CallOptions.CreateTopic[0:len(c.CallOptions.CreateTopic):len(c.CallOptions.CreateTopic)], opts...)
	var resp *pubsubpb.Topic
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
	var err error
	resp, err = c.publisherClient.CreateTopic(ctx, req, settings.GRPC...)
	return err
	}, opts...)
	if err != nil {
	return nil, err
	}
	return resp, nil
	}

	// UpdateTopic updates an existing topic. Note that certain properties of a
	// topic are not modifiable.
	func (c PublisherClient) UpdateTopic(ctx context.Context, req pubsubpb.UpdateTopicRequest, opts ...gax.CallOption) (*pubsubpb.Topic, error) {
	ctx = insertMetadata(ctx, c.xGoogMetadata)
	opts = append(c.CallOptions.UpdateTopic[0:len(c.CallOptions.UpdateTopic):len(c.CallOptions.UpdateTopic)], opts...)
	var resp *pubsubpb.Topic
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
	var err error
	resp, err = c.publisherClient.UpdateTopic(ctx, req, settings.GRPC...)
	return err
	}, opts...)
	if err != nil {
	return nil, err
	}
	return resp, nil
	}

	// Publish adds one or more messages to the topic. Returns NOT_FOUND if the topic
	// does not exist. The message payload must not be empty; it must contain
	// either a non-empty data field, or at least one attribute.
	func (c PublisherClient) Publish(ctx context.Context, req pubsubpb.PublishRequest, opts ...gax.CallOption) (*pubsubpb.PublishResponse, error) {
	ctx = insertMetadata(ctx, c.xGoogMetadata)
	opts = append(c.CallOptions.Publish[0:len(c.CallOptions.Publish):len(c.CallOptions.Publish)], opts...)
	var resp *pubsubpb.PublishResponse
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
	var err error
	resp, err = c.publisherClient.Publish(ctx, req, settings.GRPC...)
	return err
	}, opts...)
	if err != nil {
	return nil, err
	}
	return resp, nil
	}

	// GetTopic gets the configuration of a topic.
	func (c PublisherClient) GetTopic(ctx context.Context, req pubsubpb.GetTopicRequest, opts ...gax.CallOption) (*pubsubpb.Topic, error) {
	ctx = insertMetadata(ctx, c.xGoogMetadata)
	opts = append(c.CallOptions.GetTopic[0:len(c.CallOptions.GetTopic):len(c.CallOptions.GetTopic)], opts...)
	var resp *pubsubpb.Topic
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
	var err error
	resp, err = c.publisherClient.GetTopic(ctx, req, settings.GRPC...)
	return err
	}, opts...)
	if err != nil {
	return nil, err
	}
	return resp, nil
	}

	// ListTopics lists matching topics.
	func (c PublisherClient) ListTopics(ctx context.Context, req pubsubpb.ListTopicsRequest, opts ...gax.CallOption) *TopicIterator {
	ctx = insertMetadata(ctx, c.xGoogMetadata)
	opts = append(c.CallOptions.ListTopics[0:len(c.CallOptions.ListTopics):len(c.CallOptions.ListTopics)], opts...)
	it := &TopicIterator{}
	req = proto.Clone(req).(*pubsubpb.ListTopicsRequest)
	it.InternalFetch = func(pageSize int, pageToken string) ([]*pubsubpb.Topic, string, error) {
	var resp *pubsubpb.ListTopicsResponse
	req.PageToken = pageToken
	if pageSize > math.MaxInt32 {
	req.PageSize = math.MaxInt32
	} else {
	req.PageSize = int32(pageSize)
	}
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
	var err error
	resp, err = c.publisherClient.ListTopics(ctx, req, settings.GRPC...)
	return err
	}, opts...)
	if err != nil {
	return nil, "", err
	}
	return resp.Topics, resp.NextPageToken, nil
	}
	fetch := func(pageSize int, pageToken string) (string, error) {
	items, nextPageToken, err := it.InternalFetch(pageSize, pageToken)
	if err != nil {
	return "", err
	}
	it.items = append(it.items, items...)
	return nextPageToken, nil
	}
	it.pageInfo, it.nextFunc = iterator.NewPageInfo(fetch, it.bufLen, it.takeBuf)
	it.pageInfo.MaxSize = int(req.PageSize)
	return it
	}

	// ListTopicSubscriptions lists the names of the subscriptions on this topic.
	func (c PublisherClient) ListTopicSubscriptions(ctx context.Context, req pubsubpb.ListTopicSubscriptionsRequest, opts ...gax.CallOption) *StringIterator {
	ctx = insertMetadata(ctx, c.xGoogMetadata)
	opts = append(c.CallOptions.ListTopicSubscriptions[0:len(c.CallOptions.ListTopicSubscriptions):len(c.CallOptions.ListTopicSubscriptions)], opts...)
	it := &StringIterator{}
	req = proto.Clone(req).(*pubsubpb.ListTopicSubscriptionsRequest)
	it.InternalFetch = func(pageSize int, pageToken string) ([]string, string, error) {
	var resp *pubsubpb.ListTopicSubscriptionsResponse
	req.PageToken = pageToken
	if pageSize > math.MaxInt32 {
	req.PageSize = math.MaxInt32
	} else {
	req.PageSize = int32(pageSize)
	}
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
	var err error
	resp, err = c.publisherClient.ListTopicSubscriptions(ctx, req, settings.GRPC...)
	return err
	}, opts...)
	if err != nil {
	return nil, "", err
	}
	return resp.Subscriptions, resp.NextPageToken, nil
	}
	fetch := func(pageSize int, pageToken string) (string, error) {
	items, nextPageToken, err := it.InternalFetch(pageSize, pageToken)
	if err != nil {
	return "", err
	}
	it.items = append(it.items, items...)
	return nextPageToken, nil
	}
	it.pageInfo, it.nextFunc = iterator.NewPageInfo(fetch, it.bufLen, it.takeBuf)
	it.pageInfo.MaxSize = int(req.PageSize)
	return it
	}

	// DeleteTopic deletes the topic with the given name. Returns NOT_FOUND if the topic
	// does not exist. After a topic is deleted, a new topic may be created with
	// the same name; this is an entirely new topic with none of the old
	// configuration or subscriptions. Existing subscriptions to this topic are
	// not deleted, but their topic field is set to _deleted-topic_.
	func (c PublisherClient) DeleteTopic(ctx context.Context, req pubsubpb.DeleteTopicRequest, opts ...gax.CallOption) error {
	ctx = insertMetadata(ctx, c.xGoogMetadata)
	opts = append(c.CallOptions.DeleteTopic[0:len(c.CallOptions.DeleteTopic):len(c.CallOptions.DeleteTopic)], opts...)
	err := gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
	var err error
	_, err = c.publisherClient.DeleteTopic(ctx, req, settings.GRPC...)
	return err
	}, opts...)
	return err
	}

	// StringIterator manages a stream of string.
	type StringIterator struct {
	items []string
	pageInfo *iterator.PageInfo
	nextFunc func() error

	// InternalFetch is for use by the Google Cloud Libraries only.
	// It is not part of the stable interface of this package.
	//
	// InternalFetch returns results from a single call to the underlying RPC.
	// The number of results is no greater than pageSize.
	// If there are no more results, nextPageToken is empty and err is nil.
	InternalFetch func(pageSize int, pageToken string) (results []string, nextPageToken string, err error)
	}

	// PageInfo supports pagination. See the google.golang.org/api/iterator package for details.
	func (it StringIterator) PageInfo() iterator.PageInfo {
	return it.pageInfo
	}

	// Next returns the next result. Its second return value is iterator.Done if there are no more
	// results. Once Next returns Done, all subsequent calls will return Done.
	func (it *StringIterator) Next() (string, error) {
	var item string
	if err := it.nextFunc(); err != nil {
	return item, err
	}
	item = it.items[0]
	it.items = it.items[1:]
	return item, nil
	}

	func (it *StringIterator) bufLen() int {
	return len(it.items)
	}

	func (it *StringIterator) takeBuf() interface{} {
	b := it.items
	it.items = nil
	return b
	}

	// TopicIterator manages a stream of *pubsubpb.Topic.
	type TopicIterator struct {
	items []*pubsubpb.Topic
	pageInfo *iterator.PageInfo
	nextFunc func() error

	// InternalFetch is for use by the Google Cloud Libraries only.
	// It is not part of the stable interface of this package.
	//
	// InternalFetch returns results from a single call to the underlying RPC.
	// The number of results is no greater than pageSize.
	// If there are no more results, nextPageToken is empty and err is nil.
	InternalFetch func(pageSize int, pageToken string) (results []*pubsubpb.Topic, nextPageToken string, err error)
	}

	// PageInfo supports pagination. See the google.golang.org/api/iterator package for details.
	func (it TopicIterator) PageInfo() iterator.PageInfo {
	return it.pageInfo
	}

	// Next returns the next result. Its second return value is iterator.Done if there are no more
	// results. Once Next returns Done, all subsequent calls will return Done.
	func (it TopicIterator) Next() (pubsubpb.Topic, error) {
	var item *pubsubpb.Topic
	if err := it.nextFunc(); err != nil {
	return item, err
	}
	item = it.items[0]
	it.items = it.items[1:]
	return item, nil
	}

	func (it *TopicIterator) bufLen() int {
	return len(it.items)
	}

	func (it *TopicIterator) takeBuf() interface{} {
	b := it.items
	it.items = nil
	return b
	}