118 lines
3.8 KiB
Go
118 lines
3.8 KiB
Go
// Package client is an interface for an RPC client
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package client
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import (
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"context"
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"time"
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)
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// Client is the interface used to make requests to services.
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// It supports Request/Response via Transport and Publishing via the Broker.
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// It also supports bidiectional streaming of requests.
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type Client interface {
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Init(...Option) error
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Options() Options
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NewMessage(topic string, msg interface{}, opts ...MessageOption) Message
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NewRequest(service, method string, req interface{}, reqOpts ...RequestOption) Request
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Call(ctx context.Context, req Request, rsp interface{}, opts ...CallOption) error
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Stream(ctx context.Context, req Request, opts ...CallOption) (Stream, error)
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Publish(ctx context.Context, msg Message, opts ...PublishOption) error
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String() string
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}
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// Message is the interface for publishing asynchronously
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type Message interface {
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Topic() string
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Payload() interface{}
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ContentType() string
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}
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// Request is the interface for a synchronous request used by Call or Stream
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type Request interface {
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Service() string
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Method() string
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ContentType() string
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Request() interface{}
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// indicates whether the request will be a streaming one rather than unary
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Stream() bool
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}
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// Stream is the inteface for a bidirectional synchronous stream
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type Stream interface {
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Context() context.Context
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Request() Request
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Send(interface{}) error
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Recv(interface{}) error
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Error() error
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Close() error
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}
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// Option used by the Client
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type Option func(*Options)
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// CallOption used by Call or Stream
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type CallOption func(*CallOptions)
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// PublishOption used by Publish
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type PublishOption func(*PublishOptions)
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// MessageOption used by NewMessage
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type MessageOption func(*MessageOptions)
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// RequestOption used by NewRequest
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type RequestOption func(*RequestOptions)
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var (
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// DefaultClient is a default client to use out of the box
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DefaultClient Client = newRpcClient()
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// DefaultBackoff is the default backoff function for retries
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DefaultBackoff = exponentialBackoff
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// DefaultRetry is the default check-for-retry function for retries
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DefaultRetry = alwaysRetry
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// DefaultRetries is the default number of times a request is tried
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DefaultRetries = 1
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// DefaultRequestTimeout is the default request timeout
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DefaultRequestTimeout = time.Second * 5
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// DefaultPoolSize sets the connection pool size
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DefaultPoolSize = 1
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// DefaultPoolTTL sets the connection pool ttl
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DefaultPoolTTL = time.Minute
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)
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// Makes a synchronous call to a service using the default client
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func Call(ctx context.Context, request Request, response interface{}, opts ...CallOption) error {
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return DefaultClient.Call(ctx, request, response, opts...)
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}
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// Publishes a publication using the default client. Using the underlying broker
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// set within the options.
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func Publish(ctx context.Context, msg Message, opts ...PublishOption) error {
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return DefaultClient.Publish(ctx, msg, opts...)
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}
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// Creates a new message using the default client
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func NewMessage(topic string, payload interface{}, opts ...MessageOption) Message {
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return DefaultClient.NewMessage(topic, payload, opts...)
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}
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// Creates a new client with the options passed in
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func NewClient(opt ...Option) Client {
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return newRpcClient(opt...)
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}
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// Creates a new request using the default client. Content Type will
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// be set to the default within options and use the appropriate codec
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func NewRequest(service, method string, request interface{}, reqOpts ...RequestOption) Request {
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return DefaultClient.NewRequest(service, method, request, reqOpts...)
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}
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// Creates a streaming connection with a service and returns responses on the
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// channel passed in. It's up to the user to close the streamer.
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func NewStream(ctx context.Context, request Request, opts ...CallOption) (Stream, error) {
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return DefaultClient.Stream(ctx, request, opts...)
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}
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func String() string {
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return DefaultClient.String()
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}
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