client

package
v3.3.1 Latest Latest
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 Go to latest Published: Mar 24, 2021 License: Apache-2.0 Imports: 16 Imported by: 0

Documentation

Overview

Package client is an interface for an RPC client

Index

Constants

This section is empty.

Variables

View Source 
var (
	// DefaultClient is the global default client
	DefaultClient Client = NewClient()
	// DefaultContentType is the default content-type if not specified
	DefaultContentType = "application/json"
	// DefaultBackoff is the default backoff function for retries
	DefaultBackoff = exponentialBackoff
	// DefaultRetry is the default check-for-retry function for retries
	DefaultRetry = RetryNever
	// DefaultRetries is the default number of times a request is tried
	DefaultRetries = 0
	// DefaultRequestTimeout is the default request timeout
	DefaultRequestTimeout = time.Second * 5
	// DefaultPoolSize sets the connection pool size
	DefaultPoolSize = 100
	// DefaultPoolTTL sets the connection pool ttl
	DefaultPoolTTL = time.Minute
)
View Source 
var (
	// DefaultCodecs will be used to encode/decode data
	DefaultCodecs = map[string]codec.Codec{

		"application/octet-stream": codec.NewCodec(),
	}
)

Functions

func LookupRoute 

func LookupRoute(ctx context.Context, req Request, opts CallOptions) ([]string, error)

LookupRoute for a request using the router and then choose one using the selector

func NewContext 

func NewContext(ctx context.Context, c Client) context.Context

NewContext put client in context

func RetryAlways 

func RetryAlways(ctx context.Context, req Request, retryCount int, err error) (bool, error)

RetryAlways always retry on error

func RetryNever added in v3.1.0 

func RetryNever(ctx context.Context, req Request, retryCount int, err error) (bool, error)

RetryNever never retry on error

func RetryOnError 

func RetryOnError(ctx context.Context, req Request, retryCount int, err error) (bool, error)

RetryOnError retries a request on a 500 or timeout error

Types

type BackoffFunc 

type BackoffFunc func(ctx context.Context, req Request, attempts int) (time.Duration, error)

BackoffFunc is the backoff call func

type CallFunc 

type CallFunc func(ctx context.Context, addr string, req Request, rsp interface{}, opts CallOptions) error

CallFunc represents the individual call func

type CallOption 

type CallOption func(*CallOptions)

CallOption used by Call or Stream

func SetCallOption added in v3.1.2 

func SetCallOption(k, v interface{}) CallOption

SetCallOption returns a function to setup a context with given value

func WithAddress 

func WithAddress(a ...string) CallOption

WithAddress sets the remote addresses to use rather than using service discovery

func WithAuthToken 

func WithAuthToken() CallOption

WithAuthToken is a CallOption which overrides the authorization header with the services own auth token

func WithBackoff 

func WithBackoff(fn BackoffFunc) CallOption

WithBackoff is a CallOption which overrides that which set in Options.CallOptions

func WithCallWrapper 

func WithCallWrapper(cw ...CallWrapper) CallOption

WithCallWrapper is a CallOption which adds to the existing CallFunc wrappers

func WithDialTimeout 

func WithDialTimeout(d time.Duration) CallOption

WithDialTimeout is a CallOption which overrides that which set in Options.CallOptions

func WithNetwork 

func WithNetwork(n string) CallOption

WithNetwork is a CallOption which sets the network attribute

func WithRequestTimeout 

func WithRequestTimeout(d time.Duration) CallOption

WithRequestTimeout is a CallOption which overrides that which set in Options.CallOptions

func WithRetries 

func WithRetries(i int) CallOption

WithRetries is a CallOption which overrides that which set in Options.CallOptions

func WithRetry 

func WithRetry(fn RetryFunc) CallOption

WithRetry is a CallOption which overrides that which set in Options.CallOptions

func WithRouter 

func WithRouter(r router.Router) CallOption

WithRouter sets the router to use for this call

func WithSelectOptions 

func WithSelectOptions(sops ...selector.SelectOption) CallOption

WithSelectOptions sets the options to pass to the selector for this call

func WithSelector 

func WithSelector(s selector.Selector) CallOption

WithSelector sets the selector to use for this call

func WithStreamTimeout 

func WithStreamTimeout(d time.Duration) CallOption

WithStreamTimeout sets the stream timeout

type CallOptions 

type CallOptions struct {
	// Router used for route
	Router router.Router
	// Selector selects addr
	Selector selector.Selector
	// Context used for deadline
	Context context.Context
	// Retry func used for retries
	Retry RetryFunc
	// Backoff func used for backoff when retry
	Backoff BackoffFunc
	// Network name
	Network string
	// CallWrappers call wrappers
	CallWrappers []CallWrapper
	// SelectOptions selector options
	SelectOptions []selector.SelectOption
	// Address specifies static addr list
	Address []string
	// Retries specifies retries num
	Retries int
	// StreamTimeout stream timeout
	StreamTimeout time.Duration
	// RequestTimeout request timeout
	RequestTimeout time.Duration
	// DialTimeout dial timeout
	DialTimeout time.Duration
	// AuthToken flag
	AuthToken bool
}

CallOptions holds client call options

func NewCallOptions 

func NewCallOptions(opts ...CallOption) CallOptions

NewCallOptions creates new call options struct

type CallWrapper 

type CallWrapper func(CallFunc) CallFunc

CallWrapper is a low level wrapper for the CallFunc

type Client 

type Client interface {
	Name() string
	Init(opts ...Option) error
	Options() Options
	NewMessage(topic string, msg interface{}, opts ...MessageOption) Message
	NewRequest(service string, endpoint string, req interface{}, opts ...RequestOption) Request
	Call(ctx context.Context, req Request, rsp interface{}, opts ...CallOption) error
	Stream(ctx context.Context, req Request, opts ...CallOption) (Stream, error)
	Publish(ctx context.Context, msg Message, opts ...PublishOption) error
	String() string
}

Client is the interface used to make requests to services. It supports Request/Response via Transport and Publishing via the Broker. It also supports bidirectional streaming of requests.

func FromContext 

func FromContext(ctx context.Context) (Client, bool)

FromContext get client from context

func NewClient 

func NewClient(opts ...Option) Client

NewClient returns new noop client

func NewClientCallOptions added in v3.1.0 

func NewClientCallOptions(c Client, opts ...CallOption) Client

NewClientCallOptions add CallOption to every call

type LookupFunc 

type LookupFunc func(context.Context, Request, CallOptions) ([]string, error)

LookupFunc is used to lookup routes for a service

type Message 

type Message interface {
	Topic() string
	Payload() interface{}
	ContentType() string
}

Message is the interface for publishing asynchronously

type MessageOption 

type MessageOption func(*MessageOptions)

MessageOption used by NewMessage

func WithMessageContentType 

func WithMessageContentType(ct string) MessageOption

WithMessageContentType sets the message content type

type MessageOptions 

type MessageOptions struct {
	// ContentType specify content-type of message
	ContentType string
}

MessageOptions holds client message options

func NewMessageOptions 

func NewMessageOptions(opts ...MessageOption) MessageOptions

NewMessageOptions creates message options struct

type Option 

type Option func(*Options)

Option used by the Client

func Backoff 

func Backoff(fn BackoffFunc) Option

Backoff is used to set the backoff function used when retrying Calls

func Broker 

func Broker(b broker.Broker) Option

Broker to be used for pub/sub

func Codec 

func Codec(contentType string, c codec.Codec) Option

Codec to be used to encode/decode requests for a given content type

func ContentType 

func ContentType(ct string) Option

ContentType used by default if not specified

func Context 

func Context(ctx context.Context) Option

Context pass context to client

func DialTimeout 

func DialTimeout(d time.Duration) Option

DialTimeout sets the dial timeout

func Logger 

func Logger(l logger.Logger) Option

Logger to be used for log mesages

func Lookup 

func Lookup(l LookupFunc) Option

Lookup sets the lookup function to use for resolving service names

func Meter added in v3.1.6 

func Meter(m meter.Meter) Option

Meter to be used for metrics

func Name added in v3.2.0 

func Name(n string) Option

Name sets the client name

func PoolSize 

func PoolSize(d int) Option

PoolSize sets the connection pool size

func PoolTTL 

func PoolTTL(d time.Duration) Option

PoolTTL sets the connection pool ttl

func Proxy 

func Proxy(addr string) Option

Proxy sets the proxy address

func Register added in v3.2.0 

func Register(r register.Register) Option

Register sets the routers register

func RequestTimeout 

func RequestTimeout(d time.Duration) Option

RequestTimeout is the request timeout.

func Retries 

func Retries(i int) Option

Retries sets the retry count when making the request.

func Retry 

func Retry(fn RetryFunc) Option

Retry sets the retry function to be used when re-trying.

func Router 

func Router(r router.Router) Option

Router is used to lookup routes for a service

func Selector 

func Selector(s selector.Selector) Option

Selector is used to select a route

func SetOption added in v3.1.2 

func SetOption(k, v interface{}) Option

SetOption returns a function to setup a context with given value

func StreamTimeout 

func StreamTimeout(d time.Duration) Option

StreamTimeout sets the stream timeout

func Tracer added in v3.1.6 

func Tracer(t tracer.Tracer) Option

Tracer to be used for tracing

func Transport 

func Transport(t transport.Transport) Option

Transport to use for communication e.g http, rabbitmq, etc

func Wrap 

func Wrap(w Wrapper) Option

Wrap adds a wrapper to the list of options passed into the client

func WrapCall 

func WrapCall(cw ...CallWrapper) Option

WrapCall adds a wrapper to the list of CallFunc wrappers

type Options 

type Options struct {
	// CallOptions contains default CallOptions
	CallOptions CallOptions
	// Logger used to log messages
	Logger logger.Logger
	// Tracer used for tracing
	Tracer tracer.Tracer
	// Broker used to publish messages
	Broker broker.Broker
	// Meter used for metrics
	Meter meter.Meter
	// Router used to get route
	Router router.Router
	// Selector used to select needed address
	Selector selector.Selector
	// Transport used for transfer messages
	Transport transport.Transport
	// Context is used for external options
	Context context.Context
	// Codecs map
	Codecs map[string]codec.Codec
	// Lookup func used to get destination addr
	Lookup LookupFunc
	// Proxy is used for proxy requests
	Proxy string
	// ContentType is Used to select codec
	ContentType string
	// Name is the client name
	Name string
	// Wrappers contains wrappers
	Wrappers []Wrapper
	// PoolSize connection pool size
	PoolSize int
	// PoolTTL connection pool ttl
	PoolTTL time.Duration
}

Options holds client options

func NewOptions 

func NewOptions(opts ...Option) Options

NewOptions creates new options struct

type PublishOption 

type PublishOption func(*PublishOptions)

PublishOption used by Publish

func PublishContext 

func PublishContext(ctx context.Context) PublishOption

PublishContext sets the context in publish options

func SetPublishOption 

func SetPublishOption(k, v interface{}) PublishOption

SetPublishOption returns a function to setup a context with given value

func WithExchange 

func WithExchange(e string) PublishOption

WithExchange sets the exchange to route a message through

type PublishOptions 

type PublishOptions struct {
	// Context used for external options
	Context context.Context
	// Exchange topic exchange name
	Exchange string
}

PublishOptions holds publish options

func NewPublishOptions 

func NewPublishOptions(opts ...PublishOption) PublishOptions

NewPublishOptions create new PublishOptions struct from option

type Request 

type Request interface {
	// The service to call
	Service() string
	// The action to take
	Method() string
	// The endpoint to invoke
	Endpoint() string
	// The content type
	ContentType() string
	// The unencoded request body
	Body() interface{}
	// Write to the encoded request writer. This is nil before a call is made
	Codec() codec.Codec
	// indicates whether the request will be a streaming one rather than unary
	Stream() bool
}

Request is the interface for a synchronous request used by Call or Stream

type RequestOption 

type RequestOption func(*RequestOptions)

RequestOption used by NewRequest

func StreamingRequest 

func StreamingRequest() RequestOption

StreamingRequest specifies that request is streaming

func WithContentType 

func WithContentType(ct string) RequestOption

WithContentType specifies request content type

type RequestOptions 

type RequestOptions struct {
	// Context used for external options
	Context context.Context
	// ContentType specify content-type of message
	ContentType string
	// Stream flag
	Stream bool
}

RequestOptions holds client request options

func NewRequestOptions 

func NewRequestOptions(opts ...RequestOption) RequestOptions

NewRequestOptions creates new RequestOptions struct

type Response 

type Response interface {
	// Read the response
	Codec() codec.Codec
	// read the header
	Header() metadata.Metadata
	// Read the undecoded response
	Read() ([]byte, error)
}

Response is the response received from a service

type RetryFunc 

type RetryFunc func(ctx context.Context, req Request, retryCount int, err error) (bool, error)

RetryFunc that returning either false or a non-nil error will result in the call not being retried

type Stream 

type Stream interface {
	// Context for the stream
	Context() context.Context
	// The request made
	Request() Request
	// The response read
	Response() Response
	// Send will encode and send a request
	Send(msg interface{}) error
	// Recv will decode and read a response
	Recv(msg interface{}) error
	// Error returns the stream error
	Error() error
	// Close closes the stream
	Close() error
}

Stream is the interface for a bidirectional synchronous stream

type StreamWrapper 

type StreamWrapper func(Stream) Stream

StreamWrapper wraps a Stream and returns the equivalent

type Wrapper 

type Wrapper func(Client) Client

Wrapper wraps a client and returns a client

Source Files

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