micro/client/client.go
Vasiliy Tolstov e143e2b547 client: allow to set metadata for message
Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>
2021-12-16 15:03:42 +03:00

115 lines
3.4 KiB
Go

// Package client is an interface for an RPC client
package client // import "go.unistack.org/micro/v3/client"
import (
"context"
"time"
"go.unistack.org/micro/v3/codec"
"go.unistack.org/micro/v3/metadata"
)
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
)
// 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.
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
BatchPublish(ctx context.Context, msg []Message, opts ...PublishOption) error
String() string
}
// Message is the interface for publishing asynchronously
type Message interface {
Topic() string
Payload() interface{}
ContentType() string
Metadata() metadata.Metadata
}
// Request is the interface for a synchronous request used by Call or Stream
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
}
// Response is the response received from a service
type Response interface {
// Read the response
Codec() codec.Codec
// read the header
Header() metadata.Metadata
// Read the undecoded response
Read() ([]byte, error)
}
// Stream is the interface for a bidirectional synchronous 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
}
// Option used by the Client
type Option func(*Options)
// CallOption used by Call or Stream
type CallOption func(*CallOptions)
// PublishOption used by Publish
type PublishOption func(*PublishOptions)
// MessageOption used by NewMessage
type MessageOption func(*MessageOptions)
// RequestOption used by NewRequest
type RequestOption func(*RequestOptions)