README

gRPC-Go

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The Go implementation of gRPC: A high performance, open source, general RPC framework that puts mobile and HTTP/2 first. For more information see the Go gRPC docs, or jump directly into the quick start.

Prerequisites

Installation

With Go module support (Go 1.11+), simply add the following import

import "google.golang.org/grpc"

to your code, and then go [build|run|test] will automatically fetch the necessary dependencies.

Otherwise, to install the grpc-go package, run the following command:

$ go get -u google.golang.org/grpc

Note: If you are trying to access grpc-go from China, see the FAQ below.

Learn more

FAQ

I/O Timeout Errors

The golang.org domain may be blocked from some countries. go get usually produces an error like the following when this happens:

$ go get -u google.golang.org/grpc
package google.golang.org/grpc: unrecognized import path "google.golang.org/grpc" (https fetch: Get https://google.golang.org/grpc?go-get=1: dial tcp 216.239.37.1:443: i/o timeout)

To build Go code, there are several options:

  • Set up a VPN and access google.golang.org through that.

  • Without Go module support: git clone the repo manually:

    git clone https://github.com/grpc/grpc-go.git $GOPATH/src/google.golang.org/grpc
    

    You will need to do the same for all of grpc's dependencies in golang.org, e.g. golang.org/x/net.

  • With Go module support: it is possible to use the replace feature of go mod to create aliases for golang.org packages. In your project's directory:

    go mod edit -replace=google.golang.org/grpc=github.com/grpc/grpc-go@latest
    go mod tidy
    go mod vendor
    go build -mod=vendor
    

    Again, this will need to be done for all transitive dependencies hosted on golang.org as well. For details, refer to golang/go issue #28652.

Compiling error, undefined: grpc.SupportPackageIsVersion
If you are using Go modules:

Ensure your gRPC-Go version is required at the appropriate version in the same module containing the generated .pb.go files. For example, SupportPackageIsVersion6 needs v1.27.0, so in your go.mod file:

module <your module name>

require (
    google.golang.org/grpc v1.27.0
)
If you are not using Go modules:

Update the proto package, gRPC package, and rebuild the .proto files:

go get -u github.com/golang/protobuf/{proto,protoc-gen-go}
go get -u google.golang.org/grpc
protoc --go_out=plugins=grpc:. *.proto
How to turn on logging

The default logger is controlled by environment variables. Turn everything on like this:

$ export GRPC_GO_LOG_VERBOSITY_LEVEL=99
$ export GRPC_GO_LOG_SEVERITY_LEVEL=info
The RPC failed with error "code = Unavailable desc = transport is closing"

This error means the connection the RPC is using was closed, and there are many possible reasons, including:

  1. mis-configured transport credentials, connection failed on handshaking
  2. bytes disrupted, possibly by a proxy in between
  3. server shutdown
  4. Keepalive parameters caused connection shutdown, for example if you have configured your server to terminate connections regularly to trigger DNS lookups. If this is the case, you may want to increase your MaxConnectionAgeGrace, to allow longer RPC calls to finish.

It can be tricky to debug this because the error happens on the client side but the root cause of the connection being closed is on the server side. Turn on logging on both client and server, and see if there are any transport errors.

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Documentation

Overview

Package grpc implements an RPC system called gRPC.

See grpc.io for more information about gRPC.

Index

Constants

const (
	SupportPackageIsVersion3 = true
	SupportPackageIsVersion4 = true
	SupportPackageIsVersion5 = true
	SupportPackageIsVersion6 = true
	SupportPackageIsVersion7 = true
)

The SupportPackageIsVersion variables are referenced from generated protocol buffer files to ensure compatibility with the gRPC version used. The latest support package version is 7.

Older versions are kept for compatibility. They may be removed if compatibility cannot be maintained.

These constants should not be referenced from any other code.


const PickFirstBalancerName = "pick_first"

PickFirstBalancerName is the name of the pick_first balancer.


const Version = "1.32.0"

Version is the current grpc version.


Variables

var DefaultBackoffConfig = BackoffConfig{
	MaxDelay: 120 * time.Second,
}

DefaultBackoffConfig uses values specified for backoff in https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md.

Deprecated: use ConnectParams instead. Will be supported throughout 1.x.


var EnableTracing bool

EnableTracing controls whether to trace RPCs using the golang.org/x/net/trace package. This should only be set before any RPCs are sent or received by this program.


var (
	// ErrClientConnClosing indicates that the operation is illegal because
	// the ClientConn is closing.
	//
	// Deprecated: this error should not be relied upon by users; use the status
	// code of Canceled instead.
	ErrClientConnClosing = status.Error(codes.Canceled, "grpc: the client connection is closing")
)

var ErrClientConnTimeout = errors.New("grpc: timed out when dialing")

ErrClientConnTimeout indicates that the ClientConn cannot establish the underlying connections within the specified timeout.

Deprecated: This error is never returned by grpc and should not be referenced by users.


var ErrServerStopped = errors.New("grpc: the server has been stopped")

ErrServerStopped indicates that the operation is now illegal because of the server being stopped.


Functions

func Code

func Code(err error) codes.Code

Code returns the error code for err if it was produced by the rpc system. Otherwise, it returns codes.Unknown.

Deprecated: use status.Code instead.

func ErrorDesc

func ErrorDesc(err error) string

ErrorDesc returns the error description of err if it was produced by the rpc system. Otherwise, it returns err.Error() or empty string when err is nil.

Deprecated: use status.Convert and Message method instead.

func Errorf

func Errorf(c codes.Code, format string, a ...interface{}) error

Errorf returns an error containing an error code and a description; Errorf returns nil if c is OK.

Deprecated: use status.Errorf instead.

func Invoke

func Invoke(ctx context.Context, method string, args, reply interface{}, cc *ClientConn, opts ...CallOption) error

Invoke sends the RPC request on the wire and returns after response is received. This is typically called by generated code.

DEPRECATED: Use ClientConn.Invoke instead.

func Method

func Method(ctx context.Context) (string, bool)

Method returns the method string for the server context. The returned string is in the format of "/service/method".

func MethodFromServerStream

func MethodFromServerStream(stream ServerStream) (string, bool)

MethodFromServerStream returns the method string for the input stream. The returned string is in the format of "/service/method".

func NewContextWithServerTransportStream

func NewContextWithServerTransportStream(ctx context.Context, stream ServerTransportStream) context.Context

NewContextWithServerTransportStream creates a new context from ctx and attaches stream to it.

This API is EXPERIMENTAL.

func SendHeader

func SendHeader(ctx context.Context, md metadata.MD) error

SendHeader sends header metadata. It may be called at most once. The provided md and headers set by SetHeader() will be sent.

func SetHeader

func SetHeader(ctx context.Context, md metadata.MD) error

SetHeader sets the header metadata. When called multiple times, all the provided metadata will be merged. All the metadata will be sent out when one of the following happens:

- grpc.SendHeader() is called;
- The first response is sent out;
- An RPC status is sent out (error or success).

func SetTrailer

func SetTrailer(ctx context.Context, md metadata.MD) error

SetTrailer sets the trailer metadata that will be sent when an RPC returns. When called more than once, all the provided metadata will be merged.

Types

type BackoffConfig

type BackoffConfig struct {
	// MaxDelay is the upper bound of backoff delay.
	MaxDelay time.Duration
}

BackoffConfig defines the parameters for the default gRPC backoff strategy.

Deprecated: use ConnectParams instead. Will be supported throughout 1.x.

type CallOption

type CallOption interface {
	// contains filtered or unexported methods
}

CallOption configures a Call before it starts or extracts information from a Call after it completes.

func CallContentSubtype

func CallContentSubtype(contentSubtype string) CallOption

CallContentSubtype returns a CallOption that will set the content-subtype for a call. For example, if content-subtype is "json", the Content-Type over the wire will be "application/grpc+json". The content-subtype is converted to lowercase before being included in Content-Type. See Content-Type on https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests for more details.

If ForceCodec is not also used, the content-subtype will be used to look up the Codec to use in the registry controlled by RegisterCodec. See the documentation on RegisterCodec for details on registration. The lookup of content-subtype is case-insensitive. If no such Codec is found, the call will result in an error with code codes.Internal.

If ForceCodec is also used, that Codec will be used for all request and response messages, with the content-subtype set to the given contentSubtype here for requests.

func CallCustomCodec

func CallCustomCodec(codec Codec) CallOption

CallCustomCodec behaves like ForceCodec, but accepts a grpc.Codec instead of an encoding.Codec.

Deprecated: use ForceCodec instead.

func FailFast

func FailFast(failFast bool) CallOption

FailFast is the opposite of WaitForReady.

Deprecated: use WaitForReady.

func ForceCodec

func ForceCodec(codec encoding.Codec) CallOption

ForceCodec returns a CallOption that will set the given Codec to be used for all request and response messages for a call. The result of calling String() will be used as the content-subtype in a case-insensitive manner.

See Content-Type on https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests for more details. Also see the documentation on RegisterCodec and CallContentSubtype for more details on the interaction between Codec and content-subtype.

This function is provided for advanced users; prefer to use only CallContentSubtype to select a registered codec instead.

This is an EXPERIMENTAL API.

func Header(md *metadata.MD) CallOption

Header returns a CallOptions that retrieves the header metadata for a unary RPC.

func MaxCallRecvMsgSize

func MaxCallRecvMsgSize(bytes int) CallOption

MaxCallRecvMsgSize returns a CallOption which sets the maximum message size in bytes the client can receive.

func MaxCallSendMsgSize

func MaxCallSendMsgSize(bytes int) CallOption

MaxCallSendMsgSize returns a CallOption which sets the maximum message size in bytes the client can send.

func MaxRetryRPCBufferSize

func MaxRetryRPCBufferSize(bytes int) CallOption

MaxRetryRPCBufferSize returns a CallOption that limits the amount of memory used for buffering this RPC's requests for retry purposes.

This API is EXPERIMENTAL.

func Peer

func Peer(p *peer.Peer) CallOption

Peer returns a CallOption that retrieves peer information for a unary RPC. The peer field will be populated *after* the RPC completes.

func PerRPCCredentials

func PerRPCCredentials(creds credentials.PerRPCCredentials) CallOption

PerRPCCredentials returns a CallOption that sets credentials.PerRPCCredentials for a call.

func Trailer

func Trailer(md *metadata.MD) CallOption

Trailer returns a CallOptions that retrieves the trailer metadata for a unary RPC.

func UseCompressor

func UseCompressor(name string) CallOption

UseCompressor returns a CallOption which sets the compressor used when sending the request. If WithCompressor is also set, UseCompressor has higher priority.

This API is EXPERIMENTAL.

func WaitForReady

func WaitForReady(waitForReady bool) CallOption

WaitForReady configures the action to take when an RPC is attempted on broken connections or unreachable servers. If waitForReady is false, the RPC will fail immediately. Otherwise, the RPC client will block the call until a connection is available (or the call is canceled or times out) and will retry the call if it fails due to a transient error. gRPC will not retry if data was written to the wire unless the server indicates it did not process the data. Please refer to https://github.com/grpc/grpc/blob/master/doc/wait-for-ready.md.

By default, RPCs don't "wait for ready".

type ClientConn

type ClientConn struct {
	// contains filtered or unexported fields
}

ClientConn represents a virtual connection to a conceptual endpoint, to perform RPCs.

A ClientConn is free to have zero or more actual connections to the endpoint based on configuration, load, etc. It is also free to determine which actual endpoints to use and may change it every RPC, permitting client-side load balancing.

A ClientConn encapsulates a range of functionality including name resolution, TCP connection establishment (with retries and backoff) and TLS handshakes. It also handles errors on established connections by re-resolving the name and reconnecting.

func Dial

func Dial(target string, opts ...DialOption) (*ClientConn, error)

Dial creates a client connection to the given target.

func DialContext

func DialContext(ctx context.Context, target string, opts ...DialOption) (conn *ClientConn, err error)

DialContext creates a client connection to the given target. By default, it's a non-blocking dial (the function won't wait for connections to be established, and connecting happens in the background). To make it a blocking dial, use WithBlock() dial option.

In the non-blocking case, the ctx does not act against the connection. It only controls the setup steps.

In the blocking case, ctx can be used to cancel or expire the pending connection. Once this function returns, the cancellation and expiration of ctx will be noop. Users should call ClientConn.Close to terminate all the pending operations after this function returns.

The target name syntax is defined in https://github.com/grpc/grpc/blob/master/doc/naming.md. e.g. to use dns resolver, a "dns:///" prefix should be applied to the target.

func (*ClientConn) Close

func (cc *ClientConn) Close() error

Close tears down the ClientConn and all underlying connections.

func (*ClientConn) GetMethodConfig

func (cc *ClientConn) GetMethodConfig(method string) MethodConfig

GetMethodConfig gets the method config of the input method. If there's an exact match for input method (i.e. /service/method), we return the corresponding MethodConfig. If there isn't an exact match for the input method, we look for the service's default config under the service (i.e /service/) and then for the default for all services (empty string).

If there is a default MethodConfig for the service, we return it. Otherwise, we return an empty MethodConfig.

func (*ClientConn) GetState

func (cc *ClientConn) GetState() connectivity.State

GetState returns the connectivity.State of ClientConn. This is an EXPERIMENTAL API.

func (*ClientConn) Invoke

func (cc *ClientConn) Invoke(ctx context.Context, method string, args, reply interface{}, opts ...CallOption) error

Invoke sends the RPC request on the wire and returns after response is received. This is typically called by generated code.

All errors returned by Invoke are compatible with the status package.

func (*ClientConn) NewStream

func (cc *ClientConn) NewStream(ctx context.Context, desc *StreamDesc, method string, opts ...CallOption) (ClientStream, error)

NewStream creates a new Stream for the client side. This is typically called by generated code. ctx is used for the lifetime of the stream.

To ensure resources are not leaked due to the stream returned, one of the following actions must be performed:

1. Call Close on the ClientConn.
2. Cancel the context provided.
3. Call RecvMsg until a non-nil error is returned. A protobuf-generated
   client-streaming RPC, for instance, might use the helper function
   CloseAndRecv (note that CloseSend does not Recv, therefore is not
   guaranteed to release all resources).
4. Receive a non-nil, non-io.EOF error from Header or SendMsg.

If none of the above happen, a goroutine and a context will be leaked, and grpc will not call the optionally-configured stats handler with a stats.End message.

func (*ClientConn) ResetConnectBackoff

func (cc *ClientConn) ResetConnectBackoff()

ResetConnectBackoff wakes up all subchannels in transient failure and causes them to attempt another connection immediately. It also resets the backoff times used for subsequent attempts regardless of the current state.

In general, this function should not be used. Typical service or network outages result in a reasonable client reconnection strategy by default. However, if a previously unavailable network becomes available, this may be used to trigger an immediate reconnect.

This API is EXPERIMENTAL.

func (*ClientConn) Target

func (cc *ClientConn) Target() string

Target returns the target string of the ClientConn. This is an EXPERIMENTAL API.

func (*ClientConn) WaitForStateChange

func (cc *ClientConn) WaitForStateChange(ctx context.Context, sourceState connectivity.State) bool

WaitForStateChange waits until the connectivity.State of ClientConn changes from sourceState or ctx expires. A true value is returned in former case and false in latter. This is an EXPERIMENTAL API.

type ClientConnInterface

type ClientConnInterface interface {
	// Invoke performs a unary RPC and returns after the response is received
	// into reply.
	Invoke(ctx context.Context, method string, args interface{}, reply interface{}, opts ...CallOption) error
	// NewStream begins a streaming RPC.
	NewStream(ctx context.Context, desc *StreamDesc, method string, opts ...CallOption) (ClientStream, error)
}

ClientConnInterface defines the functions clients need to perform unary and streaming RPCs. It is implemented by *ClientConn, and is only intended to be referenced by generated code.

type ClientStream

type ClientStream interface {
	// Header returns the header metadata received from the server if there
	// is any. It blocks if the metadata is not ready to read.
	Header() (metadata.MD, error)
	// Trailer returns the trailer metadata from the server, if there is any.
	// It must only be called after stream.CloseAndRecv has returned, or
	// stream.Recv has returned a non-nil error (including io.EOF).
	Trailer() metadata.MD
	// CloseSend closes the send direction of the stream. It closes the stream
	// when non-nil error is met. It is also not safe to call CloseSend
	// concurrently with SendMsg.
	CloseSend() error
	// Context returns the context for this stream.
	//
	// It should not be called until after Header or RecvMsg has returned. Once
	// called, subsequent client-side retries are disabled.
	Context() context.Context
	// SendMsg is generally called by generated code. On error, SendMsg aborts
	// the stream. If the error was generated by the client, the status is
	// returned directly; otherwise, io.EOF is returned and the status of
	// the stream may be discovered using RecvMsg.
	//
	// SendMsg blocks until:
	//   - There is sufficient flow control to schedule m with the transport, or
	//   - The stream is done, or
	//   - The stream breaks.
	//
	// SendMsg does not wait until the message is received by the server. An
	// untimely stream closure may result in lost messages. To ensure delivery,
	// users should ensure the RPC completed successfully using RecvMsg.
	//
	// It is safe to have a goroutine calling SendMsg and another goroutine
	// calling RecvMsg on the same stream at the same time, but it is not safe
	// to call SendMsg on the same stream in different goroutines. It is also
	// not safe to call CloseSend concurrently with SendMsg.
	SendMsg(m interface{}) error
	// RecvMsg blocks until it receives a message into m or the stream is
	// done. It returns io.EOF when the stream completes successfully. On
	// any other error, the stream is aborted and the error contains the RPC
	// status.
	//
	// It is safe to have a goroutine calling SendMsg and another goroutine
	// calling RecvMsg on the same stream at the same time, but it is not
	// safe to call RecvMsg on the same stream in different goroutines.
	RecvMsg(m interface{}) error
}

ClientStream defines the client-side behavior of a streaming RPC.

All errors returned from ClientStream methods are compatible with the status package.

func NewClientStream

func NewClientStream(ctx context.Context, desc *StreamDesc, cc *ClientConn, method string, opts ...CallOption) (ClientStream, error)

NewClientStream is a wrapper for ClientConn.NewStream.

type Codec

type Codec interface {
	// Marshal returns the wire format of v.
	Marshal(v interface{}) ([]byte, error)
	// Unmarshal parses the wire format into v.
	Unmarshal(data []byte, v interface{}) error
	// String returns the name of the Codec implementation.  This is unused by
	// gRPC.
	String() string
}

Codec defines the interface gRPC uses to encode and decode messages. Note that implementations of this interface must be thread safe; a Codec's methods can be called from concurrent goroutines.

Deprecated: use encoding.Codec instead.

type Compressor

type Compressor interface {
	// Do compresses p into w.
	Do(w io.Writer, p []byte) error
	// Type returns the compression algorithm the Compressor uses.
	Type() string
}

Compressor defines the interface gRPC uses to compress a message.

Deprecated: use package encoding.

func NewGZIPCompressor

func NewGZIPCompressor() Compressor

NewGZIPCompressor creates a Compressor based on GZIP.

Deprecated: use package encoding/gzip.

func NewGZIPCompressorWithLevel

func NewGZIPCompressorWithLevel(level int) (Compressor, error)

NewGZIPCompressorWithLevel is like NewGZIPCompressor but specifies the gzip compression level instead of assuming DefaultCompression.

The error returned will be nil if the level is valid.

Deprecated: use package encoding/gzip.

type CompressorCallOption

type CompressorCallOption struct {
	CompressorType string
}

CompressorCallOption is a CallOption that indicates the compressor to use. This is an EXPERIMENTAL API.

type ConnectParams

type ConnectParams struct {
	// Backoff specifies the configuration options for connection backoff.
	Backoff backoff.Config
	// MinConnectTimeout is the minimum amount of time we are willing to give a
	// connection to complete.
	MinConnectTimeout time.Duration
}

ConnectParams defines the parameters for connecting and retrying. Users are encouraged to use this instead of the BackoffConfig type defined above. See here for more details: https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md.

This API is EXPERIMENTAL.

type ContentSubtypeCallOption

type ContentSubtypeCallOption struct {
	ContentSubtype string
}

ContentSubtypeCallOption is a CallOption that indicates the content-subtype used for marshaling messages. This is an EXPERIMENTAL API.

type CustomCodecCallOption

type CustomCodecCallOption struct {
	Codec Codec
}

CustomCodecCallOption is a CallOption that indicates the codec used for marshaling messages.

This is an EXPERIMENTAL API.

type Decompressor

type Decompressor interface {
	// Do reads the data from r and uncompress them.
	Do(r io.Reader) ([]byte, error)
	// Type returns the compression algorithm the Decompressor uses.
	Type() string
}

Decompressor defines the interface gRPC uses to decompress a message.

Deprecated: use package encoding.

func NewGZIPDecompressor

func NewGZIPDecompressor() Decompressor

NewGZIPDecompressor creates a Decompressor based on GZIP.

Deprecated: use package encoding/gzip.

type DialOption

type DialOption interface {
	// contains filtered or unexported methods
}

DialOption configures how we set up the connection.

func FailOnNonTempDialError

func FailOnNonTempDialError(f bool) DialOption

FailOnNonTempDialError returns a DialOption that specifies if gRPC fails on non-temporary dial errors. If f is true, and dialer returns a non-temporary error, gRPC will fail the connection to the network address and won't try to reconnect. The default value of FailOnNonTempDialError is false.

FailOnNonTempDialError only affects the initial dial, and does not do anything useful unless you are also using WithBlock().

This is an EXPERIMENTAL API.

func WithAuthority

func WithAuthority(a string) DialOption

WithAuthority returns a DialOption that specifies the value to be used as the :authority pseudo-header. This value only works with WithInsecure and has no effect if TransportCredentials are present.

func WithBackoffConfig

func WithBackoffConfig(b BackoffConfig) DialOption

WithBackoffConfig configures the dialer to use the provided backoff parameters after connection failures.

Deprecated: use WithConnectParams instead. Will be supported throughout 1.x.

func WithBackoffMaxDelay

func WithBackoffMaxDelay(md time.Duration) DialOption

WithBackoffMaxDelay configures the dialer to use the provided maximum delay when backing off after failed connection attempts.

Deprecated: use WithConnectParams instead. Will be supported throughout 1.x.

func WithBalancerName

func WithBalancerName(balancerName string) DialOption

WithBalancerName sets the balancer that the ClientConn will be initialized with. Balancer registered with balancerName will be used. This function panics if no balancer was registered by balancerName.

The balancer cannot be overridden by balancer option specified by service config.

Deprecated: use WithDefaultServiceConfig and WithDisableServiceConfig instead. Will be removed in a future 1.x release.

func WithBlock

func WithBlock() DialOption

WithBlock returns a DialOption which makes caller of Dial blocks until the underlying connection is up. Without this, Dial returns immediately and connecting the server happens in background.

func WithChainStreamInterceptor

func WithChainStreamInterceptor(interceptors ...StreamClientInterceptor) DialOption

WithChainStreamInterceptor returns a DialOption that specifies the chained interceptor for streaming RPCs. The first interceptor will be the outer most, while the last interceptor will be the inner most wrapper around the real call. All interceptors added by this method will be chained, and the interceptor defined by WithStreamInterceptor will always be prepended to the chain.

func WithChainUnaryInterceptor

func WithChainUnaryInterceptor(interceptors ...UnaryClientInterceptor) DialOption

WithChainUnaryInterceptor returns a DialOption that specifies the chained interceptor for unary RPCs. The first interceptor will be the outer most, while the last interceptor will be the inner most wrapper around the real call. All interceptors added by this method will be chained, and the interceptor defined by WithUnaryInterceptor will always be prepended to the chain.

func WithChannelzParentID

func WithChannelzParentID(id int64) DialOption

WithChannelzParentID returns a DialOption that specifies the channelz ID of current ClientConn's parent. This function is used in nested channel creation (e.g. grpclb dial).

This API is EXPERIMENTAL.

func WithCodec

func WithCodec(c Codec) DialOption

WithCodec returns a DialOption which sets a codec for message marshaling and unmarshaling.

Deprecated: use WithDefaultCallOptions(ForceCodec(_)) instead. Will be supported throughout 1.x.

func WithCompressor

func WithCompressor(cp Compressor) DialOption

WithCompressor returns a DialOption which sets a Compressor to use for message compression. It has lower priority than the compressor set by the UseCompressor CallOption.

Deprecated: use UseCompressor instead. Will be supported throughout 1.x.

func WithConnectParams

func WithConnectParams(p ConnectParams) DialOption

WithConnectParams configures the dialer to use the provided ConnectParams.

The backoff configuration specified as part of the ConnectParams overrides all defaults specified in https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md. Consider using the backoff.DefaultConfig as a base, in cases where you want to override only a subset of the backoff configuration.

This API is EXPERIMENTAL.

func WithContextDialer

func WithContextDialer(f func(context.Context, string) (net.Conn, error)) DialOption

WithContextDialer returns a DialOption that sets a dialer to create connections. If FailOnNonTempDialError() is set to true, and an error is returned by f, gRPC checks the error's Temporary() method to decide if it should try to reconnect to the network address.

func WithCredentialsBundle

func WithCredentialsBundle(b credentials.Bundle) DialOption

WithCredentialsBundle returns a DialOption to set a credentials bundle for the ClientConn.WithCreds. This should not be used together with WithTransportCredentials.

This API is experimental.

func WithDecompressor

func WithDecompressor(dc Decompressor) DialOption

WithDecompressor returns a DialOption which sets a Decompressor to use for incoming message decompression. If incoming response messages are encoded using the decompressor's Type(), it will be used. Otherwise, the message encoding will be used to look up the compressor registered via encoding.RegisterCompressor, which will then be used to decompress the message. If no compressor is registered for the encoding, an Unimplemented status error will be returned.

Deprecated: use encoding.RegisterCompressor instead. Will be supported throughout 1.x.

func WithDefaultCallOptions

func WithDefaultCallOptions(cos ...CallOption) DialOption

WithDefaultCallOptions returns a DialOption which sets the default CallOptions for calls over the connection.

func WithDefaultServiceConfig

func WithDefaultServiceConfig(s string) DialOption

WithDefaultServiceConfig returns a DialOption that configures the default service config, which will be used in cases where:

1. WithDisableServiceConfig is also used. 2. Resolver does not return a service config or if the resolver returns an

invalid service config.

This API is EXPERIMENTAL.

func WithDialer

func WithDialer(f func(string, time.Duration) (net.Conn, error)) DialOption

WithDialer returns a DialOption that specifies a function to use for dialing network addresses. If FailOnNonTempDialError() is set to true, and an error is returned by f, gRPC checks the error's Temporary() method to decide if it should try to reconnect to the network address.

Deprecated: use WithContextDialer instead. Will be supported throughout 1.x.

func WithDisableHealthCheck

func WithDisableHealthCheck() DialOption

WithDisableHealthCheck disables the LB channel health checking for all SubConns of this ClientConn.

This API is EXPERIMENTAL.

func WithDisableRetry

func WithDisableRetry() DialOption

WithDisableRetry returns a DialOption that disables retries, even if the service config enables them. This does not impact transparent retries, which will happen automatically if no data is written to the wire or if the RPC is unprocessed by the remote server.

Retry support is currently disabled by default, but will be enabled by default in the future. Until then, it may be enabled by setting the environment variable "GRPC_GO_RETRY" to "on".

This API is EXPERIMENTAL.

func WithDisableServiceConfig

func WithDisableServiceConfig() DialOption

WithDisableServiceConfig returns a DialOption that causes gRPC to ignore any service config provided by the resolver and provides a hint to the resolver to not fetch service configs.

Note that this dial option only disables service config from resolver. If default service config is provided, gRPC will use the default service config.

func WithInitialConnWindowSize

func WithInitialConnWindowSize(s int32) DialOption

WithInitialConnWindowSize returns a DialOption which sets the value for initial window size on a connection. The lower bound for window size is 64K and any value smaller than that will be ignored.

func WithInitialWindowSize

func WithInitialWindowSize(s int32) DialOption

WithInitialWindowSize returns a DialOption which sets the value for initial window size on a stream. The lower bound for window size is 64K and any value smaller than that will be ignored.

func WithInsecure

func WithInsecure() DialOption

WithInsecure returns a DialOption which disables transport security for this ClientConn. Note that transport security is required unless WithInsecure is set.

func WithKeepaliveParams

func WithKeepaliveParams(kp keepalive.ClientParameters) DialOption

WithKeepaliveParams returns a DialOption that specifies keepalive parameters for the client transport.

func WithMaxHeaderListSize

func WithMaxHeaderListSize(s uint32) DialOption

WithMaxHeaderListSize returns a DialOption that specifies the maximum (uncompressed) size of header list that the client is prepared to accept.

func WithMaxMsgSize

func WithMaxMsgSize(s int) DialOption

WithMaxMsgSize returns a DialOption which sets the maximum message size the client can receive.

Deprecated: use WithDefaultCallOptions(MaxCallRecvMsgSize(s)) instead. Will be supported throughout 1.x.

func WithNoProxy

func WithNoProxy() DialOption

WithNoProxy returns a DialOption which disables the use of proxies for this ClientConn. This is ignored if WithDialer or WithContextDialer are used.

This API is EXPERIMENTAL.

func WithPerRPCCredentials

func WithPerRPCCredentials(creds credentials.PerRPCCredentials) DialOption

WithPerRPCCredentials returns a DialOption which sets credentials and places auth state on each outbound RPC.

func WithReadBufferSize

func WithReadBufferSize(s int) DialOption

WithReadBufferSize lets you set the size of read buffer, this determines how much data can be read at most for each read syscall.

The default value for this buffer is 32KB. Zero will disable read buffer for a connection so data framer can access the underlying conn directly.

func WithResolvers

func WithResolvers(rs ...resolver.Builder) DialOption

WithResolvers allows a list of resolver implementations to be registered locally with the ClientConn without needing to be globally registered via resolver.Register. They will be matched against the scheme used for the current Dial only, and will take precedence over the global registry.

This API is EXPERIMENTAL.

func WithReturnConnectionError

func WithReturnConnectionError() DialOption

WithReturnConnectionError returns a DialOption which makes the client connection return a string containing both the last connection error that occurred and the context.DeadlineExceeded error. Implies WithBlock()

This API is EXPERIMENTAL.

func WithServiceConfig

func WithServiceConfig(c <-chan ServiceConfig) DialOption

WithServiceConfig returns a DialOption which has a channel to read the service configuration.

Deprecated: service config should be received through name resolver or via WithDefaultServiceConfig, as specified at https://github.com/grpc/grpc/blob/master/doc/service_config.md. Will be removed in a future 1.x release.

func WithStatsHandler

func WithStatsHandler(h stats.Handler) DialOption

WithStatsHandler returns a DialOption that specifies the stats handler for all the RPCs and underlying network connections in this ClientConn.

func WithStreamInterceptor

func WithStreamInterceptor(f StreamClientInterceptor) DialOption

WithStreamInterceptor returns a DialOption that specifies the interceptor for streaming RPCs.

func WithTimeout

func WithTimeout(d time.Duration) DialOption

WithTimeout returns a DialOption that configures a timeout for dialing a ClientConn initially. This is valid if and only if WithBlock() is present.

Deprecated: use DialContext instead of Dial and context.WithTimeout instead. Will be supported throughout 1.x.

func WithTransportCredentials

func WithTransportCredentials(creds credentials.TransportCredentials) DialOption

WithTransportCredentials returns a DialOption which configures a connection level security credentials (e.g., TLS/SSL). This should not be used together with WithCredentialsBundle.

func WithUnaryInterceptor

func WithUnaryInterceptor(f UnaryClientInterceptor) DialOption

WithUnaryInterceptor returns a DialOption that specifies the interceptor for unary RPCs.

func WithUserAgent

func WithUserAgent(s string) DialOption

WithUserAgent returns a DialOption that specifies a user agent string for all the RPCs.

func WithWriteBufferSize

func WithWriteBufferSize(s int) DialOption

WithWriteBufferSize determines how much data can be batched before doing a write on the wire. The corresponding memory allocation for this buffer will be twice the size to keep syscalls low. The default value for this buffer is 32KB.

Zero will disable the write buffer such that each write will be on underlying connection. Note: A Send call may not directly translate to a write.

type EmptyCallOption

type EmptyCallOption struct{}

EmptyCallOption does not alter the Call configuration. It can be embedded in another structure to carry satellite data for use by interceptors.

type EmptyDialOption

type EmptyDialOption struct{}

EmptyDialOption does not alter the dial configuration. It can be embedded in another structure to build custom dial options.

This API is EXPERIMENTAL.

type EmptyServerOption

type EmptyServerOption struct{}

EmptyServerOption does not alter the server configuration. It can be embedded in another structure to build custom server options.

This API is EXPERIMENTAL.

type FailFastCallOption

type FailFastCallOption struct {
	FailFast bool
}

FailFastCallOption is a CallOption for indicating whether an RPC should fail fast or not. This is an EXPERIMENTAL API.

type ForceCodecCallOption

type ForceCodecCallOption struct {
	Codec encoding.Codec
}

ForceCodecCallOption is a CallOption that indicates the codec used for marshaling messages.

This is an EXPERIMENTAL API.

type HeaderCallOption

type HeaderCallOption struct {
	HeaderAddr *metadata.MD
}

HeaderCallOption is a CallOption for collecting response header metadata. The metadata field will be populated *after* the RPC completes. This is an EXPERIMENTAL API.

type MaxRecvMsgSizeCallOption

type MaxRecvMsgSizeCallOption struct {
	MaxRecvMsgSize int
}

MaxRecvMsgSizeCallOption is a CallOption that indicates the maximum message size in bytes the client can receive. This is an EXPERIMENTAL API.

type MaxRetryRPCBufferSizeCallOption

type MaxRetryRPCBufferSizeCallOption struct {
	MaxRetryRPCBufferSize int
}

MaxRetryRPCBufferSizeCallOption is a CallOption indicating the amount of memory to be used for caching this RPC for retry purposes. This is an EXPERIMENTAL API.

type MaxSendMsgSizeCallOption

type MaxSendMsgSizeCallOption struct {
	MaxSendMsgSize int
}

MaxSendMsgSizeCallOption is a CallOption that indicates the maximum message size in bytes the client can send. This is an EXPERIMENTAL API.

type MethodConfig

type MethodConfig struct {
	// WaitForReady indicates whether RPCs sent to this method should wait until
	// the connection is ready by default (!failfast). The value specified via the
	// gRPC client API will override the value set here.
	WaitForReady *bool
	// Timeout is the default timeout for RPCs sent to this method. The actual
	// deadline used will be the minimum of the value specified here and the value
	// set by the application via the gRPC client API.  If either one is not set,
	// then the other will be used.  If neither is set, then the RPC has no deadline.
	Timeout *time.Duration
	// MaxReqSize is the maximum allowed payload size for an individual request in a
	// stream (client->server) in bytes. The size which is measured is the serialized
	// payload after per-message compression (but before stream compression) in bytes.
	// The actual value used is the minimum of the value specified here and the value set
	// by the application via the gRPC client API. If either one is not set, then the other
	// will be used.  If neither is set, then the built-in default is used.
	MaxReqSize *int
	// MaxRespSize is the maximum allowed payload size for an individual response in a
	// stream (server->client) in bytes.
	MaxRespSize *int
	// contains filtered or unexported fields
}

MethodConfig defines the configuration recommended by the service providers for a particular method.

Deprecated: Users should not use this struct. Service config should be received through name resolver, as specified here https://github.com/grpc/grpc/blob/master/doc/service_config.md

type MethodDesc

type MethodDesc struct {
	MethodName string
	Handler    methodHandler
}

MethodDesc represents an RPC service's method specification.

type MethodInfo

type MethodInfo struct {
	// Name is the method name only, without the service name or package name.
	Name string
	// IsClientStream indicates whether the RPC is a client streaming RPC.
	IsClientStream bool
	// IsServerStream indicates whether the RPC is a server streaming RPC.
	IsServerStream bool
}

MethodInfo contains the information of an RPC including its method name and type.

type PeerCallOption

type PeerCallOption struct {
	PeerAddr *peer.Peer
}

PeerCallOption is a CallOption for collecting the identity of the remote peer. The peer field will be populated *after* the RPC completes. This is an EXPERIMENTAL API.

type PerRPCCredsCallOption

type PerRPCCredsCallOption struct {
	Creds credentials.PerRPCCredentials
}

PerRPCCredsCallOption is a CallOption that indicates the per-RPC credentials to use for the call. This is an EXPERIMENTAL API.

type PreparedMsg

type PreparedMsg struct {
	// contains filtered or unexported fields
}

PreparedMsg is responsible for creating a Marshalled and Compressed object.

This API is EXPERIMENTAL.

func (*PreparedMsg) Encode

func (p *PreparedMsg) Encode(s Stream, msg interface{}) error

Encode marshalls and compresses the message using the codec and compressor for the stream.

type Server

type Server struct {
	// contains filtered or unexported fields
}

Server is a gRPC server to serve RPC requests.

func NewServer

func NewServer(opt ...ServerOption) *Server

NewServer creates a gRPC server which has no service registered and has not started to accept requests yet.

func (*Server) GetServiceInfo

func (s *Server) GetServiceInfo() map[string]ServiceInfo

GetServiceInfo returns a map from service names to ServiceInfo. Service names include the package names, in the form of <package>.<service>.

func (*Server) GracefulStop

func (s *Server) GracefulStop()

GracefulStop stops the gRPC server gracefully. It stops the server from accepting new connections and RPCs and blocks until all the pending RPCs are finished.

func (*Server) RegisterService

func (s *Server) RegisterService(sd *ServiceDesc, ss interface{})

RegisterService registers a service and its implementation to the gRPC server. It is called from the IDL generated code. This must be called before invoking Serve. If ss is non-nil (for legacy code), its type is checked to ensure it implements sd.HandlerType.

func (*Server) Serve

func (s *Server) Serve(lis net.Listener) error

Serve accepts incoming connections on the listener lis, creating a new ServerTransport and service goroutine for each. The service goroutines read gRPC requests and then call the registered handlers to reply to them. Serve returns when lis.Accept fails with fatal errors. lis will be closed when this method returns. Serve will return a non-nil error unless Stop or GracefulStop is called.

func (*Server) ServeHTTP

func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request)

ServeHTTP implements the Go standard library's http.Handler interface by responding to the gRPC request r, by looking up the requested gRPC method in the gRPC server s.

The provided HTTP request must have arrived on an HTTP/2 connection. When using the Go standard library's server, practically this means that the Request must also have arrived over TLS.

To share one port (such as 443 for https) between gRPC and an existing http.Handler, use a root http.Handler such as:

if r.ProtoMajor == 2 && strings.HasPrefix(
	r.Header.Get("Content-Type"), "application/grpc") {
	grpcServer.ServeHTTP(w, r)
} else {
	yourMux.ServeHTTP(w, r)
}

Note that ServeHTTP uses Go's HTTP/2 server implementation which is totally separate from grpc-go's HTTP/2 server. Performance and features may vary between the two paths. ServeHTTP does not support some gRPC features available through grpc-go's HTTP/2 server, and it is currently EXPERIMENTAL and subject to change.

func (*Server) Stop

func (s *Server) Stop()

Stop stops the gRPC server. It immediately closes all open connections and listeners. It cancels all active RPCs on the server side and the corresponding pending RPCs on the client side will get notified by connection errors.

type ServerOption

type ServerOption interface {
	// contains filtered or unexported methods
}

A ServerOption sets options such as credentials, codec and keepalive parameters, etc.

func ChainStreamInterceptor

func ChainStreamInterceptor(interceptors ...StreamServerInterceptor) ServerOption

ChainStreamInterceptor returns a ServerOption that specifies the chained interceptor for streaming RPCs. The first interceptor will be the outer most, while the last interceptor will be the inner most wrapper around the real call. All stream interceptors added by this method will be chained.

func ChainUnaryInterceptor

func ChainUnaryInterceptor(interceptors ...UnaryServerInterceptor) ServerOption

ChainUnaryInterceptor returns a ServerOption that specifies the chained interceptor for unary RPCs. The first interceptor will be the outer most, while the last interceptor will be the inner most wrapper around the real call. All unary interceptors added by this method will be chained.

func ConnectionTimeout

func ConnectionTimeout(d time.Duration) ServerOption

ConnectionTimeout returns a ServerOption that sets the timeout for connection establishment (up to and including HTTP/2 handshaking) for all new connections. If this is not set, the default is 120 seconds. A zero or negative value will result in an immediate timeout.

This API is EXPERIMENTAL.

func Creds

func Creds(c credentials.TransportCredentials) ServerOption

Creds returns a ServerOption that sets credentials for server connections.

func CustomCodec

func CustomCodec(codec Codec) ServerOption

CustomCodec returns a ServerOption that sets a codec for message marshaling and unmarshaling.

This will override any lookups by content-subtype for Codecs registered with RegisterCodec.

Deprecated: register codecs using encoding.RegisterCodec. The server will automatically use registered codecs based on the incoming requests' headers. See also https://github.com/grpc/grpc-go/blob/master/Documentation/encoding.md#using-a-codec. Will be supported throughout 1.x.

func HeaderTableSize

func HeaderTableSize(s uint32) ServerOption

HeaderTableSize returns a ServerOption that sets the size of dynamic header table for stream.

This API is EXPERIMENTAL.

func InTapHandle

func InTapHandle(h tap.ServerInHandle) ServerOption

InTapHandle returns a ServerOption that sets the tap handle for all the server transport to be created. Only one can be installed.

func InitialConnWindowSize

func InitialConnWindowSize(s int32) ServerOption

InitialConnWindowSize returns a ServerOption that sets window size for a connection. The lower bound for window size is 64K and any value smaller than that will be ignored.

func InitialWindowSize

func InitialWindowSize(s int32) ServerOption

InitialWindowSize returns a ServerOption that sets window size for stream. The lower bound for window size is 64K and any value smaller than that will be ignored.

func KeepaliveEnforcementPolicy

func KeepaliveEnforcementPolicy(kep keepalive.EnforcementPolicy) ServerOption

KeepaliveEnforcementPolicy returns a ServerOption that sets keepalive enforcement policy for the server.

func KeepaliveParams

func KeepaliveParams(kp keepalive.ServerParameters) ServerOption

KeepaliveParams returns a ServerOption that sets keepalive and max-age parameters for the server.

func MaxConcurrentStreams

func MaxConcurrentStreams(n uint32) ServerOption

MaxConcurrentStreams returns a ServerOption that will apply a limit on the number of concurrent streams to each ServerTransport.

func MaxHeaderListSize

func MaxHeaderListSize(s uint32) ServerOption

MaxHeaderListSize returns a ServerOption that sets the max (uncompressed) size of header list that the server is prepared to accept.

func MaxMsgSize

func MaxMsgSize(m int) ServerOption

MaxMsgSize returns a ServerOption to set the max message size in bytes the server can receive. If this is not set, gRPC uses the default limit.

Deprecated: use MaxRecvMsgSize instead. Will be supported throughout 1.x.

func MaxRecvMsgSize

func MaxRecvMsgSize(m int) ServerOption

MaxRecvMsgSize returns a ServerOption to set the max message size in bytes the server can receive. If this is not set, gRPC uses the default 4MB.

func MaxSendMsgSize

func MaxSendMsgSize(m int) ServerOption

MaxSendMsgSize returns a ServerOption to set the max message size in bytes the server can send. If this is not set, gRPC uses the default `math.MaxInt32`.

func NumStreamWorkers

func NumStreamWorkers(numServerWorkers uint32) ServerOption

NumStreamWorkers returns a ServerOption that sets the number of worker goroutines that should be used to process incoming streams. Setting this to zero (default) will disable workers and spawn a new goroutine for each stream.

This API is EXPERIMENTAL.

func RPCCompressor

func RPCCompressor(cp Compressor) ServerOption

RPCCompressor returns a ServerOption that sets a compressor for outbound messages. For backward compatibility, all outbound messages will be sent using this compressor, regardless of incoming message compression. By default, server messages will be sent using the same compressor with which request messages were sent.

Deprecated: use encoding.RegisterCompressor instead. Will be supported throughout 1.x.

func RPCDecompressor

func RPCDecompressor(dc Decompressor) ServerOption

RPCDecompressor returns a ServerOption that sets a decompressor for inbound messages. It has higher priority than decompressors registered via encoding.RegisterCompressor.

Deprecated: use encoding.RegisterCompressor instead. Will be supported throughout 1.x.

func ReadBufferSize

func ReadBufferSize(s int) ServerOption

ReadBufferSize lets you set the size of read buffer, this determines how much data can be read at most for one read syscall. The default value for this buffer is 32KB. Zero will disable read buffer for a connection so data framer can access the underlying conn directly.

func StatsHandler

func StatsHandler(h stats.Handler) ServerOption

StatsHandler returns a ServerOption that sets the stats handler for the server.

func StreamInterceptor

func StreamInterceptor(i StreamServerInterceptor) ServerOption

StreamInterceptor returns a ServerOption that sets the StreamServerInterceptor for the server. Only one stream interceptor can be installed.

func UnaryInterceptor

func UnaryInterceptor(i UnaryServerInterceptor) ServerOption

UnaryInterceptor returns a ServerOption that sets the UnaryServerInterceptor for the server. Only one unary interceptor can be installed. The construction of multiple interceptors (e.g., chaining) can be implemented at the caller.

func UnknownServiceHandler

func UnknownServiceHandler(streamHandler StreamHandler) ServerOption

UnknownServiceHandler returns a ServerOption that allows for adding a custom unknown service handler. The provided method is a bidi-streaming RPC service handler that will be invoked instead of returning the "unimplemented" gRPC error whenever a request is received for an unregistered service or method. The handling function and stream interceptor (if set) have full access to the ServerStream, including its Context.

func WriteBufferSize

func WriteBufferSize(s int) ServerOption

WriteBufferSize determines how much data can be batched before doing a write on the wire. The corresponding memory allocation for this buffer will be twice the size to keep syscalls low. The default value for this buffer is 32KB. Zero will disable the write buffer such that each write will be on underlying connection. Note: A Send call may not directly translate to a write.

type ServerStream

type ServerStream interface {
	// SetHeader sets the header metadata. It may be called multiple times.
	// When call multiple times, all the provided metadata will be merged.
	// All the metadata will be sent out when one of the following happens:
	//  - ServerStream.SendHeader() is called;
	//  - The first response is sent out;
	//  - An RPC status is sent out (error or success).
	SetHeader(metadata.MD) error
	// SendHeader sends the header metadata.
	// The provided md and headers set by SetHeader() will be sent.
	// It fails if called multiple times.
	SendHeader(metadata.MD) error
	// SetTrailer sets the trailer metadata which will be sent with the RPC status.
	// When called more than once, all the provided metadata will be merged.
	SetTrailer(metadata.MD)
	// Context returns the context for this stream.
	Context() context.Context
	// SendMsg sends a message. On error, SendMsg aborts the stream and the
	// error is returned directly.
	//
	// SendMsg blocks until:
	//   - There is sufficient flow control to schedule m with the transport, or
	//   - The stream is done, or
	//   - The stream breaks.
	//
	// SendMsg does not wait until the message is received by the client. An
	// untimely stream closure may result in lost messages.
	//
	// It is safe to have a goroutine calling SendMsg and another goroutine
	// calling RecvMsg on the same stream at the same time, but it is not safe
	// to call SendMsg on the same stream in different goroutines.
	SendMsg(m interface{}) error
	// RecvMsg blocks until it receives a message into m or the stream is
	// done. It returns io.EOF when the client has performed a CloseSend. On
	// any non-EOF error, the stream is aborted and the error contains the
	// RPC status.
	//
	// It is safe to have a goroutine calling SendMsg and another goroutine
	// calling RecvMsg on the same stream at the same time, but it is not
	// safe to call RecvMsg on the same stream in different goroutines.
	RecvMsg(m interface{}) error
}

ServerStream defines the server-side behavior of a streaming RPC.

All errors returned from ServerStream methods are compatible with the status package.

type ServerTransportStream

type ServerTransportStream interface {
	Method() string
	SetHeader(md metadata.MD) error
	SendHeader(md metadata.MD) error
	SetTrailer(md metadata.MD) error
}

ServerTransportStream is a minimal interface that a transport stream must implement. This can be used to mock an actual transport stream for tests of handler code that use, for example, grpc.SetHeader (which requires some stream to be in context).

See also NewContextWithServerTransportStream.

This API is EXPERIMENTAL.

func ServerTransportStreamFromContext

func ServerTransportStreamFromContext(ctx context.Context) ServerTransportStream

ServerTransportStreamFromContext returns the ServerTransportStream saved in ctx. Returns nil if the given context has no stream associated with it (which implies it is not an RPC invocation context).

This API is EXPERIMENTAL.

type ServiceConfig

type ServiceConfig struct {
	serviceconfig.Config

	// LB is the load balancer the service providers recommends. The balancer
	// specified via grpc.WithBalancerName will override this.  This is deprecated;
	// lbConfigs is preferred.  If lbConfig and LB are both present, lbConfig
	// will be used.
	LB *string

	// Methods contains a map for the methods in this service.  If there is an
	// exact match for a method (i.e. /service/method) in the map, use the
	// corresponding MethodConfig.  If there's no exact match, look for the
	// default config for the service (/service/) and use the corresponding
	// MethodConfig if it exists.  Otherwise, the method has no MethodConfig to
	// use.
	Methods map[string]MethodConfig
	// contains filtered or unexported fields
}

ServiceConfig is provided by the service provider and contains parameters for how clients that connect to the service should behave.

Deprecated: Users should not use this struct. Service config should be received through name resolver, as specified here https://github.com/grpc/grpc/blob/master/doc/service_config.md

type ServiceDesc

type ServiceDesc struct {
	ServiceName string
	// The pointer to the service interface. Used to check whether the user
	// provided implementation satisfies the interface requirements.
	HandlerType interface{}
	Methods     []MethodDesc
	Streams     []StreamDesc
	Metadata    interface{}
}

ServiceDesc represents an RPC service's specification.

type ServiceInfo

type ServiceInfo struct {
	Methods []MethodInfo
	// Metadata is the metadata specified in ServiceDesc when registering service.
	Metadata interface{}
}

ServiceInfo contains unary RPC method info, streaming RPC method info and metadata for a service.

type ServiceRegistrar

type ServiceRegistrar interface {
	// RegisterService registers a service and its implementation to the
	// concrete type implementing this interface.  It may not be called
	// once the server has started serving.
	// desc describes the service and its methods and handlers. impl is the
	// service implementation which is passed to the method handlers.
	RegisterService(desc *ServiceDesc, impl interface{})
}

ServiceRegistrar wraps a single method that supports service registration. It enables users to pass concrete types other than grpc.Server to the service registration methods exported by the IDL generated code.

type Stream

type Stream interface {
	// Deprecated: See ClientStream and ServerStream documentation instead.
	Context() context.Context
	// Deprecated: See ClientStream and ServerStream documentation instead.
	SendMsg(m interface{}) error
	// Deprecated: See ClientStream and ServerStream documentation instead.
	RecvMsg(m interface{}) error
}

Stream defines the common interface a client or server stream has to satisfy.

Deprecated: See ClientStream and ServerStream documentation instead.

type StreamClientInterceptor

type StreamClientInterceptor func(ctx context.Context, desc *StreamDesc, cc *ClientConn, method string, streamer Streamer, opts ...CallOption) (ClientStream, error)

StreamClientInterceptor intercepts the creation of ClientStream. It may return a custom ClientStream to intercept all I/O operations. streamer is the handler to create a ClientStream and it is the responsibility of the interceptor to call it. This is an EXPERIMENTAL API.

type StreamDesc

type StreamDesc struct {
	StreamName string
	Handler    StreamHandler

	// At least one of these is true.
	ServerStreams bool
	ClientStreams bool
}

StreamDesc represents a streaming RPC service's method specification.

type StreamHandler

type StreamHandler func(srv interface{}, stream ServerStream) error

StreamHandler defines the handler called by gRPC server to complete the execution of a streaming RPC. If a StreamHandler returns an error, it should be produced by the status package, or else gRPC will use codes.Unknown as the status code and err.Error() as the status message of the RPC.

type StreamServerInfo

type StreamServerInfo struct {
	// FullMethod is the full RPC method string, i.e., /package.service/method.
	FullMethod string
	// IsClientStream indicates whether the RPC is a client streaming RPC.
	IsClientStream bool
	// IsServerStream indicates whether the RPC is a server streaming RPC.
	IsServerStream bool
}

StreamServerInfo consists of various information about a streaming RPC on server side. All per-rpc information may be mutated by the interceptor.

type StreamServerInterceptor

type StreamServerInterceptor func(srv interface{}, ss ServerStream, info *StreamServerInfo, handler StreamHandler) error

StreamServerInterceptor provides a hook to intercept the execution of a streaming RPC on the server. info contains all the information of this RPC the interceptor can operate on. And handler is the service method implementation. It is the responsibility of the interceptor to invoke handler to complete the RPC.

type Streamer

type Streamer func(ctx context.Context, desc *StreamDesc, cc *ClientConn, method string, opts ...CallOption) (ClientStream, error)

Streamer is called by StreamClientInterceptor to create a ClientStream.

type TrailerCallOption

type TrailerCallOption struct {
	TrailerAddr *metadata.MD
}

TrailerCallOption is a CallOption for collecting response trailer metadata. The metadata field will be populated *after* the RPC completes. This is an EXPERIMENTAL API.

type UnaryClientInterceptor

type UnaryClientInterceptor func(ctx context.Context, method string, req, reply interface{}, cc *ClientConn, invoker UnaryInvoker, opts ...CallOption) error

UnaryClientInterceptor intercepts the execution of a unary RPC on the client. invoker is the handler to complete the RPC and it is the responsibility of the interceptor to call it. This is an EXPERIMENTAL API.

type UnaryHandler

type UnaryHandler func(ctx context.Context, req interface{}) (interface{}, error)

UnaryHandler defines the handler invoked by UnaryServerInterceptor to complete the normal execution of a unary RPC. If a UnaryHandler returns an error, it should be produced by the status package, or else gRPC will use codes.Unknown as the status code and err.Error() as the status message of the RPC.

type UnaryInvoker

type UnaryInvoker func(ctx context.Context, method string, req, reply interface{}, cc *ClientConn, opts ...CallOption) error

UnaryInvoker is called by UnaryClientInterceptor to complete RPCs.

type UnaryServerInfo

type UnaryServerInfo struct {
	// Server is the service implementation the user provides. This is read-only.
	Server interface{}
	// FullMethod is the full RPC method string, i.e., /package.service/method.
	FullMethod string
}

UnaryServerInfo consists of various information about a unary RPC on server side. All per-rpc information may be mutated by the interceptor.

type UnaryServerInterceptor

type UnaryServerInterceptor func(ctx context.Context, req interface{}, info *UnaryServerInfo, handler UnaryHandler) (resp interface{}, err error)

UnaryServerInterceptor provides a hook to intercept the execution of a unary RPC on the server. info contains all the information of this RPC the interceptor can operate on. And handler is the wrapper of the service method implementation. It is the responsibility of the interceptor to invoke handler to complete the RPC.

Directories

Path Synopsis
attributes Package attributes defines a generic key/value store used in various gRPC components.
backoff Package backoff provides configuration options for backoff.
balancer Package balancer defines APIs for load balancing in gRPC.
balancer/base Package base defines a balancer base that can be used to build balancers with different picking algorithms.
balancer/grpclb Package grpclb defines a grpclb balancer.
balancer/grpclb/grpc_lb_v1
balancer/grpclb/state Package state declares grpclb types to be set by resolvers wishing to pass information to grpclb via resolver.State Attributes.
balancer/rls/internal Package rls implements the RLS LB policy.
balancer/rls/internal/adaptive Package adaptive provides functionality for adaptive client-side throttling.
balancer/rls/internal/cache Package cache provides an LRU cache implementation to be used by the RLS LB policy to cache RLS response data.
balancer/rls/internal/keys Package keys provides functionality required to build RLS request keys.
balancer/rls/internal/proto/grpc_lookup_v1
balancer/rls/internal/testutils/fakeserver Package fakeserver provides a fake implementation of the RouteLookupService, to be used in unit tests.
balancer/roundrobin Package roundrobin defines a roundrobin balancer.
balancer/weightedroundrobin Package weightedroundrobin defines a weighted roundrobin balancer.
benchmark Package benchmark implements the building blocks to setup end-to-end gRPC benchmarks.
benchmark/benchmain Package main provides benchmark with setting flags.
benchmark/benchresult To format the benchmark result: go run benchmark/benchresult/main.go resultfile To see the performance change based on a old result: go run benchmark/benchresult/main.go resultfile_old resultfile It will print the comparison result of intersection benchmarks between two files.
benchmark/client Package main provides a client used for benchmarking.
benchmark/flags Package flags provide convenience types and routines to accept specific types of flag values on the command line.
benchmark/grpc_testing
benchmark/latency Package latency provides wrappers for net.Conn, net.Listener, and net.Dialers, designed to interoperate to inject real-world latency into network connections.
benchmark/server Package main provides a server used for benchmarking.
benchmark/stats Package stats tracks the statistics associated with benchmark runs.
benchmark/worker Binary worker implements the benchmark worker that can turn into a benchmark client or server.
binarylog/grpc_binarylog_v1
channelz/grpc_channelz_v1
channelz/service Package service provides an implementation for channelz service server.
codes Package codes defines the canonical error codes used by gRPC.
connectivity Package connectivity defines connectivity semantics.
credentials Package credentials implements various credentials supported by gRPC library, which encapsulate all the state needed by a client to authenticate with a server and make various assertions, e.g., about the client's identity, role, or whether it is authorized to make a particular call.
credentials/alts Package alts implements the ALTS credential support by gRPC library, which encapsulates all the state needed by a client to authenticate with a server using ALTS and make various assertions, e.g., about the client's identity, role, or whether it is authorized to make a particular call.
credentials/alts/internal Package internal contains common core functionality for ALTS.
credentials/alts/internal/authinfo Package authinfo provide authentication information returned by handshakers.
credentials/alts/internal/conn Package conn contains an implementation of a secure channel created by gRPC handshakers.
credentials/alts/internal/handshaker Package handshaker provides ALTS handshaking functionality for GCP.
credentials/alts/internal/handshaker/service Package service manages connections between the VM application and the ALTS handshaker service.
credentials/alts/internal/proto/grpc_gcp
credentials/alts/internal/testutil Package testutil include useful test utilities for the handshaker.
credentials/google Package google defines credentials for google cloud services.
credentials/local Package local implements local transport credentials.
credentials/oauth Package oauth implements gRPC credentials using OAuth.
credentials/sts Package sts implements call credentials using STS (Security Token Service) as defined in https://tools.ietf.org/html/rfc8693.
credentials/tls/certprovider Package certprovider defines APIs for Certificate Providers in gRPC.
credentials/tls/certprovider/meshca/internal/meshca_experimental
credentials/tls/certprovider/meshca/internal/v1
encoding Package encoding defines the interface for the compressor and codec, and functions to register and retrieve compressors and codecs.
encoding/gzip Package gzip implements and registers the gzip compressor during the initialization.
encoding/proto Package proto defines the protobuf codec.
grpclog Package grpclog defines logging for grpc.
grpclog/glogger Package glogger defines glog-based logging for grpc.
health Package health provides a service that exposes server's health and it must be imported to enable support for client-side health checks.
health/grpc_health_v1
internal Package internal contains gRPC-internal code, to avoid polluting the godoc of the top-level grpc package.
internal/backoff Package backoff implement the backoff strategy for gRPC.
internal/balancer/stub Package stub implements a balancer for testing purposes.
internal/balancerload Package balancerload defines APIs to parse server loads in trailers.
internal/binarylog Package binarylog implementation binary logging as defined in https://github.com/grpc/proposal/blob/master/A16-binary-logging.md.
internal/buffer Package buffer provides an implementation of an unbounded buffer.
internal/cache Package cache implements caches to be used in gRPC.
internal/channelz Package channelz defines APIs for enabling channelz service, entry registration/deletion, and accessing channelz data.
internal/credentials Package credentials defines APIs for parsing SPIFFE ID.
internal/envconfig Package envconfig contains grpc settings configured by environment variables.
internal/grpclog Package grpclog (internal) defines depth logging for grpc.
internal/grpcrand Package grpcrand implements math/rand functions in a concurrent-safe way with a global random source, independent of math/rand's global source.
internal/grpcsync Package grpcsync implements additional synchronization primitives built upon the sync package.
internal/grpctest Package grpctest implements testing helpers.
internal/grpcutil Package grpcutil provides a bunch of utility functions to be used across the gRPC codebase.
internal/hierarchy Package hierarchy contains functions to set and get hierarchy string from addresses.
internal/leakcheck Package leakcheck contains functions to check leaked goroutines.
internal/profiling Package profiling contains two logical components: buffer.go and profiling.go.
internal/profiling/buffer Package buffer provides a high-performant lock free implementation of a circular buffer used by the profiling code.
internal/proto/grpc_service_config
internal/resolver/dns Package dns implements a dns resolver to be installed as the default resolver in grpc.
internal/resolver/passthrough Package passthrough implements a pass-through resolver.
internal/serviceconfig Package serviceconfig contains utility functions to parse service config.
internal/status Package status implements errors returned by gRPC.
internal/syscall Package syscall provides functionalities that grpc uses to get low-level operating system stats/info.
internal/testutils Package testutils contains testing helpers.
internal/transport Package transport defines and implements message oriented communication channel to complete various transactions (e.g., an RPC).
internal/wrr Package wrr contains the interface and common implementations of wrr algorithms.
interop Package interop contains functions used by interop client/server.
interop/alts/client This binary can only run on Google Cloud Platform (GCP).
interop/alts/server This binary can only run on Google Cloud Platform (GCP).
interop/client Binary client is an interop client.
interop/fake_grpclb This file is for testing only.
interop/grpc_testing
interop/grpclb_fallback Binary grpclb_fallback is an interop test client for grpclb fallback.
interop/http2 Binary http2 is used to test http2 error edge cases like GOAWAYs and RST_STREAMs Documentation: https://github.com/grpc/grpc/blob/master/doc/negative-http2-interop-test-descriptions.md
interop/server Binary server is an interop server.
interop/xds/client Binary client for xDS interop tests.
interop/xds/server Binary server for xDS interop tests.
keepalive Package keepalive defines configurable parameters for point-to-point healthcheck.
metadata Package metadata define the structure of the metadata supported by gRPC library.
peer Package peer defines various peer information associated with RPCs and corresponding utils.
profiling Package profiling exposes methods to manage profiling within gRPC.
profiling/cmd Binary cmd is a command-line tool for profiling management.
profiling/proto
profiling/service Package service defines methods to register a gRPC client/service for a profiling service that is exposed in the same server.
reflection Package reflection implements server reflection service.
reflection/grpc_reflection_v1alpha
reflection/grpc_testing
reflection/grpc_testingv3 Package grpc_testingv3 is a generated protocol buffer package.
resolver Package resolver defines APIs for name resolution in gRPC.
resolver/dns Package dns implements a dns resolver to be installed as the default resolver in grpc.
resolver/manual Package manual defines a resolver that can be used to manually send resolved addresses to ClientConn.
resolver/passthrough Package passthrough implements a pass-through resolver.
serviceconfig Package serviceconfig defines types and methods for operating on gRPC service configs.
stats Package stats is for collecting and reporting various network and RPC stats.
stats/grpc_testing
status Package status implements errors returned by gRPC.
stress/client client starts an interop client to do stress test and a metrics server to report qps.
stress/grpc_testing
stress/metrics_client Binary metrics_client is a client to retrieve metrics from the server.
tap Package tap defines the function handles which are executed on the transport layer of gRPC-Go and related information.
test Package test contains tests.
test/bufconn Package bufconn provides a net.Conn implemented by a buffer and related dialing and listening functionality.
test/codec_perf
test/grpc_testing
xds Package xds contains xds implementation.
xds/internal Package internal contains functions/structs shared by xds balancers/resolvers.
xds/internal/balancer Package balancer installs all the xds balancers.
xds/internal/balancer/balancergroup Package balancergroup implements a utility struct to bind multiple balancers into one balancer.
xds/internal/balancer/cdsbalancer Package cdsbalancer implements a balancer to handle CDS responses.
xds/internal/balancer/edsbalancer Package edsbalancer contains EDS balancer implementation.
xds/internal/balancer/lrs Package lrs implements load reporting balancer for xds.
xds/internal/balancer/orca Package orca implements Open Request Cost Aggregation.
xds/internal/balancer/weightedtarget Package weightedtarget implements the weighted_target balancer.
xds/internal/balancer/weightedtarget/weightedaggregator Package weightedaggregator implements state aggregator for weighted_target balancer.
xds/internal/balancer/xdsrouting Package xdsrouting implements the routing balancer for xds.
xds/internal/client Package client implementation a full fledged gRPC client for the xDS API used by the xds resolver and balancer implementations.
xds/internal/client/bootstrap Package bootstrap provides the functionality to initialize certain aspects of an xDS client by reading a bootstrap file.
xds/internal/client/v2 Package v2 provides xDS v2 transport protocol specific functionality.
xds/internal/client/v3 Package v3 provides xDS v3 transport protocol specific functionality.
xds/internal/resolver Package resolver implements the xds resolver, that does LDS and RDS to find the cluster to use.
xds/internal/testutils Package testutils provides utility types, for use in xds tests.
xds/internal/testutils/fakeclient Package fakeclient provides a fake implementation of an xDS client.
xds/internal/testutils/fakeserver Package fakeserver provides a fake implementation of an xDS server.
xds/internal/version Package version defines constants to distinguish between supported xDS API versions.
MODULE cmd/protoc-gen-go-grpc
MODULE examples
MODULE security/advancedtls
MODULE security/advancedtls/examples
MODULE security/authorization