grpc

package module

Version: v1.55.0 Latest Latest Go to latest Published: May 4, 2023 License: Apache-2.0 Imports: 59 Imported by: 115,312

Details

Valid go.mod file

The Go module system was introduced in Go 1.11 and is the official dependency management solution for Go.
Redistributable license

Redistributable licenses place minimal restrictions on how software can be used, modified, and redistributed.
Tagged version

Modules with tagged versions give importers more predictable builds.
Stable version

When a project reaches major version v1 it is considered stable.
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Repository

github.com/grpc/grpc-go

Links

README ¶

gRPC-Go

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

Go: any one of the three latest major releases.

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

Go gRPC docs, which include a quick start and API reference among other resources
Low-level technical docs from this repository
Performance benchmark
Examples

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:

mis-configured transport credentials, connection failed on handshaking
bytes disrupted, possibly by a proxy in between
server shutdown
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.

Documentation ¶

Overview ¶

Package grpc implements an RPC system called gRPC.

See grpc.io for more information about gRPC.

Index ¶

Constants ¶

View Source

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.

These constants should not be referenced from any other code.

View Source

const PickFirstBalancerName = "pick_first"

PickFirstBalancerName is the name of the pick_first balancer.

View Source

const Version = "1.55.0"

Version is the current grpc version.

Variables ¶

View Source

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.

View Source

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.

View Source

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")
)

View Source

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.

View Source

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 ClientSupportedCompressors ¶ added in v1.54.0

func ClientSupportedCompressors(ctx context.Context) ([]string, error)

ClientSupportedCompressors returns compressor names advertised by the client via grpc-accept-encoding header.

The context provided must be the context passed to the server's handler.

Experimental ¶

Notice: This function is EXPERIMENTAL and may be changed or removed in a later release.

func Code deprecated

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 deprecated

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 deprecated

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 ¶ added in v1.11.2

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 ¶ added in v1.8.0

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 ¶ added in v1.11.0

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

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

Experimental ¶

Notice: This API is EXPERIMENTAL and may be changed or removed in a later release.

func SendHeader ¶

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

SendHeader sends header metadata. It may be called at most once, and may not be called after any event that causes headers to be sent (see SetHeader for a complete list). The provided md and headers set by SetHeader() will be sent.

The error returned is compatible with the status package. However, the status code will often not match the RPC status as seen by the client application, and therefore, should not be relied upon for this purpose.

func SetHeader ¶ added in v1.0.3

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

SetHeader sets the header metadata to be sent from the server to the client. The context provided must be the context passed to the server's handler.

Streaming RPCs should prefer the SetHeader method of the ServerStream.

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, or for streaming handlers, stream.SendHeader.
The first response message is sent. For unary handlers, this occurs when the handler returns; for streaming handlers, this can happen when stream's SendMsg method is called.
An RPC status is sent out (error or success). This occurs when the handler returns.

SetHeader will fail if called after any of the events above.

The error returned is compatible with the status package. However, the status code will often not match the RPC status as seen by the client application, and therefore, should not be relied upon for this purpose.

func SetSendCompressor ¶ added in v1.54.0

func SetSendCompressor(ctx context.Context, name string) error

SetSendCompressor sets a compressor for outbound messages from the server. It must not be called after any event that causes headers to be sent (see ServerStream.SetHeader for the complete list). Provided compressor is used when below conditions are met:

compressor is registered via encoding.RegisterCompressor
compressor name must exist in the client advertised compressor names sent in grpc-accept-encoding header. Use ClientSupportedCompressors to get client supported compressor names.

The context provided must be the context passed to the server's handler. It must be noted that compressor name encoding.Identity disables the outbound compression. By default, server messages will be sent using the same compressor with which request messages were sent.

It is not safe to call SetSendCompressor concurrently with SendHeader and SendMsg.

Experimental ¶

Notice: This function is EXPERIMENTAL and may be changed or removed in a later release.

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.

The error returned is compatible with the status package. However, the status code will often not match the RPC status as seen by the client application, and therefore, should not be relied upon for this purpose.

Types ¶

type BackoffConfig deprecated

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 ¶ added in v1.10.0

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 deprecated added in v1.10.0

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 deprecated

func FailFast(failFast bool) CallOption

FailFast is the opposite of WaitForReady.

Deprecated: use WaitForReady.

func ForceCodec ¶ added in v1.19.0

func ForceCodec(codec encoding.Codec) CallOption

ForceCodec returns a CallOption that will set codec to be used for all request and response messages for a call. The result of calling Name() will be used as the content-subtype after converting to lowercase, unless CallContentSubtype is also used.

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.

Experimental ¶

Notice: This API is EXPERIMENTAL and may be changed or removed in a later release.

func Header(md *metadata.MD) CallOption

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

func MaxCallRecvMsgSize ¶ added in v1.4.0

func MaxCallRecvMsgSize(bytes int) CallOption

MaxCallRecvMsgSize returns a CallOption which sets the maximum message size in bytes the client can receive. If this is not set, gRPC uses the default 4MB.

func MaxCallSendMsgSize ¶ added in v1.4.0

func MaxCallSendMsgSize(bytes int) CallOption

MaxCallSendMsgSize returns a CallOption which sets the maximum message size in bytes the client can send. If this is not set, gRPC uses the default `math.MaxInt32`.

func MaxRetryRPCBufferSize ¶ added in v1.14.0

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.

Experimental ¶

Notice: This API is EXPERIMENTAL and may be changed or removed in a later release.

func OnFinish ¶ added in v1.54.0

func OnFinish(onFinish func(err error)) CallOption

OnFinish returns a CallOption that configures a callback to be called when the call completes. The error passed to the callback is the status of the RPC, and may be nil. The onFinish callback provided will only be called once by gRPC. This is mainly used to be used by streaming interceptors, to be notified when the RPC completes along with information about the status of the RPC.

Experimental ¶

Notice: This API is EXPERIMENTAL and may be changed or removed in a later release.

func Peer ¶ added in v1.2.0

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 ¶ added in v1.4.0

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 ¶ added in v1.8.0

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.

Experimental ¶

Notice: This API is EXPERIMENTAL and may be changed or removed in a later release.

func WaitForReady ¶ added in v1.18.0

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 and the connection is in the TRANSIENT_FAILURE state, 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 ¶ added in v1.0.2

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) Connect ¶ added in v1.41.0

func (cc *ClientConn) Connect()

Connect causes all subchannels in the ClientConn to attempt to connect if the channel is idle. Does not wait for the connection attempts to begin before returning.

Experimental ¶

Notice: This API is EXPERIMENTAL and may be changed or removed in a later release.

func (*ClientConn) GetMethodConfig ¶ added in v1.4.0

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 ¶ added in v1.5.2

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

GetState returns the connectivity.State of ClientConn.

Experimental ¶

Notice: This API is EXPERIMENTAL and may be changed or removed in a later release.

func (*ClientConn) Invoke ¶ added in v1.8.0

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 ¶ added in v1.8.0

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:

Call Close on the ClientConn.
Cancel the context provided.
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).
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 ¶ added in v1.15.0

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.

Experimental ¶

Notice: This API is EXPERIMENTAL and may be changed or removed in a later release.

func (*ClientConn) Target ¶ added in v1.14.0

func (cc *ClientConn) Target() string

Target returns the target string of the ClientConn.

Experimental ¶

Notice: This API is EXPERIMENTAL and may be changed or removed in a later release.

func (*ClientConn) WaitForStateChange ¶ added in v1.5.2

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.

Experimental ¶

Notice: This API is EXPERIMENTAL and may be changed or removed in a later release.

type ClientConnInterface ¶ added in v1.27.0

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 deprecated

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 deprecated

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 deprecated

func NewGZIPCompressor() Compressor

NewGZIPCompressor creates a Compressor based on GZIP.

Deprecated: use package encoding/gzip.

func NewGZIPCompressorWithLevel deprecated added in v1.11.0

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 ¶ added in v1.11.0

type CompressorCallOption struct {
	CompressorType string
}

CompressorCallOption is a CallOption that indicates the compressor to use.

Experimental ¶

Notice: This type is EXPERIMENTAL and may be changed or removed in a later release.

type ConnectParams ¶ added in v1.25.0

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.

Experimental ¶

Notice: This type is EXPERIMENTAL and may be changed or removed in a later release.

type ContentSubtypeCallOption ¶ added in v1.11.0

type ContentSubtypeCallOption struct {
	ContentSubtype string
}

ContentSubtypeCallOption is a CallOption that indicates the content-subtype used for marshaling messages.

Experimental ¶

Notice: This type is EXPERIMENTAL and may be changed or removed in a later release.

type CustomCodecCallOption ¶ added in v1.11.0

type CustomCodecCallOption struct {
	Codec Codec
}

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

Experimental ¶

Notice: This type is EXPERIMENTAL and may be changed or removed in a later release.

type Decompressor deprecated

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 deprecated

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 ¶ added in v1.0.5

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().

Use of this feature is not recommended. For more information, please see: https://github.com/grpc/grpc-go/blob/master/Documentation/anti-patterns.md

Experimental ¶

Notice: This API is EXPERIMENTAL and may be changed or removed in a later release.

func WithAuthority ¶ added in v1.2.0

func WithAuthority(a string) DialOption

WithAuthority returns a DialOption that specifies the value to be used as the :authority pseudo-header and as the server name in authentication handshake.

func WithBackoffConfig deprecated

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 deprecated

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 WithBlock ¶

func WithBlock() DialOption

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

Use of this feature is not recommended. For more information, please see: https://github.com/grpc/grpc-go/blob/master/Documentation/anti-patterns.md

func WithChainStreamInterceptor ¶ added in v1.21.0

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 ¶ added in v1.21.0

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 ¶ added in v1.12.0

func WithChannelzParentID(id *channelz.Identifier) 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).

Experimental ¶

Notice: This API is EXPERIMENTAL and may be changed or removed in a later release.

func WithCodec deprecated

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 deprecated

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 ¶ added in v1.25.0

func WithConnectParams(p ConnectParams) DialOption

WithConnectParams configures the ClientConn to use the provided ConnectParams for creating and maintaining connections to servers.

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.

func WithContextDialer ¶ added in v1.19.0

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 ¶ added in v1.16.0

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.

Experimental ¶

Notice: This API is EXPERIMENTAL and may be changed or removed in a later release.

func WithDecompressor deprecated

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 ¶ added in v1.4.0

func WithDefaultCallOptions(cos ...CallOption) DialOption

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

func WithDefaultServiceConfig ¶ added in v1.20.0

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, or

2. The name resolver does not provide a service config or provides an invalid service config.

The parameter s is the JSON representation of the default service config. For more information about service configs, see: https://github.com/grpc/grpc/blob/master/doc/service_config.md For a simple example of usage, see: examples/features/load_balancing/client/main.go

func WithDialer deprecated

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 ¶ added in v1.17.0

func WithDisableHealthCheck() DialOption

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

Experimental ¶

Notice: This API is EXPERIMENTAL and may be changed or removed in a later release.

func WithDisableRetry ¶ added in v1.14.0

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.

func WithDisableServiceConfig ¶ added in v1.12.0

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 ¶ added in v1.4.0

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 ¶ added in v1.4.0

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 deprecated

func WithInsecure() DialOption

WithInsecure returns a DialOption which disables transport security for this ClientConn. Under the hood, it uses insecure.NewCredentials().

Note that using this DialOption with per-RPC credentials (through WithCredentialsBundle or WithPerRPCCredentials) which require transport security is incompatible and will cause grpc.Dial() to fail.

Deprecated: use WithTransportCredentials and insecure.NewCredentials() instead. Will be supported throughout 1.x.

func WithKeepaliveParams ¶ added in v1.2.0

func WithKeepaliveParams(kp keepalive.ClientParameters) DialOption

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

func WithMaxHeaderListSize ¶ added in v1.14.0

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 deprecated added in v1.2.0

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 ¶ added in v1.29.0

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.

Experimental ¶

Notice: This API is EXPERIMENTAL and may be changed or removed in a later release.

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 ¶ added in v1.7.0

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 or negative values will disable read buffer for a connection so data framer can access the underlying conn directly.

func WithResolvers ¶ added in v1.27.0

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.

Experimental ¶

Notice: This API is EXPERIMENTAL and may be changed or removed in a later release.

func WithReturnConnectionError ¶ added in v1.30.0

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()

Use of this feature is not recommended. For more information, please see: https://github.com/grpc/grpc-go/blob/master/Documentation/anti-patterns.md

Experimental ¶

Notice: This API is EXPERIMENTAL and may be changed or removed in a later release.

func WithServiceConfig deprecated added in v1.2.0

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 ¶ added in v1.2.0

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 ¶ added in v1.0.2

func WithStreamInterceptor(f StreamClientInterceptor) DialOption

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

func WithTimeout deprecated

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 ¶ added in v1.0.2

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 ¶ added in v1.7.0

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 or negative values 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 ¶ added in v1.4.0

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 ¶ added in v1.14.0

type EmptyDialOption struct{}

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

Experimental ¶

Notice: This type is EXPERIMENTAL and may be changed or removed in a later release.

type EmptyServerOption ¶ added in v1.21.0

type EmptyServerOption struct{}

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

Experimental ¶

Notice: This type is EXPERIMENTAL and may be changed or removed in a later release.

type FailFastCallOption ¶ added in v1.11.0

type FailFastCallOption struct {
	FailFast bool
}

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

Experimental ¶

Notice: This type is EXPERIMENTAL and may be changed or removed in a later release.

type ForceCodecCallOption ¶ added in v1.19.0

type ForceCodecCallOption struct {
	Codec encoding.Codec
}

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

Experimental ¶

Notice: This type is EXPERIMENTAL and may be changed or removed in a later release.

type HeaderCallOption ¶ added in v1.11.0

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.

Experimental ¶

Notice: This type is EXPERIMENTAL and may be changed or removed in a later release.

type MaxRecvMsgSizeCallOption ¶ added in v1.11.0

type MaxRecvMsgSizeCallOption struct {
	MaxRecvMsgSize int
}

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

Experimental ¶

Notice: This type is EXPERIMENTAL and may be changed or removed in a later release.

type MaxRetryRPCBufferSizeCallOption ¶ added in v1.14.0

type MaxRetryRPCBufferSizeCallOption struct {
	MaxRetryRPCBufferSize int
}

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

Experimental ¶

Notice: This type is EXPERIMENTAL and may be changed or removed in a later release.

type MaxSendMsgSizeCallOption ¶ added in v1.11.0

type MaxSendMsgSizeCallOption struct {
	MaxSendMsgSize int
}

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

Experimental ¶

Notice: This type is EXPERIMENTAL and may be changed or removed in a later release.

type MethodConfig deprecated added in v1.2.0

type MethodConfig = internalserviceconfig.MethodConfig

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 OnFinishCallOption ¶ added in v1.54.0

type OnFinishCallOption struct {
	OnFinish func(error)
}

OnFinishCallOption is CallOption that indicates a callback to be called when the call completes.

Experimental ¶

Notice: This type is EXPERIMENTAL and may be changed or removed in a later release.

type PeerCallOption ¶ added in v1.11.0

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.

Experimental ¶

Notice: This type is EXPERIMENTAL and may be changed or removed in a later release.

type PerRPCCredsCallOption ¶ added in v1.11.0

type PerRPCCredsCallOption struct {
	Creds credentials.PerRPCCredentials
}

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

Experimental ¶

Notice: This type is EXPERIMENTAL and may be changed or removed in a later release.

type PreparedMsg ¶ added in v1.21.0

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

PreparedMsg is responsible for creating a Marshalled and Compressed object.

Experimental ¶

Notice: This type is EXPERIMENTAL and may be changed or removed in a later release.

func (*PreparedMsg) Encode ¶ added in v1.21.0

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 ¶ added in v1.0.2

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.

Experimental ¶

Notice: This API is EXPERIMENTAL and may be changed or removed in a later release.

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 ¶ added in v1.28.0

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 ¶ added in v1.28.0

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 ¶ added in v1.7.3

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.

Experimental ¶

Notice: This API is EXPERIMENTAL and may be changed or removed in a later release.

func Creds ¶

func Creds(c credentials.TransportCredentials) ServerOption

Creds returns a ServerOption that sets credentials for server connections.

func CustomCodec deprecated

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 ForceServerCodec ¶ added in v1.38.0

func ForceServerCodec(codec encoding.Codec) ServerOption

ForceServerCodec 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.

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 encoding.Codec and content-subtype.

This function is provided for advanced users; prefer to 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.

Experimental ¶

Notice: This API is EXPERIMENTAL and may be changed or removed in a later release.

func HeaderTableSize ¶ added in v1.25.0

func HeaderTableSize(s uint32) ServerOption

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

Experimental ¶

Notice: This API is EXPERIMENTAL and may be changed or removed in a later release.

func InTapHandle ¶ added in v1.0.5

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.

Experimental ¶

Notice: This API is EXPERIMENTAL and may be changed or removed in a later release.

func InitialConnWindowSize ¶ added in v1.4.0

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 ¶ added in v1.4.0

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 ¶ added in v1.3.0

func KeepaliveEnforcementPolicy(kep keepalive.EnforcementPolicy) ServerOption

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

func KeepaliveParams ¶ added in v1.3.0

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 ¶ added in v1.14.0

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 deprecated added in v1.0.2

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 ¶ added in v1.4.0

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 ¶ added in v1.4.0

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 ¶ added in v1.30.0

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.

Experimental ¶

Notice: This API is EXPERIMENTAL and may be changed or removed in a later release.

func RPCCompressor deprecated

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 deprecated

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 ¶ added in v1.7.0

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 or negative values will disable read buffer for a connection so data framer can access the underlying conn directly.

func StatsHandler ¶ added in v1.2.0

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 ¶ added in v1.2.0

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 ¶ added in v1.7.0

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 or negative values 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.
	//
	// It is not safe to modify the message after calling SendMsg. Tracing
	// libraries and stats handlers may use the message lazily.
	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.

Errors returned from ServerStream methods are compatible with the status package. However, the status code will often not match the RPC status as seen by the client application, and therefore, should not be relied upon for this purpose.

type ServerTransportStream ¶ added in v1.11.0

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.

Experimental ¶

Notice: This type is EXPERIMENTAL and may be changed or removed in a later release.

func ServerTransportStreamFromContext ¶ added in v1.12.0

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).

Experimental ¶

Notice: This API is EXPERIMENTAL and may be changed or removed in a later release.

type ServiceConfig deprecated added in v1.2.0

type ServiceConfig struct {
	serviceconfig.Config

	// LB is the load balancer the service providers recommends.  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 ¶ added in v1.32.0

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 deprecated

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 ¶ added in v1.0.2

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

StreamClientInterceptor intercepts the creation of a ClientStream. Stream interceptors can be specified as a DialOption, using WithStreamInterceptor() or WithChainStreamInterceptor(), when creating a ClientConn. When a stream interceptor(s) is set on the ClientConn, gRPC delegates all stream creations to the interceptor, and it is the responsibility of the interceptor to call streamer.

desc contains a description of the stream. cc is the ClientConn on which the RPC was invoked. streamer is the handler to create a ClientStream and it is the responsibility of the interceptor to call it. opts contain all applicable call options, including defaults from the ClientConn as well as per-call options.

StreamClientInterceptor may return a custom ClientStream to intercept all I/O operations. The returned error must be compatible with the status package.

type StreamDesc ¶

type StreamDesc struct {
	// StreamName and Handler are only used when registering handlers on a
	// server.
	StreamName string        // the name of the method excluding the service
	Handler    StreamHandler // the handler called for the method

	// ServerStreams and ClientStreams are used for registering handlers on a
	// server as well as defining RPC behavior when passed to NewClientStream
	// and ClientConn.NewStream.  At least one must be true.
	ServerStreams bool // indicates the server can perform streaming sends
	ClientStreams bool // indicates the client can perform streaming sends
}

StreamDesc represents a streaming RPC service's method specification. Used on the server when registering services and on the client when initiating new streams.

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 either be produced by the status package, or be one of the context errors. Otherwise, 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 ¶ added in v1.0.2

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 ¶ added in v1.11.0

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.

Experimental ¶

Notice: This type is EXPERIMENTAL and may be changed or removed in a later release.

type UnaryClientInterceptor ¶ added in v1.0.2

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. Unary interceptors can be specified as a DialOption, using WithUnaryInterceptor() or WithChainUnaryInterceptor(), when creating a ClientConn. When a unary interceptor(s) is set on a ClientConn, gRPC delegates all unary RPC invocations to the interceptor, and it is the responsibility of the interceptor to call invoker to complete the processing of the RPC.

method is the RPC name. req and reply are the corresponding request and response messages. cc is the ClientConn on which the RPC was invoked. invoker is the handler to complete the RPC and it is the responsibility of the interceptor to call it. opts contain all applicable call options, including defaults from the ClientConn as well as per-call options.

The returned error must be compatible with the status package.

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 either be produced by the status package, or be one of the context errors. Otherwise, gRPC will use codes.Unknown as the status code and err.Error() as the status message of the RPC.

type UnaryInvoker ¶ added in v1.0.2

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 ¶

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README ¶

gRPC-Go

Prerequisites

Installation

Learn more

FAQ

I/O Timeout Errors

Compiling error, undefined: grpc.SupportPackageIsVersion

If you are using Go modules:

If you are not using Go modules:

How to turn on logging

The RPC failed with error "code = Unavailable desc = transport is closing"

Documentation ¶

Overview ¶

Index ¶

Constants ¶

Variables ¶

Functions ¶

func ClientSupportedCompressors ¶ added in v1.54.0

Experimental ¶

func Code deprecated

func ErrorDesc deprecated

func Errorf deprecated

func Invoke ¶

func Method ¶ added in v1.11.2

func MethodFromServerStream ¶ added in v1.8.0

func NewContextWithServerTransportStream ¶ added in v1.11.0

Experimental ¶

func SendHeader ¶

func SetHeader ¶ added in v1.0.3

func SetSendCompressor ¶ added in v1.54.0

Experimental ¶

func SetTrailer ¶

Types ¶

type BackoffConfig deprecated

type CallOption ¶

func CallContentSubtype ¶ added in v1.10.0

func CallCustomCodec deprecated added in v1.10.0

func FailFast deprecated

func ForceCodec ¶ added in v1.19.0

Experimental ¶

func Header ¶

func MaxCallRecvMsgSize ¶ added in v1.4.0

func MaxCallSendMsgSize ¶ added in v1.4.0

func MaxRetryRPCBufferSize ¶ added in v1.14.0

Experimental ¶

func OnFinish ¶ added in v1.54.0

Experimental ¶

func Peer ¶ added in v1.2.0

func PerRPCCredentials ¶ added in v1.4.0

func Trailer ¶

func UseCompressor ¶ added in v1.8.0

Experimental ¶

func WaitForReady ¶ added in v1.18.0

type ClientConn ¶

func Dial ¶

func DialContext ¶ added in v1.0.2

func (*ClientConn) Close ¶

func (*ClientConn) Connect ¶ added in v1.41.0

Experimental ¶

func (*ClientConn) GetMethodConfig ¶ added in v1.4.0

func (*ClientConn) GetState ¶ added in v1.5.2

Experimental ¶

func (*ClientConn) Invoke ¶ added in v1.8.0

func (*ClientConn) NewStream ¶ added in v1.8.0

func (*ClientConn) ResetConnectBackoff ¶ added in v1.15.0

Experimental ¶

func (*ClientConn) Target ¶ added in v1.14.0

Experimental ¶

func (*ClientConn) WaitForStateChange ¶ added in v1.5.2

Experimental ¶

type ClientConnInterface ¶ added in v1.27.0

type ClientStream ¶

func NewClientStream ¶

type Codec deprecated

type Compressor deprecated

func NewGZIPCompressor deprecated

func NewGZIPCompressorWithLevel deprecated added in v1.11.0

type CompressorCallOption ¶ added in v1.11.0

Experimental ¶

The RPC failed with error `"code = Unavailable desc = transport is closing"`