Package-Level Type Names (total 109, in which 49 are exported)
/* sort exporteds by: | */
BackoffConfig defines the parameters for the default gRPC backoff strategy.
Deprecated: use ConnectParams instead. Will be supported throughout 1.x. MaxDelay is the upper bound of backoff delay.
func WithBackoffConfig(b BackoffConfig) DialOption
var DefaultBackoffConfig
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. // See determineAuthority(). // Uses gracefulswitch.balancer underneath.blockingpicker*pickerWrapper // Cancelled on close. // Channelz identifier for the channel. // Set to nil on close. The following provide their own synchronization, and therefore don't
require cc.mu to be held to access them. // Initialized using the background context at dial time.czData*channelzData // Default and user specified dial options. firstResolveEvent is used to track whether the name resolver sent us at
least one update. RPCs block on this event.lastConnectionErrorerror // protects lastConnectionError // May be updated upon receipt of a GoAway. mu protects the following fields.
TODO: split mu so the same mutex isn't used for everything. // See parseTargetAndFindResolver(). // Initialized in Dial; cleared in Close. // Updated from service config.safeConfigSelectoriresolver.SafeConfigSelector // Latest service config received from the resolver. The following are initialized at dial time, and are read-only after that. // User's dial target. Close tears down the ClientConn and all underlying connections. 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. 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. GetState returns the connectivity.State of ClientConn.
# Experimental
Notice: This API is EXPERIMENTAL and may be changed or removed in a later
release. 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. 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. 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. Target returns the target string of the ClientConn.
# Experimental
Notice: This API is EXPERIMENTAL and may be changed or removed in a
later release. 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. applyFailingLB is akin to configuring an LB policy on the channel which
always fails RPCs. Here, an actual LB policy is not configured, but an always
erroring picker is configured, which returns errors with information about
what was invalid in the received service config. A config selector with no
service config is configured, and the connectivity state of the channel is
set to TransientFailure.
Caller must hold cc.mu.(*ClientConn) applyServiceConfigAndBalancer(sc *ServiceConfig, configSelector iresolver.ConfigSelector, addrs []resolver.Address)(*ClientConn) channelzMetric() *channelz.ChannelInternalMetric(*ClientConn) connectionError() error(*ClientConn) getResolver(scheme string) resolver.Builder getServerName determines the serverName to be used in the connection
handshake. The default value for the serverName is the authority on the
ClientConn, which either comes from the user's dial target or through an
authority override specified using the WithAuthority dial option. Name
resolvers can specify a per-address override for the serverName through the
resolver.Address.ServerName field which is used only if the WithAuthority
dial option was not used. The rationale is that per-address authority
overrides specified by the name resolver can represent a security risk, while
an override specified by the user is more dependable since they probably know
what they are doing.(*ClientConn) getTransport(ctx context.Context, failfast bool, method string) (transport.ClientTransport, balancer.PickResult, error)(*ClientConn) handleSubConnStateChange(sc balancer.SubConn, s connectivity.State, err error)(*ClientConn) healthCheckConfig() *healthCheckConfig(*ClientConn) incrCallsFailed()(*ClientConn) incrCallsStarted()(*ClientConn) incrCallsSucceeded()(*ClientConn) maybeApplyDefaultServiceConfig(addrs []resolver.Address) newAddrConn creates an addrConn for addrs and adds it to cc.conns.
Caller needs to make sure len(addrs) > 0.(*ClientConn) parseTargetAndFindResolver() (resolver.Builder, error) removeAddrConn removes the addrConn in the subConn from clientConn.
It also tears down the ac with the given error.(*ClientConn) resolveNow(o resolver.ResolveNowOptions)(*ClientConn) scWatcher()(*ClientConn) updateConnectionError(err error)(*ClientConn) updateResolverState(s resolver.State, err error) error waitForResolvedAddrs blocks until the resolver has provided addresses or the
context expires. Returns nil unless the context expires first; otherwise
returns a status error based on the context.
*ClientConn : ClientConnInterface
*ClientConn : io.Closer
func Dial(target string, opts ...DialOption) (*ClientConn, error)
func DialContext(ctx context.Context, target string, opts ...DialOption) (conn *ClientConn, err error)
func Invoke(ctx context.Context, method string, args, reply interface{}, cc *ClientConn, opts ...CallOption) error
func NewClientStream(ctx context.Context, desc *StreamDesc, cc *ClientConn, method string, opts ...CallOption) (ClientStream, error)
func chainStreamClientInterceptors(cc *ClientConn)
func chainUnaryClientInterceptors(cc *ClientConn)
func invoke(ctx context.Context, method string, req, reply interface{}, cc *ClientConn, opts ...CallOption) error
func newCCBalancerWrapper(cc *ClientConn, bopts balancer.BuildOptions) *ccBalancerWrapper
func newCCResolverWrapper(cc *ClientConn, rb resolver.Builder) (*ccResolverWrapper, error)
func newClientStream(ctx context.Context, desc *StreamDesc, cc *ClientConn, method string, opts ...CallOption) (_ ClientStream, err error)
func newClientStreamWithParams(ctx context.Context, desc *StreamDesc, cc *ClientConn, method string, mc serviceconfig.MethodConfig, onCommit, doneFunc func(), opts ...CallOption) (_ iresolver.ClientStream, err 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. Invoke performs a unary RPC and returns after the response is received
into reply. NewStream begins a streaming RPC.
*ClientConn
*acBalancerWrapper
ClientStream defines the client-side behavior of a streaming RPC.
All errors returned from ClientStream methods are compatible with the
status package. 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. 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. Header returns the header metadata received from the server if there
is any. It blocks if the metadata is not ready to read. 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. 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. 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).
google.golang.org/grpc/internal/resolver.ClientStream(interface)
*addrConnStream
*clientStream
ClientStream : Stream
ClientStream : google.golang.org/grpc/internal/resolver.ClientStream
func NewClientStream(ctx context.Context, desc *StreamDesc, cc *ClientConn, method string, opts ...CallOption) (ClientStream, error)
func (*ClientConn).NewStream(ctx context.Context, desc *StreamDesc, method string, opts ...CallOption) (ClientStream, error)
func ClientConnInterface.NewStream(ctx context.Context, desc *StreamDesc, method string, opts ...CallOption) (ClientStream, error)
func newClientStream(ctx context.Context, desc *StreamDesc, cc *ClientConn, method string, opts ...CallOption) (_ ClientStream, err error)
func newNonRetryClientStream(ctx context.Context, desc *StreamDesc, method string, t transport.ClientTransport, ac *addrConn, opts ...CallOption) (_ ClientStream, err error)
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. Marshal returns the wire format of v. String returns the name of the Codec implementation. This is unused by
gRPC. Unmarshal parses the wire format into v.
Codec : expvar.Var
Codec : fmt.Stringer
Codec : baseCodec
Codec : context.stringer
Codec : github.com/aws/smithy-go/middleware.stringer
Codec : runtime.stringer
func CallCustomCodec(codec Codec) CallOption
func CustomCodec(codec Codec) ServerOption
func WithCodec(c Codec) DialOption
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.CompressorTypestring( CompressorCallOption) after(c *callInfo, attempt *csAttempt)( CompressorCallOption) before(c *callInfo) error
CompressorCallOption : CallOption
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. Backoff specifies the configuration options for connection backoff. MinConnectTimeout is the minimum amount of time we are willing to give a
connection to complete.
func WithConnectParams(p ConnectParams) DialOption
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.ContentSubtypestring( ContentSubtypeCallOption) after(c *callInfo, attempt *csAttempt)( ContentSubtypeCallOption) before(c *callInfo) error
ContentSubtypeCallOption : CallOption
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.CodecCodec( CustomCodecCallOption) after(c *callInfo, attempt *csAttempt)( CustomCodecCallOption) before(c *callInfo) error
CustomCodecCallOption : CallOption
EmptyCallOption does not alter the Call configuration.
It can be embedded in another structure to carry satellite data for use
by interceptors.( EmptyCallOption) after(*callInfo, *csAttempt)( EmptyCallOption) before(*callInfo) error
EmptyCallOption : CallOption
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.( EmptyDialOption) apply(*dialOptions)
EmptyDialOption : DialOption
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.( EmptyServerOption) apply(*serverOptions)
EmptyServerOption : ServerOption
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.FailFastbool( FailFastCallOption) after(c *callInfo, attempt *csAttempt)( FailFastCallOption) before(c *callInfo) error
FailFastCallOption : CallOption
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.Codecencoding.Codec( ForceCodecCallOption) after(c *callInfo, attempt *csAttempt)( ForceCodecCallOption) before(c *callInfo) error
ForceCodecCallOption : CallOption
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.HeaderAddr*metadata.MD( HeaderCallOption) after(c *callInfo, attempt *csAttempt)( HeaderCallOption) before(c *callInfo) error
HeaderCallOption : CallOption
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.MaxRecvMsgSizeint( MaxRecvMsgSizeCallOption) after(c *callInfo, attempt *csAttempt)( MaxRecvMsgSizeCallOption) before(c *callInfo) error
MaxRecvMsgSizeCallOption : CallOption
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.MaxRetryRPCBufferSizeint( MaxRetryRPCBufferSizeCallOption) after(c *callInfo, attempt *csAttempt)( MaxRetryRPCBufferSizeCallOption) before(c *callInfo) error
MaxRetryRPCBufferSizeCallOption : CallOption
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.MaxSendMsgSizeint( MaxSendMsgSizeCallOption) after(c *callInfo, attempt *csAttempt)( MaxSendMsgSizeCallOption) before(c *callInfo) error
MaxSendMsgSizeCallOption : CallOption
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
MethodInfo contains the information of an RPC including its method name and type. IsClientStream indicates whether the RPC is a client streaming RPC. IsServerStream indicates whether the RPC is a server streaming RPC. Name is the method name only, without the service name or package name.
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.PeerAddr*peer.Peer( PeerCallOption) after(c *callInfo, attempt *csAttempt)( PeerCallOption) before(c *callInfo) error
PeerCallOption : CallOption
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.Credscredentials.PerRPCCredentials( PerRPCCredsCallOption) after(c *callInfo, attempt *csAttempt)( PerRPCCredsCallOption) before(c *callInfo) error
PerRPCCredsCallOption : CallOption
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. Struct for preparing msg before sending themhdr[]bytepayload[]byte Encode marshalls and compresses the message using the codec and compressor for the stream.
Server is a gRPC server to serve RPC requests.channelzID*channelz.IdentifierchannelzRemoveOncesync.Once conns contains all active server transports. It is a map keyed on a
listener address with the value being the set of active transports
belonging to that listener. // signaled when connections close for GracefulStopczData*channelzDatadone*grpcsync.Eventdrainbooleventstrace.EventLoglismap[net.Listener]bool // guards followingoptsserverOptionsquit*grpcsync.Eventservebool // counts active Serve goroutines for GracefulStopserverWorkerChannels[]chan *serverWorkerData // service name -> service info GetServiceInfo returns a map from service names to ServiceInfo.
Service names include the package names, in the form of <package>.<service>. 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. 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. 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. 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. 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.(*Server) addConn(addr string, st transport.ServerTransport) bool(*Server) channelzMetric() *channelz.ServerInternalMetric(*Server) drainServerTransports(addr string) errorf records an error in s's event log, unless s has been stopped.
REQUIRES s.mu is held. contentSubtype must be lowercase
cannot return nil handleRawConn forks a goroutine to handle a just-accepted connection that
has not had any I/O performed on it yet.(*Server) handleStream(t transport.ServerTransport, stream *transport.Stream, trInfo *traceInfo)(*Server) incrCallsFailed()(*Server) incrCallsStarted()(*Server) incrCallsSucceeded() initServerWorkers creates worker goroutines and channels to process incoming
connections to reduce the time spent overall on runtime.morestack. newHTTP2Transport sets up a http/2 transport (using the
gRPC http2 server transport in transport/http2_server.go). printf records an event in s's event log, unless s has been stopped.
REQUIRES s.mu is held.(*Server) processStreamingRPC(t transport.ServerTransport, stream *transport.Stream, info *serviceInfo, sd *StreamDesc, trInfo *traceInfo) (err error)(*Server) processUnaryRPC(t transport.ServerTransport, stream *transport.Stream, info *serviceInfo, md *MethodDesc, trInfo *traceInfo) (err error)(*Server) register(sd *ServiceDesc, ss interface{})(*Server) removeConn(addr string, st transport.ServerTransport)(*Server) sendResponse(t transport.ServerTransport, stream *transport.Stream, msg interface{}, cp Compressor, opts *transport.Options, comp encoding.Compressor) error(*Server) serveStreams(st transport.ServerTransport) serverWorkers blocks on a *transport.Stream channel forever and waits for
data to be fed by serveStreams. This allows different requests to be
processed by the same goroutine, removing the need for expensive stack
re-allocations (see the runtime.morestack problem [1]).
[1] https://github.com/golang/go/issues/18138(*Server) stopServerWorkers() traceInfo returns a traceInfo and associates it with stream, if tracing is enabled.
If tracing is not enabled, it returns nil.
*Server : ServiceRegistrar
*Server : net/http.Handler
func NewServer(opt ...ServerOption) *Server
func go.pact.im/x/grpcprocess.Server(srv *Server, lis net.Listener) process.Runnable
func chainStreamServerInterceptors(s *Server)
func chainUnaryServerInterceptors(s *Server)
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. Context returns the context for this stream. 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. SendHeader sends the header metadata.
The provided md and headers set by SetHeader() will be sent.
It fails if called multiple times. 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. 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). 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.
*serverStream
ServerStream : Stream
func MethodFromServerStream(stream ServerStream) (string, bool)
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.( ServerTransportStream) Method() string( ServerTransportStream) SendHeader(md metadata.MD) error( ServerTransportStream) SetHeader(md metadata.MD) error( ServerTransportStream) SetTrailer(md metadata.MD) error
*google.golang.org/grpc/internal/transport.Stream
func ServerTransportStreamFromContext(ctx context.Context) ServerTransportStream
func NewContextWithServerTransportStream(ctx context.Context, stream ServerTransportStream) context.Context
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.mdConfigserviceconfig.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. 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. healthCheckConfig must be set as one of the requirement to enable LB channel
health check. lbConfig is the service config's load balancing configuration. If
lbConfig and LB are both present, lbConfig will be used. rawJSONString stores service config json string that get parsed into
this service config struct. If a retryThrottlingPolicy is provided, gRPC will automatically throttle
retry attempts and hedged RPCs when the client’s ratio of failures to
successes exceeds a threshold.
For each server name, the gRPC client will maintain a token_count which is
initially set to maxTokens, and can take values between 0 and maxTokens.
Every outgoing RPC (regardless of service or method invoked) will change
token_count as follows:
- Every failed RPC will decrement the token_count by 1.
- Every successful RPC will increment the token_count by tokenRatio.
If token_count is less than or equal to maxTokens / 2, then RPCs will not
be retried and hedged RPCs will not be sent.( ServiceConfig) isServiceConfig()
ServiceConfig : google.golang.org/grpc/serviceconfig.Config
func WithServiceConfig(c <-chan ServiceConfig) DialOption
func getMethodConfig(sc *ServiceConfig, method string) MethodConfig
func (*ClientConn).applyServiceConfigAndBalancer(sc *ServiceConfig, configSelector iresolver.ConfigSelector, addrs []resolver.Address)
var emptyServiceConfig *ServiceConfig
ServiceInfo contains unary RPC method info, streaming RPC method info and metadata for a service. Metadata is the metadata specified in ServiceDesc when registering service.Methods[]MethodInfo
func (*Server).GetServiceInfo() map[string]ServiceInfo
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. 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.
*Server
Stream defines the common interface a client or server stream has to satisfy.
Deprecated: See ClientStream and ServerStream documentation instead. Deprecated: See ClientStream and ServerStream documentation instead. Deprecated: See ClientStream and ServerStream documentation instead. Deprecated: See ClientStream and ServerStream documentation instead.ClientStream(interface)ServerStream(interface)
google.golang.org/grpc/internal/resolver.ClientStream(interface)
*addrConnStream
*clientStream
*serverStream
func (*PreparedMsg).Encode(s Stream, msg interface{}) 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.
func WithChainStreamInterceptor(interceptors ...StreamClientInterceptor) DialOption
func WithStreamInterceptor(f StreamClientInterceptor) DialOption
func getChainStreamer(interceptors []StreamClientInterceptor, curr int, finalStreamer Streamer) Streamer
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.
func getChainStreamHandler(interceptors []StreamServerInterceptor, curr int, info *StreamServerInfo, finalHandler StreamHandler) StreamHandler
func UnknownServiceHandler(streamHandler StreamHandler) ServerOption
func getChainStreamHandler(interceptors []StreamServerInterceptor, curr int, info *StreamServerInfo, finalHandler StreamHandler) StreamHandler
StreamServerInfo consists of various information about a streaming RPC on
server side. All per-rpc information may be mutated by the interceptor. FullMethod is the full RPC method string, i.e., /package.service/method. IsClientStream indicates whether the RPC is a client streaming RPC. IsServerStream indicates whether the RPC is a server streaming RPC.
func getChainStreamHandler(interceptors []StreamServerInterceptor, curr int, info *StreamServerInfo, finalHandler StreamHandler) StreamHandler
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.
func chainStreamInterceptors(interceptors []StreamServerInterceptor) StreamServerInterceptor
func ChainStreamInterceptor(interceptors ...StreamServerInterceptor) ServerOption
func StreamInterceptor(i StreamServerInterceptor) ServerOption
func chainStreamInterceptors(interceptors []StreamServerInterceptor) StreamServerInterceptor
func getChainStreamHandler(interceptors []StreamServerInterceptor, curr int, info *StreamServerInfo, finalHandler StreamHandler) StreamHandler
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.TrailerAddr*metadata.MD( TrailerCallOption) after(c *callInfo, attempt *csAttempt)( TrailerCallOption) before(c *callInfo) error
TrailerCallOption : CallOption
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.
func WithChainUnaryInterceptor(interceptors ...UnaryClientInterceptor) DialOption
func WithUnaryInterceptor(f UnaryClientInterceptor) DialOption
func getChainUnaryInvoker(interceptors []UnaryClientInterceptor, curr int, finalInvoker UnaryInvoker) UnaryInvoker
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.
func getChainUnaryHandler(interceptors []UnaryServerInterceptor, curr int, info *UnaryServerInfo, finalHandler UnaryHandler) UnaryHandler
func getChainUnaryHandler(interceptors []UnaryServerInterceptor, curr int, info *UnaryServerInfo, finalHandler UnaryHandler) UnaryHandler
UnaryServerInfo consists of various information about a unary RPC on
server side. All per-rpc information may be mutated by the interceptor. FullMethod is the full RPC method string, i.e., /package.service/method. Server is the service implementation the user provides. This is read-only.
func getChainUnaryHandler(interceptors []UnaryServerInterceptor, curr int, info *UnaryServerInfo, finalHandler UnaryHandler) UnaryHandler
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.
func chainUnaryInterceptors(interceptors []UnaryServerInterceptor) UnaryServerInterceptor
func ChainUnaryInterceptor(interceptors ...UnaryServerInterceptor) ServerOption
func UnaryInterceptor(i UnaryServerInterceptor) ServerOption
func chainUnaryInterceptors(interceptors []UnaryServerInterceptor) UnaryServerInterceptor
func getChainUnaryHandler(interceptors []UnaryServerInterceptor, curr int, info *UnaryServerInfo, finalHandler UnaryHandler) UnaryHandler
addrConn is a network connection to a given address.acbwbalancer.SubConn // All addresses that the resolver resolved to. // Needs to be stateful for resetConnectBackoff.cancelcontext.CancelFunccc*ClientConnchannelzID*channelz.Identifierctxcontext.Context // The current address.czData*channelzDatadoptsdialOptionsmusync.MutexresetBackoffchan struct{}scoptsbalancer.NewSubConnOptions Use updateConnectivityState for updating addrConn's connectivity state. transport is set when there's a viable transport (note: ac state may not be READY as LB channel
health checking may require server to report healthy to set ac to READY), and is reset
to nil when the current transport should no longer be used to create a stream (e.g. after GoAway
is received, transport is closed, ac has been torn down). // The current transport.(*addrConn) ChannelzMetric() *channelz.ChannelInternalMetric adjustParams updates parameters used to create transports upon
receiving a GoAway. connect starts creating a transport.
It does nothing if the ac is not IDLE.
TODO(bar) Move this to the addrConn section. createTransport creates a connection to addr. It returns an error if the
address was not successfully connected, or updates ac appropriately with the
new transport. getReadyTransport returns the transport if ac's state is READY or nil if not.(*addrConn) getState() connectivity.State(*addrConn) incrCallsFailed()(*addrConn) incrCallsStarted()(*addrConn) incrCallsSucceeded()(*addrConn) resetConnectBackoff()(*addrConn) resetTransport() startHealthCheck starts the health checking stream (RPC) to watch the health
stats of this connection if health checking is requested and configured.
LB channel health checking is enabled when all requirements below are met:
1. it is not disabled by the user with the WithDisableHealthCheck DialOption
2. internal.HealthCheckFunc is set by importing the grpc/health package
3. a service config with non-empty healthCheckConfig field is provided
4. the load balancer requests it
It sets addrConn to READY if the health checking stream is not started.
Caller must hold ac.mu. tearDown starts to tear down the addrConn.
Note that tearDown doesn't remove ac from ac.cc.conns, so the addrConn struct
will leak. In most cases, call cc.removeAddrConn() instead. tryAllAddrs tries to creates a connection to the addresses, and stop when at
the first successful one. It returns an error if no address was successfully
connected, or updates ac appropriately with the new transport. tryUpdateAddrs tries to update ac.addrs with the new addresses list.
If ac is TransientFailure, it updates ac.addrs and returns true. The updated
addresses will be picked up by retry in the next iteration after backoff.
If ac is Shutdown or Idle, it updates ac.addrs and returns true.
If the addresses is the same as the old list, it does nothing and returns
true.
If ac is Connecting, it returns false. The caller should tear down the ac and
create a new one. Note that the backoff will be reset when this happens.
If ac is Ready, it checks whether current connected address of ac is in the
new addrs list.
- If true, it updates ac.addrs and returns true. The ac will keep using
the existing connection.
- If false, it does nothing and returns false. Note: this requires a lock on ac.mu.
*addrConn : google.golang.org/grpc/internal/channelz.Channel
func (*ClientConn).newAddrConn(addrs []resolver.Address, opts balancer.NewSubConnOptions) (*addrConn, error)
func newNonRetryClientStream(ctx context.Context, desc *StreamDesc, method string, t transport.ClientTransport, ac *addrConn, opts ...CallOption) (_ ClientStream, err error)
func (*ClientConn).removeAddrConn(ac *addrConn, err error)
ccBalancerWrapper sits between the ClientConn and the Balancer.
ccBalancerWrapper implements methods corresponding to the ones on the
balancer.Balancer interface. The ClientConn is free to call these methods
concurrently and the ccBalancerWrapper ensures that calls from the ClientConn
to the Balancer happen synchronously and in order.
ccBalancerWrapper also implements the balancer.ClientConn interface and is
passed to the Balancer implementations. It invokes unexported methods on the
ClientConn to handle these calls from the Balancer.
It uses the gracefulswitch.Balancer internally to ensure that balancer
switches happen in a graceful manner. Since these fields are accessed only from handleXxx() methods which are
synchronized by the watcher goroutine, we do not need a mutex to protect
these fields.cc*ClientConn // Indicates if close has been called.curBalancerNamestring // Indicates if close has completed its work. // Results of calls to UpdateClientConnState() are pushed here. // Updates written on this channel are processed by watcher().(*ccBalancerWrapper) NewSubConn(addrs []resolver.Address, opts balancer.NewSubConnOptions) (balancer.SubConn, error)(*ccBalancerWrapper) RemoveSubConn(sc balancer.SubConn)(*ccBalancerWrapper) ResolveNow(o resolver.ResolveNowOptions)(*ccBalancerWrapper) Target() string(*ccBalancerWrapper) UpdateAddresses(sc balancer.SubConn, addrs []resolver.Address)(*ccBalancerWrapper) UpdateState(s balancer.State)(*ccBalancerWrapper) close()(*ccBalancerWrapper) exitIdle() handleClientConnStateChange handles a ClientConnState update from the update
channel and invokes the appropriate method on the underlying balancer.
If the addresses specified in the update contain addresses of type "grpclb"
and the selected LB policy is not "grpclb", these addresses will be filtered
out and ccs will be modified with the updated address list.(*ccBalancerWrapper) handleClose()(*ccBalancerWrapper) handleExitIdle() handleRemoveSucConn handles a request from the underlying balancer to remove
a subConn.
See comments in RemoveSubConn() for more details.(*ccBalancerWrapper) handleResolverError(err error) handleSubConnStateChange handles a SubConnState update from the update
channel and invokes the appropriate method on the underlying balancer. handleSwitchTo handles a balancer switch update from the update channel. It
calls the SwitchTo() method on the gracefulswitch.Balancer with a
balancer.Builder corresponding to name. If no balancer.Builder is registered
for the given name, it uses the default LB policy which is "pick_first".(*ccBalancerWrapper) resolverError(err error) switchTo is invoked by grpc to instruct the balancer wrapper to switch to the
LB policy identified by name.
ClientConn calls newCCBalancerWrapper() at creation time. Upon receipt of the
first good update from the name resolver, it determines the LB policy to use
and invokes the switchTo() method. Upon receipt of every subsequent update
from the name resolver, it invokes this method.
the ccBalancerWrapper keeps track of the current LB policy name, and skips
the graceful balancer switching process if the name does not change. updateClientConnState is invoked by grpc to push a ClientConnState update to
the underlying balancer.
Unlike other methods invoked by grpc to push updates to the underlying
balancer, this method cannot simply push the update onto the update channel
and return. It needs to return the error returned by the underlying balancer
back to grpc which propagates that to the resolver. updateSubConnState is invoked by grpc to push a subConn state update to the
underlying balancer. watcher is a long-running goroutine which reads updates from a channel and
invokes corresponding methods on the underlying balancer. It ensures that
these methods are invoked in a synchronous fashion. It also ensures that
these methods are invoked in the order in which the updates were received.
*ccBalancerWrapper : google.golang.org/grpc/balancer.ClientConn
func newCCBalancerWrapper(cc *ClientConn, bopts balancer.BuildOptions) *ccBalancerWrapper
channelzData is used to store channelz related data for ClientConn, addrConn and Server.
These fields cannot be embedded in the original structs (e.g. ClientConn), since to do atomic
operation on int64 variable on 32-bit machine, user is responsible to enforce memory alignment.
Here, by grouping those int64 fields inside a struct, we are enforcing the alignment.callsFailedint64callsStartedint64callsSucceededint64 lastCallStartedTime stores the timestamp that last call starts. It is of int64 type instead of
time.Time since it's more costly to atomically update time.Time variable than int64 variable.
clientStream implements a client side Stream. attempt is the active client stream attempt.
The only place where it is written is the newAttemptLocked method and this method never writes nil.
So, attempt can be nil only inside newClientStream function when clientStream is first created.
One of the first things done after clientStream's creation, is to call newAttemptLocked which either
assigns a non nil value to the attempt or returns an error. If an error is returned from newAttemptLocked,
then newClientStream calls finish on the clientStream and returns. So, finish method is the only
place where we need to check if the attempt is nil.binlogs[]binarylog.MethodLogger // operations to replay on retry // current size of buffercallHdr*transport.CallHdrcallInfo*callInfo // cancels all attemptscc*ClientConncodecbaseCodec TODO(hedging): hedging will have multiple attempts simultaneously. // active attempt committed for retry?compencoding.CompressorcpCompressor // the application's context, wrapped by stats/tracingdesc*StreamDesc // TODO: replace with atomic cmpxchg or sync.Once? // if true, transparent retry is validmethodConfig*MethodConfigmusync.Mutex // exclusive of transparent retry attempt(s) // retries since pushback; to reset backoffonCommitfunc()opts[]CallOption // The throttler active when the RPC began. // sent an end stream serverHeaderBinlogged is a boolean for whether server header has been
logged. Server header will be logged when the first time one of those
happens: stream.Header(), stream.Recv().
It's only read and used by Recv() and Header(), so it doesn't need to be
synchronized.(*clientStream) CloseSend() error(*clientStream) Context() context.Context(*clientStream) Header() (metadata.MD, error)(*clientStream) RecvMsg(m interface{}) error(*clientStream) SendMsg(m interface{}) (err error)(*clientStream) Trailer() metadata.MD(*clientStream) bufferForRetryLocked(sz int, op func(a *csAttempt) error)(*clientStream) commitAttempt()(*clientStream) commitAttemptLocked()(*clientStream) finish(err error) newAttemptLocked creates a new csAttempt without a transport or stream.(*clientStream) replayBufferLocked(attempt *csAttempt) error Returns nil if a retry was performed and succeeded; error otherwise.(*clientStream) withRetry(op func(a *csAttempt) error, onSuccess func()) error
*clientStream : ClientStream
*clientStream : Stream
*clientStream : google.golang.org/grpc/internal/resolver.ClientStream
Information about Preloader
Responsible for storing codec, and compressors
If stream (s) has context s.Context which stores rpcInfo that has non nil
pointers to codec, and compressors, then we can use preparedMsg for Async message prep
and reuse marshalled bytescodecbaseCodeccompencoding.CompressorcpCompressor
connectivityStateManager keeps the connectivity.State of ClientConn.
This struct will eventually be exported so the balancers can access it.channelzID*channelz.Identifiermusync.MutexnotifyChanchan struct{}stateconnectivity.State(*connectivityStateManager) getNotifyChan() <-chan struct{}(*connectivityStateManager) getState() connectivity.State updateState updates the connectivity.State of ClientConn.
If there's a change it notifies goroutines waiting on state change to
happen.
dropError is a wrapper error that indicates the LB policy wishes to drop the
RPC and not retry it.errorerror( dropError) Error() builtin.string
dropError : error
firstLine is the first line of an RPC trace.
It may be mutated after construction; remoteAddr specifically may change
during client-side use. // whether this is a client (outgoing) RPC // may be zeromusync.MutexremoteAddrnet.Addr(*firstLine) SetRemoteAddr(addr net.Addr)(*firstLine) String() string
*firstLine : expvar.Var
*firstLine : fmt.Stringer
*firstLine : context.stringer
*firstLine : github.com/aws/smithy-go/middleware.stringer
*firstLine : runtime.stringer
healthCheckConfig defines the go-native version of the LB channel health check config. serviceName is the service name to use in the health-checking request.
func (*ClientConn).healthCheckConfig() *healthCheckConfig
parser reads complete gRPC messages from the underlying reader. The header of a gRPC message. Find more detail at
https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md r is the underlying reader.
See the comment on recvMsg for the permissible
error types. recvMsg reads a complete gRPC message from the stream.
It returns the message and its payload (compression/encoding)
format. The caller owns the returned msg memory.
If there is an error, possible values are:
- io.EOF, when no messages remain
- io.ErrUnexpectedEOF
- of type transport.ConnectionError
- an error from the status package
No other error values or types must be returned, which also means
that the underlying io.Reader must not return an incompatible
error.
func recv(p *parser, c baseCodec, s *transport.Stream, dc Decompressor, m interface{}, maxReceiveMessageSize int, payInfo *payloadInfo, compressor encoding.Compressor) error
func recvAndDecompress(p *parser, s *transport.Stream, dc Decompressor, maxReceiveMessageSize int, payInfo *payloadInfo, compressor encoding.Compressor) ([]byte, error)
payload represents an RPC request or response payload. // e.g. a proto.Message // whether this is an outgoing payload( payload) String() string
payload : expvar.Var
payload : fmt.Stringer
payload : context.stringer
payload : github.com/aws/smithy-go/middleware.stringer
payload : runtime.stringer
pickerWrapper is a wrapper of balancer.Picker. It blocks on certain pick
actions and unblock when there's a picker update.blockingChchan struct{}doneboolmusync.Mutexpickerbalancer.Picker(*pickerWrapper) close() pick returns the transport that will be used for the RPC.
It may block in the following cases:
- there's no picker
- the current picker returns ErrNoSubConnAvailable
- the current picker returns other errors and failfast is false.
- the subConn returned by the current picker is not READY
When one of these situations happens, pick blocks until the picker gets updated. updatePicker is called by UpdateBalancerState. It unblocks all blocked pick.
func newPickerWrapper() *pickerWrapper
maxfloat64musync.Mutexratiofloat64threshfloat64 // TODO(dfawley): replace with atomic and remove lock.(*retryThrottler) successfulRPC() throttle subtracts a retry token from the pool and returns whether a retry
should be throttled (disallowed) based upon the retry throttling policy in
the service config.
retryThrottlingPolicy defines the go-native version of the retry throttling
policy defined by the service config here:
https://github.com/grpc/proposal/blob/master/A6-client-retries.md#integration-with-service-config The number of tokens starts at maxTokens. The token_count will always be
between 0 and maxTokens.
This field is required and must be greater than zero. The amount of tokens to add on each successful RPC. Typically this will
be some number between 0 and 1, e.g., 0.1.
This field is required and must be greater than zero. Up to 3 decimal
places are supported.
Package-Level Functions (total 160, in which 96 are exported)
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.
CallCustomCodec behaves like ForceCodec, but accepts a grpc.Codec instead of
an encoding.Codec.
Deprecated: use ForceCodec instead.
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.
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.
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.
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.
Creds returns a ServerOption that sets credentials for server connections.
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.
Dial creates a client connection to the given target.
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.
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.
Errorf returns an error containing an error code and a description;
Errorf returns nil if c is OK.
Deprecated: use status.Errorf instead.
FailFast is the opposite of WaitForReady.
Deprecated: use WaitForReady.
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().
# Experimental
Notice: This API is EXPERIMENTAL and may be changed or removed in a
later release.
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.
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.
Header returns a CallOptions that retrieves the header metadata
for a unary RPC.
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.
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.
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.
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.
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.
KeepaliveEnforcementPolicy returns a ServerOption that sets keepalive enforcement policy for the server.
KeepaliveParams returns a ServerOption that sets keepalive and max-age parameters for the server.
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.
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`.
MaxConcurrentStreams returns a ServerOption that will apply a limit on the number
of concurrent streams to each ServerTransport.
MaxHeaderListSize returns a ServerOption that sets the max (uncompressed) size
of header list that the server is prepared to accept.
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.
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.
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.
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`.
Method returns the method string for the server context. The returned
string is in the format of "/service/method".
MethodFromServerStream returns the method string for the input stream.
The returned string is in the format of "/service/method".
NewClientStream is a wrapper for ClientConn.NewStream.
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.
NewGZIPCompressor creates a Compressor based on GZIP.
Deprecated: use package encoding/gzip.
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.
NewGZIPDecompressor creates a Decompressor based on GZIP.
Deprecated: use package encoding/gzip.
NewServer creates a gRPC server which has no service registered and has not
started to accept requests yet.
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.
Peer returns a CallOption that retrieves peer information for a unary RPC.
The peer field will be populated *after* the RPC completes.
PerRPCCredentials returns a CallOption that sets credentials.PerRPCCredentials
for a call.
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.
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.
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.
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.
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.
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.
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.
StatsHandler returns a ServerOption that sets the stats handler for the server.
StreamInterceptor returns a ServerOption that sets the StreamServerInterceptor for the
server. Only one stream interceptor can be installed.
Trailer returns a CallOptions that retrieves the trailer metadata
for a unary RPC.
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.
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.
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.
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".
WithAuthority returns a DialOption that specifies the value to be used as the
:authority pseudo-header and as the server name in authentication handshake.
WithBackoffConfig configures the dialer to use the provided backoff
parameters after connection failures.
Deprecated: use WithConnectParams instead. Will be supported throughout 1.x.
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.
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.
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.
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.
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.
WithCodec returns a DialOption which sets a codec for message marshaling and
unmarshaling.
Deprecated: use WithDefaultCallOptions(ForceCodec(_)) instead. Will be
supported throughout 1.x.
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.
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.
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.
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.
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.
WithDefaultCallOptions returns a DialOption which sets the default
CallOptions for calls over the connection.
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
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.
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.
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.
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.
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.
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.
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.
WithKeepaliveParams returns a DialOption that specifies keepalive parameters
for the client transport.
WithMaxHeaderListSize returns a DialOption that specifies the maximum
(uncompressed) size of header list that the client is prepared to accept.
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.
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.
WithPerRPCCredentials returns a DialOption which sets credentials and places
auth state on each outbound RPC.
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.
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.
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()
# Experimental
Notice: This API is EXPERIMENTAL and may be changed or removed in a
later release.
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.
WithStatsHandler returns a DialOption that specifies the stats handler for
all the RPCs and underlying network connections in this ClientConn.
WithStreamInterceptor returns a DialOption that specifies the interceptor for
streaming RPCs.
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.
WithTransportCredentials returns a DialOption which configures a connection
level security credentials (e.g., TLS/SSL). This should not be used together
with WithCredentialsBundle.
WithUnaryInterceptor returns a DialOption that specifies the interceptor for
unary RPCs.
WithUserAgent returns a DialOption that specifies a user agent string for all
the RPCs.
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.
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.
binaryLogger returns a ServerOption that can set the binary logger for the
server.
chainStreamClientInterceptors chains all stream client interceptors into one.
compress returns the input bytes compressed by compressor or cp. If both
compressors are nil, returns nil.
TODO(dfawley): eliminate cp parameter by wrapping Compressor in an encoding.Compressor.
Determine channel authority. The order of precedence is as follows:
- user specified authority override using `WithAuthority` dial option
- creds' notion of server name for the authentication handshake
- endpoint from dial target of the form "scheme://[authority]/endpoint"
doneChannelzWrapper performs the following:
- increments the calls started channelz counter
- wraps the done function in the passed in result to increment the calls
failed or calls succeeded channelz counter before invoking the actual
done function.
encode serializes msg and returns a buffer containing the message, or an
error if it is too large to be transmitted by grpc. If msg is nil, it
generates an empty message.
equalServiceConfig compares two configs. The rawJSONString field is ignored,
because they may diff in white spaces.
If any of them is NOT *ServiceConfig, return false.
getChainStreamer recursively generate the chained client stream constructor.
newClientStream creates a ClientStream with the specified transport, on the
given addrConn.
It's expected that the given transport is either the same one in addrConn, or
is already closed. To avoid race, transport is specified separately, instead
of using ac.transpot.
Main difference between this and ClientConn.NewStream:
- no retry
- no service config (or wait for service config)
- no tracing or stats
parseTarget uses RFC 3986 semantics to parse the given target into a
resolver.Target struct containing scheme, authority and url. Query
params are stripped from the endpoint.
prepareMsg returns the hdr, payload and data
using the compressors passed or using the
passed preparedmsg
For the two compressor parameters, both should not be set, but if they are,
dc takes precedence over compressor.
TODO(dfawley): wrap the old compressor/decompressor using the new API?
withBackoff sets the backoff strategy used for connectRetryNum after a failed
connection attempt.
This can be exported if arbitrary backoff strategies are allowed by gRPC.
withBinaryLogger returns a DialOption that specifies the binary logger for
this ClientConn.
withHealthCheckFunc replaces the default health check function with the
provided one. It makes tests easier to change the health check function.
For testing purpose only.
withGetMinConnectDeadline specifies the function that clientconn uses to
get minConnectDeadline. This can be used to make connection attempts happen
faster/slower.
For testing purpose only.
Package-Level Variables (total 22, in which 5 are exported)
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.
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.
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.
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.
ErrServerStopped indicates that the operation is now illegal because of
the server being stopped.
errNoTransportCredsInBundle indicated that the configured creds bundle
returned a transport credentials which was nil.
errNoTransportSecurity indicates that there is no transport security
being set for ClientConn. Users should either set one or explicitly
call WithInsecure DialOption to disable security.
errTransportCredentialsMissing indicates that users want to transmit
security information (e.g., OAuth2 token) which requires secure
connection on an insecure connection.
errTransportCredsAndBundle indicates that creds bundle is used together
with other individual Transport Credentials.
Package-Level Constants (total 25, in which 7 are exported)
PickFirstBalancerName is the name of the pick_first balancer.
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.
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.
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.
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.
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.
Server transports are tracked in a map which is keyed on listener
address. For regular gRPC traffic, connections are accepted in Serve()
through a call to Accept(), and we use the actual listener address as key
when we add it to the map. But for connections received through
ServeHTTP(), we do not have a listener and hence use this dummy value.
serverWorkerResetThreshold defines how often the stack must be reset. Every
N requests, by spawning a new goroutine in its place, a worker can reset its
stack so that large stacks don't live in memory forever. 2^16 should allow
each goroutine stack to live for at least a few seconds in a typical
workload (assuming a QPS of a few thousand requests/sec).