[chore] update dependencies (#4196)

- go.opentelemetry.io/contrib/exporters/autoexport v0.60.0 -> v0.61.0
- go.opentelemetry.io/contrib/instrumentation/runtime v0.60.0 -> v0.61.0

Reviewed-on: https://codeberg.org/superseriousbusiness/gotosocial/pulls/4196
Co-authored-by: kim <grufwub@gmail.com>
Co-committed-by: kim <grufwub@gmail.com>
This commit is contained in:
kim 2025-05-26 16:13:55 +02:00 committed by tobi
commit 143febb318
152 changed files with 2635 additions and 1688 deletions

View file

@ -51,10 +51,24 @@ var (
// xDS server in the list of server configs will be used.
XDSFallbackSupport = boolFromEnv("GRPC_EXPERIMENTAL_XDS_FALLBACK", true)
// NewPickFirstEnabled is set if the new pickfirst leaf policy is to be used
// instead of the exiting pickfirst implementation. This can be enabled by
// instead of the exiting pickfirst implementation. This can be disabled by
// setting the environment variable "GRPC_EXPERIMENTAL_ENABLE_NEW_PICK_FIRST"
// to "true".
NewPickFirstEnabled = boolFromEnv("GRPC_EXPERIMENTAL_ENABLE_NEW_PICK_FIRST", false)
// to "false".
NewPickFirstEnabled = boolFromEnv("GRPC_EXPERIMENTAL_ENABLE_NEW_PICK_FIRST", true)
// XDSEndpointHashKeyBackwardCompat controls the parsing of the endpoint hash
// key from EDS LbEndpoint metadata. Endpoint hash keys can be disabled by
// setting "GRPC_XDS_ENDPOINT_HASH_KEY_BACKWARD_COMPAT" to "true". When the
// implementation of A76 is stable, we will flip the default value to false
// in a subsequent release. A final release will remove this environment
// variable, enabling the new behavior unconditionally.
XDSEndpointHashKeyBackwardCompat = boolFromEnv("GRPC_XDS_ENDPOINT_HASH_KEY_BACKWARD_COMPAT", true)
// RingHashSetRequestHashKey is set if the ring hash balancer can get the
// request hash header by setting the "requestHashHeader" field, according
// to gRFC A76. It can be enabled by setting the environment variable
// "GRPC_EXPERIMENTAL_RING_HASH_SET_REQUEST_HASH_KEY" to "true".
RingHashSetRequestHashKey = boolFromEnv("GRPC_EXPERIMENTAL_RING_HASH_SET_REQUEST_HASH_KEY", false)
)
func boolFromEnv(envVar string, def bool) bool {

View file

@ -259,6 +259,13 @@ var (
// SetBufferPoolingThresholdForTesting updates the buffer pooling threshold, for
// testing purposes.
SetBufferPoolingThresholdForTesting any // func(int)
// TimeAfterFunc is used to create timers. During tests the function is
// replaced to track allocated timers and fail the test if a timer isn't
// cancelled.
TimeAfterFunc = func(d time.Duration, f func()) Timer {
return time.AfterFunc(d, f)
}
)
// HealthChecker defines the signature of the client-side LB channel health
@ -300,3 +307,9 @@ type EnforceSubConnEmbedding interface {
type EnforceClientConnEmbedding interface {
enforceClientConnEmbedding()
}
// Timer is an interface to allow injecting different time.Timer implementations
// during tests.
type Timer interface {
Stop() bool
}

View file

@ -97,13 +97,11 @@ func hasNotPrintable(msg string) bool {
return false
}
// ValidatePair validate a key-value pair with the following rules (the pseudo-header will be skipped) :
//
// - key must contain one or more characters.
// - the characters in the key must be contained in [0-9 a-z _ - .].
// - if the key ends with a "-bin" suffix, no validation of the corresponding value is performed.
// - the characters in the every value must be printable (in [%x20-%x7E]).
func ValidatePair(key string, vals ...string) error {
// ValidateKey validates a key with the following rules (pseudo-headers are
// skipped):
// - the key must contain one or more characters.
// - the characters in the key must be in [0-9 a-z _ - .].
func ValidateKey(key string) error {
// key should not be empty
if key == "" {
return fmt.Errorf("there is an empty key in the header")
@ -119,6 +117,20 @@ func ValidatePair(key string, vals ...string) error {
return fmt.Errorf("header key %q contains illegal characters not in [0-9a-z-_.]", key)
}
}
return nil
}
// ValidatePair validates a key-value pair with the following rules
// (pseudo-header are skipped):
// - the key must contain one or more characters.
// - the characters in the key must be in [0-9 a-z _ - .].
// - if the key ends with a "-bin" suffix, no validation of the corresponding
// value is performed.
// - the characters in every value must be printable (in [%x20-%x7E]).
func ValidatePair(key string, vals ...string) error {
if err := ValidateKey(key); err != nil {
return err
}
if strings.HasSuffix(key, "-bin") {
return nil
}

View file

@ -28,6 +28,8 @@ import (
"google.golang.org/grpc/grpclog"
"google.golang.org/grpc/internal/proxyattributes"
"google.golang.org/grpc/internal/transport"
"google.golang.org/grpc/internal/transport/networktype"
"google.golang.org/grpc/resolver"
"google.golang.org/grpc/serviceconfig"
)
@ -40,19 +42,26 @@ var (
// delegatingResolver manages both target URI and proxy address resolution by
// delegating these tasks to separate child resolvers. Essentially, it acts as
// a intermediary between the gRPC ClientConn and the child resolvers.
// an intermediary between the gRPC ClientConn and the child resolvers.
//
// It implements the [resolver.Resolver] interface.
type delegatingResolver struct {
target resolver.Target // parsed target URI to be resolved
cc resolver.ClientConn // gRPC ClientConn
targetResolver resolver.Resolver // resolver for the target URI, based on its scheme
proxyResolver resolver.Resolver // resolver for the proxy URI; nil if no proxy is configured
proxyURL *url.URL // proxy URL, derived from proxy environment and target
target resolver.Target // parsed target URI to be resolved
cc resolver.ClientConn // gRPC ClientConn
proxyURL *url.URL // proxy URL, derived from proxy environment and target
// We do not hold both mu and childMu in the same goroutine. Avoid holding
// both locks when calling into the child, as the child resolver may
// synchronously callback into the channel.
mu sync.Mutex // protects all the fields below
targetResolverState *resolver.State // state of the target resolver
proxyAddrs []resolver.Address // resolved proxy addresses; empty if no proxy is configured
// childMu serializes calls into child resolvers. It also protects access to
// the following fields.
childMu sync.Mutex
targetResolver resolver.Resolver // resolver for the target URI, based on its scheme
proxyResolver resolver.Resolver // resolver for the proxy URI; nil if no proxy is configured
}
// nopResolver is a resolver that does nothing.
@ -62,8 +71,8 @@ func (nopResolver) ResolveNow(resolver.ResolveNowOptions) {}
func (nopResolver) Close() {}
// proxyURLForTarget determines the proxy URL for the given address based on
// the environment. It can return the following:
// proxyURLForTarget determines the proxy URL for the given address based on the
// environment. It can return the following:
// - nil URL, nil error: No proxy is configured or the address is excluded
// using the `NO_PROXY` environment variable or if req.URL.Host is
// "localhost" (with or without // a port number)
@ -82,7 +91,8 @@ func proxyURLForTarget(address string) (*url.URL, error) {
// resolvers:
// - one to resolve the proxy address specified using the supported
// environment variables. This uses the registered resolver for the "dns"
// scheme.
// scheme. It is lazily built when a target resolver update contains at least
// one TCP address.
// - one to resolve the target URI using the resolver specified by the scheme
// in the target URI or specified by the user using the WithResolvers dial
// option. As a special case, if the target URI's scheme is "dns" and a
@ -91,8 +101,10 @@ func proxyURLForTarget(address string) (*url.URL, error) {
// resolution is enabled using the dial option.
func New(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOptions, targetResolverBuilder resolver.Builder, targetResolutionEnabled bool) (resolver.Resolver, error) {
r := &delegatingResolver{
target: target,
cc: cc,
target: target,
cc: cc,
proxyResolver: nopResolver{},
targetResolver: nopResolver{},
}
var err error
@ -111,41 +123,34 @@ func New(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOpti
logger.Infof("Proxy URL detected : %s", r.proxyURL)
}
// Resolver updates from one child may trigger calls into the other. Block
// updates until the children are initialized.
r.childMu.Lock()
defer r.childMu.Unlock()
// When the scheme is 'dns' and target resolution on client is not enabled,
// resolution should be handled by the proxy, not the client. Therefore, we
// bypass the target resolver and store the unresolved target address.
if target.URL.Scheme == "dns" && !targetResolutionEnabled {
state := resolver.State{
r.targetResolverState = &resolver.State{
Addresses: []resolver.Address{{Addr: target.Endpoint()}},
Endpoints: []resolver.Endpoint{{Addresses: []resolver.Address{{Addr: target.Endpoint()}}}},
}
r.targetResolverState = &state
} else {
wcc := &wrappingClientConn{
stateListener: r.updateTargetResolverState,
parent: r,
}
if r.targetResolver, err = targetResolverBuilder.Build(target, wcc, opts); err != nil {
return nil, fmt.Errorf("delegating_resolver: unable to build the resolver for target %s: %v", target, err)
}
r.updateTargetResolverState(*r.targetResolverState)
return r, nil
}
if r.proxyResolver, err = r.proxyURIResolver(opts); err != nil {
return nil, fmt.Errorf("delegating_resolver: failed to build resolver for proxy URL %q: %v", r.proxyURL, err)
wcc := &wrappingClientConn{
stateListener: r.updateTargetResolverState,
parent: r,
}
if r.targetResolver == nil {
r.targetResolver = nopResolver{}
}
if r.proxyResolver == nil {
r.proxyResolver = nopResolver{}
if r.targetResolver, err = targetResolverBuilder.Build(target, wcc, opts); err != nil {
return nil, fmt.Errorf("delegating_resolver: unable to build the resolver for target %s: %v", target, err)
}
return r, nil
}
// proxyURIResolver creates a resolver for resolving proxy URIs using the
// "dns" scheme. It adjusts the proxyURL to conform to the "dns:///" format and
// builds a resolver with a wrappingClientConn to capture resolved addresses.
// proxyURIResolver creates a resolver for resolving proxy URIs using the "dns"
// scheme. It adjusts the proxyURL to conform to the "dns:///" format and builds
// a resolver with a wrappingClientConn to capture resolved addresses.
func (r *delegatingResolver) proxyURIResolver(opts resolver.BuildOptions) (resolver.Resolver, error) {
proxyBuilder := resolver.Get("dns")
if proxyBuilder == nil {
@ -165,11 +170,15 @@ func (r *delegatingResolver) proxyURIResolver(opts resolver.BuildOptions) (resol
}
func (r *delegatingResolver) ResolveNow(o resolver.ResolveNowOptions) {
r.childMu.Lock()
defer r.childMu.Unlock()
r.targetResolver.ResolveNow(o)
r.proxyResolver.ResolveNow(o)
}
func (r *delegatingResolver) Close() {
r.childMu.Lock()
defer r.childMu.Unlock()
r.targetResolver.Close()
r.targetResolver = nil
@ -177,18 +186,43 @@ func (r *delegatingResolver) Close() {
r.proxyResolver = nil
}
// updateClientConnStateLocked creates a list of combined addresses by
// pairing each proxy address with every target address. For each pair, it
// generates a new [resolver.Address] using the proxy address, and adding the
// target address as the attribute along with user info. It returns nil if
// either resolver has not sent update even once and returns the error from
// ClientConn update once both resolvers have sent update atleast once.
func networkTypeFromAddr(addr resolver.Address) string {
networkType, ok := networktype.Get(addr)
if !ok {
networkType, _ = transport.ParseDialTarget(addr.Addr)
}
return networkType
}
func isTCPAddressPresent(state *resolver.State) bool {
for _, addr := range state.Addresses {
if networkType := networkTypeFromAddr(addr); networkType == "tcp" {
return true
}
}
for _, endpoint := range state.Endpoints {
for _, addr := range endpoint.Addresses {
if networktype := networkTypeFromAddr(addr); networktype == "tcp" {
return true
}
}
}
return false
}
// updateClientConnStateLocked constructs a combined list of addresses by
// pairing each proxy address with every target address of type TCP. For each
// pair, it creates a new [resolver.Address] using the proxy address and
// attaches the corresponding target address and user info as attributes. Target
// addresses that are not of type TCP are appended to the list as-is. The
// function returns nil if either resolver has not yet provided an update, and
// returns the result of ClientConn.UpdateState once both resolvers have
// provided at least one update.
func (r *delegatingResolver) updateClientConnStateLocked() error {
if r.targetResolverState == nil || r.proxyAddrs == nil {
return nil
}
curState := *r.targetResolverState
// If multiple resolved proxy addresses are present, we send only the
// unresolved proxy host and let net.Dial handle the proxy host name
// resolution when creating the transport. Sending all resolved addresses
@ -206,24 +240,30 @@ func (r *delegatingResolver) updateClientConnStateLocked() error {
}
var addresses []resolver.Address
for _, targetAddr := range (*r.targetResolverState).Addresses {
// Avoid proxy when network is not tcp.
if networkType := networkTypeFromAddr(targetAddr); networkType != "tcp" {
addresses = append(addresses, targetAddr)
continue
}
addresses = append(addresses, proxyattributes.Set(proxyAddr, proxyattributes.Options{
User: r.proxyURL.User,
ConnectAddr: targetAddr.Addr,
}))
}
// Create a list of combined endpoints by pairing all proxy endpoints
// with every target endpoint. Each time, it constructs a new
// [resolver.Endpoint] using the all addresses from all the proxy endpoint
// and the target addresses from one endpoint. The target address and user
// information from the proxy URL are added as attributes to the proxy
// address.The resulting list of addresses is then grouped into endpoints,
// covering all combinations of proxy and target endpoints.
// For each target endpoint, construct a new [resolver.Endpoint] that
// includes all addresses from all proxy endpoints and the addresses from
// that target endpoint, preserving the number of target endpoints.
var endpoints []resolver.Endpoint
for _, endpt := range (*r.targetResolverState).Endpoints {
var addrs []resolver.Address
for _, proxyAddr := range r.proxyAddrs {
for _, targetAddr := range endpt.Addresses {
for _, targetAddr := range endpt.Addresses {
// Avoid proxy when network is not tcp.
if networkType := networkTypeFromAddr(targetAddr); networkType != "tcp" {
addrs = append(addrs, targetAddr)
continue
}
for _, proxyAddr := range r.proxyAddrs {
addrs = append(addrs, proxyattributes.Set(proxyAddr, proxyattributes.Options{
User: r.proxyURL.User,
ConnectAddr: targetAddr.Addr,
@ -234,8 +274,9 @@ func (r *delegatingResolver) updateClientConnStateLocked() error {
}
// Use the targetResolverState for its service config and attributes
// contents. The state update is only sent after both the target and proxy
// resolvers have sent their updates, and curState has been updated with
// the combined addresses.
// resolvers have sent their updates, and curState has been updated with the
// combined addresses.
curState := *r.targetResolverState
curState.Addresses = addresses
curState.Endpoints = endpoints
return r.cc.UpdateState(curState)
@ -245,7 +286,8 @@ func (r *delegatingResolver) updateClientConnStateLocked() error {
// addresses and endpoints, marking the resolver as ready, and triggering a
// state update if both proxy and target resolvers are ready. If the ClientConn
// returns a non-nil error, it calls `ResolveNow()` on the target resolver. It
// is a StateListener function of wrappingClientConn passed to the proxy resolver.
// is a StateListener function of wrappingClientConn passed to the proxy
// resolver.
func (r *delegatingResolver) updateProxyResolverState(state resolver.State) error {
r.mu.Lock()
defer r.mu.Unlock()
@ -253,8 +295,8 @@ func (r *delegatingResolver) updateProxyResolverState(state resolver.State) erro
logger.Infof("Addresses received from proxy resolver: %s", state.Addresses)
}
if len(state.Endpoints) > 0 {
// We expect exactly one address per endpoint because the proxy
// resolver uses "dns" resolution.
// We expect exactly one address per endpoint because the proxy resolver
// uses "dns" resolution.
r.proxyAddrs = make([]resolver.Address, 0, len(state.Endpoints))
for _, endpoint := range state.Endpoints {
r.proxyAddrs = append(r.proxyAddrs, endpoint.Addresses...)
@ -267,20 +309,29 @@ func (r *delegatingResolver) updateProxyResolverState(state resolver.State) erro
err := r.updateClientConnStateLocked()
// Another possible approach was to block until updates are received from
// both resolvers. But this is not used because calling `New()` triggers
// `Build()` for the first resolver, which calls `UpdateState()`. And the
// `Build()` for the first resolver, which calls `UpdateState()`. And the
// second resolver hasn't sent an update yet, so it would cause `New()` to
// block indefinitely.
if err != nil {
r.targetResolver.ResolveNow(resolver.ResolveNowOptions{})
go func() {
r.childMu.Lock()
defer r.childMu.Unlock()
if r.targetResolver != nil {
r.targetResolver.ResolveNow(resolver.ResolveNowOptions{})
}
}()
}
return err
}
// updateTargetResolverState updates the target resolver state by storing target
// addresses, endpoints, and service config, marking the resolver as ready, and
// triggering a state update if both resolvers are ready. If the ClientConn
// returns a non-nil error, it calls `ResolveNow()` on the proxy resolver. It
// is a StateListener function of wrappingClientConn passed to the target resolver.
// updateTargetResolverState is the StateListener function provided to the
// target resolver via wrappingClientConn. It updates the resolver state and
// marks the target resolver as ready. If the update includes at least one TCP
// address and the proxy resolver has not yet been constructed, it initializes
// the proxy resolver. A combined state update is triggered once both resolvers
// are ready. If all addresses are non-TCP, it proceeds without waiting for the
// proxy resolver. If ClientConn.UpdateState returns a non-nil error,
// ResolveNow() is called on the proxy resolver.
func (r *delegatingResolver) updateTargetResolverState(state resolver.State) error {
r.mu.Lock()
defer r.mu.Unlock()
@ -289,9 +340,40 @@ func (r *delegatingResolver) updateTargetResolverState(state resolver.State) err
logger.Infof("Addresses received from target resolver: %v", state.Addresses)
}
r.targetResolverState = &state
// If no addresses returned by resolver have network type as tcp , do not
// wait for proxy update.
if !isTCPAddressPresent(r.targetResolverState) {
return r.cc.UpdateState(*r.targetResolverState)
}
// The proxy resolver may be rebuilt multiple times, specifically each time
// the target resolver sends an update, even if the target resolver is built
// successfully but building the proxy resolver fails.
if len(r.proxyAddrs) == 0 {
go func() {
r.childMu.Lock()
defer r.childMu.Unlock()
if _, ok := r.proxyResolver.(nopResolver); !ok {
return
}
proxyResolver, err := r.proxyURIResolver(resolver.BuildOptions{})
if err != nil {
r.cc.ReportError(fmt.Errorf("delegating_resolver: unable to build the proxy resolver: %v", err))
return
}
r.proxyResolver = proxyResolver
}()
}
err := r.updateClientConnStateLocked()
if err != nil {
r.proxyResolver.ResolveNow(resolver.ResolveNowOptions{})
go func() {
r.childMu.Lock()
defer r.childMu.Unlock()
if r.proxyResolver != nil {
r.proxyResolver.ResolveNow(resolver.ResolveNowOptions{})
}
}()
}
return nil
}
@ -311,7 +393,8 @@ func (wcc *wrappingClientConn) UpdateState(state resolver.State) error {
return wcc.stateListener(state)
}
// ReportError intercepts errors from the child resolvers and passes them to ClientConn.
// ReportError intercepts errors from the child resolvers and passes them to
// ClientConn.
func (wcc *wrappingClientConn) ReportError(err error) {
wcc.parent.cc.ReportError(err)
}
@ -322,8 +405,8 @@ func (wcc *wrappingClientConn) NewAddress(addrs []resolver.Address) {
wcc.UpdateState(resolver.State{Addresses: addrs})
}
// ParseServiceConfig parses the provided service config and returns an
// object that provides the parsed config.
// ParseServiceConfig parses the provided service config and returns an object
// that provides the parsed config.
func (wcc *wrappingClientConn) ParseServiceConfig(serviceConfigJSON string) *serviceconfig.ParseResult {
return wcc.parent.cc.ParseServiceConfig(serviceConfigJSON)
}

View file

@ -59,7 +59,7 @@ func (s *ClientStream) Read(n int) (mem.BufferSlice, error) {
return b, err
}
// Close closes the stream and popagates err to any readers.
// Close closes the stream and propagates err to any readers.
func (s *ClientStream) Close(err error) {
var (
rst bool

View file

@ -176,7 +176,7 @@ func dial(ctx context.Context, fn func(context.Context, string) (net.Conn, error
return fn(ctx, address)
}
if !ok {
networkType, address = parseDialTarget(address)
networkType, address = ParseDialTarget(address)
}
if opts, present := proxyattributes.Get(addr); present {
return proxyDial(ctx, addr, grpcUA, opts)
@ -1242,7 +1242,8 @@ func (t *http2Client) handleRSTStream(f *http2.RSTStreamFrame) {
statusCode = codes.DeadlineExceeded
}
}
t.closeStream(s, io.EOF, false, http2.ErrCodeNo, status.Newf(statusCode, "stream terminated by RST_STREAM with error code: %v", f.ErrCode), nil, false)
st := status.Newf(statusCode, "stream terminated by RST_STREAM with error code: %v", f.ErrCode)
t.closeStream(s, st.Err(), false, http2.ErrCodeNo, st, nil, false)
}
func (t *http2Client) handleSettings(f *http2.SettingsFrame, isFirst bool) {
@ -1390,8 +1391,7 @@ func (t *http2Client) handleGoAway(f *http2.GoAwayFrame) error {
// the caller.
func (t *http2Client) setGoAwayReason(f *http2.GoAwayFrame) {
t.goAwayReason = GoAwayNoReason
switch f.ErrCode {
case http2.ErrCodeEnhanceYourCalm:
if f.ErrCode == http2.ErrCodeEnhanceYourCalm {
if string(f.DebugData()) == "too_many_pings" {
t.goAwayReason = GoAwayTooManyPings
}

View file

@ -35,6 +35,7 @@ import (
"golang.org/x/net/http2"
"golang.org/x/net/http2/hpack"
"google.golang.org/grpc/internal"
"google.golang.org/grpc/internal/grpclog"
"google.golang.org/grpc/internal/grpcutil"
"google.golang.org/grpc/internal/pretty"
@ -598,6 +599,22 @@ func (t *http2Server) operateHeaders(ctx context.Context, frame *http2.MetaHeade
if len(t.activeStreams) == 1 {
t.idle = time.Time{}
}
// Start a timer to close the stream on reaching the deadline.
if timeoutSet {
// We need to wait for s.cancel to be updated before calling
// t.closeStream to avoid data races.
cancelUpdated := make(chan struct{})
timer := internal.TimeAfterFunc(timeout, func() {
<-cancelUpdated
t.closeStream(s, true, http2.ErrCodeCancel, false)
})
oldCancel := s.cancel
s.cancel = func() {
oldCancel()
timer.Stop()
}
close(cancelUpdated)
}
t.mu.Unlock()
if channelz.IsOn() {
t.channelz.SocketMetrics.StreamsStarted.Add(1)
@ -1274,7 +1291,6 @@ func (t *http2Server) Close(err error) {
// deleteStream deletes the stream s from transport's active streams.
func (t *http2Server) deleteStream(s *ServerStream, eosReceived bool) {
t.mu.Lock()
if _, ok := t.activeStreams[s.id]; ok {
delete(t.activeStreams, s.id)
@ -1324,7 +1340,10 @@ func (t *http2Server) closeStream(s *ServerStream, rst bool, rstCode http2.ErrCo
// called to interrupt the potential blocking on other goroutines.
s.cancel()
s.swapState(streamDone)
oldState := s.swapState(streamDone)
if oldState == streamDone {
return
}
t.deleteStream(s, eosReceived)
t.controlBuf.put(&cleanupStream{

View file

@ -439,8 +439,8 @@ func getWriteBufferPool(size int) *sync.Pool {
return pool
}
// parseDialTarget returns the network and address to pass to dialer.
func parseDialTarget(target string) (string, string) {
// ParseDialTarget returns the network and address to pass to dialer.
func ParseDialTarget(target string) (string, string) {
net := "tcp"
m1 := strings.Index(target, ":")
m2 := strings.Index(target, ":/")

View file

@ -35,8 +35,10 @@ type ServerStream struct {
*Stream // Embed for common stream functionality.
st internalServerTransport
ctxDone <-chan struct{} // closed at the end of stream. Cache of ctx.Done() (for performance)
cancel context.CancelFunc // invoked at the end of stream to cancel ctx.
ctxDone <-chan struct{} // closed at the end of stream. Cache of ctx.Done() (for performance)
// cancel is invoked at the end of stream to cancel ctx. It also stops the
// timer for monitoring the rpc deadline if configured.
cancel func()
// Holds compressor names passed in grpc-accept-encoding metadata from the
// client.