Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

transport: remove decodeState from server to reduce allocations #4423

Merged
merged 6 commits into from May 17, 2021
Merged
Show file tree
Hide file tree
Changes from 5 commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Jump to
Jump to file
Failed to load files.
Diff view
Diff view
121 changes: 88 additions & 33 deletions internal/transport/http2_server.go
Expand Up @@ -304,37 +304,92 @@ func newHTTP2Server(conn net.Conn, config *ServerConfig) (_ ServerTransport, err
// operateHeader takes action on the decoded headers.
func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(*Stream), traceCtx func(context.Context, string) context.Context) (fatal bool) {
streamID := frame.Header().StreamID
state := &decodeState{
serverSide: true,
}
if h2code, err := state.decodeHeader(frame); err != nil {
if _, ok := status.FromError(err); ok {
t.controlBuf.put(&cleanupStream{
streamID: streamID,
rst: true,
rstCode: h2code,
onWrite: func() {},
})
}

// frame.Truncated is set to true when framer detects that the current header
// list size hits MaxHeaderListSize limit.
if frame.Truncated {
t.controlBuf.put(&cleanupStream{
streamID: streamID,
rst: true,
rstCode: http2.ErrCodeFrameSize,
onWrite: func() {},
})
return false
}

buf := newRecvBuffer()
s := &Stream{
id: streamID,
st: t,
buf: buf,
fc: &inFlow{limit: uint32(t.initialWindowSize)},
recvCompress: state.data.encoding,
method: state.data.method,
contentSubtype: state.data.contentSubtype,
id: streamID,
st: t,
buf: buf,
fc: &inFlow{limit: uint32(t.initialWindowSize)},
}

var (
// If a gRPC Response-Headers has already been received, then it means
// that the peer is speaking gRPC and we are in gRPC mode.
isGRPC = false
mdata = make(map[string][]string)
httpMethod string
// headerError is set if an error is encountered while parsing the headers
headerError bool

timeoutSet bool
timeout time.Duration
)

for _, hf := range frame.Fields {
switch hf.Name {
case "content-type":
contentSubtype, validContentType := grpcutil.ContentSubtype(hf.Value)
if !validContentType {
break
dfawley marked this conversation as resolved.
Show resolved Hide resolved
}
mdata[hf.Name] = append(mdata[hf.Name], hf.Value)
s.contentSubtype = contentSubtype
isGRPC = true
case "grpc-encoding":
s.recvCompress = hf.Value
case ":method":
httpMethod = hf.Value
case ":path":
s.method = hf.Value
case "grpc-timeout":
timeoutSet = true
var err error
if timeout, err = decodeTimeout(hf.Value); err != nil {
headerError = true
}
default:
if isReservedHeader(hf.Name) && !isWhitelistedHeader(hf.Name) {
break
}
v, err := decodeMetadataHeader(hf.Name, hf.Value)
if err != nil {
headerError = true
logger.Warningf("Failed to decode metadata header (%q, %q): %v", hf.Name, hf.Value, err)
break
}
mdata[hf.Name] = append(mdata[hf.Name], v)
}
}

if !isGRPC || headerError {
t.controlBuf.put(&cleanupStream{
streamID: streamID,
rst: true,
rstCode: http2.ErrCodeProtocol,
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

FWIW, I believe this behavior is wrong - there was no HTTP/2 protocol violation that happened here, but since this is what it did before, let's not change it here.

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Ack - should I add a TODO?

Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

No, I think we have a few things we're doing wrong similarly and we can fix them all together.

onWrite: func() {},
})
return false
}

if frame.StreamEnded() {
// s is just created by the caller. No lock needed.
s.state = streamReadDone
}
if state.data.timeoutSet {
s.ctx, s.cancel = context.WithTimeout(t.ctx, state.data.timeout)
if timeoutSet {
s.ctx, s.cancel = context.WithTimeout(t.ctx, timeout)
} else {
s.ctx, s.cancel = context.WithCancel(t.ctx)
}
Expand All @@ -347,14 +402,14 @@ func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(
}
s.ctx = peer.NewContext(s.ctx, pr)
// Attach the received metadata to the context.
if len(state.data.mdata) > 0 {
s.ctx = metadata.NewIncomingContext(s.ctx, state.data.mdata)
}
if state.data.statsTags != nil {
s.ctx = stats.SetIncomingTags(s.ctx, state.data.statsTags)
}
if state.data.statsTrace != nil {
s.ctx = stats.SetIncomingTrace(s.ctx, state.data.statsTrace)
if len(mdata) > 0 {
s.ctx = metadata.NewIncomingContext(s.ctx, mdata)
if statsTags := mdata["grpc-tags-bin"]; len(statsTags) > 0 {
s.ctx = stats.SetIncomingTags(s.ctx, []byte(statsTags[len(statsTags)-1]))
}
if statsTrace := mdata["grpc-trace-bin"]; len(statsTrace) > 0 {
s.ctx = stats.SetIncomingTrace(s.ctx, []byte(statsTrace[0]))
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Same thing re: 0 -> len(statsTrace)-1

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Done!

}
}
t.mu.Lock()
if t.state != reachable {
Expand Down Expand Up @@ -383,10 +438,10 @@ func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(
return true
}
t.maxStreamID = streamID
if state.data.httpMethod != http.MethodPost {
if httpMethod != http.MethodPost {
t.mu.Unlock()
if logger.V(logLevel) {
logger.Warningf("transport: http2Server.operateHeaders parsed a :method field: %v which should be POST", state.data.httpMethod)
logger.Infof("transport: http2Server.operateHeaders parsed a :method field: %v which should be POST", httpMethod)
}
t.controlBuf.put(&cleanupStream{
streamID: streamID,
Expand All @@ -399,7 +454,7 @@ func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(
}
if t.inTapHandle != nil {
var err error
if s.ctx, err = t.inTapHandle(s.ctx, &tap.Info{FullMethodName: state.data.method}); err != nil {
if s.ctx, err = t.inTapHandle(s.ctx, &tap.Info{FullMethodName: s.method}); err != nil {
t.mu.Unlock()
if logger.V(logLevel) {
logger.Infof("transport: http2Server.operateHeaders got an error from InTapHandle: %v", err)
Expand Down Expand Up @@ -437,7 +492,7 @@ func (t *http2Server) operateHeaders(frame *http2.MetaHeadersFrame, handle func(
LocalAddr: t.localAddr,
Compression: s.recvCompress,
WireLength: int(frame.Header().Length),
Header: metadata.MD(state.data.mdata).Copy(),
Header: metadata.MD(mdata).Copy(),
}
t.stats.HandleRPC(s.ctx, inHeader)
}
Expand Down
198 changes: 0 additions & 198 deletions internal/transport/http_util.go
Expand Up @@ -39,7 +39,6 @@ import (
spb "google.golang.org/genproto/googleapis/rpc/status"
"google.golang.org/grpc/codes"
"google.golang.org/grpc/grpclog"
"google.golang.org/grpc/internal/grpcutil"
"google.golang.org/grpc/status"
)

Expand Down Expand Up @@ -96,53 +95,6 @@ var (
logger = grpclog.Component("transport")
)

type parsedHeaderData struct {
encoding string
// statusGen caches the stream status received from the trailer the server
// sent. Client side only. Do not access directly. After all trailers are
// parsed, use the status method to retrieve the status.
statusGen *status.Status
// rawStatusCode and rawStatusMsg are set from the raw trailer fields and are not
// intended for direct access outside of parsing.
rawStatusCode *int
rawStatusMsg string
httpStatus *int
// Server side only fields.
timeoutSet bool
timeout time.Duration
method string
httpMethod string
// key-value metadata map from the peer.
mdata map[string][]string
statsTags []byte
statsTrace []byte
contentSubtype string

// isGRPC field indicates whether the peer is speaking gRPC (otherwise HTTP).
//
// We are in gRPC mode (peer speaking gRPC) if:
// * We are client side and have already received a HEADER frame that indicates gRPC peer.
// * The header contains valid a content-type, i.e. a string starts with "application/grpc"
// And we should handle error specific to gRPC.
//
// Otherwise (i.e. a content-type string starts without "application/grpc", or does not exist), we
// are in HTTP fallback mode, and should handle error specific to HTTP.
isGRPC bool
grpcErr error
httpErr error
contentTypeErr string
}

// decodeState configures decoding criteria and records the decoded data.
type decodeState struct {
// whether decoding on server side or not
serverSide bool

// Records the states during HPACK decoding. It will be filled with info parsed from HTTP HEADERS
// frame once decodeHeader function has been invoked and returned.
data parsedHeaderData
}

// isReservedHeader checks whether hdr belongs to HTTP2 headers
// reserved by gRPC protocol. Any other headers are classified as the
// user-specified metadata.
Expand Down Expand Up @@ -221,63 +173,6 @@ func decodeGRPCStatusDetails(rawDetails string) (*status.Status, error) {
return status.FromProto(st), nil
}

func (d *decodeState) decodeHeader(frame *http2.MetaHeadersFrame) (http2.ErrCode, error) {
// frame.Truncated is set to true when framer detects that the current header
// list size hits MaxHeaderListSize limit.
if frame.Truncated {
return http2.ErrCodeFrameSize, status.Error(codes.Internal, "peer header list size exceeded limit")
}

for _, hf := range frame.Fields {
d.processHeaderField(hf)
}

if d.data.isGRPC {
if d.data.grpcErr != nil {
return http2.ErrCodeProtocol, d.data.grpcErr
}
if d.serverSide {
return http2.ErrCodeNo, nil
}
if d.data.rawStatusCode == nil && d.data.statusGen == nil {
// gRPC status doesn't exist.
// Set rawStatusCode to be unknown and return nil error.
// So that, if the stream has ended this Unknown status
// will be propagated to the user.
// Otherwise, it will be ignored. In which case, status from
// a later trailer, that has StreamEnded flag set, is propagated.
code := int(codes.Unknown)
d.data.rawStatusCode = &code
}
return http2.ErrCodeNo, nil
}

// HTTP fallback mode
if d.data.httpErr != nil {
return http2.ErrCodeProtocol, d.data.httpErr
}

var (
code = codes.Internal // when header does not include HTTP status, return INTERNAL
ok bool
)

if d.data.httpStatus != nil {
code, ok = HTTPStatusConvTab[*(d.data.httpStatus)]
if !ok {
code = codes.Unknown
}
}

return http2.ErrCodeProtocol, status.Error(code, d.constructHTTPErrMsg())
}

// constructErrMsg constructs error message to be returned in HTTP fallback mode.
// Format: HTTP status code and its corresponding message + content-type error message.
func (d *decodeState) constructHTTPErrMsg() string {
return constructHTTPErrMsg(d.data.httpStatus, d.data.contentTypeErr)
}

// constructErrMsg constructs error message to be returned in HTTP fallback mode.
// Format: HTTP status code and its corresponding message + content-type error message.
func constructHTTPErrMsg(httpStatus *int, contentTypeErr string) string {
Expand All @@ -298,99 +193,6 @@ func constructHTTPErrMsg(httpStatus *int, contentTypeErr string) string {
return strings.Join(errMsgs, "; ")
}

func (d *decodeState) addMetadata(k, v string) {
if d.data.mdata == nil {
d.data.mdata = make(map[string][]string)
}
d.data.mdata[k] = append(d.data.mdata[k], v)
}

func (d *decodeState) processHeaderField(f hpack.HeaderField) {
switch f.Name {
case "content-type":
contentSubtype, validContentType := grpcutil.ContentSubtype(f.Value)
if !validContentType {
d.data.contentTypeErr = fmt.Sprintf("transport: received the unexpected content-type %q", f.Value)
return
}
d.data.contentSubtype = contentSubtype
// TODO: do we want to propagate the whole content-type in the metadata,
// or come up with a way to just propagate the content-subtype if it was set?
// ie {"content-type": "application/grpc+proto"} or {"content-subtype": "proto"}
// in the metadata?
d.addMetadata(f.Name, f.Value)
d.data.isGRPC = true
case "grpc-encoding":
d.data.encoding = f.Value
case "grpc-status":
code, err := strconv.Atoi(f.Value)
if err != nil {
d.data.grpcErr = status.Errorf(codes.Internal, "transport: malformed grpc-status: %v", err)
return
}
d.data.rawStatusCode = &code
case "grpc-message":
d.data.rawStatusMsg = decodeGrpcMessage(f.Value)
case "grpc-status-details-bin":
v, err := decodeBinHeader(f.Value)
if err != nil {
d.data.grpcErr = status.Errorf(codes.Internal, "transport: malformed grpc-status-details-bin: %v", err)
return
}
s := &spb.Status{}
if err := proto.Unmarshal(v, s); err != nil {
d.data.grpcErr = status.Errorf(codes.Internal, "transport: malformed grpc-status-details-bin: %v", err)
return
}
d.data.statusGen = status.FromProto(s)
case "grpc-timeout":
d.data.timeoutSet = true
var err error
if d.data.timeout, err = decodeTimeout(f.Value); err != nil {
d.data.grpcErr = status.Errorf(codes.Internal, "transport: malformed time-out: %v", err)
}
case ":path":
d.data.method = f.Value
case ":status":
code, err := strconv.Atoi(f.Value)
if err != nil {
d.data.httpErr = status.Errorf(codes.Internal, "transport: malformed http-status: %v", err)
return
}
d.data.httpStatus = &code
case "grpc-tags-bin":
v, err := decodeBinHeader(f.Value)
if err != nil {
d.data.grpcErr = status.Errorf(codes.Internal, "transport: malformed grpc-tags-bin: %v", err)
return
}
d.data.statsTags = v
d.addMetadata(f.Name, string(v))
case "grpc-trace-bin":
v, err := decodeBinHeader(f.Value)
if err != nil {
d.data.grpcErr = status.Errorf(codes.Internal, "transport: malformed grpc-trace-bin: %v", err)
return
}
d.data.statsTrace = v
d.addMetadata(f.Name, string(v))
case ":method":
d.data.httpMethod = f.Value
default:
if isReservedHeader(f.Name) && !isWhitelistedHeader(f.Name) {
break
}
v, err := decodeMetadataHeader(f.Name, f.Value)
if err != nil {
if logger.V(logLevel) {
logger.Errorf("Failed to decode metadata header (%q, %q): %v", f.Name, f.Value, err)
}
return
}
d.addMetadata(f.Name, v)
}
}

type timeoutUnit uint8

const (
Expand Down