Source: trace.go in package google.golang.org/grpc

* * Copyright 2015 gRPC authors. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http:www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. *


package grpc

import (
	"bytes"
	"fmt"
	"io"
	"net"
	"strings"
	"sync"
	"time"

	"golang.org/x/net/trace"
)

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

var EnableTracing bool

methodFamily returns the trace family for the given method. It turns "/pkg.Service/GetFoo" into "pkg.Service".

func methodFamily(m string) string {
	m = strings.TrimPrefix(m, "/") // remove leading slash
	if i := strings.Index(m, "/"); i >= 0 {
		m = m[:i] // remove everything from second slash
	}
	return m
}

traceInfo contains tracing information for an RPC.

type traceInfo struct {
	tr        trace.Trace
	firstLine firstLine
}

firstLine is the first line of an RPC trace. It may be mutated after construction; remoteAddr specifically may change during client-side use.

type firstLine struct {
	mu         sync.Mutex
	client     bool // whether this is a client (outgoing) RPC
	remoteAddr net.Addr
	deadline   time.Duration // may be zero
}

func (f *firstLine) SetRemoteAddr(addr net.Addr) {
	f.mu.Lock()
	f.remoteAddr = addr
	f.mu.Unlock()
}

func (f *firstLine) String() string {
	f.mu.Lock()
	defer f.mu.Unlock()

	var line bytes.Buffer
	io.WriteString(&line, "RPC: ")
	if f.client {
		io.WriteString(&line, "to")
	} else {
		io.WriteString(&line, "from")
	}
	fmt.Fprintf(&line, " %v deadline:", f.remoteAddr)
	if f.deadline != 0 {
		fmt.Fprint(&line, f.deadline)
	} else {
		io.WriteString(&line, "none")
	}
	return line.String()
}

const truncateSize = 100

func truncate(x string, l int) string {
	if l > len(x) {
		return x
	}
	return x[:l]
}

payload represents an RPC request or response payload.

type payload struct {
	sent bool        // whether this is an outgoing payload

TODO(dsymonds): add stringifying info to codec, and limit how much we hold here?

}

func (p payload) String() string {
	if p.sent {
		return truncate(fmt.Sprintf("sent: %v", p.msg), truncateSize)
	}
	return truncate(fmt.Sprintf("recv: %v", p.msg), truncateSize)
}

type fmtStringer struct {
	format string
	a      []interface{}
}

func (f *fmtStringer) String() string {
	return fmt.Sprintf(f.format, f.a...)
}

type stringer string