mirror of
https://github.com/golang/go.git
synced 2025-10-19 11:03:18 +00:00
4a7fde922f
This change takes the EvEndOfGeneration event and promotes it to a real event that appears in the trace. This allows the trace parser to unambiguously identify truncated traces vs. broken traces. It also makes a lot of the logic around parsing simpler, because there's no more batch spilling necessary. Fixes #73904. Change-Id: I37c359b32b6b5f894825aafc02921adeaacf2595 Reviewed-on: https://go-review.googlesource.com/c/go/+/693398 Reviewed-by: Carlos Amedee <carlos@golang.org> Reviewed-by: Michael Pratt <mpratt@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
87 lines
2.2 KiB
Go
87 lines
2.2 KiB
Go
// Copyright 2023 The Go Authors. All rights reserved.
|
||
// Use of this source code is governed by a BSD-style
|
||
// license that can be found in the LICENSE file.
|
||
|
||
package version
|
||
|
||
import (
|
||
"fmt"
|
||
"io"
|
||
|
||
"internal/trace/tracev2"
|
||
)
|
||
|
||
// Version represents the version of a trace file.
|
||
type Version uint32
|
||
|
||
const (
|
||
Go111 Version = 11 // v1
|
||
Go119 Version = 19 // v1
|
||
Go121 Version = 21 // v1
|
||
Go122 Version = 22 // v2
|
||
Go123 Version = 23 // v2
|
||
Go125 Version = 25 // v2
|
||
Go126 Version = 26 // v2
|
||
Current = Go126
|
||
)
|
||
|
||
var versions = map[Version][]tracev2.EventSpec{
|
||
// Go 1.11–1.21 use a different parser and are only set here for the sake of
|
||
// Version.Valid.
|
||
Go111: nil,
|
||
Go119: nil,
|
||
Go121: nil,
|
||
|
||
Go122: tracev2.Specs()[:tracev2.EvUserLog+1], // All events after are Go 1.23+.
|
||
Go123: tracev2.Specs()[:tracev2.EvExperimentalBatch+1], // All events after are Go 1.25+.
|
||
Go125: tracev2.Specs()[:tracev2.EvClockSnapshot+1], // All events after are Go 1.26+.
|
||
Go126: tracev2.Specs(),
|
||
}
|
||
|
||
// Specs returns the set of event.Specs for this version.
|
||
func (v Version) Specs() []tracev2.EventSpec {
|
||
return versions[v]
|
||
}
|
||
|
||
// EventName returns a string name of a wire format event
|
||
// for a particular trace version.
|
||
func (v Version) EventName(typ tracev2.EventType) string {
|
||
if !v.Valid() {
|
||
return "<invalid trace version>"
|
||
}
|
||
s := v.Specs()
|
||
if len(s) == 0 {
|
||
return "<v1 trace event type>"
|
||
}
|
||
if int(typ) < len(s) && s[typ].Name != "" {
|
||
return s[typ].Name
|
||
}
|
||
return fmt.Sprintf("Invalid(%d)", typ)
|
||
}
|
||
|
||
func (v Version) Valid() bool {
|
||
_, ok := versions[v]
|
||
return ok
|
||
}
|
||
|
||
// headerFmt is the format of the header of all Go execution traces.
|
||
const headerFmt = "go 1.%d trace\x00\x00\x00"
|
||
|
||
// ReadHeader reads the version of the trace out of the trace file's
|
||
// header, whose prefix must be present in v.
|
||
func ReadHeader(r io.Reader) (Version, error) {
|
||
var v Version
|
||
_, err := fmt.Fscanf(r, headerFmt, &v)
|
||
if err != nil {
|
||
return v, fmt.Errorf("bad file format: not a Go execution trace?")
|
||
}
|
||
if !v.Valid() {
|
||
return v, fmt.Errorf("unknown or unsupported trace version go 1.%d", v)
|
||
}
|
||
return v, nil
|
||
}
|
||
|
||
// WriteHeader writes a header for a trace version v to w.
|
||
func WriteHeader(w io.Writer, v Version) (int, error) {
|
||
return fmt.Fprintf(w, headerFmt, v)
|
||
}
|