blob: 2c5ccc4155726483d3f8822be11e40a253721efa [file] [log] [blame]
// Copyright 2022 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 benchfmt
import (
"bytes"
"fmt"
"io"
)
// A Writer writes the Go benchmark format.
type Writer struct {
w io.Writer
buf bytes.Buffer
first bool
fileConfig map[string]Config
order []string
}
// NewWriter returns a writer that writes Go benchmark results to w.
func NewWriter(w io.Writer) *Writer {
return &Writer{w: w, first: true, fileConfig: make(map[string]Config)}
}
// Write writes Record rec to w. If rec is a *Result and rec's file
// configuration differs from the current file configuration in w, it
// first emits the appropriate file configuration lines. For
// Result.Values that have a non-zero OrigUnit, this uses OrigValue and
// OrigUnit in order to better reproduce the original input.
func (w *Writer) Write(rec Record) error {
switch rec := rec.(type) {
case *Result:
w.writeResult(rec)
case *UnitMetadata:
w.writeUnitMetadata(rec)
case *SyntaxError:
// Ignore
return nil
default:
return fmt.Errorf("unknown Record type %T", rec)
}
// Flush the buffer out to the io.Writer. Write to the buffer
// can't fail, so we only have to check if this fails.
_, err := w.w.Write(w.buf.Bytes())
w.buf.Reset()
return err
}
func (w *Writer) writeResult(res *Result) {
// If any file config changed, write out the changes.
if len(w.fileConfig) != len(res.Config) {
w.writeFileConfig(res)
} else {
for _, cfg := range res.Config {
if have, ok := w.fileConfig[cfg.Key]; !ok || !bytes.Equal(cfg.Value, have.Value) || cfg.File != have.File {
w.writeFileConfig(res)
break
}
}
}
// Print the benchmark line.
fmt.Fprintf(&w.buf, "Benchmark%s %d", res.Name, res.Iters)
for _, val := range res.Values {
if val.OrigUnit == "" {
fmt.Fprintf(&w.buf, " %v %s", val.Value, val.Unit)
} else {
fmt.Fprintf(&w.buf, " %v %s", val.OrigValue, val.OrigUnit)
}
}
w.buf.WriteByte('\n')
w.first = false
}
func (w *Writer) writeFileConfig(res *Result) {
if !w.first {
// Configuration blocks after results get an extra blank.
w.buf.WriteByte('\n')
w.first = true
}
// Walk keys we know to find changes and deletions.
for i := 0; i < len(w.order); i++ {
key := w.order[i]
have := w.fileConfig[key]
idx, ok := res.ConfigIndex(key)
if !ok {
// Key was deleted.
fmt.Fprintf(&w.buf, "%s:\n", key)
delete(w.fileConfig, key)
copy(w.order[i:], w.order[i+1:])
w.order = w.order[:len(w.order)-1]
i--
continue
}
cfg := &res.Config[idx]
if bytes.Equal(have.Value, cfg.Value) && have.File == cfg.File {
// Value did not change.
continue
}
// Value changed.
if cfg.File {
// Omit internal config.
fmt.Fprintf(&w.buf, "%s: %s\n", key, cfg.Value)
}
have.Value = append(have.Value[:0], cfg.Value...)
have.File = cfg.File
w.fileConfig[key] = have
}
// Find new keys.
if len(w.fileConfig) != len(res.Config) {
for _, cfg := range res.Config {
if _, ok := w.fileConfig[cfg.Key]; ok {
continue
}
// New key.
if cfg.File {
fmt.Fprintf(&w.buf, "%s: %s\n", cfg.Key, cfg.Value)
}
w.fileConfig[cfg.Key] = Config{cfg.Key, append([]byte(nil), cfg.Value...), cfg.File}
w.order = append(w.order, cfg.Key)
}
}
w.buf.WriteByte('\n')
}
func (w *Writer) writeUnitMetadata(m *UnitMetadata) {
fmt.Fprintf(&w.buf, "Unit %s %s=%s\n", m.OrigUnit, m.Key, m.Value)
}