/
benchcmp.go
184 lines (162 loc) · 4.08 KB
/
benchcmp.go
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// Copyright 2014 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 main
import (
"flag"
"fmt"
"os"
"sort"
"strconv"
"text/tabwriter"
"golang.org/x/tools/benchmark/parse"
)
var (
changedOnly = flag.Bool("changed", false, "show only benchmarks that have changed")
magSort = flag.Bool("mag", false, "sort benchmarks by magnitude of change")
best = flag.Bool("best", false, "compare best times from old and new")
)
const usageFooter = `
Each input file should be from:
go test -run=NONE -bench=. > [old,new].txt
Benchcmp compares old and new for each benchmark.
If -test.benchmem=true is added to the "go test" command
benchcmp will also compare memory allocations.
`
func main() {
flag.Usage = func() {
fmt.Fprintf(os.Stderr, "usage: %s old.txt new.txt\n\n", os.Args[0])
flag.PrintDefaults()
fmt.Fprint(os.Stderr, usageFooter)
os.Exit(2)
}
flag.Parse()
if flag.NArg() != 2 {
flag.Usage()
}
before := parseFile(flag.Arg(0))
after := parseFile(flag.Arg(1))
cmps, warnings := Correlate(before, after)
for _, warn := range warnings {
fmt.Fprintln(os.Stderr, warn)
}
if len(cmps) == 0 {
fatal("benchcmp: no repeated benchmarks")
}
w := new(tabwriter.Writer)
w.Init(os.Stdout, 0, 0, 5, ' ', 0)
defer w.Flush()
var header bool // Has the header has been displayed yet for a given block?
if *magSort {
sort.Sort(ByDeltaNsPerOp(cmps))
} else {
sort.Sort(ByParseOrder(cmps))
}
for _, cmp := range cmps {
if !cmp.Measured(parse.NsPerOp) {
continue
}
if delta := cmp.DeltaNsPerOp(); !*changedOnly || delta.Changed() {
if !header {
fmt.Fprint(w, "benchmark\told ns/op\tnew ns/op\tdelta\n")
header = true
}
fmt.Fprintf(w, "%s\t%s\t%s\t%s\n", cmp.Name(), formatNs(cmp.Before.NsPerOp), formatNs(cmp.After.NsPerOp), delta.Percent())
}
}
header = false
if *magSort {
sort.Sort(ByDeltaMBPerS(cmps))
}
for _, cmp := range cmps {
if !cmp.Measured(parse.MBPerS) {
continue
}
if delta := cmp.DeltaMBPerS(); !*changedOnly || delta.Changed() {
if !header {
fmt.Fprint(w, "\nbenchmark\told MB/s\tnew MB/s\tspeedup\n")
header = true
}
fmt.Fprintf(w, "%s\t%.2f\t%.2f\t%s\n", cmp.Name(), cmp.Before.MBPerS, cmp.After.MBPerS, delta.Multiple())
}
}
header = false
if *magSort {
sort.Sort(ByDeltaAllocsPerOp(cmps))
}
for _, cmp := range cmps {
if !cmp.Measured(parse.AllocsPerOp) {
continue
}
if delta := cmp.DeltaAllocsPerOp(); !*changedOnly || delta.Changed() {
if !header {
fmt.Fprint(w, "\nbenchmark\told allocs\tnew allocs\tdelta\n")
header = true
}
fmt.Fprintf(w, "%s\t%d\t%d\t%s\n", cmp.Name(), cmp.Before.AllocsPerOp, cmp.After.AllocsPerOp, delta.Percent())
}
}
header = false
if *magSort {
sort.Sort(ByDeltaAllocedBytesPerOp(cmps))
}
for _, cmp := range cmps {
if !cmp.Measured(parse.AllocedBytesPerOp) {
continue
}
if delta := cmp.DeltaAllocedBytesPerOp(); !*changedOnly || delta.Changed() {
if !header {
fmt.Fprint(w, "\nbenchmark\told bytes\tnew bytes\tdelta\n")
header = true
}
fmt.Fprintf(w, "%s\t%d\t%d\t%s\n", cmp.Name(), cmp.Before.AllocedBytesPerOp, cmp.After.AllocedBytesPerOp, cmp.DeltaAllocedBytesPerOp().Percent())
}
}
}
func fatal(msg interface{}) {
fmt.Fprintln(os.Stderr, msg)
os.Exit(1)
}
func parseFile(path string) parse.Set {
f, err := os.Open(path)
if err != nil {
fatal(err)
}
defer f.Close()
bb, err := parse.ParseSet(f)
if err != nil {
fatal(err)
}
if *best {
selectBest(bb)
}
return bb
}
func selectBest(bs parse.Set) {
for name, bb := range bs {
if len(bb) < 2 {
continue
}
ord := bb[0].Ord
best := bb[0]
for _, b := range bb {
if b.NsPerOp < best.NsPerOp {
b.Ord = ord
best = b
}
}
bs[name] = []*parse.Benchmark{best}
}
}
// formatNs formats ns measurements to expose a useful amount of
// precision. It mirrors the ns precision logic of testing.B.
func formatNs(ns float64) string {
prec := 0
switch {
case ns < 10:
prec = 2
case ns < 100:
prec = 1
}
return strconv.FormatFloat(ns, 'f', prec, 64)
}