diff options
author | Brad Fitzpatrick <bradfitz@golang.org> | 2016-10-04 23:34:01 +0000 |
---|---|---|
committer | Brad Fitzpatrick <bradfitz@golang.org> | 2016-10-05 04:29:07 +0000 |
commit | efaa36017e34b87a5731793594b42d483209d808 (patch) | |
tree | c3aeb14fd8513d34b11a5076dc109e7ce52cc4c3 /src/encoding/csv | |
parent | d1d798dd15e7abbeab335804bd6dfaec6c016018 (diff) | |
download | go-efaa36017e34b87a5731793594b42d483209d808.tar.gz go-efaa36017e34b87a5731793594b42d483209d808.zip |
encoding/csv: update and add CSV reading benchmarks
Benchmarks broken off from https://golang.org/cl/24723 and modified to
allocate less in the places we're not trying to measure.
Updates #16791
Change-Id: I508e4cfeac60322d56f1d71ff1912f6a6f183a63
Reviewed-on: https://go-review.googlesource.com/30357
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Diffstat (limited to 'src/encoding/csv')
-rw-r--r-- | src/encoding/csv/reader_test.go | 72 |
1 files changed, 64 insertions, 8 deletions
diff --git a/src/encoding/csv/reader_test.go b/src/encoding/csv/reader_test.go index be1002d034..7b3aca4c5f 100644 --- a/src/encoding/csv/reader_test.go +++ b/src/encoding/csv/reader_test.go @@ -5,6 +5,7 @@ package csv import ( + "io" "reflect" "strings" "testing" @@ -292,8 +293,52 @@ func TestRead(t *testing.T) { } } -func BenchmarkRead(b *testing.B) { - data := `x,y,z,w +// nTimes is an io.Reader which yields the string s n times. +type nTimes struct { + s string + n int + off int +} + +func (r *nTimes) Read(p []byte) (n int, err error) { + for { + if r.n <= 0 || r.s == "" { + return n, io.EOF + } + n0 := copy(p, r.s[r.off:]) + p = p[n0:] + n += n0 + r.off += n0 + if r.off == len(r.s) { + r.off = 0 + r.n-- + } + if len(p) == 0 { + return + } + } +} + +// benchmarkRead measures reading the provided CSV rows data. +// initReader, if non-nil, modifies the Reader before it's used. +func benchmarkRead(b *testing.B, initReader func(*Reader), rows string) { + b.ReportAllocs() + r := NewReader(&nTimes{s: rows, n: b.N}) + if initReader != nil { + initReader(r) + } + for { + _, err := r.Read() + if err == io.EOF { + break + } + if err != nil { + b.Fatal(err) + } + } +} + +const benchmarkCSVData = `x,y,z,w x,y,z, x,y,, x,,, @@ -305,11 +350,22 @@ x,,, "","","","" ` - for i := 0; i < b.N; i++ { - _, err := NewReader(strings.NewReader(data)).ReadAll() +func BenchmarkRead(b *testing.B) { + benchmarkRead(b, nil, benchmarkCSVData) +} - if err != nil { - b.Fatalf("could not read data: %s", err) - } - } +func BenchmarkReadWithFieldsPerRecord(b *testing.B) { + benchmarkRead(b, func(r *Reader) { r.FieldsPerRecord = 4 }, benchmarkCSVData) +} + +func BenchmarkReadWithoutFieldsPerRecord(b *testing.B) { + benchmarkRead(b, func(r *Reader) { r.FieldsPerRecord = -1 }, benchmarkCSVData) +} + +func BenchmarkReadLargeFields(b *testing.B) { + benchmarkRead(b, nil, strings.Repeat(`xxxxxxxxxxxxxxxx,yyyyyyyyyyyyyyyy,zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz,wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww,vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv +xxxxxxxxxxxxxxxxxxxxxxxx,yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy,zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz,wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww,vvvv +,,zzzz,wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww,vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv +xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx,yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy,zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz,wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww,vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv +`, 3)) } |