diff options
author | Anthony Martin <ality@pbrane.org> | 2014-05-15 20:12:06 -0700 |
---|---|---|
committer | Rob Pike <r@golang.org> | 2014-05-15 20:12:06 -0700 |
commit | c6aa2e5ac8097f9491a407c3bb2385159d9aed32 (patch) | |
tree | 7fb5941023f324f10fcfde4a5a25a989112c92e3 /src/cmd/pack | |
parent | 74fe67f22e41f06ab93fc5123964f144040191aa (diff) | |
download | go-c6aa2e5ac8097f9491a407c3bb2385159d9aed32.tar.gz go-c6aa2e5ac8097f9491a407c3bb2385159d9aed32.zip |
cmd/pack: buffer writes in TestLargeDefs
TestLargeDefs was issuing over one million small writes to
create a 7MB file (large.go). This is quite slow on Plan 9
since our disk file systems aren't very fast and they're
usually accessed over the network.
Buffering the writes makes the test about six times faster.
Even on Linux, it's about 1.5 times faster.
Here are the results on a slow Plan 9 machine:
Before:
% ./pack.test -test.v -test.run TestLargeDefs
=== RUN TestLargeDefs
--- PASS: TestLargeDefs (125.11 seconds)
PASS
After:
% ./pack.test -test.v -test.run TestLargeDefs
=== RUN TestLargeDefs
--- PASS: TestLargeDefs (20.835 seconds)
PASS
LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/95040044
Diffstat (limited to 'src/cmd/pack')
-rw-r--r-- | src/cmd/pack/pack_test.go | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/src/cmd/pack/pack_test.go b/src/cmd/pack/pack_test.go index 8ecca98e63..e634c86f76 100644 --- a/src/cmd/pack/pack_test.go +++ b/src/cmd/pack/pack_test.go @@ -5,6 +5,7 @@ package main import ( + "bufio" "bytes" "fmt" "io" @@ -223,9 +224,10 @@ func TestLargeDefs(t *testing.T) { if err != nil { t.Fatal(err) } + b := bufio.NewWriter(f) printf := func(format string, args ...interface{}) { - _, err := fmt.Fprintf(f, format, args...) + _, err := fmt.Fprintf(b, format, args...) if err != nil { t.Fatalf("Writing to %s: %v", large, err) } @@ -240,6 +242,9 @@ func TestLargeDefs(t *testing.T) { printf("\"`\n") } printf("}\n") + if err = b.Flush(); err != nil { + t.Fatal(err) + } if err = f.Close(); err != nil { t.Fatal(err) } |