qbit/go
1
0
Fork 0
mirror of https://github.com/golang/go synced 2024-11-18 11:55:01 -07:00
Code Releases Activity

os: avoid calulating fileStat.path until it is needed

Browse Source 
This CL improves

on my Windows 7

name         old time/op    new time/op    delta
Readdirname    58.1µs ± 1%    58.1µs ± 0%     ~     (p=0.817 n=8+8)
Readdir        58.0µs ± 3%    57.8µs ± 0%     ~     (p=0.944 n=9+8)

name         old alloc/op   new alloc/op   delta
Readdirname    3.03kB ± 0%    2.84kB ± 0%   -6.33%  (p=0.000 n=10+10)
Readdir        3.00kB ± 0%    2.81kB ± 0%   -6.40%  (p=0.000 n=10+10)

name         old allocs/op  new allocs/op  delta
Readdirname      34.0 ± 0%      30.0 ± 0%  -11.76%  (p=0.000 n=10+10)
Readdir          33.0 ± 0%      29.0 ± 0%  -12.12%  (p=0.000 n=10+10)

on my Windows XP

name           old time/op    new time/op    delta
Readdirname-2    85.5µs ± 0%    84.0µs ± 0%   -1.83%  (p=0.000 n=10+10)
Readdir-2        84.6µs ± 0%    83.5µs ± 0%   -1.31%  (p=0.000 n=10+9)

name           old alloc/op   new alloc/op   delta
Readdirname-2    6.52kB ± 0%    5.66kB ± 0%  -13.25%  (p=0.000 n=10+10)
Readdir-2        6.39kB ± 0%    5.53kB ± 0%  -13.52%  (p=0.000 n=10+10)

name           old allocs/op  new allocs/op  delta
Readdirname-2      78.0 ± 0%      66.0 ± 0%  -15.38%  (p=0.000 n=10+10)
Readdir-2          77.0 ± 0%      65.0 ± 0%  -15.58%  (p=0.000 n=10+10)

Change-Id: I5d698eca86b8e94a46b6cfbd5947898b7b3fbdbd
Reviewed-on: https://go-review.googlesource.com/42894
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This commit is contained in:
Alex Brainman 2017-05-08 12:49:04 +10:00
parent f5352a7763
commit 6dcaa095c5
2 changed files with 14 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
src/os/dir_windows.go
View File

@ -56,7 +56,8 @@ func (file *File) readdir(n int) (fi []FileInfo, err error) {
FileSizeHigh: d.FileSizeHigh,
FileSizeLow: d.FileSizeLow,
},
path: file.dirinfo.path + `\` + name,
path: file.dirinfo.path,
appendNameToPath: true,
}
n--
fi = append(fi, f)

17
src/os/types_windows.go
View File

@ -18,10 +18,11 @@ type fileStat struct {
// used to implement SameFile
sync.Mutex
path string
vol uint32
idxhi uint32
idxlo uint32
path string
vol uint32
idxhi uint32
idxlo uint32
appendNameToPath bool
}
func (fs *fileStat) Size() int64 {
@ -66,7 +67,13 @@ func (fs *fileStat) loadFileId() error {
// already done
return nil
}
pathp, err := syscall.UTF16PtrFromString(fs.path)
var path string
if fs.appendNameToPath {
path = fs.path + `\` + fs.name
} else {
path = fs.path
}
pathp, err := syscall.UTF16PtrFromString(path)
if err != nil {
return err
}