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| author | Daniel Martí <mvdan@mvdan.cc> | 2023-04-07 18:21:00 +0100 |
|---|---|---|
| committer | Daniel Martí <mvdan@mvdan.cc> | 2023-04-07 19:49:28 +0000 |
| commit | 10c079a0ad2283be3761a47eda6e41bde38fd16b (patch) | |
| tree | 3cbf2b566b2b11b5aeb05286228190d00fe8f483 /src/encoding/xml/read.go | |
| parent | 97df9c0b051b6c06bff7ec7e61522e7bbef40c91 (diff) | |
| download | go-10c079a0ad2283be3761a47eda6e41bde38fd16b.tar.xz | |
encoding/xml: use reflect.Value.Grow
Like https://go.dev/cl/481376 did for encoding/gob,
but now for encoding/xml, which had very similar code.
One minor difference is that encoding/xml now needs a SetLen before the
call to Index, as otherwise we index just past the length.
Still, calling Grow and SetLen is easier to understand,
and avoids needing to make a new zero value.
goos: linux
goarch: amd64
pkg: encoding/xml
cpu: AMD Ryzen 7 PRO 5850U with Radeon Graphics
│ old │ new │
│ sec/op │ sec/op vs base │
Unmarshal-8 6.904µ ± 1% 6.980µ ± 1% +1.10% (p=0.009 n=6)
│ old │ new │
│ B/op │ B/op vs base │
Unmarshal-8 7.656Ki ± 0% 7.586Ki ± 0% -0.92% (p=0.002 n=6)
│ old │ new │
│ allocs/op │ allocs/op vs base │
Unmarshal-8 188.0 ± 0% 185.0 ± 0% -1.60% (p=0.002 n=6)
Change-Id: Id83feb467a9c59c80c7936aa892780aae7e8b809
Reviewed-on: https://go-review.googlesource.com/c/go/+/483135
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Diffstat (limited to 'src/encoding/xml/read.go')
| -rw-r--r-- | src/encoding/xml/read.go | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/src/encoding/xml/read.go b/src/encoding/xml/read.go index 43be08eeef..c1c843e4c0 100644 --- a/src/encoding/xml/read.go +++ b/src/encoding/xml/read.go @@ -284,7 +284,8 @@ func (d *Decoder) unmarshalAttr(val reflect.Value, attr Attr) error { // Slice of element values. // Grow slice. n := val.Len() - val.Set(reflect.Append(val, reflect.Zero(val.Type().Elem()))) + val.Grow(1) + val.SetLen(n + 1) // Recur to read element into slice. if err := d.unmarshalAttr(val.Index(n), attr); err != nil { @@ -410,7 +411,8 @@ func (d *Decoder) unmarshal(val reflect.Value, start *StartElement, depth int) e // Slice of element values. // Grow slice. n := v.Len() - v.Set(reflect.Append(val, reflect.Zero(v.Type().Elem()))) + v.Grow(1) + v.SetLen(n + 1) // Recur to read element into slice. if err := d.unmarshal(v.Index(n), start, depth+1); err != nil { |