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| author | Alberto Donizetti <alb.donizetti@gmail.com> | 2018-01-08 13:03:57 +0100 |
|---|---|---|
| committer | Brad Fitzpatrick <bradfitz@golang.org> | 2018-02-19 23:42:57 +0000 |
| commit | 252ee90971d87f099a2e67c3536a0481a535157f (patch) | |
| tree | 29d6b800393c1bfe5da66cc97113780adc9a1756 /src/encoding/xml | |
| parent | bb355ed5ebb24179be4e1093c3dce12e23f21d56 (diff) | |
| download | go-252ee90971d87f099a2e67c3536a0481a535157f.tar.gz go-252ee90971d87f099a2e67c3536a0481a535157f.zip | |
encoding/xml: simplify slice-growing logic in rawToken
It appears that old code (from 2009) in xml.(*Decoder).rawToken
replicates append's slice-growing functionality by allocating a new,
bigger backing array and then calling copy.
Simplifying the code by replacing it with a single append call does
not seem to hurt performance:
name old time/op new time/op delta
Marshal-4 11.2µs ± 1% 11.3µs ±10% ~ (p=0.069 n=19+17)
Unmarshal-4 28.6µs ± 1% 28.4µs ± 1% -0.60% (p=0.000 n=20+18)
name old alloc/op new alloc/op delta
Marshal-4 5.78kB ± 0% 5.78kB ± 0% ~ (all equal)
Unmarshal-4 8.61kB ± 0% 8.27kB ± 0% -3.90% (p=0.000 n=20+20)
name old allocs/op new allocs/op delta
Marshal-4 23.0 ± 0% 23.0 ± 0% ~ (all equal)
Unmarshal-4 189 ± 0% 190 ± 0% +0.53% (p=0.000 n=20+20)
Change-Id: Ie580d1216a44760e611e63dee2c339af5465aea5
Reviewed-on: https://go-review.googlesource.com/86655
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Diffstat (limited to 'src/encoding/xml')
| -rw-r--r-- | src/encoding/xml/xml.go | 14 |
1 files changed, 2 insertions, 12 deletions
diff --git a/src/encoding/xml/xml.go b/src/encoding/xml/xml.go index f408623de5..b379544dab 100644 --- a/src/encoding/xml/xml.go +++ b/src/encoding/xml/xml.go @@ -806,18 +806,7 @@ func (d *Decoder) rawToken() (Token, error) { } d.ungetc(b) - n := len(attr) - if n >= cap(attr) { - nCap := 2 * cap(attr) - if nCap == 0 { - nCap = 4 - } - nattr := make([]Attr, n, nCap) - copy(nattr, attr) - attr = nattr - } - attr = attr[0 : n+1] - a := &attr[n] + a := Attr{} if a.Name, ok = d.nsname(); !ok { if d.err == nil { d.err = d.syntaxError("expected attribute name in element") @@ -843,6 +832,7 @@ func (d *Decoder) rawToken() (Token, error) { } a.Value = string(data) } + attr = append(attr, a) } if empty { d.needClose = true |