ref: a843ca53b5e0f29df9535fa0e88408a63cdc2cd7
parent: 02397e76cece28b467de30ff0cb0f471d9b212ee
author: HyeonGyu Lee <vazrupe@naver.com>
date: Tue Aug 6 20:46:20 EDT 2019
transform/urlreplacers: Cache the next position of `urlreplacer.prefix` Improved performance due to `bytes.Index` repeated calls Fixes #5942
--- a/transform/urlreplacers/absurlreplacer.go
+++ b/transform/urlreplacers/absurlreplacer.go
@@ -41,8 +41,30 @@
disabled bool
b []byte
f func(l *absurllexer)
+
+ nextPos int
}
+func (p *prefix) find(bs []byte, start int) bool {+ if p.disabled {+ return false
+ }
+
+ if p.nextPos == -1 {+ idx := bytes.Index(bs[start:], p.b)
+
+ if idx == -1 {+ p.disabled = true
+ // Find the closest match
+ return false
+ }
+
+ p.nextPos = start + idx + len(p.b)
+ }
+
+ return true
+}
+
func newPrefixState() []*prefix { return []*prefix{ {b: []byte("src="), f: checkCandidateBase},@@ -179,35 +201,28 @@
break
}
- nextPos := -1
-
var match *prefix
for _, p := range prefixes {- if p.disabled {+ if !p.find(l.content, l.pos) {continue
}
- idx := bytes.Index(l.content[l.pos:], p.b)
- if idx == -1 {- p.disabled = true
- // Find the closest match
- } else if nextPos == -1 || idx < nextPos {- nextPos = idx
+ if match == nil || p.nextPos < match.nextPos {match = p
}
}
- if nextPos == -1 {+ if match == nil {// Done!
l.pos = contentLength
break
} else {- l.pos += nextPos + len(match.b)
+ l.pos = match.nextPos
+ match.nextPos = -1
match.f(l)
}
}
-
// Done!
if l.pos > l.start {l.emit()