benchmark old ns/op new ns/op delta
BenchmarkByteReplacerWriteString 7359 3661 -50.25%
LGTM=dave
R=golang-codereviews, dave
CC=golang-codereviews
https://golang.org/cl/102550043
Use WriteString instead of allocating a byte slice as a
buffer. This was a TODO.
benchmark old ns/op new ns/op delta
BenchmarkWriteString 40139 19991 -50.20%
LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/107190044
genericReplacer.lookup is called for each byte of an input
string. In many (most?) cases, lookup will fail for the first
byte, and it will return immediately. Adding a fast path for
that case seems worth it.
Benchmark on my Xeon 3.5GHz Linux box:
benchmark old ns/op new ns/op delta
BenchmarkGenericNoMatch 2691 774 -71.24%
BenchmarkGenericMatch1 7920 8151 +2.92%
BenchmarkGenericMatch2 52336 39927 -23.71%
BenchmarkSingleMaxSkipping 1575 1575 +0.00%
BenchmarkSingleLongSuffixFail 1429 1429 +0.00%
BenchmarkSingleMatch 56228 55444 -1.39%
BenchmarkByteByteNoMatch 568 568 +0.00%
BenchmarkByteByteMatch 977 972 -0.51%
BenchmarkByteStringMatch 1669 1687 +1.08%
BenchmarkHTMLEscapeNew 422 422 +0.00%
BenchmarkHTMLEscapeOld 692 670 -3.18%
BenchmarkByteByteReplaces 8492 8474 -0.21%
BenchmarkByteByteMap 2817 2808 -0.32%
LGTM=rsc
R=golang-codereviews, bradfitz, dave, rsc
CC=golang-codereviews
https://golang.org/cl/79200044
bi is a slice and not an array, so bi[:] does not make much sense.
LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/79280043
singleStringReplacer had a bug where if a string was replaced
at the beginning and no output had yet been produced into the
temp buffer before matching ended, an invalid nil check (used
as a proxy for having matched anything) meant it always
returned its input.
Fixes#6659
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/16880043
The string searching is implemented separately so other functions
may make use of it in the future.
benchmark old ns/op new ns/op delta
BenchmarkSingleMaxSkipping 125889 2474 -98.03%
BenchmarkSingleLongSuffixFail 16252 1996 -87.72%
BenchmarkSingleMatch 260793 136266 -47.75%
benchmark old MB/s new MB/s speedup
BenchmarkSingleMaxSkipping 79.43 4041.57 50.88x
BenchmarkSingleLongSuffixFail 61.65 501.81 8.14x
BenchmarkSingleMatch 57.52 110.08 1.91x
R=nigeltao
CC=golang-dev
https://golang.org/cl/6545049
This also fixes the semantics of some corner cases with the empty
match. TODOs for genericReplacer in the tests are fixed.
benchmark old ns/op new ns/op delta
BenchmarkGenericNoMatch 71395 3132 -95.61%
BenchmarkGenericMatch1 75610 20280 -73.18%
BenchmarkGenericMatch2 837995 86725 -89.65%
R=nigeltao, rsc
CC=golang-dev
https://golang.org/cl/6492076
This implements a replacer for when all old strings are single
bytes, but new values are not.
BenchmarkHTMLEscapeNew 1000000 1090 ns/op
BenchmarkHTMLEscapeOld 1000000 2049 ns/op
R=rsc
CC=golang-dev
https://golang.org/cl/5176043
When all old & new string values are single bytes,
byteReplacer is now used, instead of the generic
algorithm.
BenchmarkGenericMatch 10000 102519 ns/op
BenchmarkByteByteMatch 1000000 2178 ns/op
fast path, when nothing matches:
BenchmarkByteByteNoMatch 1000000 1109 ns/op
comparisons to multiple Replace calls:
BenchmarkByteByteReplaces 100000 16164 ns/op
comparison to strings.Map:
BenchmarkByteByteMap 500000 5454 ns/op
R=rsc
CC=golang-dev
https://golang.org/cl/5175050
This is just a new API to do many replacements at once.
While the point of this API is to be faster than doing replacements one
at a time, the implementation in this CL has the optimizations removed
and may actually be slower.
Future CLs will bring back & add optimizations.
R=r, rsc, rogpeppe
CC=golang-dev
https://golang.org/cl/5081042
Rui Ueyama
Brad Fitzpatrick
Eric Roshan-Eisner
Nigel Tao
Russ Cox