1fb4e4de26
This makes compress/flate's version of Snappy diverge from the upstream golang/snappy version, but the latter has a goal of matching C++ snappy output byte-for-byte. Both C++ and the asm version of golang/snappy can use a smaller N for the O(N) zero-initialization of the hash table when the input is small, even if the pure Go golang/snappy algorithm cannot: "var table [tableSize]uint16" zeroes all tableSize elements. For this package, we don't have the match-C++-snappy goal, so we can use a different (constant) hash table size. This is a small win, in terms of throughput and output size, but it also enables us to re-use the (constant size) hash table between encodeBestSpeed calls, avoiding the cost of zero-initializing the hash table altogether. This will be implemented in follow-up commits. This package's benchmarks: name old speed new speed delta EncodeDigitsSpeed1e4-8 72.8MB/s ± 1% 73.5MB/s ± 1% +0.86% (p=0.000 n=10+10) EncodeDigitsSpeed1e5-8 77.5MB/s ± 1% 78.0MB/s ± 0% +0.69% (p=0.000 n=10+10) EncodeDigitsSpeed1e6-8 82.0MB/s ± 1% 82.7MB/s ± 1% +0.85% (p=0.000 n=10+9) EncodeTwainSpeed1e4-8 65.1MB/s ± 1% 65.6MB/s ± 0% +0.78% (p=0.000 n=10+9) EncodeTwainSpeed1e5-8 80.0MB/s ± 0% 80.6MB/s ± 1% +0.66% (p=0.000 n=9+10) EncodeTwainSpeed1e6-8 81.6MB/s ± 1% 82.1MB/s ± 1% +0.55% (p=0.017 n=10+10) Input size in bytes, output size (and time taken) before and after on some larger files: 1073741824 57269781 ( 3183ms) 57269781 ( 3177ms) adresser.001 1000000000 391052000 ( 11071ms) 391051996 ( 11067ms) enwik9 1911399616 378679516 ( 13450ms) 378679514 ( 13079ms) gob-stream 8558382592 3972329193 ( 99962ms) 3972329193 ( 91290ms) rawstudio-mint14.tar 200000000 200015265 ( 776ms) 200015265 ( 774ms) sharnd.out Thanks to Klaus Post for the original suggestion on cl/21021. Change-Id: Ia4c63a8d1b92c67e1765ec5c3c8c69d289d9a6ce Reviewed-on: https://go-review.googlesource.com/22604 Reviewed-by: Russ Cox <rsc@golang.org> |
||
|---|---|---|
| .github | ||
| api | ||
| doc | ||
| lib/time | ||
| misc | ||
| src | ||
| test | ||
| .gitattributes | ||
| .gitignore | ||
| AUTHORS | ||
| CONTRIBUTING.md | ||
| CONTRIBUTORS | ||
| favicon.ico | ||
| LICENSE | ||
| PATENTS | ||
| README.md | ||
| robots.txt | ||
The Go Programming Language
Go is an open source programming language that makes it easy to build simple, reliable, and efficient software.
For documentation about how to install and use Go, visit https://golang.org/ or load doc/install-source.html in your web browser.
Our canonical Git repository is located at https://go.googlesource.com/go. There is a mirror of the repository at https://github.com/golang/go.
Go is the work of hundreds of contributors. We appreciate your help!
To contribute, please read the contribution guidelines: https://golang.org/doc/contribute.html
Note that we do not accept pull requests and that we use the issue tracker for bug reports and proposals only. Please ask questions on https://forum.golangbridge.org or https://groups.google.com/forum/#!forum/golang-nuts.
Unless otherwise noted, the Go source files are distributed under the BSD-style license found in the LICENSE file.
--
Binary Distribution Notes
If you have just untarred a binary Go distribution, you need to set the environment variable $GOROOT to the full path of the go directory (the one containing this file). You can omit the variable if you unpack it into /usr/local/go, or if you rebuild from sources by running all.bash (see doc/install-source.html). You should also add the Go binary directory $GOROOT/bin to your shell's path.
For example, if you extracted the tar file into $HOME/go, you might put the following in your .profile:
export GOROOT=$HOME/go
export PATH=$PATH:$GOROOT/bin
See https://golang.org/doc/install or doc/install.html for more details.