No Description

Nigel Tao b62d312cd2 Add some benchmark numbers to the README. 10 years ago
cmd 9bc0b5ad10 Make heuristic match skipping more aggressive. 10 years ago
testdata 70f093abd7 Use a more compressible golden input for the tests. 10 years ago
.gitignore 343d0f4579 Add a snappytool command that uses the C++ library. 10 years ago
AUTHORS 92d8f39f9c A+C: remove Klaus Post <klauspost@gmail.com>. 10 years ago
CONTRIBUTORS 92d8f39f9c A+C: remove Klaus Post <klauspost@gmail.com>. 10 years ago
LICENSE a0354efc61 Initial check-in. 14 years ago
README b62d312cd2 Add some benchmark numbers to the README. 10 years ago
decode.go 3675542200 Don't allow EOF in the middle of a framing chunk. 10 years ago
decode_amd64.go 3588d1dd84 Add appengine and noasm build tags. 10 years ago
decode_amd64.s 4f2f9a13dd Write the encoder's extendMatch in asm. 10 years ago
decode_other.go 3588d1dd84 Add appengine and noasm build tags. 10 years ago
encode.go 988ce01844 Add a fast path for short emitLiteral calls. 10 years ago
encode_amd64.go 6880122951 Write the encoder's encodeBlock in asm. 10 years ago
encode_amd64.s dfb3612ba2 Inline the extendMatch call. 10 years ago
encode_other.go 2dbf365277 Inline extendMatch for the noasm encoder. 10 years ago
golden_test.go 4f2f9a13dd Write the encoder's extendMatch in asm. 10 years ago
snappy.go bf2ded9d81 Use 64K blocks when encoding long inputs. 10 years ago
snappy.test 6ffc20e64a Add more comments for the asm workaround. 10 years ago
snappy_test.go 4f2f9a13dd Write the encoder's extendMatch in asm. 10 years ago

README

The Snappy compression format in the Go programming language.

To download and install from source:
$ go get github.com/golang/snappy

Unless otherwise noted, the Snappy-Go source files are distributed
under the BSD-style license found in the LICENSE file.



Benchmarks.

The golang/snappy benchmarks include compressing (Z) and decompressing (U) ten
or so files, the same set used by the C++ Snappy code (github.com/google/snappy
and note the "google", not "golang"). On an "Intel(R) Core(TM) i7-3770 CPU @
3.40GHz", Go's GOARCH=amd64 numbers as of 2016-04-29:

"go test -test.bench=."

_UFlat0-8 2.23GB/s ± 1% html
_UFlat1-8 1.43GB/s ± 0% urls
_UFlat2-8 23.7GB/s ± 1% jpg
_UFlat3-8 1.93GB/s ± 0% jpg_200
_UFlat4-8 13.9GB/s ± 2% pdf
_UFlat5-8 2.00GB/s ± 0% html4
_UFlat6-8 829MB/s ± 0% txt1
_UFlat7-8 799MB/s ± 0% txt2
_UFlat8-8 871MB/s ± 0% txt3
_UFlat9-8 730MB/s ± 0% txt4
_UFlat10-8 2.87GB/s ± 0% pb
_UFlat11-8 1.07GB/s ± 0% gaviota

_ZFlat0-8 1.04GB/s ± 0% html
_ZFlat1-8 536MB/s ± 0% urls
_ZFlat2-8 16.3GB/s ± 2% jpg
_ZFlat3-8 762MB/s ± 0% jpg_200
_ZFlat4-8 9.48GB/s ± 1% pdf
_ZFlat5-8 990MB/s ± 0% html4
_ZFlat6-8 381MB/s ± 0% txt1
_ZFlat7-8 353MB/s ± 0% txt2
_ZFlat8-8 398MB/s ± 0% txt3
_ZFlat9-8 329MB/s ± 0% txt4
_ZFlat10-8 1.35GB/s ± 1% pb
_ZFlat11-8 608MB/s ± 0% gaviota



"go test -test.bench=. -tags=noasm"

_UFlat0-8 637MB/s ± 0% html
_UFlat1-8 506MB/s ± 0% urls
_UFlat2-8 23.0GB/s ± 5% jpg
_UFlat3-8 1.17GB/s ± 0% jpg_200
_UFlat4-8 4.44GB/s ± 1% pdf
_UFlat5-8 623MB/s ± 0% html4
_UFlat6-8 300MB/s ± 1% txt1
_UFlat7-8 293MB/s ± 0% txt2
_UFlat8-8 316MB/s ± 0% txt3
_UFlat9-8 285MB/s ± 0% txt4
_UFlat10-8 768MB/s ± 0% pb
_UFlat11-8 406MB/s ± 1% gaviota

_ZFlat0-8 411MB/s ± 1% html
_ZFlat1-8 250MB/s ± 1% urls
_ZFlat2-8 12.7GB/s ± 1% jpg
_ZFlat3-8 157MB/s ± 0% jpg_200
_ZFlat4-8 2.95GB/s ± 0% pdf
_ZFlat5-8 406MB/s ± 0% html4
_ZFlat6-8 182MB/s ± 0% txt1
_ZFlat7-8 173MB/s ± 1% txt2
_ZFlat8-8 191MB/s ± 0% txt3
_ZFlat9-8 166MB/s ± 0% txt4
_ZFlat10-8 480MB/s ± 0% pb
_ZFlat11-8 272MB/s ± 0% gaviota



For comparison (Go's encoded output is byte-for-byte identical to C++'s), here
are the numbers from C++ Snappy's

make CXXFLAGS="-O2 -DNDEBUG -g" clean snappy_unittest.log && cat snappy_unittest.log

BM_UFlat/0 2.4GB/s html
BM_UFlat/1 1.4GB/s urls
BM_UFlat/2 21.8GB/s jpg
BM_UFlat/3 1.5GB/s jpg_200
BM_UFlat/4 13.3GB/s pdf
BM_UFlat/5 2.1GB/s html4
BM_UFlat/6 1.0GB/s txt1
BM_UFlat/7 959.4MB/s txt2
BM_UFlat/8 1.0GB/s txt3
BM_UFlat/9 864.5MB/s txt4
BM_UFlat/10 2.9GB/s pb
BM_UFlat/11 1.2GB/s gaviota

BM_ZFlat/0 944.3MB/s html (22.31 %)
BM_ZFlat/1 501.6MB/s urls (47.78 %)
BM_ZFlat/2 14.3GB/s jpg (99.95 %)
BM_ZFlat/3 538.3MB/s jpg_200 (73.00 %)
BM_ZFlat/4 8.3GB/s pdf (83.30 %)
BM_ZFlat/5 903.5MB/s html4 (22.52 %)
BM_ZFlat/6 336.0MB/s txt1 (57.88 %)
BM_ZFlat/7 312.3MB/s txt2 (61.91 %)
BM_ZFlat/8 353.1MB/s txt3 (54.99 %)
BM_ZFlat/9 289.9MB/s txt4 (66.26 %)
BM_ZFlat/10 1.2GB/s pb (19.68 %)
BM_ZFlat/11 527.4MB/s gaviota (37.72 %)