Commit Graph

114 Commits

Author SHA1 Message Date
Jeremy Jay b325799cad compress/gzip: clarify that Multistream gzip requires a ByteReader
Change-Id: Ib24778f3172c011e6a39ee65dce8764f3cc911ea
GitHub-Last-Rev: 9c617c1e60
GitHub-Pull-Request: golang/go#30284
Reviewed-on: https://go-review.googlesource.com/c/162999
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2019-02-26 23:02:40 +00:00
Robert Griesemer fae44a2be3 src, misc: apply gofmt
This applies the new gofmt literal normalizations to the library.

Change-Id: I8c1e8ef62eb556fc568872c9f77a31ef236348e7
Reviewed-on: https://go-review.googlesource.com/c/162539
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2019-02-19 20:38:28 +00:00
Osamu TONOMORI 1e708337b2 compress/flate: fix the old url for the flate algorithm
Change-Id: I84b74bc96516033bbf4a01f9aa81fe60d5a41355
Reviewed-on: https://go-review.googlesource.com/c/155317
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-12-20 18:15:50 +00:00
Igor Zhilianin f90e89e675 all: fix a bunch of misspellings
Change-Id: If2954bdfc551515403706b2cd0dde94e45936e08
GitHub-Last-Rev: d4cfc41a55
GitHub-Pull-Request: golang/go#28049
Reviewed-on: https://go-review.googlesource.com/c/140299
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-10-06 15:40:03 +00:00
Katie Hockman 43cd907017 Revert "compress: move benchmark text from src/testdata to src/compress/testdata"
This reverts commit 067bb443af.

Reason for revert:
Failing Darwin-arm builds because that testing environment does not access testdata
from sibling directories. A future change will likely be made to move this testdata
out of src/testdata to create a solution that doesn't require the single-file directory.

Updates #27151

Change-Id: I8dbf5dd9512c94a605ee749ff4655cb00b0de686
Reviewed-on: https://go-review.googlesource.com/138737
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
2018-10-01 16:16:21 +00:00
Katie Hockman 067bb443af compress: move benchmark text from src/testdata to src/compress/testdata
This text is used mainly for benchmark compression testing, and in one
net test. The text was prevoiusly in a src/testdata directory, but since
that directory would only include one file, the text is moved to the
existing src/compression/testdata directory.

This does not cause any change to the benchmark results.

Updates #27151

Change-Id: I38ab5089dfe744189a970947d15be50ef1d48517
Reviewed-on: https://go-review.googlesource.com/138495
Run-TryBot: Katie Hockman <katie@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-09-28 18:41:40 +00:00
Katie Hockman fdceb2a11b compress: reduce copies of new text for compression testing
The previous book was 387 KiB decompressed and 119 KiB compressed, the
new book is 567 KiB decompressed and 132 KiB compressed. Overall, this
change will reduce the release binary size by 196 KiB. The new book will
allow for slightly more extensive compression testing with a larger
text.

Command to run the benchmark tests used with benchstat:
`../bin/go test -run='^$' -count=4 -bench=. compress/bzip2 compress/flate`

When running the benchmarks locally, changed "Newton" to "Twain" and
filtered the tests with the -bench flag to include only those which were
relevant to these changes.

benchstat results below:

name                            old time/op    new time/op     delta
DecodeTwain-8                     19.6ms ± 2%     24.1ms ± 1%  +23.04%  (p=0.029 n=4+4)
Decode/Twain/Huffman/1e4-8         140µs ± 3%      139µs ± 5%     ~     (p=0.886 n=4+4)
Decode/Twain/Huffman/1e5-8        1.27ms ± 3%     1.26ms ± 1%     ~     (p=1.000 n=4+4)
Decode/Twain/Huffman/1e6-8        12.4ms ± 0%     13.2ms ± 1%   +6.42%  (p=0.029 n=4+4)
Decode/Twain/Speed/1e4-8           133µs ± 1%      123µs ± 1%   -7.35%  (p=0.029 n=4+4)
Decode/Twain/Speed/1e5-8          1.20ms ± 0%     1.02ms ± 3%  -15.32%  (p=0.029 n=4+4)
Decode/Twain/Speed/1e6-8          12.0ms ± 2%     10.1ms ± 3%  -15.89%  (p=0.029 n=4+4)
Decode/Twain/Default/1e4-8         131µs ± 6%      108µs ± 5%  -17.84%  (p=0.029 n=4+4)
Decode/Twain/Default/1e5-8        1.06ms ± 2%     0.80ms ± 1%  -24.97%  (p=0.029 n=4+4)
Decode/Twain/Default/1e6-8        10.0ms ± 3%      8.0ms ± 3%  -20.06%  (p=0.029 n=4+4)
Decode/Twain/Compression/1e4-8     128µs ± 4%      115µs ± 4%   -9.70%  (p=0.029 n=4+4)
Decode/Twain/Compression/1e5-8    1.04ms ± 2%     0.83ms ± 4%  -20.37%  (p=0.029 n=4+4)
Decode/Twain/Compression/1e6-8    10.4ms ± 4%      8.1ms ± 5%  -22.25%  (p=0.029 n=4+4)
Encode/Twain/Huffman/1e4-8        55.7µs ± 2%     55.6µs ± 1%     ~     (p=1.000 n=4+4)
Encode/Twain/Huffman/1e5-8         441µs ± 0%      435µs ± 2%     ~     (p=0.343 n=4+4)
Encode/Twain/Huffman/1e6-8        4.31ms ± 4%     4.30ms ± 4%     ~     (p=0.886 n=4+4)
Encode/Twain/Speed/1e4-8           193µs ± 1%      166µs ± 2%  -14.09%  (p=0.029 n=4+4)
Encode/Twain/Speed/1e5-8          1.54ms ± 1%     1.22ms ± 1%  -20.53%  (p=0.029 n=4+4)
Encode/Twain/Speed/1e6-8          15.3ms ± 1%     12.2ms ± 3%  -20.62%  (p=0.029 n=4+4)
Encode/Twain/Default/1e4-8         393µs ± 1%      390µs ± 1%     ~     (p=0.114 n=4+4)
Encode/Twain/Default/1e5-8        6.12ms ± 4%     6.02ms ± 5%     ~     (p=0.486 n=4+4)
Encode/Twain/Default/1e6-8        69.4ms ± 5%     59.0ms ± 4%  -15.07%  (p=0.029 n=4+4)
Encode/Twain/Compression/1e4-8     423µs ± 2%      379µs ± 2%  -10.34%  (p=0.029 n=4+4)
Encode/Twain/Compression/1e5-8    7.00ms ± 1%     7.88ms ± 3%  +12.49%  (p=0.029 n=4+4)
Encode/Twain/Compression/1e6-8    76.6ms ± 5%     80.9ms ± 3%     ~     (p=0.114 n=4+4)

name                            old speed      new speed       delta
DecodeTwain-8                   19.8MB/s ± 2%   23.6MB/s ± 1%  +18.84%  (p=0.029 n=4+4)
Decode/Twain/Huffman/1e4-8      71.7MB/s ± 3%   72.1MB/s ± 6%     ~     (p=0.943 n=4+4)
Decode/Twain/Huffman/1e5-8      78.8MB/s ± 3%   79.5MB/s ± 1%     ~     (p=1.000 n=4+4)
Decode/Twain/Huffman/1e6-8      80.5MB/s ± 0%   75.6MB/s ± 1%   -6.03%  (p=0.029 n=4+4)
Decode/Twain/Speed/1e4-8        75.2MB/s ± 1%   81.2MB/s ± 1%   +7.93%  (p=0.029 n=4+4)
Decode/Twain/Speed/1e5-8        83.4MB/s ± 0%   98.6MB/s ± 3%  +18.16%  (p=0.029 n=4+4)
Decode/Twain/Speed/1e6-8        83.6MB/s ± 2%   99.5MB/s ± 3%  +18.91%  (p=0.029 n=4+4)
Decode/Twain/Default/1e4-8      76.3MB/s ± 6%   92.8MB/s ± 4%  +21.62%  (p=0.029 n=4+4)
Decode/Twain/Default/1e5-8      94.4MB/s ± 3%  125.7MB/s ± 1%  +33.24%  (p=0.029 n=4+4)
Decode/Twain/Default/1e6-8       100MB/s ± 3%    125MB/s ± 3%  +25.12%  (p=0.029 n=4+4)
Decode/Twain/Compression/1e4-8  78.4MB/s ± 4%   86.8MB/s ± 4%  +10.73%  (p=0.029 n=4+4)
Decode/Twain/Compression/1e5-8  95.7MB/s ± 2%  120.3MB/s ± 4%  +25.65%  (p=0.029 n=4+4)
Decode/Twain/Compression/1e6-8  96.4MB/s ± 4%  124.0MB/s ± 5%  +28.64%  (p=0.029 n=4+4)
Encode/Twain/Huffman/1e4-8       179MB/s ± 2%    180MB/s ± 1%     ~     (p=1.000 n=4+4)
Encode/Twain/Huffman/1e5-8       227MB/s ± 0%    230MB/s ± 2%     ~     (p=0.343 n=4+4)
Encode/Twain/Huffman/1e6-8       232MB/s ± 4%    233MB/s ± 4%     ~     (p=0.886 n=4+4)
Encode/Twain/Speed/1e4-8        51.8MB/s ± 1%   60.4MB/s ± 2%  +16.43%  (p=0.029 n=4+4)
Encode/Twain/Speed/1e5-8        65.1MB/s ± 1%   81.9MB/s ± 1%  +25.83%  (p=0.029 n=4+4)
Encode/Twain/Speed/1e6-8        65.2MB/s ± 1%   82.2MB/s ± 3%  +26.00%  (p=0.029 n=4+4)
Encode/Twain/Default/1e4-8      25.4MB/s ± 1%   25.6MB/s ± 1%     ~     (p=0.114 n=4+4)
Encode/Twain/Default/1e5-8      16.4MB/s ± 4%   16.6MB/s ± 5%     ~     (p=0.486 n=4+4)
Encode/Twain/Default/1e6-8      14.4MB/s ± 6%   17.0MB/s ± 4%  +17.67%  (p=0.029 n=4+4)
Encode/Twain/Compression/1e4-8  23.6MB/s ± 2%   26.4MB/s ± 2%  +11.54%  (p=0.029 n=4+4)
Encode/Twain/Compression/1e5-8  14.3MB/s ± 1%   12.7MB/s ± 3%  -11.08%  (p=0.029 n=4+4)
Encode/Twain/Compression/1e6-8  13.1MB/s ± 4%   12.4MB/s ± 3%     ~     (p=0.114 n=4+4)

name                            old alloc/op   new alloc/op    delta
DecodeTwain-8                     3.63MB ± 0%     3.63MB ± 0%   +0.15%  (p=0.029 n=4+4)
Decode/Twain/Huffman/1e4-8        42.0kB ± 0%     41.3kB ± 0%   -1.62%  (p=0.029 n=4+4)
Decode/Twain/Huffman/1e5-8        43.5kB ± 0%     45.1kB ± 0%   +3.74%  (p=0.029 n=4+4)
Decode/Twain/Huffman/1e6-8        71.7kB ± 0%     80.0kB ± 0%  +11.55%  (p=0.029 n=4+4)
Decode/Twain/Speed/1e4-8          41.2kB ± 0%     41.3kB ± 0%     ~     (p=0.286 n=4+4)
Decode/Twain/Speed/1e5-8          45.1kB ± 0%     43.9kB ± 0%   -2.80%  (p=0.029 n=4+4)
Decode/Twain/Speed/1e6-8          72.8kB ± 0%     81.3kB ± 0%  +11.72%  (p=0.029 n=4+4)
Decode/Twain/Default/1e4-8        41.2kB ± 0%     41.2kB ± 0%   -0.22%  (p=0.029 n=4+4)
Decode/Twain/Default/1e5-8        44.4kB ± 0%     43.0kB ± 0%   -3.02%  (p=0.029 n=4+4)
Decode/Twain/Default/1e6-8        71.0kB ± 0%     61.8kB ± 0%  -13.00%  (p=0.029 n=4+4)
Decode/Twain/Compression/1e4-8    41.3kB ± 0%     41.2kB ± 0%   -0.29%  (p=0.029 n=4+4)
Decode/Twain/Compression/1e5-8    43.3kB ± 0%     43.0kB ± 0%   -0.72%  (p=0.029 n=4+4)
Decode/Twain/Compression/1e6-8    69.1kB ± 0%     63.7kB ± 0%   -7.90%  (p=0.029 n=4+4)

name                            old allocs/op  new allocs/op   delta
DecodeTwain-8                       51.0 ± 0%       51.2 ± 1%     ~     (p=1.000 n=4+4)
Decode/Twain/Huffman/1e4-8          15.0 ± 0%       14.0 ± 0%   -6.67%  (p=0.029 n=4+4)
Decode/Twain/Huffman/1e5-8          20.0 ± 0%       23.0 ± 0%  +15.00%  (p=0.029 n=4+4)
Decode/Twain/Huffman/1e6-8           134 ± 0%        161 ± 0%  +20.15%  (p=0.029 n=4+4)
Decode/Twain/Speed/1e4-8            17.0 ± 0%       18.0 ± 0%   +5.88%  (p=0.029 n=4+4)
Decode/Twain/Speed/1e5-8            30.0 ± 0%       31.0 ± 0%   +3.33%  (p=0.029 n=4+4)
Decode/Twain/Speed/1e6-8             193 ± 0%        228 ± 0%  +18.13%  (p=0.029 n=4+4)
Decode/Twain/Default/1e4-8          17.0 ± 0%       15.0 ± 0%  -11.76%  (p=0.029 n=4+4)
Decode/Twain/Default/1e5-8          28.0 ± 0%       32.0 ± 0%  +14.29%  (p=0.029 n=4+4)
Decode/Twain/Default/1e6-8           199 ± 0%        158 ± 0%  -20.60%  (p=0.029 n=4+4)
Decode/Twain/Compression/1e4-8      17.0 ± 0%       15.0 ± 0%  -11.76%  (p=0.029 n=4+4)
Decode/Twain/Compression/1e5-8      28.0 ± 0%       32.0 ± 0%  +14.29%  (p=0.029 n=4+4)
Decode/Twain/Compression/1e6-8       196 ± 0%        150 ± 0%  -23.47%  (p=0.029 n=4+4)

Updates #27151

Change-Id: I6c439694ed16a33bb4c63fbfb8570c7de46b4f2d
Reviewed-on: https://go-review.googlesource.com/135495
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2018-09-24 18:26:02 +00:00
Lynn Boger aa4fc0e736 cmd/link,compress/zip,image/png: use binary.{Big,Little}Endian methods
Use the binary.{Big,Little}Endian integer encoding methods rather than
variations found in local implementations. The functions in
the binary package have been tested to ensure they inline correctly and
don't add unnecessary bounds checking.

Change-Id: Ie10111ca6edb7c11e8e5e21c58a5748ae99b7f87
Reviewed-on: https://go-review.googlesource.com/134375
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Munday <mike.munday@ibm.com>
2018-09-11 15:14:56 +00:00
Tim Cooper 161874da2a all: update comment URLs from HTTP to HTTPS, where possible
Each URL was manually verified to ensure it did not serve up incorrect
content.

Change-Id: I4dc846227af95a73ee9a3074d0c379ff0fa955df
Reviewed-on: https://go-review.googlesource.com/115798
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
2018-06-01 21:52:00 +00:00
Russ Cox d474f582fe compress/flate: do not rename math/bits import
Makes compress/flate work better with cmd/dist bootstrap.

Change-Id: Ifc7d74027367008e82c1d14ec77141830583ba82
Reviewed-on: https://go-review.googlesource.com/111815
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-05-07 15:42:46 +00:00
Elias Naur 51bda1ff08 compress/gzip: skip builder-only test on iOS
The new iOS test harness forwards environment variables to the
test program, which means that it runs builder-only tests that were
previously skipped because GO_BUILDER_NAME was missing.

Skip one such unblocked test, TestGZIPFilesHaveZeroMTimes, which
assumes a valid GOROOT.

Change-Id: I5daf0f4c1897afbeb8b1a380669a1d2aa47e764a
Reviewed-on: https://go-review.googlesource.com/111475
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-05-04 14:46:19 +00:00
Ilya Tocar 4984d843d9 compress/flate: optimize huffSym
By using local variables and assigning them back to decompressor
at the end of huffSym, we allow compiler to keep them in registers
and avoid reloading/storing them repeatedly. To archive this,
moreBits was inlined and specialized to work with local variables.
Also move EOF error conversion to helper function, to make inlined
part of moreBits more readable. Together this results in nice speed-up:

name                             old time/op    new time/op    delta
Decode/Digits/Huffman/1e4-6         278µs ± 1%     240µs ± 2%  -13.72%  (p=0.000 n=10+10)
Decode/Digits/Huffman/1e5-6        2.38ms ± 1%    2.05ms ± 1%  -14.12%  (p=0.000 n=10+10)
Decode/Digits/Huffman/1e6-6        23.4ms ± 1%    19.9ms ± 0%  -14.69%  (p=0.000 n=9+9)
Decode/Digits/Speed/1e4-6           280µs ± 2%     254µs ± 1%   -9.28%  (p=0.000 n=10+9)
Decode/Digits/Speed/1e5-6          2.53ms ± 1%    2.35ms ± 1%   -7.17%  (p=0.000 n=10+10)
Decode/Digits/Speed/1e6-6          24.8ms ± 1%    23.0ms ± 1%   -7.22%  (p=0.000 n=10+10)
Decode/Digits/Default/1e4-6         281µs ± 2%     259µs ± 3%   -8.03%  (p=0.000 n=10+10)
Decode/Digits/Default/1e5-6        2.45ms ± 1%    2.30ms ± 1%   -6.15%  (p=0.000 n=10+10)
Decode/Digits/Default/1e6-6        24.1ms ± 1%    22.6ms ± 0%   -6.31%  (p=0.000 n=9+9)
Decode/Digits/Compression/1e4-6     279µs ± 2%     261µs ± 2%   -6.53%  (p=0.000 n=8+9)
Decode/Digits/Compression/1e5-6    2.44ms ± 1%    2.30ms ± 1%   -5.72%  (p=0.000 n=10+9)
Decode/Digits/Compression/1e6-6    24.0ms ± 1%    22.6ms ± 0%   -6.10%  (p=0.000 n=10+9)
Decode/Twain/Huffman/1e4-6          316µs ± 2%     267µs ± 3%  -15.30%  (p=0.000 n=9+10)
Decode/Twain/Huffman/1e5-6         2.62ms ± 0%    2.22ms ± 0%  -15.24%  (p=0.000 n=10+10)
Decode/Twain/Huffman/1e6-6         25.7ms ± 1%    21.8ms ± 0%  -15.19%  (p=0.000 n=10+10)
Decode/Twain/Speed/1e4-6            290µs ± 1%     264µs ± 2%   -9.17%  (p=0.000 n=9+10)
Decode/Twain/Speed/1e5-6           2.35ms ± 1%    2.13ms ± 1%   -9.74%  (p=0.000 n=9+10)
Decode/Twain/Speed/1e6-6           22.9ms ± 0%    20.7ms ± 0%   -9.68%  (p=0.000 n=10+9)
Decode/Twain/Default/1e4-6          270µs ± 2%     252µs ± 2%   -6.67%  (p=0.000 n=9+10)
Decode/Twain/Default/1e5-6         2.02ms ± 1%    1.84ms ± 1%   -8.85%  (p=0.000 n=10+10)
Decode/Twain/Default/1e6-6         19.1ms ± 0%    17.5ms ± 1%   -8.73%  (p=0.000 n=9+10)
Decode/Twain/Compression/1e4-6      272µs ± 1%     250µs ± 4%   -8.20%  (p=0.000 n=9+10)
Decode/Twain/Compression/1e5-6     2.01ms ± 0%    1.84ms ± 1%   -8.57%  (p=0.000 n=9+10)
Decode/Twain/Compression/1e6-6     19.1ms ± 0%    17.4ms ± 1%   -8.75%  (p=0.000 n=9+10)

name                             old speed      new speed      delta
Decode/Digits/Huffman/1e4-6      35.9MB/s ± 1%  41.7MB/s ± 2%  +15.91%  (p=0.000 n=10+10)
Decode/Digits/Huffman/1e5-6      41.9MB/s ± 1%  48.8MB/s ± 1%  +16.44%  (p=0.000 n=10+10)
Decode/Digits/Huffman/1e6-6      42.8MB/s ± 1%  50.2MB/s ± 0%  +17.22%  (p=0.000 n=9+9)
Decode/Digits/Speed/1e4-6        35.7MB/s ± 2%  39.4MB/s ± 1%  +10.22%  (p=0.000 n=10+9)
Decode/Digits/Speed/1e5-6        39.6MB/s ± 1%  42.6MB/s ± 1%   +7.73%  (p=0.000 n=10+10)
Decode/Digits/Speed/1e6-6        40.3MB/s ± 1%  43.4MB/s ± 1%   +7.78%  (p=0.000 n=10+10)
Decode/Digits/Default/1e4-6      35.6MB/s ± 2%  38.7MB/s ± 2%   +8.74%  (p=0.000 n=10+10)
Decode/Digits/Default/1e5-6      40.9MB/s ± 1%  43.6MB/s ± 1%   +6.55%  (p=0.000 n=10+10)
Decode/Digits/Default/1e6-6      41.5MB/s ± 1%  44.3MB/s ± 0%   +6.73%  (p=0.000 n=9+9)
Decode/Digits/Compression/1e4-6  35.8MB/s ± 2%  38.3MB/s ± 2%   +6.99%  (p=0.000 n=8+9)
Decode/Digits/Compression/1e5-6  40.9MB/s ± 1%  43.4MB/s ± 1%   +6.07%  (p=0.000 n=10+9)
Decode/Digits/Compression/1e6-6  41.6MB/s ± 1%  44.3MB/s ± 0%   +6.49%  (p=0.000 n=10+9)
Decode/Twain/Huffman/1e4-6       31.7MB/s ± 2%  37.4MB/s ± 3%  +18.08%  (p=0.000 n=9+10)
Decode/Twain/Huffman/1e5-6       38.2MB/s ± 0%  45.0MB/s ± 0%  +17.97%  (p=0.000 n=10+10)
Decode/Twain/Huffman/1e6-6       38.9MB/s ± 1%  45.9MB/s ± 0%  +17.90%  (p=0.000 n=10+10)
Decode/Twain/Speed/1e4-6         34.5MB/s ± 1%  38.0MB/s ± 2%  +10.11%  (p=0.000 n=9+10)
Decode/Twain/Speed/1e5-6         42.5MB/s ± 1%  47.0MB/s ± 1%  +10.79%  (p=0.000 n=9+10)
Decode/Twain/Speed/1e6-6         43.7MB/s ± 0%  48.3MB/s ± 0%  +10.72%  (p=0.000 n=10+9)
Decode/Twain/Default/1e4-6       37.1MB/s ± 2%  39.8MB/s ± 2%   +7.15%  (p=0.000 n=9+10)
Decode/Twain/Default/1e5-6       49.5MB/s ± 1%  54.3MB/s ± 1%   +9.71%  (p=0.000 n=10+10)
Decode/Twain/Default/1e6-6       52.3MB/s ± 0%  57.3MB/s ± 1%   +9.57%  (p=0.000 n=9+10)
Decode/Twain/Compression/1e4-6   36.7MB/s ± 1%  40.0MB/s ± 4%   +8.96%  (p=0.000 n=9+10)
Decode/Twain/Compression/1e5-6   49.8MB/s ± 0%  54.5MB/s ± 1%   +9.38%  (p=0.000 n=9+10)
Decode/Twain/Compression/1e6-6   52.3MB/s ± 0%  57.3MB/s ± 1%   +9.58%  (p=0.000 n=9+10)

Change-Id: Iabfd285535ddb210f7f48f33317c6463b5532400
Reviewed-on: https://go-review.googlesource.com/102235
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-04-17 22:37:49 +00:00
Travis Bischel f1deee0e8c compress/gzip: do not count header bytes written in Write
Before, if an underlying writer errored within 10 bytes (plus any gzip
header metadata), a gzip.Write would erroneously report up to 10 bytes
written that were not actually written of the input slice. This is
especially problematic when the input slice is less than 10 bytes.

The error came from counting the 10 header byte write. If writing the
header is completely successful, the 10 bytes written is overridden by
the flate write with the input slice.

This removes counting the 10 required header bytes, and also changes the
return to use zero until the slice is used.

The old Write could return one byte written when it actually was not.
This is difficult to verify because the smallest input slice is one
byte; a test checking that the input slice was the byte written would be
quite involved. Thankfully, gzip's minimum header write is 10 bytes. If
we test that two bytes are not falsely written, we indirectly cover the
one byte case.

Fixes #24625

Change-Id: I1c1f8cd791e0c4cffc22aa8acd95186582c832ba
Reviewed-on: https://go-review.googlesource.com/103861
Reviewed-by: Joe Tsai <joetsai@google.com>
Run-TryBot: Joe Tsai <joetsai@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-04-02 20:18:14 +00:00
Ilya Tocar 9eb219480e compress/bzip2: remove bit-tricks
Since compiler is now able to generate conditional moves, we can replace
bit-tricks with simple if/else. This even results in slightly better performance:

name            old time/op    new time/op    delta
DecodeDigits-6    13.4ms ± 4%    13.0ms ± 2%  -2.63%  (p=0.003 n=10+10)
DecodeTwain-6     37.5ms ± 1%    36.3ms ± 1%  -3.03%  (p=0.000 n=10+9)
DecodeRand-6      4.23ms ± 1%    4.07ms ± 1%  -3.67%  (p=0.000 n=10+9)

name            old speed      new speed      delta
DecodeDigits-6  7.47MB/s ± 4%  7.67MB/s ± 2%  +2.69%  (p=0.002 n=10+10)
DecodeTwain-6   10.4MB/s ± 1%  10.7MB/s ± 1%  +3.25%  (p=0.000 n=10+8)
DecodeRand-6    3.87MB/s ± 1%  4.03MB/s ± 2%  +4.08%  (p=0.000 n=10+10)
diff --git a/src/compress/bzip2/huffman.go b/src/compress/bzip2/huffman.go

Change-Id: Ie96ef1a9e07013b07e78f22cdccd531f3341caca
Reviewed-on: https://go-review.googlesource.com/102015
Run-TryBot: Ilya Tocar <ilya.tocar@intel.com>
Reviewed-by: Joe Tsai <joetsai@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-03-21 21:57:15 +00:00
Diogo Pinela 0dfc740e68 compress/gzip, compress/zlib: fix Writer documentation inconsistencies
Fixes #24379.

Change-Id: Ibdc763a0c2b56e26f4269f8be429880e34a2558f
Reviewed-on: https://go-review.googlesource.com/100495
Reviewed-by: Joe Tsai <joetsai@google.com>
2018-03-13 20:58:19 +00:00
Joe Kyo b26a4a1401 compress/bzip2: use sort.Slice in huffman.go
Change-Id: Ie4d23cdb81473a4c989a977a127479cf825084dc
Reviewed-on: https://go-review.googlesource.com/77850
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2018-02-17 00:34:26 +00:00
Joe Tsai 57f7bc3a05 compress/bzip2: fix checksum mismatch on empty reads
Previously, the read method checked whether the current block
was fully consumed or not based on whether the buffer could be filled
with a non-zero number of bytes. This check is problematic because
zero bytes could be read if the provided buffer is empty.

We fix this case by simply checking for whether the input buffer
provided by the user was empty or not. If empty, we assume that
we could not read any bytes because the buffer was too small,
rather than indicating that the current block was fully exhausted.

This check causes bzip2.Reader to be unable to make progress
on the next block unless a non-empty buffer is provided.
However, that is an entirely reasonable expectation since a
non-empty buffer needs to be provided eventually anyways to
read the actual contents of subsequent blocks.

Fixes #22028

Change-Id: I2bb1b2d54e78567baf2bf7b490a272c0853d7bfe
Reviewed-on: https://go-review.googlesource.com/66110
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-09-25 23:05:58 +00:00
Kunpei Sakai 5a986eca86 all: fix article typos
a -> an

Change-Id: I7362bdc199e83073a712be657f5d9ba16df3077e
Reviewed-on: https://go-review.googlesource.com/63850
Reviewed-by: Rob Pike <r@golang.org>
2017-09-15 02:39:16 +00:00
Joe Tsai d39649087b compress/flate: remove non-standard extensions to flate
Some constants were added to flate that seem to be an experimental
attempt at increasing the window size. However, according to RFC1951,
the largest window size is 32KiB, so these constants are non-standard.
Delete them.

Fixes #18458

Change-Id: Ia94989637ca031a56bce2548624fa48044caa7b9
Reviewed-on: https://go-review.googlesource.com/60490
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2017-08-31 03:30:43 +00:00
Nigel Tao 32d42fb6ec compress/lzw: don't follow code == hi if last is invalid.
Fixes #20597.

Change-Id: Iaa059277c02e80a2fbef59cf8bb3c58d2b90fda0
Reviewed-on: https://go-review.googlesource.com/45111
Reviewed-by: David Symonds <dsymonds@golang.org>
2017-06-08 01:27:37 +00:00
Joe Tsai cba4b41671 compress/gzip: clarify behavior of Writer.Close
Fixes #20551

Change-Id: Ia47cae14a26fe5f278ad7209218d083cc50a3ff8
Reviewed-on: https://go-review.googlesource.com/44572
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-06-02 01:03:19 +00:00
Joe Tsai e0e4891827 compress/bzip2: remove dead code in huffman.go
The logic performs a series of shifts, which are useless given
that they are followed by an assignment that overrides the
value of the previous computation.

I suspect (but cannot prove) that this is leftover logic from an
original approach that attempted to store both the Huffman code
and the length within the same variable instead of using two
different variables as it currently does now.

Fixes #17949

Change-Id: Ibf6c807c6cef3b28bfdaf2b68d9bc13503ac21b2
Reviewed-on: https://go-review.googlesource.com/44091
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2017-05-24 21:56:48 +00:00
Nigel Tao 642a1cc756 compress/lzw: fix hi code overflow.
Change-Id: I2d3c3c715d857305944cd96c45554a16cb7967e9
Reviewed-on: https://go-review.googlesource.com/42032
Reviewed-by: David Symonds <dsymonds@golang.org>
2017-04-28 05:59:30 +00:00
Elias Naur 2b780af08e Revert "all: test adjustments for the iOS builder"
This reverts commit 467109bf56.

Replaced by a improved strategy later in the CL relation chain.

Change-Id: Ib90813b5a6c4716b563c8496013d2d57f9c022b8
Reviewed-on: https://go-review.googlesource.com/36066
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-03-04 00:01:14 +00:00
Robert Griesemer bca0320641 compress/flate: use math/bits.Reverse8/16 instead of local implementation
No measurable impact on performance (specifically, no degradation).
Reverse is used in Huffman en/de-coding. For completeness, here are
all the speed-related benchmark results:

name                             old time/op    new time/op    delta
Decode/Digits/Huffman/1e4-8         181µs ± 0%     178µs ± 1%   ~             (p=0.100 n=3+3)
Decode/Digits/Huffman/1e5-8        1.60ms ± 3%    1.56ms ± 3%   ~             (p=0.400 n=3+3)
Decode/Digits/Huffman/1e6-8        15.7ms ± 1%    15.3ms ± 3%   ~             (p=0.700 n=3+3)
Decode/Digits/Speed/1e4-8           179µs ± 0%     180µs ± 0%   ~             (p=0.200 n=3+3)
Decode/Digits/Speed/1e5-8          1.68ms ± 0%    1.66ms ± 3%   ~             (p=0.700 n=3+3)
Decode/Digits/Speed/1e6-8          16.6ms ± 2%    16.6ms ± 5%   ~             (p=0.700 n=3+3)
Decode/Digits/Default/1e4-8         179µs ± 1%     178µs ± 1%   ~             (p=0.700 n=3+3)
Decode/Digits/Default/1e5-8        1.62ms ± 3%    1.62ms ± 4%   ~             (p=1.000 n=3+3)
Decode/Digits/Default/1e6-8        16.0ms ± 2%    16.0ms ± 3%   ~             (p=1.000 n=3+3)
Decode/Digits/Compression/1e4-8     179µs ± 1%     179µs ± 0%   ~             (p=0.200 n=3+3)
Decode/Digits/Compression/1e5-8    1.62ms ± 2%    1.62ms ± 3%   ~             (p=1.000 n=3+3)
Decode/Digits/Compression/1e6-8    16.1ms ± 3%    16.0ms ± 3%   ~             (p=1.000 n=3+3)
Decode/Twain/Huffman/1e4-8          205µs ± 2%     207µs ± 1%   ~             (p=1.000 n=3+3)
Decode/Twain/Huffman/1e5-8         1.77ms ± 2%    1.77ms ± 4%   ~             (p=0.700 n=3+3)
Decode/Twain/Huffman/1e6-8         17.4ms ± 2%    17.4ms ± 3%   ~             (p=1.000 n=3+3)
Decode/Twain/Speed/1e4-8            186µs ± 1%     186µs ± 1%   ~             (p=0.400 n=3+3)
Decode/Twain/Speed/1e5-8           1.53ms ± 2%    1.52ms ± 0%   ~             (p=0.700 n=3+3)
Decode/Twain/Speed/1e6-8           14.9ms ± 1%    14.8ms ± 1%   ~             (p=1.000 n=3+3)
Decode/Twain/Default/1e4-8          176µs ± 1%     174µs ± 0%   ~             (p=0.200 n=3+3)
Decode/Twain/Default/1e5-8         1.30ms ± 2%    1.31ms ± 1%   ~             (p=0.700 n=3+3)
Decode/Twain/Default/1e6-8         12.6ms ± 3%    12.5ms ± 0%   ~             (p=0.700 n=3+3)
Decode/Twain/Compression/1e4-8      177µs ± 0%     174µs ± 1%   ~             (p=0.100 n=3+3)
Decode/Twain/Compression/1e5-8     1.30ms ± 1%    1.31ms ± 0%   ~             (p=0.700 n=3+3)
Decode/Twain/Compression/1e6-8     12.5ms ± 1%    12.5ms ± 1%   ~             (p=1.000 n=3+3)
Encode/Digits/Huffman/1e4-8        47.4µs ± 1%    46.5µs ± 0%   ~             (p=0.100 n=3+3)
Encode/Digits/Huffman/1e5-8         453µs ± 2%     446µs ± 1%   ~             (p=0.700 n=3+3)
Encode/Digits/Huffman/1e6-8        4.44ms ± 3%    4.39ms ± 0%   ~             (p=1.000 n=3+3)
Encode/Digits/Speed/1e4-8           190µs ± 4%     185µs ± 0%   ~             (p=0.100 n=3+3)
Encode/Digits/Speed/1e5-8          1.78ms ± 5%    1.75ms ± 1%   ~             (p=1.000 n=3+3)
Encode/Digits/Speed/1e6-8          17.9ms ± 7%    17.3ms ± 1%   ~             (p=0.400 n=3+3)
Encode/Digits/Default/1e4-8         366µs ± 1%     361µs ± 0%   ~             (p=0.200 n=3+3)
Encode/Digits/Default/1e5-8        5.58ms ± 5%    5.44ms ± 1%   ~             (p=0.400 n=3+3)
Encode/Digits/Default/1e6-8        59.0ms ± 3%    58.2ms ± 1%   ~             (p=0.700 n=3+3)
Encode/Digits/Compression/1e4-8     369µs ± 3%     362µs ± 0%   ~             (p=0.100 n=3+3)
Encode/Digits/Compression/1e5-8    5.50ms ± 2%    5.47ms ± 1%   ~             (p=1.000 n=3+3)
Encode/Digits/Compression/1e6-8    59.4ms ± 2%    58.5ms ± 1%   ~             (p=0.400 n=3+3)
Encode/Twain/Huffman/1e4-8         64.4µs ± 3%    64.7µs ± 1%   ~             (p=0.700 n=3+3)
Encode/Twain/Huffman/1e5-8          526µs ± 1%     526µs ± 2%   ~             (p=1.000 n=3+3)
Encode/Twain/Huffman/1e6-8         5.18ms ± 2%    5.17ms ± 1%   ~             (p=0.700 n=3+3)
Encode/Twain/Speed/1e4-8            206µs ± 1%     204µs ± 0%   ~             (p=0.100 n=3+3)
Encode/Twain/Speed/1e5-8           1.73ms ± 2%    1.70ms ± 0%   ~             (p=0.100 n=3+3)
Encode/Twain/Speed/1e6-8           16.7ms ± 0%    16.7ms ± 1%   ~             (p=1.000 n=3+3)
Encode/Twain/Default/1e4-8          423µs ± 3%     418µs ± 1%   ~             (p=1.000 n=3+3)
Encode/Twain/Default/1e5-8         6.34ms ± 4%    6.23ms ± 0%   ~             (p=1.000 n=3+3)
Encode/Twain/Default/1e6-8         68.0ms ± 3%    67.5ms ± 0%   ~             (p=0.700 n=3+3)
Encode/Twain/Compression/1e4-8      435µs ± 3%     424µs ± 0%   ~             (p=0.700 n=3+3)
Encode/Twain/Compression/1e5-8     7.01ms ± 1%    6.92ms ± 0%   ~             (p=0.100 n=3+3)
Encode/Twain/Compression/1e6-8     77.1ms ± 4%    75.5ms ± 1%   ~             (p=0.400 n=3+3)

name                             old speed      new speed      delta
Decode/Digits/Huffman/1e4-8      55.2MB/s ± 0%  56.2MB/s ± 1%   ~             (p=0.100 n=3+3)
Decode/Digits/Huffman/1e5-8      62.4MB/s ± 3%  64.1MB/s ± 3%   ~             (p=0.400 n=3+3)
Decode/Digits/Huffman/1e6-8      63.8MB/s ± 1%  65.3MB/s ± 3%   ~             (p=0.700 n=3+3)
Decode/Digits/Speed/1e4-8        55.8MB/s ± 0%  55.4MB/s ± 0%   ~             (p=0.200 n=3+3)
Decode/Digits/Speed/1e5-8        59.6MB/s ± 0%  60.3MB/s ± 3%   ~             (p=0.700 n=3+3)
Decode/Digits/Speed/1e6-8        60.1MB/s ± 2%  60.3MB/s ± 4%   ~             (p=0.700 n=3+3)
Decode/Digits/Default/1e4-8      55.8MB/s ± 1%  56.1MB/s ± 1%   ~             (p=0.700 n=3+3)
Decode/Digits/Default/1e5-8      61.8MB/s ± 3%  61.7MB/s ± 4%   ~             (p=1.000 n=3+3)
Decode/Digits/Default/1e6-8      62.4MB/s ± 2%  62.4MB/s ± 3%   ~             (p=1.000 n=3+3)
Decode/Digits/Compression/1e4-8  55.7MB/s ± 1%  56.0MB/s ± 0%   ~             (p=0.300 n=3+3)
Decode/Digits/Compression/1e5-8  61.7MB/s ± 2%  61.9MB/s ± 3%   ~             (p=1.000 n=3+3)
Decode/Digits/Compression/1e6-8  62.2MB/s ± 3%  62.6MB/s ± 3%   ~             (p=1.000 n=3+3)
Decode/Twain/Huffman/1e4-8       48.8MB/s ± 2%  48.4MB/s ± 1%   ~             (p=1.000 n=3+3)
Decode/Twain/Huffman/1e5-8       56.4MB/s ± 2%  56.6MB/s ± 4%   ~             (p=0.700 n=3+3)
Decode/Twain/Huffman/1e6-8       57.6MB/s ± 2%  57.5MB/s ± 3%   ~             (p=1.000 n=3+3)
Decode/Twain/Speed/1e4-8         53.7MB/s ± 1%  53.9MB/s ± 1%   ~             (p=0.400 n=3+3)
Decode/Twain/Speed/1e5-8         65.5MB/s ± 2%  65.6MB/s ± 0%   ~             (p=0.700 n=3+3)
Decode/Twain/Speed/1e6-8         66.9MB/s ± 1%  67.4MB/s ± 1%   ~             (p=1.000 n=3+3)
Decode/Twain/Default/1e4-8       56.9MB/s ± 1%  57.3MB/s ± 0%   ~             (p=0.200 n=3+3)
Decode/Twain/Default/1e5-8       77.2MB/s ± 2%  76.6MB/s ± 1%   ~             (p=0.700 n=3+3)
Decode/Twain/Default/1e6-8       79.3MB/s ± 3%  80.0MB/s ± 0%   ~             (p=0.700 n=3+3)
Decode/Twain/Compression/1e4-8   56.4MB/s ± 0%  57.5MB/s ± 1%   ~             (p=0.100 n=3+3)
Decode/Twain/Compression/1e5-8   76.8MB/s ± 1%  76.5MB/s ± 0%   ~             (p=0.700 n=3+3)
Decode/Twain/Compression/1e6-8   80.1MB/s ± 1%  79.8MB/s ± 1%   ~             (p=1.000 n=3+3)
Encode/Digits/Huffman/1e4-8       211MB/s ± 1%   215MB/s ± 0%   ~             (p=0.100 n=3+3)
Encode/Digits/Huffman/1e5-8       221MB/s ± 2%   224MB/s ± 1%   ~             (p=0.700 n=3+3)
Encode/Digits/Huffman/1e6-8       225MB/s ± 3%   228MB/s ± 0%   ~             (p=1.000 n=3+3)
Encode/Digits/Speed/1e4-8        52.8MB/s ± 4%  54.1MB/s ± 0%   ~             (p=0.100 n=3+3)
Encode/Digits/Speed/1e5-8        56.2MB/s ± 5%  57.0MB/s ± 1%   ~             (p=1.000 n=3+3)
Encode/Digits/Speed/1e6-8        56.0MB/s ± 6%  57.7MB/s ± 1%   ~             (p=0.400 n=3+3)
Encode/Digits/Default/1e4-8      27.3MB/s ± 1%  27.7MB/s ± 0%   ~             (p=0.200 n=3+3)
Encode/Digits/Default/1e5-8      17.9MB/s ± 4%  18.4MB/s ± 1%   ~             (p=0.400 n=3+3)
Encode/Digits/Default/1e6-8      17.0MB/s ± 3%  17.2MB/s ± 1%   ~             (p=0.500 n=3+3)
Encode/Digits/Compression/1e4-8  27.1MB/s ± 3%  27.6MB/s ± 0%   ~             (p=0.100 n=3+3)
Encode/Digits/Compression/1e5-8  18.2MB/s ± 2%  18.3MB/s ± 1%   ~             (p=1.000 n=3+3)
Encode/Digits/Compression/1e6-8  16.9MB/s ± 2%  17.1MB/s ± 1%   ~             (p=0.400 n=3+3)
Encode/Twain/Huffman/1e4-8        155MB/s ± 3%   155MB/s ± 1%   ~             (p=0.700 n=3+3)
Encode/Twain/Huffman/1e5-8        190MB/s ± 1%   190MB/s ± 2%   ~             (p=1.000 n=3+3)
Encode/Twain/Huffman/1e6-8        193MB/s ± 2%   193MB/s ± 1%   ~             (p=0.700 n=3+3)
Encode/Twain/Speed/1e4-8         48.5MB/s ± 1%  49.1MB/s ± 0%   ~             (p=0.100 n=3+3)
Encode/Twain/Speed/1e5-8         57.7MB/s ± 2%  59.0MB/s ± 0%   ~             (p=0.100 n=3+3)
Encode/Twain/Speed/1e6-8         59.7MB/s ± 0%  59.7MB/s ± 1%   ~             (p=1.000 n=3+3)
Encode/Twain/Default/1e4-8       23.6MB/s ± 3%  23.9MB/s ± 1%   ~             (p=1.000 n=3+3)
Encode/Twain/Default/1e5-8       15.8MB/s ± 4%  16.1MB/s ± 0%   ~             (p=1.000 n=3+3)
Encode/Twain/Default/1e6-8       14.7MB/s ± 3%  14.8MB/s ± 0%   ~             (p=0.700 n=3+3)
Encode/Twain/Compression/1e4-8   23.0MB/s ± 3%  23.6MB/s ± 0%   ~             (p=0.700 n=3+3)
Encode/Twain/Compression/1e5-8   14.3MB/s ± 1%  14.5MB/s ± 0%   ~             (p=0.100 n=3+3)
Encode/Twain/Compression/1e6-8   13.0MB/s ± 4%  13.2MB/s ± 1%   ~             (p=0.400 n=3+3)

Measured on a "quiet" (no browser running) 2.3 GHz Intel Core i7, running macOS 10.12.3.

See also #19279.

Change-Id: Ice759eb34eb37442b543957447c264e0aadc1fa9
Reviewed-on: https://go-review.googlesource.com/37460
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-03-01 00:15:32 +00:00
David Crawshaw 467109bf56 all: test adjustments for the iOS builder
The working directory is now adjusted to match the typical Go test
working directory in main, as the old trick for adjusting earlier
stopped working with the latest version of LLDB bugs.

That means the small number of places where testdata files are
read before main is called no longer work. This CL adjusts those
reads to happen after main is called. (This has the bonus effect of
not reading some benchmark testdata files in all.bash.)

Fixes compress/bzip2, go/doc, go/parser, os, and time package
tests on the iOS builder.

Change-Id: If60f026aa7848b37511c36ac5e3985469ec25209
Reviewed-on: https://go-review.googlesource.com/35255
Run-TryBot: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-01-14 03:27:53 +00:00
Joe Tsai 9c3630f578 compress/flate: avoid large stack growth in fillDeflate
Ranging over an array causes the array to be copied over to the
stack, which cause large re-growths. Instead, we should iterate
over slices of the array.

Also, assigning a large struct literal uses the stack even
though the actual fields being populated are small in comparison
to the entirety of the struct (see #18636).

Fixing the stack growth does not alter CPU-time performance much
since the stack-growth and copying was such a tiny portion of the
compression work:

name                         old time/op    new time/op    delta
Encode/Digits/Default/1e4-8     332µs ± 1%     332µs ± 1%   ~     (p=0.796 n=10+10)
Encode/Digits/Default/1e5-8    5.07ms ± 2%    5.05ms ± 1%   ~       (p=0.815 n=9+8)
Encode/Digits/Default/1e6-8    53.7ms ± 1%    53.9ms ± 1%   ~     (p=0.075 n=10+10)
Encode/Twain/Default/1e4-8      380µs ± 1%     380µs ± 1%   ~     (p=0.684 n=10+10)
Encode/Twain/Default/1e5-8     5.79ms ± 2%    5.79ms ± 1%   ~      (p=0.497 n=9+10)
Encode/Twain/Default/1e6-8     61.5ms ± 1%    61.8ms ± 1%   ~     (p=0.247 n=10+10)

name                         old speed      new speed      delta
Encode/Digits/Default/1e4-8  30.1MB/s ± 1%  30.1MB/s ± 1%   ~     (p=0.753 n=10+10)
Encode/Digits/Default/1e5-8  19.7MB/s ± 2%  19.8MB/s ± 1%   ~       (p=0.795 n=9+8)
Encode/Digits/Default/1e6-8  18.6MB/s ± 1%  18.5MB/s ± 1%   ~     (p=0.072 n=10+10)
Encode/Twain/Default/1e4-8   26.3MB/s ± 1%  26.3MB/s ± 1%   ~     (p=0.616 n=10+10)
Encode/Twain/Default/1e5-8   17.3MB/s ± 2%  17.3MB/s ± 1%   ~      (p=0.484 n=9+10)
Encode/Twain/Default/1e6-8   16.3MB/s ± 1%  16.2MB/s ± 1%   ~     (p=0.238 n=10+10)

Updates #18636
Fixes #18625

Change-Id: I471b20339bf675f63dc56d38b3acdd824fe23328
Reviewed-on: https://go-review.googlesource.com/35122
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2017-01-12 19:15:57 +00:00
Joe Tsai 641ef2a733 compress/gzip: skip TestGZIPFilesHaveZeroMTimes on non-builders
Fixes #18604

Change-Id: I89221d5e632042167dfced068e1dc14e932cd618
Reviewed-on: https://go-review.googlesource.com/35111
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2017-01-11 17:48:09 +00:00
Joe Tsai 091ba60bd8 compress/flate: add examples
Updates #16360

Change-Id: I66ff23e0501363f58fe891d5e95806422071f93b
Reviewed-on: https://go-review.googlesource.com/30162
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-11-12 18:42:35 +00:00
Brad Fitzpatrick 2341631506 all: sprinkle t.Parallel on some slow tests
I used the slowtests.go tool as described in
https://golang.org/cl/32684 on packages that stood out.

go test -short std drops from ~56 to ~52 seconds.

This isn't a huge win, but it was mostly an exercise.

Updates #17751

Change-Id: I9f3402e36a038d71e662d06ce2c1d52f6c4b674d
Reviewed-on: https://go-review.googlesource.com/32751
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2016-11-04 16:56:57 +00:00
Nigel Tao 590fce4884 compress/flate: tighten the BestSpeed max match offset bound.
Previously, we were off by one.

Also fix a comment typo.

Change-Id: Ib94d23acc56d5fccd44144f71655481f98803ac8
Reviewed-on: https://go-review.googlesource.com/32149
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-10-30 22:52:14 +00:00
Joe Tsai b4e714e59e compress/gzip: only encode MTIME if it is valid
The GZIP format records the ModTime as an uint32 counting seconds since
the Unix epoch. The zero value is explicitly defined in section 2.3.1
as meaning no timestamp is available.

Currently, the Writer always encodes the ModTime even if it is the zero
time.Time value, which causes the Writer to try and encode the value
-62135596800 into the uint32 MTIME field. This causes an overflow and
results in our GZIP files having MTIME fields indicating a date in 2042-07-13.

We alter the Writer to only encode ModTime if the value does not underflow
the MTIME field (i.e., it is newer than the Unix epoch). We do not attempt
to fix what happens when the timestamp overflows in the year 2106.

We alter the Reader to only decode ModTime if the value is non-zero.
There is no risk of overflowing time.Time when decoding.

Fixes #17663

Change-Id: Ie1b65770c6342cd7b14aeebe10e5a49e6c9eb730
Reviewed-on: https://go-review.googlesource.com/32325
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-10-29 23:29:13 +00:00
Klaus Post 461adfd817 compress/flate: make compression level 0 consistent
Tests for determinism was not working as intended since io.Copybuffer
uses the io.WriterTo if available.

This exposed that level 0 (no compression) changed output
based on the number of writes and buffers given to the
writer.

Previously, Write would emit a new raw block (BTYPE=00) for
every non-empty call to Write.

This CL fixes it such that a raw block is only emitted upon
the following conditions:
 	* A full window is obtained (every 65535 bytes)
 	* Flush is called
 	* Close is called

Change-Id: I807f866d97e2db7820f11febab30a96266a6cbf1
Reviewed-on: https://go-review.googlesource.com/31174
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2016-10-27 00:58:30 +00:00
Klaus Post 2e196b15b9 compress/flate: level 1 (best speed) match across blocks
This change makes deflate level 1 (best speed) match across
block boundaries. This comes at a small speed penalty,
but improves compression on almost all output.

Sample numbers on various content types:

enwik9:            391052014 ->  382578469 bytes, 77.59 -> 74.28 MB/s
adresser.001:       57269799 ->   47756095 bytes, 287.84 -> 357.86 MB/s
10gb:             5233055166 -> 5198328382 bytes, 105.85 -> 96.99 MB/s
rawstudio-mint14: 3972329211 -> 3927423364 bytes, 100.07 -> 94.22 MB/s
sites:             165556800 ->  163178702 bytes, 72.31 -> 70.15 MB/s
objectfiles:       115962472 ->  111649524 bytes, 132.60 -> 128.05 MB/s
sharnd.out:        200015283 ->  200015283 bytes, 221.50 -> 218.83 MB/s

Change-Id: I62a139e5c06976e803439a4268acede5139b8cfc
Reviewed-on: https://go-review.googlesource.com/31640
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Reviewed-by: Nigel Tao <nigeltao@golang.org>
2016-10-27 00:50:06 +00:00
Josh Bleecher Snyder accf5cc386 all: minor vet fixes
Change-Id: I22f0f3e792052762499f632571155768b4052bc9
Reviewed-on: https://go-review.googlesource.com/31759
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-10-24 17:27:37 +00:00
Klaus Post c9517b1ffe compress/gzip, compress/zlib: add HuffmanOnly as compression levels.
This exposes HuffmanOnly in zlib and gzip packages, which is currently
unavailable.

Change-Id: If5d103bbc8b5fce2f5d740fd103a235c5d1ed7cd
Reviewed-on: https://go-review.googlesource.com/31186
Reviewed-by: Nigel Tao <nigeltao@golang.org>
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-10-20 23:11:05 +00:00
Klaus Post c1cd64d0ac compress/flate: use correct table for size estimation
The incorrect table was used for estimating output size.
This can give suboptimal selection of entropy encoder in rare cases.

Change-Id: I8b358200f2d1f9a3f9b79a44269d7be704e1d2d9
Reviewed-on: https://go-review.googlesource.com/31172
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-10-17 09:00:41 +00:00
Emmanuel Odeke 56d35d42e1 compress/gzip: document Reader.Read
Fixes #17374.

Change-Id: Ic89c35aaa31f35a8a4e3ffa09f49b68f08127625
Reviewed-on: https://go-review.googlesource.com/30718
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2016-10-09 00:22:59 +00:00
Emmanuel Odeke dcbbd319e9 compress/gzip: add examples
Updates #16360.

Adds examples uing:
+ Writer, Reader
+ Reader.Multistream to concatenate and then
individually retrieve multiple gzipped files
+ Reset

Change-Id: I9ad9b92729a5cd58f7368eaf2db05f1cdf21063d
Reviewed-on: https://go-review.googlesource.com/29218
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-09-22 06:41:11 +00:00
Joe Tsai 960016eca2 compress/flate: clarify the behavior of Writer.Flush
Fixes #16068

Change-Id: I04e80a181c0b7356996f7a1158ea4895ff9e1e39
Reviewed-on: https://go-review.googlesource.com/28477
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-09-04 03:09:08 +00:00
Joe Tsai d309246462 compress/flate: always return uncompressed data in the event of error
In the event of an unexpected error, we should always flush available
decompressed data to the user.

Fixes #16924

Change-Id: I0bc0824c3201f3149e84e6a26e3dbcba72a1aae5
Reviewed-on: https://go-review.googlesource.com/28216
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2016-08-31 01:12:02 +00:00
Joe Tsai 8cd04da762 compress/flate: make huffmanBitWriter errors persistent
For persistent error handling, the methods of huffmanBitWriter have to be
consistent about how they check errors. It must either consistently
check error *before* every operation OR immediately *after* every
operation. Since most of the current logic uses the previous approach,
we apply the same style of error checking to writeBits and all calls
to Write such that they only operate if w.err is already nil going
into them.

The error handling approach is brittle and easily broken by future commits to
the code. In the near future, we should switch the logic to use panic at the
lowest levels and a recover at the edge of the public API to ensure
that errors are always persistent.

Fixes #16749

Change-Id: Ie1d83e4ed8842f6911a31e23311cd3cbf38abe8c
Reviewed-on: https://go-review.googlesource.com/27200
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-08-20 00:36:40 +00:00
Joe Tsai d0256118de compress/flate: document HuffmanOnly
Fixes #16489

Change-Id: I13e2ed6de59102f977566de637d8d09b4e541980
Reviewed-on: https://go-review.googlesource.com/25200
Reviewed-by: Andrew Gerrand <adg@golang.org>
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-07-25 23:20:40 +00:00
Vladimir Mihailenco 0ce100dc96 compress/flate: don't ignore dict in Reader.Reset
Fixes #16162.

Change-Id: I6f4ae906630079ef5fc29ee5f70e2e3d1c962170
Reviewed-on: https://go-review.googlesource.com/24390
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-06-27 21:28:34 +00:00
Joe Tsai 7cd6cae6a6 compress/flate: use seperate const block for exported constants
As rendered on https://tip.golang.org/pkg/compress/flate/, there is an
extra new-line because of the unexported constants in the same block.

<<<
const (
    NoCompression      = 0
    BestSpeed          = 1
    BestCompression    = 9
    DefaultCompression = -1
    HuffmanOnly        = -2 // Disables match search and only does Huffman entropy reduction.

)
>>>

Instead, seperate the exported compression level constants into its own
const block. This is both more readable and also fixes the issue.

Change-Id: I60b7966c83fb53356c02e4640d05f55a3bee35b7
Reviewed-on: https://go-review.googlesource.com/23557
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-31 18:28:44 +00:00
Marcel van Lohuizen d2aa5f95cc compress/flate: simplify using subtests and sub-benchmarks
This causes the large files to be loaded only once per benchmark.

This CL also serves as an example use case of sub(tests|-benchmarks).

This CL ensures that names are identical to the original
except for an added slashes. Things could be
simplified further if this restriction were dropped.

Change-Id: I45e303e158e3152e33d0d751adfef784713bf997
Reviewed-on: https://go-review.googlesource.com/23420
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Marcel van Lohuizen <mpvl@golang.org>
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-25 17:44:22 +00:00
Marcel van Lohuizen 5dd922c935 compress/lzw: use Run for benchmarks
load file only once per group.

Change-Id: I965661507055e6e100506bf14d37133ecdd2cc5e
Reviewed-on: https://go-review.googlesource.com/23423
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Marcel van Lohuizen <mpvl@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-25 17:11:12 +00:00
Joe Tsai 7ba54d4573 compress: update documentation regarding footer verification
Address two documentation issues:
1) Document that the GZIP and ZLIB footer is only verified when the
reader has been fully consumed.
2) The zlib reader is guaranteed to not read past the EOF if the
input io.Reader is also a io.ByteReader. This functionality was
documented in the flate and gzip packages but not on zlib.

Fixes #14867

Change-Id: I43d46b93e38f98a04901dc7d4f18ed2f9e09f6fb
Reviewed-on: https://go-review.googlesource.com/21218
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2016-05-09 19:19:24 +00:00
Nigel Tao 27d0d849fe compress/flate: distinguish between base and min match length.
Change-Id: I93db5cd86e3fb568e4444cad95268ba4a02ce8a0
Reviewed-on: https://go-review.googlesource.com/22787
Reviewed-by: Nigel Tao <nigeltao@golang.org>
2016-05-05 00:16:39 +00:00
Nigel Tao 1fb4e4de26 compress/flate: use a constant hash table size for Best Speed.
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>
2016-04-29 14:00:39 +00:00