state of ip_ after decompression (or attempted decompresion) is
completely irrelevant, so we don't need the trailer.
Performance is, as expected, mostly flat -- there's a curious ~3-5%
loss in the "lsp" test, but that test case is so short it is hard to say
anything definitive about why (most likely, it's some sort of
unrelated effect).
R=jeff
git-svn-id: https://snappy.googlecode.com/svn/trunk@39 03e5f5b5-db94-4691-08a0-1a8bf15f6143
It is seemingly hard for the compiler to understand that ip_, the current input
pointer into the compressed data stream, can not alias on anything else, and
thus using it directly will incur memory traffic as it cannot be kept in a
register. The code already knew about this and cached it into a local
variable, but since Step() only decoded one tag, it had to move ip_ back into
place between every tag. This seems to have cost us a significant amount of
performance, so changing Step() into a function that decodes as much as it can
before it saves ip_ back and returns. (Note that Step() was already inlined,
so it is not the manual inlining that buys the performance here.)
The wins are about 3-6% for Core 2, 6-13% on Core i7 and 5-12% on Opteron
(for plain array-to-array decompression, in 64-bit opt mode).
There is a tiny difference in the behavior here; if an invalid literal is
encountered (ie., the writer refuses the Append() operation), ip_ will now
point to the byte past the tag byte, instead of where the literal was
originally thought to end. However, we don't use ip_ for anything after
DecompressAllTags() has returned, so this should not change external behavior
in any way.
Microbenchmark results for Core i7, 64-bit (Opteron results are similar):
Benchmark Time(ns) CPU(ns) Iterations
---------------------------------------------------
BM_UFlat/0 79134 79110 8835 1.2GB/s html [ +6.2%]
BM_UFlat/1 786126 786096 891 851.8MB/s urls [+10.0%]
BM_UFlat/2 9948 9948 69125 11.9GB/s jpg [ -1.3%]
BM_UFlat/3 31999 31998 21898 2.7GB/s pdf [ +6.5%]
BM_UFlat/4 318909 318829 2204 1.2GB/s html4 [ +6.5%]
BM_UFlat/5 31384 31390 22363 747.5MB/s cp [ +9.2%]
BM_UFlat/6 14037 14034 49858 757.7MB/s c [+10.6%]
BM_UFlat/7 4612 4612 151395 769.5MB/s lsp [ +9.5%]
BM_UFlat/8 1203174 1203007 582 816.3MB/s xls [+19.3%]
BM_UFlat/9 253869 253955 2757 571.1MB/s txt1 [+11.4%]
BM_UFlat/10 219292 219290 3194 544.4MB/s txt2 [+12.1%]
BM_UFlat/11 672135 672131 1000 605.5MB/s txt3 [+11.2%]
BM_UFlat/12 902512 902492 776 509.2MB/s txt4 [+12.5%]
BM_UFlat/13 372110 371998 1881 1.3GB/s bin [ +5.8%]
BM_UFlat/14 50407 50407 10000 723.5MB/s sum [+13.5%]
BM_UFlat/15 5699 5701 100000 707.2MB/s man [+12.4%]
BM_UFlat/16 83448 83424 8383 1.3GB/s pb [ +5.7%]
BM_UFlat/17 256958 256963 2723 684.1MB/s gaviota [ +7.9%]
BM_UValidate/0 42795 42796 16351 2.2GB/s html [+25.8%]
BM_UValidate/1 490672 490622 1427 1.3GB/s urls [+22.7%]
BM_UValidate/2 237 237 2950297 499.0GB/s jpg [+24.9%]
BM_UValidate/3 14610 14611 47901 6.0GB/s pdf [+26.8%]
BM_UValidate/4 171973 171990 4071 2.2GB/s html4 [+25.7%]
git-svn-id: https://snappy.googlecode.com/svn/trunk@38 03e5f5b5-db94-4691-08a0-1a8bf15f6143
This text is new, but an earlier version from Zeev Tarantov was used
as reference.
R=csilvers
DELTA=112 (111 added, 0 deleted, 1 changed)
Revision created by MOE tool push_codebase.
MOE_MIGRATION=1867
git-svn-id: https://snappy.googlecode.com/svn/trunk@36 03e5f5b5-db94-4691-08a0-1a8bf15f6143
not real time. Also, use nth_element instead of sort, since we
only need one element.
R=csilvers
DELTA=5 (3 added, 0 deleted, 2 changed)
Revision created by MOE tool push_codebase.
MOE_MIGRATION=1799
git-svn-id: https://snappy.googlecode.com/svn/trunk@35 03e5f5b5-db94-4691-08a0-1a8bf15f6143
properly cases where gettimeofday() can stand return the same
result twice (as sometimes on GNU/Hurd) or go backwards
(as when the user adjusts the clock). We avoid a division-by-zero,
and put a lower bound on the number of iterations -- the same
amount as we use to calibrate.
We should probably use CLOCK_MONOTONIC for platforms that support
it, to be robust against clock adjustments; we already use Windows'
monotonic timers. However, that's for a later changelist.
R=csilvers
DELTA=7 (5 added, 0 deleted, 2 changed)
Revision created by MOE tool push_codebase.
MOE_MIGRATION=1798
git-svn-id: https://snappy.googlecode.com/svn/trunk@34 03e5f5b5-db94-4691-08a0-1a8bf15f6143
libraries, not libsnappy.so (which doesn't need any such dependency).
R=csilvers
DELTA=20 (14 added, 0 deleted, 6 changed)
Revision created by MOE tool push_codebase.
MOE_MIGRATION=1710
git-svn-id: https://snappy.googlecode.com/svn/trunk@33 03e5f5b5-db94-4691-08a0-1a8bf15f6143
as MSVC doesn't include it. Replace with QueryPerformanceCounter(),
which is monotonic and probably reasonably high-resolution.
(Some machines have traditionally had bugs in QPC, but they should
be relatively rare these days, and there's really no much better
alternative that I know of.)
R=csilvers
DELTA=74 (55 added, 19 deleted, 0 changed)
Revision created by MOE tool push_codebase.
MOE_MIGRATION=1556
git-svn-id: https://snappy.googlecode.com/svn/trunk@31 03e5f5b5-db94-4691-08a0-1a8bf15f6143
we need for our own build system internally.
R=csilvers
DELTA=16 (13 added, 1 deleted, 2 changed)
Revision created by MOE tool push_codebase.
MOE_MIGRATION=1555
git-svn-id: https://snappy.googlecode.com/svn/trunk@30 03e5f5b5-db94-4691-08a0-1a8bf15f6143
so we won't pull in macro definitions of things like min() and max(),
which can conflict with <algorithm>.
R=csilvers
DELTA=1 (1 added, 0 deleted, 0 changed)
Revision created by MOE tool push_codebase.
MOE_MIGRATION=1485
git-svn-id: https://snappy.googlecode.com/svn/trunk@29 03e5f5b5-db94-4691-08a0-1a8bf15f6143
instead of getursage().
I thought I'd already committed this patch, so that the 1.0.1 release already
would have a Windows-compatible snappy_unittest, but I'd seemingly deleted it
instead, so this is a reconstruction.
R=csilvers
DELTA=43 (39 added, 3 deleted, 1 changed)
Revision created by MOE tool push_codebase.
MOE_MIGRATION=1295
git-svn-id: https://snappy.googlecode.com/svn/trunk@28 03e5f5b5-db94-4691-08a0-1a8bf15f6143
I've made a few changes since Martin's version; mostly style nits, but also
a semantic change -- most functions that return bool in the C++ version now
return an enum, to better match typical C (and zlib) semantics.
I've kept the copyright notice, since Martin is obviously the author here;
he has signed the contributor license agreement, though, so this should not
hinder Google's use in the future.
We'll need to update the libtool version number to match the added interface,
but as of http://www.gnu.org/software/libtool/manual/html_node/Updating-version-info.html
I'm going to wait until public release.
R=csilvers
DELTA=238 (233 added, 0 deleted, 5 changed)
Revision created by MOE tool push_codebase.
MOE_MIGRATION=1294
git-svn-id: https://snappy.googlecode.com/svn/trunk@27 03e5f5b5-db94-4691-08a0-1a8bf15f6143
The data compresses/decompresses slightly faster than the old data, and has
similar density.
R=lookingbill
DELTA=1 (0 added, 0 deleted, 1 changed)
Revision created by MOE tool push_codebase.
MOE_MIGRATION=1288
git-svn-id: https://snappy.googlecode.com/svn/trunk@26 03e5f5b5-db94-4691-08a0-1a8bf15f6143
Measure() loop. This gives all algorithms a small speed boost, except Snappy which
already didn't do reallocation (so the measurements were slightly biased in its
favor).
R=csilvers
DELTA=92 (69 added, 9 deleted, 14 changed)
Revision created by MOE tool push_codebase.
MOE_MIGRATION=1151
git-svn-id: https://snappy.googlecode.com/svn/trunk@24 03e5f5b5-db94-4691-08a0-1a8bf15f6143
the differences from the opensource code. Will make it easier
in the future to mix-and-match third-party code that uses
snappy with google code.
Currently, csearch shows that the only external user of
"namespace zippy" is some bigtable code that accesses
a TEST variable, which is temporarily kept in the zippy
namespace.
R=sesse
DELTA=123 (18 added, 3 deleted, 102 changed)
Revision created by MOE tool push_codebase.
MOE_MIGRATION=1150
git-svn-id: https://snappy.googlecode.com/svn/trunk@23 03e5f5b5-db94-4691-08a0-1a8bf15f6143
Replace the Apache 2.0 license header by the BSD-type license header;
somehow a lot of the files were missed in the last round.
R=dannyb,csilvers
DELTA=147 (74 added, 2 deleted, 71 changed)
Change on 2011-03-25 19:25:07-07:00 by sesse
Unbreak the build; the relicensing removed a bit too much (only comments
were intended, but I also accidentially removed some of the top lines of
the actual source).
Revision created by MOE tool push_codebase.
MOE_MIGRATION=1072
git-svn-id: https://snappy.googlecode.com/svn/trunk@21 03e5f5b5-db94-4691-08a0-1a8bf15f6143
that have been made since release.
R=csilvers
DELTA=266 (260 added, 0 deleted, 6 changed)
Revision created by MOE tool push_codebase.
MOE_MIGRATION=1057
git-svn-id: https://snappy.googlecode.com/svn/trunk@19 03e5f5b5-db94-4691-08a0-1a8bf15f6143
gflags package isn't (Google Test is not properly initialized).
Patch by Martin Gieseking.
R=csilvers
DELTA=2 (1 added, 0 deleted, 1 changed)
Revision created by MOE tool push_codebase.
MOE_MIGRATION=1033
git-svn-id: https://snappy.googlecode.com/svn/trunk@17 03e5f5b5-db94-4691-08a0-1a8bf15f6143
among others, Windows support. For Windows in specific, we could have used
CreateFileMapping/MapViewOfFile, but this should at least get us a bit closer
to compiling, and is of course also relevant for embedded systems with no MMU.
(Part 2/2)
R=csilvers
DELTA=15 (12 added, 3 deleted, 0 changed)
Revision created by MOE tool push_codebase.
MOE_MIGRATION=1032
git-svn-id: https://snappy.googlecode.com/svn/trunk@16 03e5f5b5-db94-4691-08a0-1a8bf15f6143
among others, Windows support. For Windows in specific, we could have used
CreateFileMapping/MapViewOfFile, but this should at least get us a bit closer
to compiling, and is of course also relevant for embedded systems with no MMU.
(Part 1/2)
R=csilvers
DELTA=9 (8 added, 0 deleted, 1 changed)
Revision created by MOE tool push_codebase.
MOE_MIGRATION=1031
git-svn-id: https://snappy.googlecode.com/svn/trunk@15 03e5f5b5-db94-4691-08a0-1a8bf15f6143
it causes problems with others sending patches etc..
We can't get this 100% hermetic anyhow, due to files like lt~obsolete.m4,
so we can just as well go cleanly in the other direction.
R=csilvers
DELTA=21038 (0 added, 21036 deleted, 2 changed)
Revision created by MOE tool push_codebase.
MOE_MIGRATION=1012
git-svn-id: https://snappy.googlecode.com/svn/trunk@14 03e5f5b5-db94-4691-08a0-1a8bf15f6143
it's not needed (CPPFLAGS are always included when compiling).
R=csilvers
DELTA=1 (0 added, 1 deleted, 0 changed)
Revision created by MOE tool push_codebase.
MOE_MIGRATION=994
git-svn-id: https://snappy.googlecode.com/svn/trunk@12 03e5f5b5-db94-4691-08a0-1a8bf15f6143
and using a manually given setting (use/don't use) instead.
R=csilvers
DELTA=16 (13 added, 0 deleted, 3 changed)
Revision created by MOE tool push_codebase.
MOE_MIGRATION=991
git-svn-id: https://snappy.googlecode.com/svn/trunk@9 03e5f5b5-db94-4691-08a0-1a8bf15f6143
slightly more standard, that also doesn't leak libtool command-line into
configure.ac.
R=csilvers
DELTA=7 (0 added, 4 deleted, 3 changed)
Revision created by MOE tool push_codebase.
MOE_MIGRATION=990
git-svn-id: https://snappy.googlecode.com/svn/trunk@8 03e5f5b5-db94-4691-08a0-1a8bf15f6143
snappy.mirrorbot@gmail.com