Merge pull request #5759 from JoshuaS3/master

2021-01-06T11:49:00+00:00

Add documentation for git_blob_filter_options.version

blob: add git_blob_filter_options_init

2021-01-05T14:29:58+00:00

The `git_blob_filter_options_init` function should be included, to allow
callers in FFI environments to let us initialize an options structure
for them.

Merge pull request #5583 from 0xdky/dhruva/build-with-nommap

2021-01-05T12:12:19+00:00

Build with NO_MMAP

Use an option instead of a flag for USE_BUNDLED_ZLIB

2021-01-04T14:10:10+00:00

Now `USE_BUNDLED_ZLIB` can be set to the string `Chromium` to enable the
Chromium implementation of zlib.

Support build with NO_MMAP to disable use of system mmap

2020-12-30T14:55:40+00:00

    * Use pread/pwrite to avoid updating position in file descriptor
    * Emulate missing pread/pwrite on win32 using overlapped file IO

Remove broken support for write in emulated mmap

2020-12-27T20:27:21+00:00

    * Emulated mmap based write without pagefault handling is not
    possible since IO happens outside of call to mmap and data is
    written to mapped memory
    * Potential emulation using userfaultfd() might be possible

zlib: Add support for building with Chromium's zlib implementation

2020-12-24T02:18:16+00:00

This change builds libgit2 using Chromium's zlib implementation by
invoking cmake with `-DUSE_BUNDLED_ZLIB=ON -DUSE_CHROMIUM_ZLIB=ON`,
which is ~10% faster than the bundled zlib for the core::zstream suite.

This version of zlib has some optimizations:

a) Decompression (Intel+ARM): inflate_fast, adler32, crc32, etc.
b) Compression (Intel): fill_window, longest_match, hash function, etc.

Due to the introduction of SIMD optimizations, and to get the maximum
performance out of this fork of zlib, this requires an x86_64 processor
with SSE4.2 and CLMUL (anything Westmere or later, ~2010). The Chromium
zlib implementation also supports ARM with NEON, but it has not been
enabled in this patch.

Performance
===========

TL;DR: Running just `./libgit2_clar -score::zstream` 100 times in a loop
took 0:56.30 before and 0:50.67 after (~10% reduction!).

The bundled and system zlib implementations on an Ubuntu Focal system
perform relatively similar (the bundled one is marginally better due to
the compiler being able to inline some functions), so only the bundled
and Chromium zlibs were compared.

For a more balanced comparison (to ensure that nothing regressed
overall), `libgit2_clar` under `perf` was also run, and the zlib-related
functions were compared.

Bundled
-------

```shell
cmake \
  -DUSE_BUNDLED_ZLIB=ON \
  -DUSE_CHROMIUM_ZLIB=OFF \
  -DCMAKE_BUILD_TYPE="RelWithDebInfo" \
  -DCMAKE_C_FLAGS="-fPIC -fno-omit-frame-pointer" \
  -GNinja \
  ..
ninja
perf record --call-graph=dwarf ./libgit2_clar
perf report --children
```

```
Samples: 87K of event 'cycles', Event count (approx.): 75923450603
  Children      Self  Command       Shared Objec  Symbol
+    4.14%     0.01%  libgit2_clar  libgit2_clar  [.] git_zstream_get_output_chunk
+    2.91%     0.00%  libgit2_clar  libgit2_clar  [.] git_zstream_get_output
+    0.69%     0.00%  libgit2_clar  libgit2_clar  [.] git_zstream_get_output (inlined)
     0.17%     0.00%  libgit2_clar  libgit2_clar  [.] git_zstream_init
     0.02%     0.00%  libgit2_clar  libgit2_clar  [.] git_zstream_reset
     0.00%     0.00%  libgit2_clar  libgit2_clar  [.] git_zstream_eos
     0.00%     0.00%  libgit2_clar  libgit2_clar  [.] git_zstream_done
     0.00%     0.00%  libgit2_clar  libgit2_clar  [.] git_zstream_free (inlined)

Samples: 87K of event 'cycles', Event count (approx.): 75923450603
  Children      Self  Command       Shared Objec  Symbol
+    3.12%     0.01%  libgit2_clar  libgit2_clar  [.] deflate
+    2.65%     1.48%  libgit2_clar  libgit2_clar  [.] deflate_slow
+    1.60%     0.55%  libgit2_clar  libgit2_clar  [.] inflate
+    0.53%     0.00%  libgit2_clar  libgit2_clar  [.] write_deflate
     0.49%     0.36%  libgit2_clar  libgit2_clar  [.] inflate_fast
     0.46%     0.02%  libgit2_clar  libgit2_clar  [.] deflate_fast
     0.19%     0.19%  libgit2_clar  libgit2_clar  [.] inflate_table
     0.16%     0.01%  libgit2_clar  libgit2_clar  [.] inflateInit_
     0.15%     0.00%  libgit2_clar  libgit2_clar  [.] inflateInit2_ (inlined)
     0.10%     0.00%  libgit2_clar  libgit2_clar  [.] deflateInit_
     0.10%     0.00%  libgit2_clar  libgit2_clar  [.] deflateInit2_
     0.03%     0.00%  libgit2_clar  libgit2_clar  [.] deflateReset (inlined)
     0.02%     0.00%  libgit2_clar  libgit2_clar  [.] deflateReset
     0.02%     0.00%  libgit2_clar  libgit2_clar  [.] inflateEnd
     0.02%     0.00%  libgit2_clar  libgit2_clar  [.] deflateEnd
     0.01%     0.00%  libgit2_clar  libgit2_clar  [.] deflateResetKeep
     0.01%     0.01%  libgit2_clar  libgit2_clar  [.] inflateReset2
     0.01%     0.00%  libgit2_clar  libgit2_clar  [.] deflateReset (inlined)
     0.00%     0.00%  libgit2_clar  libgit2_clar  [.] inflateStateCheck (inlined)
     0.00%     0.00%  libgit2_clar  libgit2_clar  [.] inflateReset (inlined)
     0.00%     0.00%  libgit2_clar  libgit2_clar  [.] inflateStateCheck (inlined)
     0.00%     0.00%  libgit2_clar  libgit2_clar  [.] deflateStateCheck (inlined)
     0.00%     0.00%  libgit2_clar  libgit2_clar  [.] inflateResetKeep (inlined)
```

Chromium
--------

```shell
cmake \
  -DUSE_BUNDLED_ZLIB=ON \
  -DUSE_CHROMIUM_ZLIB=ON \
  -DCMAKE_BUILD_TYPE="RelWithDebInfo" \
  -DCMAKE_C_FLAGS="-fPIC -fno-omit-frame-pointer" \
  -GNinja \
  ..
ninja
perf record --call-graph=dwarf ./libgit2_clar
perf report --children
```

```
Samples: 97K of event 'cycles', Event count (approx.): 80862210917
  Children      Self  Command       Shared Objec  Symbol
+    3.31%     0.00%  libgit2_clar  libgit2_clar  [.] git_zstream_get_output_chunk
+    2.27%     0.01%  libgit2_clar  libgit2_clar  [.] git_zstream_get_output
+    0.55%     0.00%  libgit2_clar  libgit2_clar  [.] git_zstream_get_output (inlined)
     0.18%     0.00%  libgit2_clar  libgit2_clar  [.] git_zstream_init
     0.02%     0.00%  libgit2_clar  libgit2_clar  [.] git_zstream_reset
     0.00%     0.00%  libgit2_clar  libgit2_clar  [.] git_zstream_free (inlined)
     0.00%     0.00%  libgit2_clar  libgit2_clar  [.] git_zstream_done
     0.00%     0.00%  libgit2_clar  libgit2_clar  [.] git_zstream_free

Samples: 97K of event 'cycles', Event count (approx.): 80862210917
  Children      Self  Command       Shared Objec  Symbol
+    2.55%     0.01%  libgit2_clar  libgit2_clar  [.] deflate
+    2.25%     1.41%  libgit2_clar  libgit2_clar  [.] deflate_slow
+    1.10%     0.52%  libgit2_clar  libgit2_clar  [.] inflate
     0.36%     0.00%  libgit2_clar  libgit2_clar  [.] write_deflate
     0.30%     0.03%  libgit2_clar  libgit2_clar  [.] deflate_fast
     0.28%     0.15%  libgit2_clar  libgit2_clar  [.] inflate_fast_chunk_
     0.19%     0.19%  libgit2_clar  libgit2_clar  [.] inflate_table
     0.17%     0.01%  libgit2_clar  libgit2_clar  [.] inflateInit_
     0.16%     0.00%  libgit2_clar  libgit2_clar  [.] inflateInit2_ (inlined)
     0.15%     0.00%  libgit2_clar  libgit2_clar  [.] deflateInit_
     0.15%     0.00%  libgit2_clar  libgit2_clar  [.] deflateInit2_
     0.11%     0.01%  libgit2_clar  libgit2_clar  [.] adler32_z
     0.09%     0.09%  libgit2_clar  libgit2_clar  [.] adler32_simd_
     0.05%     0.00%  libgit2_clar  libgit2_clar  [.] deflateReset (inlined)
     0.05%     0.00%  libgit2_clar  libgit2_clar  [.] deflate_read_buf
     0.03%     0.00%  libgit2_clar  libgit2_clar  [.] inflateEnd
     0.02%     0.00%  libgit2_clar  libgit2_clar  [.] deflateReset
     0.01%     0.00%  libgit2_clar  libgit2_clar  [.] deflateEnd
     0.01%     0.01%  libgit2_clar  libgit2_clar  [.] inflateReset2
     0.01%     0.00%  libgit2_clar  libgit2_clar  [.] inflateReset (inlined)
     0.00%     0.00%  libgit2_clar  libgit2_clar  [.] adler32
     0.00%     0.00%  libgit2_clar  libgit2_clar  [.] inflateResetKeep (inlined)
     0.00%     0.00%  libgit2_clar  libgit2_clar  [.] deflateResetKeep
     0.00%     0.00%  libgit2_clar  libgit2_clar  [.] inflateStateCheck (inlined)
     0.00%     0.00%  libgit2_clar  libgit2_clar  [.] inflateStateCheck (inlined)
     0.00%     0.00%  libgit2_clar  libgit2_clar  [.] inflateStateCheck (inlined)
     0.00%     0.00%  libgit2_clar  libgit2_clar  [.] deflateStateCheck (inlined)
```

Merge pull request #5741 from libgit2/ethomson/ipv6

2020-12-23T12:32:58+00:00

Handle ipv6 addresses

net: function to identify ipv6 addresses in URLs

2020-12-23T12:00:34+00:00

net: is_default_port is a bool