Upgrade Snappy to 1.2.1

c_src/snappy/COPYING

@@ -26,3 +26,29 @@ DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+===
+
+Some of the benchmark data in testdata/ is licensed differently:
+
+ - fireworks.jpeg is Copyright 2013 Steinar H. Gunderson, and
+   is licensed under the Creative Commons Attribution 3.0 license
+   (CC-BY-3.0). See https://creativecommons.org/licenses/by/3.0/
+   for more information.
+
+ - kppkn.gtb is taken from the Gaviota chess tablebase set, and
+   is licensed under the MIT License. See
+   https://sites.google.com/site/gaviotachessengine/Home/endgame-tablebases-1
+   for more information.
+
+ - paper-100k.pdf is an excerpt (bytes 92160 to 194560) from the paper
+   “Combinatorial Modeling of Chromatin Features Quantitatively Predicts DNA
+   Replication Timing in _Drosophila_” by Federico Comoglio and Renato Paro,
+   which is licensed under the CC-BY license. See
+   http://www.ploscompbiol.org/static/license for more ifnormation.
+
+ - alice29.txt, asyoulik.txt, plrabn12.txt and lcet10.txt are from Project
+   Gutenberg. The first three have expired copyrights and are in the public
+   domain; the latter does not have expired copyright, but is still in the
+   public domain according to the license information
+   (http://www.gutenberg.org/ebooks/53).

c_src/snappy/NEWS

@@ -1,3 +1,63 @@
+Snappy v1.1.10, Mar 8th 2023:
+
+  * Performance improvements
+
+  * Compilation fixes for various environments
+
+Snappy v1.1.9, May 4th 2021:
+
+  * Performance improvements.
+
+  * Google Test and Google Benchmark are now bundled in third_party/.
+
+Snappy v1.1.8, January 15th 2020:
+
+  * Small performance improvements.
+
+  * Removed snappy::string alias for std::string.
+
+  * Improved CMake configuration.
+
+Snappy v1.1.7, August 24th 2017:
+
+  * Improved CMake build support for 64-bit Linux distributions.
+
+  * MSVC builds now use MSVC-specific intrinsics that map to clzll.
+
+  * ARM64 (AArch64) builds use the code paths optimized for 64-bit processors.
+
+Snappy v1.1.6, July 12th 2017:
+
+This is a re-release of v1.1.5 with proper SONAME / SOVERSION values.
+
+Snappy v1.1.5, June 28th 2017:
+
+This release has broken SONAME / SOVERSION values. Users of snappy as a shared
+library should avoid 1.1.5 and use 1.1.6 instead. SONAME / SOVERSION errors will
+manifest as the dynamic library loader complaining that it cannot find snappy's
+shared library file (libsnappy.so / libsnappy.dylib), or that the library it
+found does not have the required version. 1.1.6 has the same code as 1.1.5, but
+carries build configuration fixes for the issues above.
+
+  * Add CMake build support. The autoconf build support is now deprecated, and
+    will be removed in the next release.
+
+  * Add AppVeyor configuration, for Windows CI coverage.
+
+  * Small performance improvement on little-endian PowerPC.
+
+  * Small performance improvement on LLVM with position-independent executables.
+
+  * Fix a few issues with various build environments.
+
+Snappy v1.1.4, January 25th 2017:
+
+  * Fix a 1% performance regression when snappy is used in PIE executables.
+
+  * Improve compression performance by 5%.
+
+  * Improve decompression performance by 20%.
+
 Snappy v1.1.3, July 6th 2015:
 
 This is the first release to be done from GitHub, which means that

c_src/snappy/README → c_src/snappy/README.md

@@ -1,5 +1,6 @@
 Snappy, a fast compressor/decompressor.
 
+[![Build Status](https://github.com/google/snappy/actions/workflows/build.yml/badge.svg)](https://github.com/google/snappy/actions/workflows/build.yml)
 
 Introduction
 ============
@@ -29,12 +30,12 @@ and the like.
 
 Performance
 ===========
- 
+
 Snappy is intended to be fast. On a single core of a Core i7 processor
 in 64-bit mode, it compresses at about 250 MB/sec or more and decompresses at
 about 500 MB/sec or more. (These numbers are for the slowest inputs in our
 benchmark suite; others are much faster.) In our tests, Snappy usually
-is faster than algorithms in the same class (e.g. LZO, LZF, FastLZ, QuickLZ,
+is faster than algorithms in the same class (e.g. LZO, LZF, QuickLZ,
 etc.) while achieving comparable compression ratios.
 
 Typical compression ratios (based on the benchmark suite) are about 1.5-1.7x
@@ -51,8 +52,8 @@ In particular:
 
  - Snappy uses 64-bit operations in several places to process more data at
    once than would otherwise be possible.
- - Snappy assumes unaligned 32- and 64-bit loads and stores are cheap.
-   On some platforms, these must be emulated with single-byte loads 
+ - Snappy assumes unaligned 32 and 64-bit loads and stores are cheap.
+   On some platforms, these must be emulated with single-byte loads
    and stores, which is much slower.
  - Snappy assumes little-endian throughout, and needs to byte-swap data in
    several places if running on a big-endian platform.
@@ -62,25 +63,41 @@ Performance optimizations, whether for 64-bit x86 or other platforms,
 are of course most welcome; see "Contact", below.
 
 
+Building
+========
+
+You need the CMake version specified in [CMakeLists.txt](./CMakeLists.txt)
+or later to build:
+
+```bash
+git submodule update --init
+mkdir build
+cd build && cmake ../ && make
+```
+
 Usage
 =====
 
 Note that Snappy, both the implementation and the main interface,
 is written in C++. However, several third-party bindings to other languages
-are available; see the Google Code page at http://code.google.com/p/snappy/
-for more information. Also, if you want to use Snappy from C code, you can
-use the included C bindings in snappy-c.h.
+are available; see the [home page](docs/README.md) for more information.
+Also, if you want to use Snappy from C code, you can use the included C
+bindings in snappy-c.h.
 
 To use Snappy from your own C++ program, include the file "snappy.h" from
 your calling file, and link against the compiled library.
 
 There are many ways to call Snappy, but the simplest possible is
 
-  snappy::Compress(input.data(), input.size(), &output);
+```c++
+snappy::Compress(input.data(), input.size(), &output);
+```
 
 and similarly
 
-  snappy::Uncompress(input.data(), input.size(), &output);
+```c++
+snappy::Uncompress(input.data(), input.size(), &output);
+```
 
 where "input" and "output" are both instances of std::string.
 
@@ -92,44 +109,57 @@ information.
 Tests and benchmarks
 ====================
 
-When you compile Snappy, snappy_unittest is compiled in addition to the
-library itself. You do not need it to use the compressor from your own library,
-but it contains several useful components for Snappy development.
-
-First of all, it contains unit tests, verifying correctness on your machine in
-various scenarios. If you want to change or optimize Snappy, please run the
-tests to verify you have not broken anything. Note that if you have the
-Google Test library installed, unit test behavior (especially failures) will be
-significantly more user-friendly. You can find Google Test at
-
-  http://code.google.com/p/googletest/
-
-You probably also want the gflags library for handling of command-line flags;
-you can find it at
-
-  http://code.google.com/p/google-gflags/
-
-In addition to the unit tests, snappy contains microbenchmarks used to
-tune compression and decompression performance. These are automatically run
-before the unit tests, but you can disable them using the flag
---run_microbenchmarks=false if you have gflags installed (otherwise you will
-need to edit the source).
-
-Finally, snappy can benchmark Snappy against a few other compression libraries
-(zlib, LZO, LZF, FastLZ and QuickLZ), if they were detected at configure time.
-To benchmark using a given file, give the compression algorithm you want to test
-Snappy against (e.g. --zlib) and then a list of one or more file names on the
-command line. The testdata/ directory contains the files used by the
-microbenchmark, which should provide a reasonably balanced starting point for
-benchmarking. (Note that baddata[1-3].snappy are not intended as benchmarks; they
-are used to verify correctness in the presence of corrupted data in the unit
-test.)
-
+When you compile Snappy, the following binaries are compiled in addition to the
+library itself. You do not need them to use the compressor from your own
+library, but they are useful for Snappy development.
+
+* `snappy_benchmark` contains microbenchmarks used to tune compression and
+  decompression performance.
+* `snappy_unittests` contains unit tests, verifying correctness on your machine
+  in various scenarios.
+* `snappy_test_tool` can benchmark Snappy against a few other compression
+  libraries (zlib, LZO, LZF, and QuickLZ), if they were detected at configure
+  time. To benchmark using a given file, give the compression algorithm you want
+  to test Snappy against (e.g. --zlib) and then a list of one or more file names
+  on the command line.
+
+If you want to change or optimize Snappy, please run the tests and benchmarks to
+verify you have not broken anything.
+
+The testdata/ directory contains the files used by the microbenchmarks, which
+should provide a reasonably balanced starting point for benchmarking. (Note that
+baddata[1-3].snappy are not intended as benchmarks; they are used to verify
+correctness in the presence of corrupted data in the unit test.)
+
+Contributing to the Snappy Project
+==================================
+
+In addition to the aims listed at the top of the [README](README.md) Snappy
+explicitly supports the following:
+
+1. C++11
+2. Clang (gcc and MSVC are best-effort).
+3. Low level optimizations (e.g. assembly or equivalent intrinsics) for:
+     - [x86](https://en.wikipedia.org/wiki/X86)
+     - [x86-64](https://en.wikipedia.org/wiki/X86-64)
+     - ARMv7 (32-bit)
+     - ARMv8 (AArch64)
+4. Supports only the Snappy compression scheme as described in
+  [format_description.txt](format_description.txt).
+5. CMake for building
+
+Changes adding features or dependencies outside of the core area of focus listed
+above might not be accepted. If in doubt post a message to the
+[Snappy discussion mailing list](https://groups.google.com/g/snappy-compression).
+
+We are unlikely to accept contributions to the build configuration files, such
+as `CMakeLists.txt`. We are focused on maintaining a build configuration that
+allows us to test that the project works in a few supported configurations
+inside Google. We are not currently interested in supporting other requirements,
+such as different operating systems, compilers, or build systems.
 
 Contact
 =======
 
-Snappy is distributed through Google Code. For the latest version, a bug tracker,
-and other information, see
-
-  http://code.google.com/p/snappy/
+Snappy is distributed through GitHub. For the latest version and other
+information, see https://github.com/google/snappy.