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-r00587dc
+r981e22c
 :Author: Francesc Alted
 :Contact: f[email protected]
+:Contact: f[email protected]
 :URL: http://www.blosc.org
+:Gitter: |gitter|
+:Travis CI: |travis|
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 What is it?
 …
 It uses the blocking technique (as described in [2]_) to reduce
 activity on the memory bus as much as possible.  In short, this
+activity on the memory bus as much as possible. In short, this
 technique works by dividing datasets in blocks that are small enough
 to fit in caches of modern processors and perform compression /
 decompression there.  It also leverages, if available, SIMD
+instructions (SSE2) and multi-threading capabilities of CPUs, in order
+to accelerate the compression / decompression process to a maximum.
+You can see some recent benchmarks about Blosc performance in [3]_
+instructions (SSE2, AVX2) and multi-threading capabilities of CPUs, in
+order to accelerate the compression / decompression process to a
+maximum.
+Blosc is actually a metacompressor, that meaning that it can use a range
+of compression libraries for performing the actual
+compression/decompression. Right now, it comes with integrated support
+for BloscLZ (the original one), LZ4, LZ4HC, Snappy, Zlib and Zstd. Blosc
+comes with full sources for all compressors, so in case it does not find
+the libraries installed in your system, it will compile from the
+included sources and they will be integrated into the Blosc library
+anyway. That means that you can trust in having all supported
+compressors integrated in Blosc in all supported platforms.
+You can see some benchmarks about Blosc performance in [3]_
 Blosc is distributed using the MIT license, see LICENSES/BLOSC.txt for
 …
 .. [1] http://www.blosc.org
 .. [2] http://blosc.org/docs/StarvingCPUs-CISE-2010.pdf
 .. [3] http://blosc.org/trac/wiki/SyntheticBenchmarks
+.. [3] http://blosc.org/synthetic-benchmarks.html
 Meta-compression and other advantages over existing compressors
 ===============================================================
 Blosc is not like other compressors: it should rather be called a
+C-Blosc is not like other compressors: it should rather be called a
 meta-compressor.  This is so because it can use different compressors
+and pre-conditioners (programs that generally improve compression
+ratio).  At any rate, it can also be called a compressor because it
+happens that it already integrates one compressor and one
+pre-conditioner, so it can actually work like so.
+Currently it uses BloscLZ, a compressor heavily based on FastLZ
+(http://fastlz.org/), and a highly optimized (it can use SSE2
+instructions, if available) Shuffle pre-conditioner. However,
+different compressors or pre-conditioners may be added in the future.
+Blosc is in charge of coordinating the compressor and pre-conditioners
+so that they can leverage the blocking technique (described above) as
+well as multi-threaded execution (if several cores are available)
+automatically. That makes that every compressor and pre-conditioner
+and filters (programs that generally improve compression ratio).  At
+any rate, it can also be called a compressor because it happens that
+it already comes with several compressor and filters, so it can
+actually work like so.
+Currently C-Blosc comes with support of BloscLZ, a compressor heavily
+based on FastLZ (http://fastlz.org/), LZ4 and LZ4HC
+(https://github.com/Cyan4973/lz4), Snappy
+(https://github.com/google/snappy) and Zlib (http://www.zlib.net/), as
+well as a highly optimized (it can use SSE2 or AVX2 instructions, if
+available) shuffle and bitshuffle filters (for info on how and why
+shuffling works, see slide 17 of
+http://www.slideshare.net/PyData/blosc-py-data-2014).  However,
+different compressors or filters may be added in the future.
+C-Blosc is in charge of coordinating the different compressor and
+filters so that they can leverage the blocking technique (described
+above) as well as multi-threaded execution (if several cores are
+available) automatically. That makes that every compressor and filter
 will work at very high speeds, even if it was not initially designed
 for doing blocking or multi-threading.
 …
 * Meant for binary data: can take advantage of the type size
   meta-information for improved compression ratio (using the
+  integrated shuffle pre-conditioner).
+* Small overhead on non-compressible data: only a maximum of 16
+  additional bytes over the source buffer length are needed to
+  compress *every* input.
+* Maximum destination length: contrarily to many other
+  compressors, both compression and decompression routines have
+  support for maximum size lengths for the destination buffer.
+* Replacement for memcpy(): it supports a 0 compression level that
+  does not compress at all and only adds 16 bytes of overhead. In
+  this mode Blosc can copy memory usually faster than a plain
+  memcpy().
+  integrated shuffle and bitshuffle filters).
+* Small overhead on non-compressible data: only a maximum of (16 + 4 *
+  nthreads) additional bytes over the source buffer length are needed
+  to compress *any kind of input*.
+* Maximum destination length: contrarily to many other compressors,
+  both compression and decompression routines have support for maximum
+  size lengths for the destination buffer.
 When taken together, all these features set Blosc apart from other
 similar solutions.
+Compiling your application with Blosc
+=====================================
+Blosc consists of the next files (in blosc/ directory)::
+    blosc.h and blosc.c      -- the main routines
+    blosclz.h and blosclz.c  -- the actual compressor
+    shuffle.h and shuffle.c  -- the shuffle code
+Compiling your application with a minimalistic Blosc
+====================================================
+The minimal Blosc consists of the next files (in `blosc/ directory
+<https://github.com/Blosc/c-blosc/tree/master/blosc>`_)::
+    blosc.h and blosc.c        -- the main routines
+    shuffle*.h and shuffle*.c  -- the shuffle code
+    blosclz.h and blosclz.c    -- the blosclz compressor
 Just add these files to your project in order to use Blosc.  For
+information on compression and decompression routines, see blosc.h.
+To compile using GCC (4.4 or higher recommended) on Unix:
+.. code-block:: console
+   $ gcc -O3 -msse2 -o myprog myprog.c blosc/*.c -lpthread
+information on compression and decompression routines, see `blosc.h
+<https://github.com/Blosc/c-blosc/blob/master/blosc/blosc.h>`_.
+To compile using GCC (4.9 or higher recommended) on Unix:
+.. code-block:: console
+   $ gcc -O3 -mavx2 -o myprog myprog.c blosc/*.c -Iblosc -lpthread
 Using Windows and MINGW:
 …
 .. code-block:: console
+   $ gcc -O3 -msse2 -o myprog myprog.c blosc\*.c
+Using Windows and MSVC (2008 or higher recommended):
+.. code-block:: console
+  $ cl /Ox /Femyprog.exe myprog.c blosc\*.c
+A simple usage example is the benchmark in the bench/bench.c file.
+Also, another example for using Blosc as a generic HDF5 filter is in
+the hdf5/ directory.
+I have not tried to compile this with compilers other than GCC, MINGW,
+Intel ICC or MSVC yet. Please report your experiences with your own
+platforms.
+Testing Blosc
+=============
+Go to the test/ directory and issue:
+.. code-block:: console
+  $ make test
+These tests are very basic, and only valid for platforms where GNU
+make/gcc tools are available.  If you really want to test Blosc the
+hard way, look at:
+http://blosc.org/trac/wiki/SyntheticBenchmarks
+where instructions on how to intensively test (and benchmark) Blosc
+are given.  If while running these tests you get some error, please
+report it back!
+   $ gcc -O3 -mavx2 -o myprog myprog.c -Iblosc blosc\*.c
+Using Windows and MSVC (2013 or higher recommended):
+.. code-block:: console
+  $ cl /Ox /Femyprog.exe /Iblosc myprog.c blosc\*.c
+In the `examples/ directory
+<https://github.com/Blosc/c-blosc/tree/master/examples>`_ you can find
+more hints on how to link your app with Blosc.
+I have not tried to compile this with compilers other than GCC, clang,
+MINGW, Intel ICC or MSVC yet. Please report your experiences with your
+own platforms.
+Adding support for other compressors with a minimalistic Blosc
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+The official cmake files (see below) for Blosc try hard to include
+support for LZ4, LZ4HC, Snappy, Zlib inside the Blosc library, so
+using them is just a matter of calling the appropriate
+`blosc_set_compressor() API call
+<https://github.com/Blosc/c-blosc/blob/master/blosc/blosc.h>`_.  See
+an `example here
+<https://github.com/Blosc/c-blosc/blob/master/examples/many_compressors.c>`_.
+Having said this, it is also easy to use a minimalistic Blosc and just
+add the symbols HAVE_LZ4 (will include both LZ4 and LZ4HC),
+HAVE_SNAPPY and HAVE_ZLIB during compilation as well as the
+appropriate libraries. For example, for compiling with minimalistic
+Blosc but with added Zlib support do:
+.. code-block:: console
+   $ gcc -O3 -msse2 -o myprog myprog.c blosc/*.c -Iblosc -lpthread -DHAVE_ZLIB -lz
+In the `bench/ directory
+<https://github.com/Blosc/c-blosc/tree/master/bench>`_ there a couple
+of Makefile files (one for UNIX and the other for MinGW) with more
+complete building examples, like switching between libraries or
+internal sources for the compressors.
+Supported platforms
+~~~~~~~~~~~~~~~~~~~
+Blosc is meant to support all platforms where a C89 compliant C
+compiler can be found.  The ones that are mostly tested are Intel
+(Linux, Mac OSX and Windows) and ARM (Linux), but exotic ones as IBM
+Blue Gene Q embedded "A2" processor are reported to work too.
 Compiling the Blosc library with CMake
 ======================================
+Blosc can also be built, tested and installed using CMake_.
+Blosc can also be built, tested and installed using CMake_. Although
+this procedure might seem a bit more involved than the one described
+above, it is the most general because it allows to integrate other
+compressors than BloscLZ either from libraries or from internal
+sources. Hence, serious library developers are encouraged to use this
+way.
 The following procedure describes the "out of source" build.
 …
   $ cd build
+Configure Blosc in release mode (enable optimizations) specifying the
+installation directory:
+.. code-block:: console
+  $ cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=INSTALL_DIR \
+      PATH_TO_BLOSC_SOURCE_DIR
+Please note that configuration can also be performed using UI tools
+provided by CMake_ (ccmake or cmake-gui):
+.. code-block:: console
+  $ cmake-gui PATH_TO_BLOSC_SOURCE_DIR
+Now run CMake configuration and optionally specify the installation
+directory (e.g. '/usr' or '/usr/local'):
+.. code-block:: console
+  $ cmake -DCMAKE_INSTALL_PREFIX=your_install_prefix_directory ..
+CMake allows to configure Blosc in many different ways, like prefering
+internal or external sources for compressors or enabling/disabling
+them.  Please note that configuration can also be performed using UI
+tools provided by CMake_ (ccmake or cmake-gui):
+.. code-block:: console
+  $ ccmake ..      # run a curses-based interface
+  $ cmake-gui ..   # run a graphical interface
 Build, test and install Blosc:
 …
 .. code-block:: console
   $ make
   $ make test
   $ make install
+  $ cmake --build .
+  $ ctest
+  $ cmake --build . --target install
 The static and dynamic version of the Blosc library, together with
+header files, will be installed into the specified INSTALL_DIR.
+header files, will be installed into the specified
+CMAKE_INSTALL_PREFIX.
 .. _CMake: http://www.cmake.org
+Once you have compiled your Blosc library, you can easily link your
+apps with it as shown in the `example/ directory
+<https://github.com/Blosc/c-blosc/blob/master/examples>`_.
+Adding support for other compressors (LZ4, LZ4HC, Snappy, Zlib) with CMake
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+The CMake files in Blosc are configured to automatically detect other
+compressors like LZ4, LZ4HC, Snappy or Zlib by default.  So as long as
+the libraries and the header files for these libraries are accessible,
+these will be used by default.  See an `example here
+<https://github.com/Blosc/c-blosc/blob/master/examples/many_compressors.c>`_.
+*Note on Zlib*: the library should be easily found on UNIX systems,
+although on Windows, you can help CMake to find it by setting the
+environment variable 'ZLIB_ROOT' to where zlib 'include' and 'lib'
+directories are. Also, make sure that Zlib DDL library is in your
+'\Windows' directory.
+However, the full sources for LZ4, LZ4HC, Snappy and Zlib have been
+included in Blosc too. So, in general, you should not worry about not
+having (or CMake not finding) the libraries in your system because in
+this case, their sources will be automatically compiled for you. That
+effectively means that you can be confident in having a complete
+support for all the supported compression libraries in all supported
+platforms.
+If you want to force Blosc to use external libraries instead of
+the included compression sources:
+.. code-block:: console
+  $ cmake -DPREFER_EXTERNAL_LZ4=ON ..
+You can also disable support for some compression libraries:
+.. code-block:: console
+  $ cmake -DDEACTIVATE_SNAPPY=ON ..
+Mac OSX troubleshooting
+~~~~~~~~~~~~~~~~~~~~~~~
+If you run into compilation troubles when using Mac OSX, please make
+sure that you have installed the command line developer tools.  You
+can always install them with:
+.. code-block:: console
+  $ xcode-select --install
 Wrapper for Python
 …
 Blosc has an official wrapper for Python.  See:
+https://github.com/FrancescAlted/python-blosc
+https://github.com/Blosc/python-blosc
+Command line interface and serialization format for Blosc
+=========================================================
+Blosc can be used from command line by using Bloscpack.  See:
+https://github.com/Blosc/bloscpack
 Filter for HDF5
 ===============
+For those that want to use Blosc as a filter in the HDF5 library,
+there is a sample implementation in the hdf5/ directory.
+For those who want to use Blosc as a filter in the HDF5 library,
+there is a sample implementation in the blosc/hdf5 project in:
+https://github.com/Blosc/hdf5
 Mailing list
 …
 ===============
+I'd like to thank the PyTables community that have collaborated in the
+exhaustive testing of Blosc.  With an aggregate amount of more than 300 TB of
+different datasets compressed *and* decompressed successfully, I can say that
+Blosc is pretty safe now and ready for production purposes.
+Other important contributions:
+* Thibault North contributed a way to call Blosc from different threads in a
+  safe way.
+* The cmake support was a contribution of Thibault North, Antonio Valentino
+  and Mark Wiebe.
+* Valentin Haenel did a terrific work fixing typos and improving docs and the
+  plotting script.
+See THANKS.rst.

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