1 # Copyright (c) 2016-present, Gregory Szorc

     2 # All rights reserved.

     3 #

     4 # This software may be modified and distributed under the terms

     5 # of the BSD license. See the LICENSE file for details.

     6 

     7 from __future__ import absolute_import

     8 

     9 import cffi

    10 import os

    11 

    12 

    13 HERE = os.path.abspath(os.path.dirname(__file__))

    14 

    15 SOURCES = ['zstd/%s' % p for p in (

    16     'common/entropy_common.c',

    17     'common/error_private.c',

    18     'common/fse_decompress.c',

    19     'common/xxhash.c',

    20     'common/zstd_common.c',

    21     'compress/fse_compress.c',

    22     'compress/huf_compress.c',

    23     'compress/zbuff_compress.c',

    24     'compress/zstd_compress.c',

    25     'decompress/huf_decompress.c',

    26     'decompress/zbuff_decompress.c',

    27     'decompress/zstd_decompress.c',

    28     'dictBuilder/divsufsort.c',

    29     'dictBuilder/zdict.c',

    30 )]

    31 

    32 INCLUDE_DIRS = [os.path.join(HERE, d) for d in (

    33     'zstd',

    34     'zstd/common',

    35     'zstd/compress',

    36     'zstd/decompress',

    37     'zstd/dictBuilder',

    38 )]

    39 

    40 with open(os.path.join(HERE, 'zstd', 'zstd.h'), 'rb') as fh:

    41     zstd_h = fh.read()

    42 

    43 ffi = cffi.FFI()

    44 ffi.set_source('_zstd_cffi', '''

    45 /* needed for typedefs like U32 references in zstd.h */

    46 #include "mem.h"

    47 #define ZSTD_STATIC_LINKING_ONLY

    48 #include "zstd.h"

    49 ''',

    50     sources=SOURCES, include_dirs=INCLUDE_DIRS)

    51 

    52 # Rather than define the API definitions from zstd.h inline, munge the

    53 # source in a way that cdef() will accept.

    54 lines = zstd_h.splitlines()

    55 lines = [l.rstrip() for l in lines if l.strip()]

    56 

    57 # Strip preprocessor directives - they aren't important for our needs.

    58 lines = [l for l in lines

    59          if not l.startswith((b'#if', b'#else', b'#endif', b'#include'))]

    60 

    61 # Remove extern C block

    62 lines = [l for l in lines if l not in (b'extern "C" {', b'}')]

    63 

    64 # The version #defines don't parse and aren't necessary. Strip them.

    65 lines = [l for l in lines if not l.startswith((

    66     b'#define ZSTD_H_235446',

    67     b'#define ZSTD_LIB_VERSION',

    68     b'#define ZSTD_QUOTE',

    69     b'#define ZSTD_EXPAND_AND_QUOTE',

    70     b'#define ZSTD_VERSION_STRING',

    71     b'#define ZSTD_VERSION_NUMBER'))]

    72 

    73 # The C parser also doesn't like some constant defines referencing

    74 # other constants.

    75 # TODO we pick the 64-bit constants here. We should assert somewhere

    76 # we're compiling for 64-bit.

    77 def fix_constants(l):

    78     if l.startswith(b'#define ZSTD_WINDOWLOG_MAX '):

    79         return b'#define ZSTD_WINDOWLOG_MAX 27'

    80     elif l.startswith(b'#define ZSTD_CHAINLOG_MAX '):

    81         return b'#define ZSTD_CHAINLOG_MAX 28'

    82     elif l.startswith(b'#define ZSTD_HASHLOG_MAX '):

    83         return b'#define ZSTD_HASHLOG_MAX 27'

    84     elif l.startswith(b'#define ZSTD_CHAINLOG_MAX '):

    85         return b'#define ZSTD_CHAINLOG_MAX 28'

    86     elif l.startswith(b'#define ZSTD_CHAINLOG_MIN '):

    87         return b'#define ZSTD_CHAINLOG_MIN 6'

    88     elif l.startswith(b'#define ZSTD_SEARCHLOG_MAX '):

    89         return b'#define ZSTD_SEARCHLOG_MAX 26'

    90     elif l.startswith(b'#define ZSTD_BLOCKSIZE_ABSOLUTEMAX '):

    91         return b'#define ZSTD_BLOCKSIZE_ABSOLUTEMAX 131072'

    92     else:

    93         return l

    94 lines = map(fix_constants, lines)

    95 

    96 # ZSTDLIB_API isn't handled correctly. Strip it.

    97 lines = [l for l in lines if not l.startswith(b'#  define ZSTDLIB_API')]

    98 def strip_api(l):

    99     if l.startswith(b'ZSTDLIB_API '):

   100         return l[len(b'ZSTDLIB_API '):]

   101     else:

   102         return l

   103 lines = map(strip_api, lines)

   104 

   105 source = b'\n'.join(lines)

   106 ffi.cdef(source.decode('latin1'))

   107 

   108 

   109 if __name__ == '__main__':

   110     ffi.compile()