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Have the binascii module use zlib's optimized crc32() function when available

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to reduce our code size (1k data table and tiny bit of code).  It falls back
to its own without zlib.
This commit is contained in:
Gregory P. Smith 2008-03-24 00:08:01 +00:00
parent dd10284516
commit 440ca772f3
2 changed files with 41 additions and 3 deletions
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24
Modules/binascii.c
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@ -56,6 +56,9 @@
#define PY_SSIZE_T_CLEAN
#include "Python.h"
#ifdef USE_ZLIB_CRC32
#include "zlib.h"
#endif
static PyObject *Error;
static PyObject *Incomplete;
@ -748,6 +751,26 @@ binascii_crc_hqx(PyObject *self, PyObject *args)
PyDoc_STRVAR(doc_crc32,
"(data, oldcrc = 0) -> newcrc. Compute CRC-32 incrementally");
#ifdef USE_ZLIB_CRC32
/* This was taken from zlibmodule.c PyZlib_crc32 (but is PY_SSIZE_T_CLEAN) */
static PyObject *
binascii_crc32(PyObject *self, PyObject *args)
{
uLong crc32val = 0; /* crc32(0L, Z_NULL, 0) */
Byte *buf;
Py_ssize_t len;
int signed_val;
if (!PyArg_ParseTuple(args, "s#|k:crc32", &buf, &len, &crc32val))
return NULL;
/* In Python 2.x we return a signed integer regardless of native platform
* long size (the 32bit unsigned long is treated as 32-bit signed and sign
* extended into a 64-bit long inside the integer object). 3.0 does the
* right thing and returns unsigned. http://bugs.python.org/issue1202 */
signed_val = crc32(crc32val, buf, len);
return PyInt_FromLong(signed_val);
}
#else /* USE_ZLIB_CRC32 */
/* Crc - 32 BIT ANSI X3.66 CRC checksum files
Also known as: ISO 3307
**********************************************************************|
@ -898,6 +921,7 @@ binascii_crc32(PyObject *self, PyObject *args)
#endif
return PyInt_FromLong(result);
}
#endif /* USE_ZLIB_CRC32 */
static PyObject *