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Viewing changes to _groupcompress_c.pyx

  • Committer: John Arbash Meinel
  • Date: 2009-02-27 18:21:04 UTC
  • mto: (0.23.23 groupcompress_rabin)
  • mto: This revision was merged to the branch mainline in revision 4280.
  • Revision ID: john@arbash-meinel.com-20090227182104-ogr8fu5548ewpzx3
Add a apply_delta2 function, just in case it matters.

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_groupcompress_c.pyx
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    unsigned long get_delta_hdr_size(unsigned char **datap,
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                                     unsigned char *top)
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    Py_ssize_t DELTA_SIZE_MIN
 
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    void *patch_delta(void *src_buf, unsigned long src_size,
 
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                      void *delta_buf, unsigned long delta_size,
 
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                      unsigned long *dst_size)
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cdef extern from "Python.h":
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    int PyString_CheckExact(object)
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    # *dst_size = out - dst_buf;
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    assert (out - dst_buf) == PyString_GET_SIZE(result)
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    return result
 
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def apply_delta2(source_bytes, delta_bytes):
 
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    """Apply a delta generated by make_delta to source_bytes."""
 
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    # This defers to the patch-delta code rather than implementing it here
 
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    # If this is faster, we can bring the memory allocation and error handling
 
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    # into apply_delta(), and leave the primary loop in a separate C func.
 
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    cdef char *source, *delta, *target
 
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    cdef Py_ssize_t source_size, delta_size
 
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    cdef unsigned long target_size
 
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    if not PyString_CheckExact(source_bytes):
 
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        raise TypeError('source is not a str')
 
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    if not PyString_CheckExact(delta_bytes):
 
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        raise TypeError('delta is not a str')
 
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    source = PyString_AS_STRING(source_bytes)
 
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    source_size = PyString_GET_SIZE(source_bytes)
 
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    delta = PyString_AS_STRING(delta_bytes)
 
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    delta_size = PyString_GET_SIZE(delta_bytes)
 
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    target = <char *>patch_delta(source, source_size,
 
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                                 delta, delta_size,
 
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                                 &target_size)
 
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    if target == NULL:
 
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        return None
 
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    result = PyString_FromStringAndSize(target, target_size)
 
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    free(target)
 
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    return result