def decompress_ptr(bytesobj, address):
"""decompress_ptr(bytesobj, address)
Decompresses a bytesobj compressed object into the memory at address.
Parameters
----------
bytesobj : str / bytes
The data to be decompressed.
address : int or long
the pointer to the data to be compressed
Returns
-------
nbytes : int
the number of bytes written to the buffer
Raises
------
TypeError
If bytesobj is not of type bytes or string.
If address is not of type int or long.
Notes
-----
This function can be used anywhere that a memory address is available in
Python. For example the Numpy "__array_interface__['data'][0]" construct,
or when using the ctypes modules.
Importantly, the user is responsible for making sure that the memory
address is valid and that the memory pointed to is contiguous and can be
written to. Passing a non-valid address has a high likelihood of crashing
the interpreter by segfault.
Examples
--------
>>> import numpy
>>> items = 7
>>> np_array = numpy.arange(items)
>>> c = blosc.compress_ptr(np_array.__array_interface__['data'][0], \
items, np_array.dtype.itemsize)
>>> np_ans = numpy.empty(items, dtype=np_array.dtype)
>>> nbytes = blosc.decompress_ptr(c, np_ans.__array_interface__['data'][0])
>>> (np_array == np_ans).all()
True
>>> nbytes == items * np_array.dtype.itemsize
True
>>> import ctypes
>>> typesize = 8
>>> data = [float(i) for i in range(items)]
>>> Array = ctypes.c_double * items
>>> in_array = Array(*data)
>>> c = blosc.compress_ptr(ctypes.addressof(in_array), items, typesize)
>>> out_array = ctypes.create_string_buffer(items*typesize)
>>> nbytes = blosc.decompress_ptr(c, ctypes.addressof(out_array))
>>> import struct
>>> ans = [struct.unpack('d', out_array[i:i+typesize])[0] \
for i in range(0, items*typesize, typesize)]
>>> data == ans
True
>>> nbytes == items * typesize
True
"""
_check_bytesobj(bytesobj)
_check_address(address)
return _ext.decompress_ptr(bytesobj, address)
def decompress_ptr(bytesobj, address):
"""decompress_ptr(bytesobj, address)
Decompresses a bytesobj compressed object into the memory at address.
Parameters
----------
bytesobj : str / bytes
The data to be decompressed.
address : int or long
the pointer to the data to be compressed
Returns
-------
nbytes : int
the number of bytes written to the buffer
Raises
------
TypeError
If bytesobj is not of type bytes or string.
If address is not of type int or long.
Notes
-----
This function can be used anywhere that a memory address is available in
Python. For example the Numpy "__array_interface__['data'][0]" construct,
or when using the ctypes modules.
Importantly, the user is responsible for making sure that the memory
address is valid and that the memory pointed to is contiguous and can be
written to. Passing a non-valid address has a high likelihood of crashing
the interpreter by segfault.
Examples
--------
>>> import numpy
>>> items = 7
>>> np_array = numpy.arange(items)
>>> c = blosc.compress_ptr(np_array.__array_interface__['data'][0], \
items, np_array.dtype.itemsize)
>>> np_ans = numpy.empty(items, dtype=np_array.dtype)
>>> nbytes = blosc.decompress_ptr(c, np_ans.__array_interface__['data'][0])
>>> (np_array == np_ans).all()
True
>>> nbytes == items * np_array.dtype.itemsize
True
>>> import ctypes
>>> typesize = 8
>>> data = [float(i) for i in range(items)]
>>> Array = ctypes.c_double * items
>>> in_array = Array(*data)
>>> c = blosc.compress_ptr(ctypes.addressof(in_array), items, typesize)
>>> out_array = ctypes.create_string_buffer(items*typesize)
>>> nbytes = blosc.decompress_ptr(c, ctypes.addressof(out_array))
>>> import struct
>>> ans = [struct.unpack('d', out_array[i:i+typesize])[0] \
for i in range(0,items*typesize,typesize)]
>>> data == ans
True
>>> nbytes == items * typesize
True
"""
_check_bytesobj(bytesobj)
_check_address(address)
return _ext.decompress_ptr(bytesobj, address)
