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cpython/Modules/zlibmodule.c

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/* zlibmodule.c -- gzip-compatible data compression */
#include <Python.h>
#include <zlib.h>
/* The following parameters are copied from zutil.h, version 0.95 */
#define DEFLATED 8
#if MAX_MEM_LEVEL >= 8
# define DEF_MEM_LEVEL 8
#else
# define DEF_MEM_LEVEL MAX_MEM_LEVEL
#endif
#define DEF_WBITS MAX_WBITS
/* The output buffer will be increased in chunks of ADDCHUNK bytes. */
#define ADDCHUNK 2048
#define PyInit_zlib initzlib
staticforward PyTypeObject Comptype;
staticforward PyTypeObject Decomptype;
static PyObject *ZlibError;
typedef struct
{
PyObject_HEAD
z_stream zst;
} compobject;
static compobject *
newcompobject(type)
PyTypeObject *type;
{
compobject *self;
self = PyObject_NEW(compobject, type);
if (self == NULL)
return NULL;
return self;
}
static PyObject *
PyZlib_compress(self, args)
PyObject *self;
PyObject *args;
{
PyObject *ReturnVal;
Byte *input, *output;
int length, level=Z_DEFAULT_COMPRESSION, err;
z_stream zst;
if (!PyArg_ParseTuple(args, "s#|i", &input, &length, &level))
return NULL;
zst.avail_out=length+length/1000+12+1;
output=(Byte*)malloc(zst.avail_out);
if (output==NULL)
{
PyErr_SetString(PyExc_MemoryError,
"Can't allocate memory to compress data");
return NULL;
}
zst.zalloc=(alloc_func)zst.zfree=(free_func)Z_NULL;
zst.next_out=(Byte *)output;
zst.next_in =(Byte *)input;
zst.avail_in=length;
err=deflateInit(&zst, level);
switch(err)
{
case(Z_OK):
break;
case(Z_MEM_ERROR):
PyErr_SetString(PyExc_MemoryError,
"Out of memory while compressing data");
free(output);
return NULL;
break;
case(Z_STREAM_ERROR):
PyErr_SetString(ZlibError,
"Bad compression level");
free(output);
return NULL;
break;
default:
{
char temp[500];
if (zst.msg==Z_NULL) zst.msg="";
sprintf(temp, "Error %i while compressing data [%s]", err, zst.msg);
PyErr_SetString(ZlibError, temp);
deflateEnd(&zst);
free(output);
return NULL;
}
break;
}
err=deflate(&zst, Z_FINISH);
switch(err)
{
case(Z_STREAM_END):
break;
/* Are there other errors to be trapped here? */
default:
{
char temp[500];
if (zst.msg==Z_NULL) zst.msg="";
sprintf(temp, "Error %i while compressing data [%s]", err, zst.msg);
PyErr_SetString(ZlibError, temp);
deflateEnd(&zst);
free(output);
return NULL;
}
}
err=deflateEnd(&zst);
if (err!=Z_OK)
{
char temp[500];
if (zst.msg==Z_NULL) zst.msg="";
sprintf(temp, "Error %i while finishing data compression [%s]",
err, zst.msg);
PyErr_SetString(ZlibError, temp);
free(output);
return NULL;
}
ReturnVal=PyString_FromStringAndSize(output, zst.total_out);
free(output);
return ReturnVal;
}
static PyObject *
PyZlib_decompress(self, args)
PyObject *self;
PyObject *args;
{
PyObject *ReturnVal;
Byte *input, *output;
int length, err;
z_stream zst;
if (!PyArg_ParseTuple(args, "s#", &input, &length))
return NULL;
zst.avail_in=length;
zst.avail_out=length=length*2;
output=(Byte*)malloc(zst.avail_out);
if (output==NULL)
{
PyErr_SetString(PyExc_MemoryError,
"Can't allocate memory to decompress data");
return NULL;
}
zst.zalloc=(alloc_func)zst.zfree=(free_func)Z_NULL;
zst.next_out=(Byte *)output;
zst.next_in =(Byte *)input;
err=inflateInit(&zst);
switch(err)
{
case(Z_OK):
break;
case(Z_MEM_ERROR):
PyErr_SetString(PyExc_MemoryError,
"Out of memory while decompressing data");
free(output);
return NULL;
default:
{
char temp[500];
if (zst.msg==Z_NULL) zst.msg="";
sprintf(temp, "Error %i while preparing to decompress data [%s]",
err, zst.msg);
PyErr_SetString(ZlibError, temp);
inflateEnd(&zst);
free(output);
return NULL;
}
}
do
{
err=inflate(&zst, Z_FINISH);
switch(err)
{
case(Z_OK):
case(Z_STREAM_END):
output=(Byte *)realloc(output, length+ADDCHUNK);
if (output==NULL)
{
PyErr_SetString(PyExc_MemoryError,
"Out of memory while decompressing data");
inflateEnd(&zst);
return NULL;
}
zst.next_out=output+length;
zst.avail_out=ADDCHUNK;
length += ADDCHUNK;
break;
default:
{
char temp[500];
if (zst.msg==Z_NULL) zst.msg="";
sprintf(temp, "Error %i while decompressing data: [%s]",
err, zst.msg);
PyErr_SetString(ZlibError, temp);
inflateEnd(&zst);
return NULL;
}
}
} while(err!=Z_STREAM_END);
err=inflateEnd(&zst);
if (err!=Z_OK)
{
char temp[500];
if (zst.msg==Z_NULL) zst.msg="";
sprintf(temp, "Error %i while finishing data decompression [%s]",
err, zst.msg);
PyErr_SetString(ZlibError, temp);
free(output);
return NULL;
}
ReturnVal=PyString_FromStringAndSize(output, zst.total_out);
free(output);
return ReturnVal;
}
static PyObject *
PyZlib_compressobj(selfptr, args)
PyObject *selfptr;
PyObject *args;
{
compobject *self;
int level=Z_DEFAULT_COMPRESSION, method=DEFLATED;
int wbits=MAX_WBITS, memLevel=DEF_MEM_LEVEL, strategy=0, err;
/* XXX Argh! Is there a better way to have multiple levels of */
/* optional arguments? */
if (!PyArg_ParseTuple(args, "iiiii", &level, &method, &wbits, &memLevel, &strategy))
{
PyErr_Clear();
if (!PyArg_ParseTuple(args, "iiii", &level, &method, &wbits,
&memLevel))
{
PyErr_Clear();
if (!PyArg_ParseTuple(args, "iii", &level, &method, &wbits))
{
PyErr_Clear();
if (!PyArg_ParseTuple(args, "ii", &level, &method))
{
PyErr_Clear();
if (!PyArg_ParseTuple(args, "i", &level))
{
PyErr_Clear();
if (!PyArg_ParseTuple(args, ""))
return (NULL);
}
}
}
}
}
self=newcompobject(&Comptype);
if (self==NULL) return(NULL);
self->zst.zalloc=(alloc_func)self->zst.zfree=(free_func)Z_NULL;
err=deflateInit2(&self->zst, level, method, wbits, memLevel, strategy);
switch(err)
{
case (Z_OK):
return (PyObject*)self;
break;
case (Z_MEM_ERROR):
PyErr_SetString(PyExc_MemoryError,
"Can't allocate memory for compression object");
return NULL;
break;
case(Z_STREAM_ERROR):
PyErr_SetString(PyExc_ValueError,
"Invalid compression level");
return NULL;
break;
default:
{
char temp[500];
if (self->zst.msg==Z_NULL) self->zst.msg="";
sprintf(temp, "Error %i while creating compression object [%s]",
err, self->zst.msg);
PyErr_SetString(ZlibError, temp);
return NULL;
break;
}
}
}
static PyObject *
PyZlib_decompressobj(selfptr, args)
PyObject *selfptr;
PyObject *args;
{
int wbits=DEF_WBITS, err;
compobject *self;
if (!PyArg_ParseTuple(args, "|i", &wbits))
{
return NULL;
}
self=newcompobject(&Decomptype);
if (self==NULL) return(NULL);
self->zst.zalloc=(alloc_func)self->zst.zfree=(free_func)Z_NULL;
/* XXX If illegal values of wbits are allowed to get here, Python
coredumps, instead of raising an exception as it should.
This is a bug in zlib 0.95; I have reported it. */
err=inflateInit2(&self->zst, wbits);
switch(err)
{
case (Z_OK):
return (PyObject*)self;
break;
case (Z_MEM_ERROR):
PyErr_SetString(PyExc_MemoryError,
"Can't allocate memory for decompression object");
return NULL;
break;
default:
{
char temp[500];
if (self->zst.msg==Z_NULL) self->zst.msg="";
sprintf(temp, "Error %i while creating decompression object [%s]",
err, self->zst.msg);
PyErr_SetString(ZlibError, temp);
return NULL;
break;
}
}
}
static void
Comp_dealloc(self)
compobject *self;
{
int err;
err=deflateEnd(&self->zst); /* Deallocate zstream structure */
}
static void
Decomp_dealloc(self)
compobject *self;
{
int err;
err=inflateEnd(&self->zst); /* Deallocate zstream structure */
}
static PyObject *
PyZlib_objcompress(self, args)
compobject *self;
PyObject *args;
{
int length=0, err, inplen;
Byte *buf=NULL;
PyObject *RetVal;
Byte *input;
if (!PyArg_ParseTuple(args, "s#", &input, &inplen))
return NULL;
self->zst.avail_in=inplen;
self->zst.next_in=input;
do
{
buf=(Byte *)realloc(buf, length+ADDCHUNK);
if (buf==NULL)
{
PyErr_SetString(PyExc_MemoryError,
"Can't allocate memory to compress data");
return NULL;
}
self->zst.next_out=buf+length;
self->zst.avail_out=ADDCHUNK;
length += ADDCHUNK;
err=deflate(&(self->zst), Z_NO_FLUSH);
} while (self->zst.avail_in!=0 && err==Z_OK);
if (err!=Z_OK)
{
char temp[500];
if (self->zst.msg==Z_NULL) self->zst.msg="";
sprintf(temp, "Error %i while compressing [%s]",
err, self->zst.msg);
PyErr_SetString(ZlibError, temp);
return NULL;
}
RetVal=PyString_FromStringAndSize(buf, self->zst.next_out-buf);
free(buf);
return RetVal;
}
static PyObject *
PyZlib_objdecompress(self, args)
compobject *self;
PyObject *args;
{
int length=0, err, inplen;
Byte *buf=NULL;
PyObject *RetVal;
Byte *input;
if (!PyArg_ParseTuple(args, "s#", &input, &inplen))
return NULL;
self->zst.avail_in=inplen;
self->zst.next_in=input;
do
{
buf=(Byte *)realloc(buf, length+ADDCHUNK);
if (buf==NULL)
{
PyErr_SetString(PyExc_MemoryError,
"Can't allocate memory to decompress data");
return NULL;
}
self->zst.next_out=buf+length;
self->zst.avail_out=ADDCHUNK;
length += ADDCHUNK;
err=inflate(&(self->zst), Z_NO_FLUSH);
} while (self->zst.avail_in!=0 && err==Z_OK);
if (err!=Z_OK && err!=Z_STREAM_END)
{
char temp[500];
if (self->zst.msg==Z_NULL) self->zst.msg="";
sprintf(temp, "Error %i while decompressing [%s]",
err, self->zst.msg);
PyErr_SetString(ZlibError, temp);
return NULL;
}
RetVal=PyString_FromStringAndSize(buf, self->zst.next_out-buf);
free(buf);
return RetVal;
}
static PyObject *
PyZlib_flush(self, args)
compobject *self;
PyObject *args;
{
int length=0, err;
Byte *buf=NULL;
PyObject *RetVal;
if (!PyArg_NoArgs(args))
return NULL;
self->zst.avail_in=0;
do
{
buf=(Byte *)realloc(buf, length+ADDCHUNK);
if (buf==NULL)
{
PyErr_SetString(PyExc_MemoryError,
"Can't allocate memory to compress data");
return NULL;
}
self->zst.next_out=buf+length;
self->zst.avail_out=ADDCHUNK;
length += ADDCHUNK;
err=deflate(&(self->zst), Z_FINISH);
} while (err==Z_OK);
if (err!=Z_STREAM_END)
{
char temp[500];
if (self->zst.msg==Z_NULL) self->zst.msg="";
sprintf(temp, "Error %i while compressing [%s]",
err, self->zst.msg);
PyErr_SetString(ZlibError, temp);
return NULL;
}
RetVal=PyString_FromStringAndSize(buf, self->zst.next_out-buf);
free(buf);
err=deflateEnd(&(self->zst));
if (err!=Z_OK)
{
char temp[500];
if (self->zst.msg==Z_NULL) self->zst.msg="";
sprintf(temp, "Error %i while flushing compression object [%s]",
err, self->zst.msg);
PyErr_SetString(ZlibError, temp);
return NULL;
}
return RetVal;
}
static PyObject *
PyZlib_unflush(self, args)
compobject *self;
PyObject *args;
{
int length=0, err;
Byte *buf=NULL;
PyObject *RetVal;
if (!PyArg_NoArgs(args))
return NULL;
self->zst.avail_in=0;
do
{
buf=(Byte *)realloc(buf, length+ADDCHUNK);
if (buf==NULL)
{
PyErr_SetString(PyExc_MemoryError,
"Can't allocate memory to decompress data");
return NULL;
}
self->zst.next_out=buf+length;
length += ADDCHUNK;
err=inflate(&(self->zst), Z_FINISH);
} while (err==Z_OK);
if (err!=Z_STREAM_END)
{
char temp[500];
if (self->zst.msg==Z_NULL) self->zst.msg="";
sprintf(temp, "Error %i while decompressing [%s]",
err, self->zst.msg);
PyErr_SetString(ZlibError, temp);
return NULL;
}
RetVal=PyString_FromStringAndSize(buf, self->zst.next_out - buf);
free(buf);
err=inflateEnd(&(self->zst));
if (err!=Z_OK)
{
char temp[500];
if (self->zst.msg==Z_NULL) self->zst.msg="";
sprintf(temp, "Error %i while flushing decompression object [%s]",
err, self->zst.msg);
PyErr_SetString(ZlibError, temp);
return NULL;
}
return RetVal;
}
static PyMethodDef comp_methods[] =
{
{"compress", PyZlib_objcompress, 1},
{"flush", PyZlib_flush, 0},
{NULL, NULL}
};
static PyMethodDef Decomp_methods[] =
{
{"decompress", PyZlib_objdecompress, 1},
{"flush", PyZlib_unflush, 0},
{NULL, NULL}
};
static PyObject *
Comp_getattr(self, name)
compobject *self;
char *name;
{
return Py_FindMethod(comp_methods, (PyObject *)self, name);
}
static PyObject *
Decomp_getattr(self, name)
compobject *self;
char *name;
{
return Py_FindMethod(Decomp_methods, (PyObject *)self, name);
}
static PyObject *
PyZlib_adler32(self, args)
PyObject *self, *args;
{
uLong adler32val=adler32(0L, Z_NULL, 0);
Byte *buf;
int len;
if (!PyArg_ParseTuple(args, "s#|l", &buf, &len, &adler32val))
{
return NULL;
}
adler32val=adler32(adler32val, buf, len);
return Py_BuildValue("l", adler32val);
}
static PyObject *
PyZlib_crc32(self, args)
PyObject *self, *args;
{
uLong crc32val=crc32(0L, Z_NULL, 0);
Byte *buf;
int len;
if (!PyArg_ParseTuple(args, "s#|l", &buf, &len, &crc32val))
{
return NULL;
}
crc32val=crc32(crc32val, buf, len);
return Py_BuildValue("l", crc32val);
}
static PyMethodDef zlib_methods[] =
{
{"adler32", PyZlib_adler32, 1},
{"compress", PyZlib_compress, 1},
{"compressobj", PyZlib_compressobj, 1},
{"crc32", PyZlib_crc32, 1},
{"decompress", PyZlib_decompress, 1},
{"decompressobj", PyZlib_decompressobj, 1},
{NULL, NULL}
};
statichere PyTypeObject Comptype = {
PyObject_HEAD_INIT(&PyType_Type)
0,
"Compress",
sizeof(compobject),
0,
(destructor)Comp_dealloc, /*tp_dealloc*/
0, /*tp_print*/
(getattrfunc)Comp_getattr, /*tp_getattr*/
0, /*tp_setattr*/
0, /*tp_compare*/
0, /*tp_repr*/
0, /*tp_as_number*/
0, /*tp_as_sequence*/
0, /*tp_as_mapping*/
};
statichere PyTypeObject Decomptype = {
PyObject_HEAD_INIT(&PyType_Type)
0,
"Decompress",
sizeof(compobject),
0,
(destructor)Decomp_dealloc, /*tp_dealloc*/
0, /*tp_print*/
(getattrfunc)Decomp_getattr, /*tp_getattr*/
0, /*tp_setattr*/
0, /*tp_compare*/
0, /*tp_repr*/
0, /*tp_as_number*/
0, /*tp_as_sequence*/
0, /*tp_as_mapping*/
};
/* The following insint() routine was blatantly ripped off from
socketmodule.c */
/* Convenience routine to export an integer value.
For simplicity, errors (which are unlikely anyway) are ignored. */
static void
insint(d, name, value)
PyObject *d;
char *name;
int value;
{
PyObject *v = PyInt_FromLong((long) value);
if (v == NULL) {
/* Don't bother reporting this error */
PyErr_Clear();
}
else {
PyDict_SetItemString(d, name, v);
Py_DECREF(v);
}
}
void
PyInit_zlib()
{
PyObject *m, *d;
m = Py_InitModule("zlib", zlib_methods);
d = PyModule_GetDict(m);
ZlibError = Py_BuildValue("s", "zlib.error");
PyDict_SetItemString(d, "error", ZlibError);
insint(d, "MAX_WBITS", MAX_WBITS);
insint(d, "DEFLATED", DEFLATED);
insint(d, "DEF_MEM_LEVEL", DEF_MEM_LEVEL);
if (PyErr_Occurred())
Py_FatalError("can't initialize module zlib");
}
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