1 /**

     2 * Copyright (c) 2017-present, Gregory Szorc

     3 * All rights reserved.

     4 *

     5 * This software may be modified and distributed under the terms

     6 * of the BSD license. See the LICENSE file for details.

     7 */

     8 

     9 #include "python-zstandard.h"

    10 

    11 extern PyObject* ZstdError;

    12 

    13 PyDoc_STRVAR(FrameParameters__doc__,

    14 	"FrameParameters: information about a zstd frame");

    15 

    16 FrameParametersObject* get_frame_parameters(PyObject* self, PyObject* args) {

    17 	const char* source;

    18 	Py_ssize_t sourceSize;

    19 	ZSTD_frameParams params;

    20 	FrameParametersObject* result = NULL;

    21 	size_t zresult;

    22 

    23 #if PY_MAJOR_VERSION >= 3

    24 	if (!PyArg_ParseTuple(args, "y#:get_frame_parameters",

    25 #else

    26 	if (!PyArg_ParseTuple(args, "s#:get_frame_parameters",

    27 #endif

    28 		&source, &sourceSize)) {

    29 		return NULL;

    30 	}

    31 

    32 	/* Needed for Python 2 to reject unicode */

    33 	if (!PyBytes_Check(PyTuple_GET_ITEM(args, 0))) {

    34 		PyErr_SetString(PyExc_TypeError, "argument must be bytes");

    35 		return NULL;

    36 	}

    37 

    38 	zresult = ZSTD_getFrameParams(&params, (void*)source, sourceSize);

    39 

    40 	if (ZSTD_isError(zresult)) {

    41 		PyErr_Format(ZstdError, "cannot get frame parameters: %s", ZSTD_getErrorName(zresult));

    42 		return NULL;

    43 	}

    44 

    45 	if (zresult) {

    46 		PyErr_Format(ZstdError, "not enough data for frame parameters; need %zu bytes", zresult);

    47 		return NULL;

    48 	}

    49 

    50 	result = PyObject_New(FrameParametersObject, &FrameParametersType);

    51 	if (!result) {

    52 		return NULL;

    53 	}

    54 

    55 	result->frameContentSize = params.frameContentSize;

    56 	result->windowSize = params.windowSize;

    57 	result->dictID = params.dictID;

    58 	result->checksumFlag = params.checksumFlag ? 1 : 0;

    59 

    60 	return result;

    61 }

    62 

    63 static void FrameParameters_dealloc(PyObject* self) {

    64 	PyObject_Del(self);

    65 }

    66 

    67 static PyMemberDef FrameParameters_members[] = {

    68 	{ "content_size", T_ULONGLONG,

    69 	  offsetof(FrameParametersObject, frameContentSize), READONLY,

    70 	  "frame content size" },

    71 	{ "window_size", T_UINT,

    72 	  offsetof(FrameParametersObject, windowSize), READONLY,

    73 	  "window size" },

    74 	{ "dict_id", T_UINT,

    75 	  offsetof(FrameParametersObject, dictID), READONLY,

    76 	  "dictionary ID" },

    77 	{ "has_checksum", T_BOOL,

    78 	  offsetof(FrameParametersObject, checksumFlag), READONLY,

    79 	  "checksum flag" },

    80 	{ NULL }

    81 };

    82 

    83 PyTypeObject FrameParametersType = {

    84 	PyVarObject_HEAD_INIT(NULL, 0)

    85 	"FrameParameters",          /* tp_name */

    86 	sizeof(FrameParametersObject), /* tp_basicsize */

    87 	0,                         /* tp_itemsize */

    88 	(destructor)FrameParameters_dealloc, /* tp_dealloc */

    89 	0,                         /* tp_print */

    90 	0,                         /* tp_getattr */

    91 	0,                         /* tp_setattr */

    92 	0,                         /* tp_compare */

    93 	0,                         /* tp_repr */

    94 	0,                         /* tp_as_number */

    95 	0,                         /* tp_as_sequence */

    96 	0,                         /* tp_as_mapping */

    97 	0,                         /* tp_hash  */

    98 	0,                         /* tp_call */

    99 	0,                         /* tp_str */

   100 	0,                         /* tp_getattro */

   101 	0,                         /* tp_setattro */

   102 	0,                         /* tp_as_buffer */

   103 	Py_TPFLAGS_DEFAULT,        /* tp_flags */

   104 	FrameParameters__doc__,    /* tp_doc */

   105 	0,                         /* tp_traverse */

   106 	0,                         /* tp_clear */

   107 	0,                         /* tp_richcompare */

   108 	0,                         /* tp_weaklistoffset */

   109 	0,                         /* tp_iter */

   110 	0,                         /* tp_iternext */

   111 	0,                         /* tp_methods */

   112 	FrameParameters_members,   /* tp_members */

   113 	0,                         /* tp_getset */

   114 	0,                         /* tp_base */

   115 	0,                         /* tp_dict */

   116 	0,                         /* tp_descr_get */

   117 	0,                         /* tp_descr_set */

   118 	0,                         /* tp_dictoffset */

   119 	0,                         /* tp_init */

   120 	0,                         /* tp_alloc */

   121 	0,                         /* tp_new */

   122 };

   123 

   124 void frameparams_module_init(PyObject* mod) {

   125 	Py_TYPE(&FrameParametersType) = &PyType_Type;

   126 	if (PyType_Ready(&FrameParametersType) < 0) {

   127 		return;

   128 	}

   129 

   130 	Py_IncRef((PyObject*)&FrameParametersType);

   131 	PyModule_AddObject(mod, "FrameParameters", (PyObject*)&FrameParametersType);

   132 }