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Added tag 4.1.3 for changeset 77eaf9539499

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compressiondict.c
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/**
* Copyright (c) 2016-present, Gregory Szorc
* All rights reserved.
*
* This software may be modified and distributed under the terms
* of the BSD license. See the LICENSE file for details.
*/
#include "python-zstandard.h"
extern PyObject* ZstdError;
ZstdCompressionDict* train_dictionary(PyObject* self, PyObject* args, PyObject* kwargs) {
static char *kwlist[] = { "dict_size", "samples", "parameters", NULL };
size_t capacity;
PyObject* samples;
Py_ssize_t samplesLen;
PyObject* parameters = NULL;
ZDICT_params_t zparams;
Py_ssize_t sampleIndex;
Py_ssize_t sampleSize;
PyObject* sampleItem;
size_t zresult;
void* sampleBuffer;
void* sampleOffset;
size_t samplesSize = 0;
size_t* sampleSizes;
void* dict;
ZstdCompressionDict* result;
if (!PyArg_ParseTupleAndKeywords(args, kwargs, "nO!|O!", kwlist,
&capacity,
&PyList_Type, &samples,
(PyObject*)&DictParametersType, &parameters)) {
return NULL;
}
/* Validate parameters first since it is easiest. */
zparams.selectivityLevel = 0;
zparams.compressionLevel = 0;
zparams.notificationLevel = 0;
zparams.dictID = 0;
zparams.reserved[0] = 0;
zparams.reserved[1] = 0;
if (parameters) {
/* TODO validate data ranges */
zparams.selectivityLevel = PyLong_AsUnsignedLong(PyTuple_GetItem(parameters, 0));
zparams.compressionLevel = PyLong_AsLong(PyTuple_GetItem(parameters, 1));
zparams.notificationLevel = PyLong_AsUnsignedLong(PyTuple_GetItem(parameters, 2));
zparams.dictID = PyLong_AsUnsignedLong(PyTuple_GetItem(parameters, 3));
}
/* Figure out the size of the raw samples */
samplesLen = PyList_Size(samples);
for (sampleIndex = 0; sampleIndex < samplesLen; sampleIndex++) {
sampleItem = PyList_GetItem(samples, sampleIndex);
if (!PyBytes_Check(sampleItem)) {
PyErr_SetString(PyExc_ValueError, "samples must be bytes");
/* TODO probably need to perform DECREF here */
return NULL;
}
samplesSize += PyBytes_GET_SIZE(sampleItem);
}
/* Now that we know the total size of the raw simples, we can allocate
a buffer for the raw data */
sampleBuffer = PyMem_Malloc(samplesSize);
if (!sampleBuffer) {
PyErr_NoMemory();
return NULL;
}
sampleSizes = PyMem_Malloc(samplesLen * sizeof(size_t));
if (!sampleSizes) {
PyMem_Free(sampleBuffer);
PyErr_NoMemory();
return NULL;
}
sampleOffset = sampleBuffer;
/* Now iterate again and assemble the samples in the buffer */
for (sampleIndex = 0; sampleIndex < samplesLen; sampleIndex++) {
sampleItem = PyList_GetItem(samples, sampleIndex);
sampleSize = PyBytes_GET_SIZE(sampleItem);
sampleSizes[sampleIndex] = sampleSize;
memcpy(sampleOffset, PyBytes_AS_STRING(sampleItem), sampleSize);
sampleOffset = (char*)sampleOffset + sampleSize;
}
dict = PyMem_Malloc(capacity);
if (!dict) {
PyMem_Free(sampleSizes);
PyMem_Free(sampleBuffer);
PyErr_NoMemory();
return NULL;
}
zresult = ZDICT_trainFromBuffer_advanced(dict, capacity,
sampleBuffer, sampleSizes, (unsigned int)samplesLen,
zparams);
if (ZDICT_isError(zresult)) {
PyErr_Format(ZstdError, "Cannot train dict: %s", ZDICT_getErrorName(zresult));
PyMem_Free(dict);
PyMem_Free(sampleSizes);
PyMem_Free(sampleBuffer);
return NULL;
}
result = PyObject_New(ZstdCompressionDict, &ZstdCompressionDictType);
if (!result) {
return NULL;
}
result->dictData = dict;
result->dictSize = zresult;
return result;
}
PyDoc_STRVAR(ZstdCompressionDict__doc__,
"ZstdCompressionDict(data) - Represents a computed compression dictionary\n"
"\n"
"This type holds the results of a computed Zstandard compression dictionary.\n"
"Instances are obtained by calling ``train_dictionary()`` or by passing bytes\n"
"obtained from another source into the constructor.\n"
);
static int ZstdCompressionDict_init(ZstdCompressionDict* self, PyObject* args) {
const char* source;
Py_ssize_t sourceSize;
self->dictData = NULL;
self->dictSize = 0;
#if PY_MAJOR_VERSION >= 3
if (!PyArg_ParseTuple(args, "y#", &source, &sourceSize)) {
#else
if (!PyArg_ParseTuple(args, "s#", &source, &sourceSize)) {
#endif
return -1;
}
self->dictData = PyMem_Malloc(sourceSize);
if (!self->dictData) {
PyErr_NoMemory();
return -1;
}
memcpy(self->dictData, source, sourceSize);
self->dictSize = sourceSize;
return 0;
}
static void ZstdCompressionDict_dealloc(ZstdCompressionDict* self) {
if (self->dictData) {
PyMem_Free(self->dictData);
self->dictData = NULL;
}
PyObject_Del(self);
}
static PyObject* ZstdCompressionDict_dict_id(ZstdCompressionDict* self) {
unsigned dictID = ZDICT_getDictID(self->dictData, self->dictSize);
return PyLong_FromLong(dictID);
}
static PyObject* ZstdCompressionDict_as_bytes(ZstdCompressionDict* self) {
return PyBytes_FromStringAndSize(self->dictData, self->dictSize);
}
static PyMethodDef ZstdCompressionDict_methods[] = {
{ "dict_id", (PyCFunction)ZstdCompressionDict_dict_id, METH_NOARGS,
PyDoc_STR("dict_id() -- obtain the numeric dictionary ID") },
{ "as_bytes", (PyCFunction)ZstdCompressionDict_as_bytes, METH_NOARGS,
PyDoc_STR("as_bytes() -- obtain the raw bytes constituting the dictionary data") },
{ NULL, NULL }
};
static Py_ssize_t ZstdCompressionDict_length(ZstdCompressionDict* self) {
return self->dictSize;
}
static PySequenceMethods ZstdCompressionDict_sq = {
(lenfunc)ZstdCompressionDict_length, /* sq_length */
0, /* sq_concat */
0, /* sq_repeat */
0, /* sq_item */
0, /* sq_ass_item */
0, /* sq_contains */
0, /* sq_inplace_concat */
0 /* sq_inplace_repeat */
};
PyTypeObject ZstdCompressionDictType = {
PyVarObject_HEAD_INIT(NULL, 0)
"zstd.ZstdCompressionDict", /* tp_name */
sizeof(ZstdCompressionDict), /* tp_basicsize */
0, /* tp_itemsize */
(destructor)ZstdCompressionDict_dealloc, /* tp_dealloc */
0, /* tp_print */
0, /* tp_getattr */
0, /* tp_setattr */
0, /* tp_compare */
0, /* tp_repr */
0, /* tp_as_number */
&ZstdCompressionDict_sq, /* tp_as_sequence */
0, /* tp_as_mapping */
0, /* tp_hash */
0, /* tp_call */
0, /* tp_str */
0, /* tp_getattro */
0, /* tp_setattro */
0, /* tp_as_buffer */
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /* tp_flags */
ZstdCompressionDict__doc__, /* tp_doc */
0, /* tp_traverse */
0, /* tp_clear */
0, /* tp_richcompare */
0, /* tp_weaklistoffset */
0, /* tp_iter */
0, /* tp_iternext */
ZstdCompressionDict_methods, /* tp_methods */
0, /* tp_members */
0, /* tp_getset */
0, /* tp_base */
0, /* tp_dict */
0, /* tp_descr_get */
0, /* tp_descr_set */
0, /* tp_dictoffset */
(initproc)ZstdCompressionDict_init, /* tp_init */
0, /* tp_alloc */
PyType_GenericNew, /* tp_new */
};
void compressiondict_module_init(PyObject* mod) {
Py_TYPE(&ZstdCompressionDictType) = &PyType_Type;
if (PyType_Ready(&ZstdCompressionDictType) < 0) {
return;
}
Py_INCREF((PyObject*)&ZstdCompressionDictType);
PyModule_AddObject(mod, "ZstdCompressionDict",
(PyObject*)&ZstdCompressionDictType);
}