view contrib/python-zstandard/zstd.c @ 30911:f3c5a8a4dfd0 stable

bundle-tests: operate from outside a repository

We are about to add a test for ssh pull/cloning being denied because of bundle1
usage. For this, it is cleaner to not operate from the clone using http. So we
update the test beforehand for clarity. This is more churns that what I'm happy
to see on stable, but the rests of the series is worth it in my opinion.

/**
 * 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.
 */

/* A Python C extension for Zstandard. */

#include "python-zstandard.h"

PyObject *ZstdError;

PyDoc_STRVAR(estimate_compression_context_size__doc__,
"estimate_compression_context_size(compression_parameters)\n"
"\n"
"Give the amount of memory allocated for a compression context given a\n"
"CompressionParameters instance");

PyDoc_STRVAR(estimate_decompression_context_size__doc__,
"estimate_decompression_context_size()\n"
"\n"
"Estimate the amount of memory allocated to a decompression context.\n"
);

static PyObject* estimate_decompression_context_size(PyObject* self) {
	return PyLong_FromSize_t(ZSTD_estimateDCtxSize());
}

PyDoc_STRVAR(get_compression_parameters__doc__,
"get_compression_parameters(compression_level[, source_size[, dict_size]])\n"
"\n"
"Obtains a ``CompressionParameters`` instance from a compression level and\n"
"optional input size and dictionary size");

PyDoc_STRVAR(train_dictionary__doc__,
"train_dictionary(dict_size, samples)\n"
"\n"
"Train a dictionary from sample data.\n"
"\n"
"A compression dictionary of size ``dict_size`` will be created from the\n"
"iterable of samples provided by ``samples``.\n"
"\n"
"The raw dictionary content will be returned\n");

static char zstd_doc[] = "Interface to zstandard";

static PyMethodDef zstd_methods[] = {
	{ "estimate_compression_context_size", (PyCFunction)estimate_compression_context_size,
	METH_VARARGS, estimate_compression_context_size__doc__ },
	{ "estimate_decompression_context_size", (PyCFunction)estimate_decompression_context_size,
	METH_NOARGS, estimate_decompression_context_size__doc__ },
	{ "get_compression_parameters", (PyCFunction)get_compression_parameters,
	METH_VARARGS, get_compression_parameters__doc__ },
	{ "train_dictionary", (PyCFunction)train_dictionary,
	METH_VARARGS | METH_KEYWORDS, train_dictionary__doc__ },
	{ NULL, NULL }
};

void compressobj_module_init(PyObject* mod);
void compressor_module_init(PyObject* mod);
void compressionparams_module_init(PyObject* mod);
void constants_module_init(PyObject* mod);
void dictparams_module_init(PyObject* mod);
void compressiondict_module_init(PyObject* mod);
void compressionwriter_module_init(PyObject* mod);
void compressoriterator_module_init(PyObject* mod);
void decompressor_module_init(PyObject* mod);
void decompressobj_module_init(PyObject* mod);
void decompressionwriter_module_init(PyObject* mod);
void decompressoriterator_module_init(PyObject* mod);

void zstd_module_init(PyObject* m) {
	/* python-zstandard relies on unstable zstd C API features. This means
	   that changes in zstd may break expectations in python-zstandard.

	   python-zstandard is distributed with a copy of the zstd sources.
	   python-zstandard is only guaranteed to work with the bundled version
	   of zstd.

	   However, downstream redistributors or packagers may unbundle zstd
	   from python-zstandard. This can result in a mismatch between zstd
	   versions and API semantics. This essentially "voids the warranty"
	   of python-zstandard and may cause undefined behavior.

	   We detect this mismatch here and refuse to load the module if this
	   scenario is detected.
	*/
	if (ZSTD_VERSION_NUMBER != 10102 || ZSTD_versionNumber() != 10102) {
		PyErr_SetString(PyExc_ImportError, "zstd C API mismatch; Python bindings not compiled against expected zstd version");
		return;
	}

	compressionparams_module_init(m);
	dictparams_module_init(m);
	compressiondict_module_init(m);
	compressobj_module_init(m);
	compressor_module_init(m);
	compressionwriter_module_init(m);
	compressoriterator_module_init(m);
	constants_module_init(m);
	decompressor_module_init(m);
	decompressobj_module_init(m);
	decompressionwriter_module_init(m);
	decompressoriterator_module_init(m);
}

#if PY_MAJOR_VERSION >= 3
static struct PyModuleDef zstd_module = {
	PyModuleDef_HEAD_INIT,
	"zstd",
	zstd_doc,
	-1,
	zstd_methods
};

PyMODINIT_FUNC PyInit_zstd(void) {
	PyObject *m = PyModule_Create(&zstd_module);
	if (m) {
		zstd_module_init(m);
		if (PyErr_Occurred()) {
			Py_DECREF(m);
			m = NULL;
		}
	}
	return m;
}
#else
PyMODINIT_FUNC initzstd(void) {
	PyObject *m = Py_InitModule3("zstd", zstd_methods, zstd_doc);
	if (m) {
		zstd_module_init(m);
	}
}
#endif