/**

* 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;

	ZSTD_customMem zmem;

	Py_BEGIN_ALLOW_THREADS

	memset(&zmem, 0, sizeof(zmem));

	compressor->cdict = ZSTD_createCDict_advanced(compressor->dict->dictData,

		compressor->dict->dictSize, 1, *zparams, zmem);

	Py_END_ALLOW_THREADS

	if (!compressor->cdict) {

		PyErr_SetString(ZstdError, "could not create compression dictionary");

		return 1;

	}

	return 0;

}

/**

	ZSTD_parameters zparams;

	void* dictData = NULL;

	size_t dictSize = 0;

	size_t zresult;

	}

	if (compressor->dict) {

		dictData = compressor->dict->dictData;

		dictSize = compressor->dict->dictSize;

	}

	memset(&zparams, 0, sizeof(zparams));

	if (compressor->cparams) {

		ztopy_compression_parameters(compressor->cparams, &zparams.cParams);

		/* Do NOT call ZSTD_adjustCParams() here because the compression params

		come from the user. */

	}

	else {

		zparams.cParams = ZSTD_getCParams(compressor->compressionLevel, sourceSize, dictSize);

	}

	zparams.fParams = compressor->fparams;

	if (ZSTD_isError(zresult)) {

		PyErr_Format(ZstdError, "cannot init CStream: %s", ZSTD_getErrorName(zresult));

	}

}

PyDoc_STRVAR(ZstdCompressor__doc__,

"ZstdCompressor(level=None, dict_data=None, compression_params=None)\n"

"\n"

"Create an object used to perform Zstandard compression.\n"

"\n"

"An instance can compress data various ways. Instances can be used multiple\n"

"times. Each compression operation will use the compression parameters\n"

"defined at construction time.\n"

"\n"

"Compression can be configured via the following names arguments:\n"

"\n"

"level\n"

"   Integer compression level.\n"

"dict_data\n"

"   A ``ZstdCompressionDict`` to be used to compress with dictionary data.\n"

"compression_params\n"

"   A ``CompressionParameters`` instance defining low-level compression"

"   parameters. If defined, this will overwrite the ``level`` argument.\n"

"write_checksum\n"

"   If True, a 4 byte content checksum will be written with the compressed\n"

"   data, allowing the decompressor to perform content verification.\n"

"write_content_size\n"

"   If True, the decompressed content size will be included in the header of\n"

"   the compressed data. This data will only be written if the compressor\n"

"   knows the size of the input data.\n"

"write_dict_id\n"

"   Determines whether the dictionary ID will be written into the compressed\n"

"   data. Defaults to True. Only adds content to the compressed data if\n"

"   a dictionary is being used.\n"

);

static int ZstdCompressor_init(ZstdCompressor* self, PyObject* args, PyObject* kwargs) {

	static char* kwlist[] = {

		"level",

		"dict_data",

		"compression_params",

		"write_checksum",

		"write_content_size",

		"write_dict_id",

		NULL

	};

	int level = 3;

	ZstdCompressionDict* dict = NULL;

	CompressionParametersObject* params = NULL;

	PyObject* writeChecksum = NULL;

	PyObject* writeContentSize = NULL;

	PyObject* writeDictID = NULL;

		kwlist,	&level, &ZstdCompressionDictType, &dict,

		&CompressionParametersType, &params,

		return -1;

	}

	if (level < 1) {

		PyErr_SetString(PyExc_ValueError, "level must be greater than 0");

		return -1;

	}

	if (level > ZSTD_maxCLevel()) {

		PyErr_Format(PyExc_ValueError, "level must be less than %d",

			ZSTD_maxCLevel() + 1);

		return -1;

	}

	/* We create a ZSTD_CCtx for reuse among multiple operations to reduce the

	   overhead of each compression operation. */

	}

	self->compressionLevel = level;

	if (dict) {

		self->dict = dict;

		Py_INCREF(dict);

	}

	if (params) {

		self->cparams = params;

		Py_INCREF(params);

	}

	memset(&self->fparams, 0, sizeof(self->fparams));

	if (writeChecksum && PyObject_IsTrue(writeChecksum)) {

		self->fparams.checksumFlag = 1;

	}

	if (writeContentSize && PyObject_IsTrue(writeContentSize)) {

		self->fparams.contentSizeFlag = 1;

	}

	if (writeDictID && PyObject_Not(writeDictID)) {

		self->fparams.noDictIDFlag = 1;

	}

	return 0;

}

static void ZstdCompressor_dealloc(ZstdCompressor* self) {

	Py_XDECREF(self->cparams);

	Py_XDECREF(self->dict);

	if (self->cdict) {

		ZSTD_freeCDict(self->cdict);

		self->cdict = NULL;

	}

	if (self->cctx) {

		ZSTD_freeCCtx(self->cctx);

		self->cctx = NULL;

	}

	PyObject_Del(self);

}

PyDoc_STRVAR(ZstdCompressor_copy_stream__doc__,

"copy_stream(ifh, ofh[, size=0, read_size=default, write_size=default])\n"

"compress data between streams\n"

"\n"

"Data will be read from ``ifh``, compressed, and written to ``ofh``.\n"

"``ifh`` must have a ``read(size)`` method. ``ofh`` must have a ``write(data)``\n"

"method.\n"

"\n"

"An optional ``size`` argument specifies the size of the source stream.\n"

"If defined, compression parameters will be tuned based on the size.\n"

"\n"

"Optional arguments ``read_size`` and ``write_size`` define the chunk sizes\n"

"of ``read()`` and ``write()`` operations, respectively. By default, they use\n"

"the default compression stream input and output sizes, respectively.\n"

);

static PyObject* ZstdCompressor_copy_stream(ZstdCompressor* self, PyObject* args, PyObject* kwargs) {

	static char* kwlist[] = {

		"ifh",

		"ofh",

		"size",

		"read_size",

		"write_size",

		NULL

	};

	PyObject* source;

	PyObject* dest;

	Py_ssize_t sourceSize = 0;

	size_t inSize = ZSTD_CStreamInSize();

	size_t outSize = ZSTD_CStreamOutSize();

	ZSTD_inBuffer input;

	ZSTD_outBuffer output;

	Py_ssize_t totalRead = 0;

	Py_ssize_t totalWrite = 0;

	char* readBuffer;

	Py_ssize_t readSize;

	PyObject* readResult;

	PyObject* res = NULL;

	size_t zresult;

	PyObject* writeResult;

	PyObject* totalReadPy;

	PyObject* totalWritePy;

	if (!PyArg_ParseTupleAndKeywords(args, kwargs, "OO|nkk:copy_stream", kwlist,

		&source, &dest, &sourceSize, &inSize, &outSize)) {

		return NULL;

	}

	if (!PyObject_HasAttrString(source, "read")) {

		PyErr_SetString(PyExc_ValueError, "first argument must have a read() method");

		return NULL;

	}

	if (!PyObject_HasAttrString(dest, "write")) {

		PyErr_SetString(PyExc_ValueError, "second argument must have a write() method");

		return NULL;

	}

	/* Prevent free on uninitialized memory in finally. */

	output.dst = NULL;

	}

	output.dst = PyMem_Malloc(outSize);

	if (!output.dst) {

		PyErr_NoMemory();

		res = NULL;

		goto finally;

	}

	output.size = outSize;

	output.pos = 0;

	while (1) {

		/* Try to read from source stream. */

		readResult = PyObject_CallMethod(source, "read", "n", inSize);

		if (!readResult) {

			PyErr_SetString(ZstdError, "could not read() from source");

			goto finally;

		}

		PyBytes_AsStringAndSize(readResult, &readBuffer, &readSize);

		/* If no data was read, we're at EOF. */

		if (0 == readSize) {

			break;

		}

		totalRead += readSize;

		/* Send data to compressor */

		input.src = readBuffer;

		input.size = readSize;

		input.pos = 0;

		while (input.pos < input.size) {

			Py_BEGIN_ALLOW_THREADS

			Py_END_ALLOW_THREADS

			if (ZSTD_isError(zresult)) {

				res = NULL;

				PyErr_Format(ZstdError, "zstd compress error: %s", ZSTD_getErrorName(zresult));

				goto finally;

			}

			if (output.pos) {

#if PY_MAJOR_VERSION >= 3

				writeResult = PyObject_CallMethod(dest, "write", "y#",

#else

				writeResult = PyObject_CallMethod(dest, "write", "s#",

#endif

					output.dst, output.pos);

				Py_XDECREF(writeResult);

				totalWrite += output.pos;

				output.pos = 0;