diff -r 2e484bdea8c4 -r b86a448a2965 contrib/python-zstandard/c-ext/decompressor.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/contrib/python-zstandard/c-ext/decompressor.c	Thu Nov 10 22:15:58 2016 -0800
@@ -0,0 +1,669 @@
+/**
+* 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_DStream* DStream_from_ZstdDecompressor(ZstdDecompressor* decompressor) {
+	ZSTD_DStream* dstream;
+	void* dictData = NULL;
+	size_t dictSize = 0;
+	size_t zresult;
+
+	dstream = ZSTD_createDStream();
+	if (!dstream) {
+		PyErr_SetString(ZstdError, "could not create DStream");
+		return NULL;
+	}
+
+	if (decompressor->dict) {
+		dictData = decompressor->dict->dictData;
+		dictSize = decompressor->dict->dictSize;
+	}
+
+	if (dictData) {
+		zresult = ZSTD_initDStream_usingDict(dstream, dictData, dictSize);
+	}
+	else {
+		zresult = ZSTD_initDStream(dstream);
+	}
+
+	if (ZSTD_isError(zresult)) {
+		PyErr_Format(ZstdError, "could not initialize DStream: %s",
+			ZSTD_getErrorName(zresult));
+		return NULL;
+	}
+
+	return dstream;
+}
+
+PyDoc_STRVAR(Decompressor__doc__,
+"ZstdDecompressor(dict_data=None)\n"
+"\n"
+"Create an object used to perform Zstandard decompression.\n"
+"\n"
+"An instance can perform multiple decompression operations."
+);
+
+static int Decompressor_init(ZstdDecompressor* self, PyObject* args, PyObject* kwargs) {
+	static char* kwlist[] = {
+		"dict_data",
+		NULL
+	};
+
+	ZstdCompressionDict* dict = NULL;
+
+	self->refdctx = NULL;
+	self->dict = NULL;
+	self->ddict = NULL;
+
+	if (!PyArg_ParseTupleAndKeywords(args, kwargs, "|O!", kwlist,
+		&ZstdCompressionDictType, &dict)) {
+		return -1;
+	}
+
+	/* Instead of creating a ZSTD_DCtx for every decompression operation,
+	   we create an instance at object creation time and recycle it via
+	   ZSTD_copyDCTx() on each use. This means each use is a malloc+memcpy
+	   instead of a malloc+init. */
+	/* TODO lazily initialize the reference ZSTD_DCtx on first use since
+	   not instances of ZstdDecompressor will use a ZSTD_DCtx. */
+	self->refdctx = ZSTD_createDCtx();
+	if (!self->refdctx) {
+		PyErr_NoMemory();
+		goto except;
+	}
+
+	if (dict) {
+		self->dict = dict;
+		Py_INCREF(dict);
+	}
+
+	return 0;
+
+except:
+	if (self->refdctx) {
+		ZSTD_freeDCtx(self->refdctx);
+		self->refdctx = NULL;
+	}
+
+	return -1;
+}
+
+static void Decompressor_dealloc(ZstdDecompressor* self) {
+	if (self->refdctx) {
+		ZSTD_freeDCtx(self->refdctx);
+	}
+
+	Py_XDECREF(self->dict);
+
+	if (self->ddict) {
+		ZSTD_freeDDict(self->ddict);
+		self->ddict = NULL;
+	}
+
+	PyObject_Del(self);
+}
+
+PyDoc_STRVAR(Decompressor_copy_stream__doc__,
+	"copy_stream(ifh, ofh[, read_size=default, write_size=default]) -- decompress data between streams\n"
+	"\n"
+	"Compressed data will be read from ``ifh``, decompressed, and written to\n"
+	"``ofh``. ``ifh`` must have a ``read(size)`` method. ``ofh`` must have a\n"
+	"``write(data)`` method.\n"
+	"\n"
+	"The optional ``read_size`` and ``write_size`` arguments control the chunk\n"
+	"size of data that is ``read()`` and ``write()`` between streams. They default\n"
+	"to the default input and output sizes of zstd decompressor streams.\n"
+);
+
+static PyObject* Decompressor_copy_stream(ZstdDecompressor* self, PyObject* args, PyObject* kwargs) {
+	static char* kwlist[] = {
+		"ifh",
+		"ofh",
+		"read_size",
+		"write_size",
+		NULL
+	};
+
+	PyObject* source;
+	PyObject* dest;
+	size_t inSize = ZSTD_DStreamInSize();
+	size_t outSize = ZSTD_DStreamOutSize();
+	ZSTD_DStream* dstream;
+	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 = 0;
+	PyObject* writeResult;
+	PyObject* totalReadPy;
+	PyObject* totalWritePy;
+
+	if (!PyArg_ParseTupleAndKeywords(args, kwargs, "OO|kk", kwlist, &source,
+		&dest, &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;
+	}
+
+	dstream = DStream_from_ZstdDecompressor(self);
+	if (!dstream) {
+		res = NULL;
+		goto finally;
+	}
+
+	output.dst = PyMem_Malloc(outSize);
+	if (!output.dst) {
+		PyErr_NoMemory();
+		res = NULL;
+		goto finally;
+	}
+	output.size = outSize;
+	output.pos = 0;
+
+	/* Read source stream until EOF */
+	while (1) {
+		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 decompressor */
+		input.src = readBuffer;
+		input.size = readSize;
+		input.pos = 0;
+
+		while (input.pos < input.size) {
+			Py_BEGIN_ALLOW_THREADS
+			zresult = ZSTD_decompressStream(dstream, &output, &input);
+			Py_END_ALLOW_THREADS
+
+			if (ZSTD_isError(zresult)) {
+				PyErr_Format(ZstdError, "zstd decompressor error: %s",
+					ZSTD_getErrorName(zresult));
+				res = NULL;
+				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;
+			}
+		}
+	}
+
+	/* Source stream is exhausted. Finish up. */
+
+	ZSTD_freeDStream(dstream);
+	dstream = NULL;
+
+	totalReadPy = PyLong_FromSsize_t(totalRead);
+	totalWritePy = PyLong_FromSsize_t(totalWrite);
+	res = PyTuple_Pack(2, totalReadPy, totalWritePy);
+	Py_DecRef(totalReadPy);
+	Py_DecRef(totalWritePy);
+
+	finally:
+	if (output.dst) {
+		PyMem_Free(output.dst);
+	}
+
+	if (dstream) {
+		ZSTD_freeDStream(dstream);
+	}
+
+	return res;
+}
+
+PyDoc_STRVAR(Decompressor_decompress__doc__,
+"decompress(data[, max_output_size=None]) -- Decompress data in its entirety\n"
+"\n"
+"This method will decompress the entirety of the argument and return the\n"
+"result.\n"
+"\n"
+"The input bytes are expected to contain a full Zstandard frame (something\n"
+"compressed with ``ZstdCompressor.compress()`` or similar). If the input does\n"
+"not contain a full frame, an exception will be raised.\n"
+"\n"
+"If the frame header of the compressed data does not contain the content size\n"
+"``max_output_size`` must be specified or ``ZstdError`` will be raised. An\n"
+"allocation of size ``max_output_size`` will be performed and an attempt will\n"
+"be made to perform decompression into that buffer. If the buffer is too\n"
+"small or cannot be allocated, ``ZstdError`` will be raised. The buffer will\n"
+"be resized if it is too large.\n"
+"\n"
+"Uncompressed data could be much larger than compressed data. As a result,\n"
+"calling this function could result in a very large memory allocation being\n"
+"performed to hold the uncompressed data. Therefore it is **highly**\n"
+"recommended to use a streaming decompression method instead of this one.\n"
+);
+
+PyObject* Decompressor_decompress(ZstdDecompressor* self, PyObject* args, PyObject* kwargs) {
+	static char* kwlist[] = {
+		"data",
+		"max_output_size",
+		NULL
+	};
+
+	const char* source;
+	Py_ssize_t sourceSize;
+	Py_ssize_t maxOutputSize = 0;
+	unsigned long long decompressedSize;
+	size_t destCapacity;
+	PyObject* result = NULL;
+	ZSTD_DCtx* dctx = NULL;
+	void* dictData = NULL;
+	size_t dictSize = 0;
+	size_t zresult;
+
+#if PY_MAJOR_VERSION >= 3
+	if (!PyArg_ParseTupleAndKeywords(args, kwargs, "y#|n", kwlist,
+#else
+	if (!PyArg_ParseTupleAndKeywords(args, kwargs, "s#|n", kwlist,
+#endif
+		&source, &sourceSize, &maxOutputSize)) {
+		return NULL;
+	}
+
+	dctx = PyMem_Malloc(ZSTD_sizeof_DCtx(self->refdctx));
+	if (!dctx) {
+		PyErr_NoMemory();
+		return NULL;
+	}
+
+	ZSTD_copyDCtx(dctx, self->refdctx);
+
+	if (self->dict) {
+		dictData = self->dict->dictData;
+		dictSize = self->dict->dictSize;
+	}
+
+	if (dictData && !self->ddict) {
+		Py_BEGIN_ALLOW_THREADS
+		self->ddict = ZSTD_createDDict(dictData, dictSize);
+		Py_END_ALLOW_THREADS
+
+		if (!self->ddict) {
+			PyErr_SetString(ZstdError, "could not create decompression dict");
+			goto except;
+		}
+	}
+
+	decompressedSize = ZSTD_getDecompressedSize(source, sourceSize);
+	/* 0 returned if content size not in the zstd frame header */
+	if (0 == decompressedSize) {
+		if (0 == maxOutputSize) {
+			PyErr_SetString(ZstdError, "input data invalid or missing content size "
+				"in frame header");
+			goto except;
+		}
+		else {
+			result = PyBytes_FromStringAndSize(NULL, maxOutputSize);
+			destCapacity = maxOutputSize;
+		}
+	}
+	else {
+		result = PyBytes_FromStringAndSize(NULL, decompressedSize);
+		destCapacity = decompressedSize;
+	}
+
+	if (!result) {
+		goto except;
+	}
+
+	Py_BEGIN_ALLOW_THREADS
+	if (self->ddict) {
+		zresult = ZSTD_decompress_usingDDict(dctx, PyBytes_AsString(result), destCapacity,
+			source, sourceSize, self->ddict);
+	}
+	else {
+		zresult = ZSTD_decompressDCtx(dctx, PyBytes_AsString(result), destCapacity, source, sourceSize);
+	}
+	Py_END_ALLOW_THREADS
+
+	if (ZSTD_isError(zresult)) {
+		PyErr_Format(ZstdError, "decompression error: %s", ZSTD_getErrorName(zresult));
+		goto except;
+	}
+	else if (decompressedSize && zresult != decompressedSize) {
+		PyErr_Format(ZstdError, "decompression error: decompressed %zu bytes; expected %llu",
+			zresult, decompressedSize);
+		goto except;
+	}
+	else if (zresult < destCapacity) {
+		if (_PyBytes_Resize(&result, zresult)) {
+			goto except;
+		}
+	}
+
+	goto finally;
+
+except:
+	Py_DecRef(result);
+	result = NULL;
+
+finally:
+	if (dctx) {
+		PyMem_FREE(dctx);
+	}
+
+	return result;
+}
+
+PyDoc_STRVAR(Decompressor_decompressobj__doc__,
+"decompressobj()\n"
+"\n"
+"Incrementally feed data into a decompressor.\n"
+"\n"
+"The returned object exposes a ``decompress(data)`` method. This makes it\n"
+"compatible with ``zlib.decompressobj`` and ``bz2.BZ2Decompressor`` so that\n"
+"callers can swap in the zstd decompressor while using the same API.\n"
+);
+
+static ZstdDecompressionObj* Decompressor_decompressobj(ZstdDecompressor* self) {
+	ZstdDecompressionObj* result = PyObject_New(ZstdDecompressionObj, &ZstdDecompressionObjType);
+	if (!result) {
+		return NULL;
+	}
+
+	result->dstream = DStream_from_ZstdDecompressor(self);
+	if (!result->dstream) {
+		Py_DecRef((PyObject*)result);
+		return NULL;
+	}
+
+	result->decompressor = self;
+	Py_INCREF(result->decompressor);
+
+	result->finished = 0;
+
+	return result;
+}
+
+PyDoc_STRVAR(Decompressor_read_from__doc__,
+"read_from(reader[, read_size=default, write_size=default, skip_bytes=0])\n"
+"Read compressed data and return an iterator\n"
+"\n"
+"Returns an iterator of decompressed data chunks produced from reading from\n"
+"the ``reader``.\n"
+"\n"
+"Compressed data will be obtained from ``reader`` by calling the\n"
+"``read(size)`` method of it. The source data will be streamed into a\n"
+"decompressor. As decompressed data is available, it will be exposed to the\n"
+"returned iterator.\n"
+"\n"
+"Data is ``read()`` in chunks of size ``read_size`` and exposed to the\n"
+"iterator in chunks of size ``write_size``. The default values are the input\n"
+"and output sizes for a zstd streaming decompressor.\n"
+"\n"
+"There is also support for skipping the first ``skip_bytes`` of data from\n"
+"the source.\n"
+);
+
+static ZstdDecompressorIterator* Decompressor_read_from(ZstdDecompressor* self, PyObject* args, PyObject* kwargs) {
+	static char* kwlist[] = {
+		"reader",
+		"read_size",
+		"write_size",
+		"skip_bytes",
+		NULL
+	};
+
+	PyObject* reader;
+	size_t inSize = ZSTD_DStreamInSize();
+	size_t outSize = ZSTD_DStreamOutSize();
+	ZstdDecompressorIterator* result;
+	size_t skipBytes = 0;
+
+	if (!PyArg_ParseTupleAndKeywords(args, kwargs, "O|kkk", kwlist, &reader,
+		&inSize, &outSize, &skipBytes)) {
+		return NULL;
+	}
+
+	if (skipBytes >= inSize) {
+		PyErr_SetString(PyExc_ValueError,
+			"skip_bytes must be smaller than read_size");
+		return NULL;
+	}
+
+	result = PyObject_New(ZstdDecompressorIterator, &ZstdDecompressorIteratorType);
+	if (!result) {
+		return NULL;
+	}
+
+	result->decompressor = NULL;
+	result->reader = NULL;
+	result->buffer = NULL;
+	result->dstream = NULL;
+	result->input.src = NULL;
+	result->output.dst = NULL;
+
+	if (PyObject_HasAttrString(reader, "read")) {
+		result->reader = reader;
+		Py_INCREF(result->reader);
+	}
+	else if (1 == PyObject_CheckBuffer(reader)) {
+		/* Object claims it is a buffer. Try to get a handle to it. */
+		result->buffer = PyMem_Malloc(sizeof(Py_buffer));
+		if (!result->buffer) {
+			goto except;
+		}
+
+		memset(result->buffer, 0, sizeof(Py_buffer));
+
+		if (0 != PyObject_GetBuffer(reader, result->buffer, PyBUF_CONTIG_RO)) {
+			goto except;
+		}
+
+		result->bufferOffset = 0;
+	}
+	else {
+		PyErr_SetString(PyExc_ValueError,
+			"must pass an object with a read() method or conforms to buffer protocol");
+		goto except;
+	}
+
+	result->decompressor = self;
+	Py_INCREF(result->decompressor);
+
+	result->inSize = inSize;
+	result->outSize = outSize;
+	result->skipBytes = skipBytes;
+
+	result->dstream = DStream_from_ZstdDecompressor(self);
+	if (!result->dstream) {
+		goto except;
+	}
+
+	result->input.src = PyMem_Malloc(inSize);
+	if (!result->input.src) {
+		PyErr_NoMemory();
+		goto except;
+	}
+	result->input.size = 0;
+	result->input.pos = 0;
+
+	result->output.dst = NULL;
+	result->output.size = 0;
+	result->output.pos = 0;
+
+	result->readCount = 0;
+	result->finishedInput = 0;
+	result->finishedOutput = 0;
+
+	goto finally;
+
+except:
+	if (result->reader) {
+		Py_DECREF(result->reader);
+		result->reader = NULL;
+	}
+
+	if (result->buffer) {
+		PyBuffer_Release(result->buffer);
+		Py_DECREF(result->buffer);
+		result->buffer = NULL;
+	}
+
+	Py_DECREF(result);
+	result = NULL;
+
+finally:
+
+	return result;
+}
+
+PyDoc_STRVAR(Decompressor_write_to__doc__,
+"Create a context manager to write decompressed data to an object.\n"
+"\n"
+"The passed object must have a ``write()`` method.\n"
+"\n"
+"The caller feeds intput data to the object by calling ``write(data)``.\n"
+"Decompressed data is written to the argument given as it is decompressed.\n"
+"\n"
+"An optional ``write_size`` argument defines the size of chunks to\n"
+"``write()`` to the writer. It defaults to the default output size for a zstd\n"
+"streaming decompressor.\n"
+);
+
+static ZstdDecompressionWriter* Decompressor_write_to(ZstdDecompressor* self, PyObject* args, PyObject* kwargs) {
+	static char* kwlist[] = {
+		"writer",
+		"write_size",
+		NULL
+	};
+
+	PyObject* writer;
+	size_t outSize = ZSTD_DStreamOutSize();
+	ZstdDecompressionWriter* result;
+
+	if (!PyArg_ParseTupleAndKeywords(args, kwargs, "O|k", kwlist, &writer, &outSize)) {
+		return NULL;
+	}
+
+	if (!PyObject_HasAttrString(writer, "write")) {
+		PyErr_SetString(PyExc_ValueError, "must pass an object with a write() method");
+		return NULL;
+	}
+
+	result = PyObject_New(ZstdDecompressionWriter, &ZstdDecompressionWriterType);
+	if (!result) {
+		return NULL;
+	}
+
+	result->decompressor = self;
+	Py_INCREF(result->decompressor);
+
+	result->writer = writer;
+	Py_INCREF(result->writer);
+
+	result->outSize = outSize;
+
+	result->entered = 0;
+	result->dstream = NULL;
+
+	return result;
+}
+
+static PyMethodDef Decompressor_methods[] = {
+	{ "copy_stream", (PyCFunction)Decompressor_copy_stream, METH_VARARGS | METH_KEYWORDS,
+	Decompressor_copy_stream__doc__ },
+	{ "decompress", (PyCFunction)Decompressor_decompress, METH_VARARGS | METH_KEYWORDS,
+	Decompressor_decompress__doc__ },
+	{ "decompressobj", (PyCFunction)Decompressor_decompressobj, METH_NOARGS,
+	Decompressor_decompressobj__doc__ },
+	{ "read_from", (PyCFunction)Decompressor_read_from, METH_VARARGS | METH_KEYWORDS,
+	Decompressor_read_from__doc__ },
+	{ "write_to", (PyCFunction)Decompressor_write_to, METH_VARARGS | METH_KEYWORDS,
+	Decompressor_write_to__doc__ },
+	{ NULL, NULL }
+};
+
+PyTypeObject ZstdDecompressorType = {
+	PyVarObject_HEAD_INIT(NULL, 0)
+	"zstd.ZstdDecompressor",        /* tp_name */
+	sizeof(ZstdDecompressor),       /* tp_basicsize */
+	0,                              /* tp_itemsize */
+	(destructor)Decompressor_dealloc, /* tp_dealloc */
+	0,                              /* tp_print */
+	0,                              /* tp_getattr */
+	0,                              /* tp_setattr */
+	0,                              /* tp_compare */
+	0,                              /* tp_repr */
+	0,                              /* tp_as_number */
+	0,                              /* 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 */
+	Decompressor__doc__,            /* tp_doc */
+	0,                              /* tp_traverse */
+	0,                              /* tp_clear */
+	0,                              /* tp_richcompare */
+	0,                              /* tp_weaklistoffset */
+	0,                              /* tp_iter */
+	0,                              /* tp_iternext */
+	Decompressor_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)Decompressor_init,    /* tp_init */
+	0,                              /* tp_alloc */
+	PyType_GenericNew,              /* tp_new */
+};
+
+void decompressor_module_init(PyObject* mod) {
+	Py_TYPE(&ZstdDecompressorType) = &PyType_Type;
+	if (PyType_Ready(&ZstdDecompressorType) < 0) {
+		return;
+	}
+
+	Py_INCREF((PyObject*)&ZstdDecompressorType);
+	PyModule_AddObject(mod, "ZstdDecompressor",
+		(PyObject*)&ZstdDecompressorType);
+}