view contrib/python-zstandard/c-ext/compressionchunker.c @ 51929:93d872a06132 default tip

typing: add type annotations to the dirstate classes

The basic procedure here was to use `merge-pyi` to merge the `git/dirstate.pyi`
file in (after renaming the interface class to match), cleaning up the import
statement mess, and then repeating the procedure for `mercurial/dirstate.pyi`.
Surprisingly, git's dirstate had more hints inferred in its *.pyi file.

After that, it was a manual examination of each method in the interface, and how
they were implemented in the core and git classes to verify what was inferred by
pytype, and fill in the missing gaps.  Since this involved jumping around
between three different files, I applied the same type info to all three at the
same time.  Complex types I rolled up into type aliases in the interface module,
and used that as needed.  That way if it changes, there's one place to edit.

There are some hints still missing, and some documentation that doesn't match
the signatures.  They should all be marked with TODOs.  There are also a bunch
of methods on the core class that aren't on the Protocol class that seem like
maybe they should be (like `set_tracked()`).  There are even more methods
missing from the git class.  But that's a project for another time.

/**
* Copyright (c) 2018-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;

PyDoc_STRVAR(ZstdCompressionChunkerIterator__doc__,
	"Iterator of output chunks from ZstdCompressionChunker.\n"
);

static void ZstdCompressionChunkerIterator_dealloc(ZstdCompressionChunkerIterator* self) {
	Py_XDECREF(self->chunker);

	PyObject_Del(self);
}

static PyObject* ZstdCompressionChunkerIterator_iter(PyObject* self) {
	Py_INCREF(self);
	return self;
}

static PyObject* ZstdCompressionChunkerIterator_iternext(ZstdCompressionChunkerIterator* self) {
	size_t zresult;
	PyObject* chunk;
	ZstdCompressionChunker* chunker = self->chunker;
	ZSTD_EndDirective zFlushMode;

	if (self->mode != compressionchunker_mode_normal && chunker->input.pos != chunker->input.size) {
		PyErr_SetString(ZstdError, "input should have been fully consumed before calling flush() or finish()");
		return NULL;
	}

	if (chunker->finished) {
		return NULL;
	}

	/* If we have data left in the input, consume it. */
	while (chunker->input.pos < chunker->input.size) {
		Py_BEGIN_ALLOW_THREADS
		zresult = ZSTD_compressStream2(chunker->compressor->cctx, &chunker->output,
			&chunker->input, ZSTD_e_continue);
		Py_END_ALLOW_THREADS

		/* Input is fully consumed. */
		if (chunker->input.pos == chunker->input.size) {
			chunker->input.src = NULL;
			chunker->input.pos = 0;
			chunker->input.size = 0;
			PyBuffer_Release(&chunker->inBuffer);
		}

		if (ZSTD_isError(zresult)) {
			PyErr_Format(ZstdError, "zstd compress error: %s", ZSTD_getErrorName(zresult));
			return NULL;
		}

		/* If it produced a full output chunk, emit it. */
		if (chunker->output.pos == chunker->output.size) {
			chunk = PyBytes_FromStringAndSize(chunker->output.dst, chunker->output.pos);
			if (!chunk) {
				return NULL;
			}

			chunker->output.pos = 0;

			return chunk;
		}

		/* Else continue to compress available input data. */
	}

	/* We also need this here for the special case of an empty input buffer. */
	if (chunker->input.pos == chunker->input.size) {
		chunker->input.src = NULL;
		chunker->input.pos = 0;
		chunker->input.size = 0;
		PyBuffer_Release(&chunker->inBuffer);
	}

	/* No more input data. A partial chunk may be in chunker->output.
	 * If we're in normal compression mode, we're done. Otherwise if we're in
	 * flush or finish mode, we need to emit what data remains.
	 */
	if (self->mode == compressionchunker_mode_normal) {
		/* We don't need to set StopIteration. */
		return NULL;
	}

	if (self->mode == compressionchunker_mode_flush) {
		zFlushMode = ZSTD_e_flush;
	}
	else if (self->mode == compressionchunker_mode_finish) {
		zFlushMode = ZSTD_e_end;
	}
	else {
		PyErr_SetString(ZstdError, "unhandled compression mode; this should never happen");
		return NULL;
	}

	Py_BEGIN_ALLOW_THREADS
	zresult = ZSTD_compressStream2(chunker->compressor->cctx, &chunker->output,
		&chunker->input, zFlushMode);
	Py_END_ALLOW_THREADS

	if (ZSTD_isError(zresult)) {
		PyErr_Format(ZstdError, "zstd compress error: %s",
			ZSTD_getErrorName(zresult));
		return NULL;
	}

	if (!zresult && chunker->output.pos == 0) {
		return NULL;
	}

	chunk = PyBytes_FromStringAndSize(chunker->output.dst, chunker->output.pos);
	if (!chunk) {
		return NULL;
	}

	chunker->output.pos = 0;

	if (!zresult && self->mode == compressionchunker_mode_finish) {
		chunker->finished = 1;
	}

	return chunk;
}

PyTypeObject ZstdCompressionChunkerIteratorType = {
	PyVarObject_HEAD_INIT(NULL, 0)
	"zstd.ZstdCompressionChunkerIterator", /* tp_name */
	sizeof(ZstdCompressionChunkerIterator), /* tp_basicsize */
	0,                               /* tp_itemsize */
	(destructor)ZstdCompressionChunkerIterator_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 */
	ZstdCompressionChunkerIterator__doc__, /* tp_doc */
	0,                               /* tp_traverse */
	0,                               /* tp_clear */
	0,                               /* tp_richcompare */
	0,                               /* tp_weaklistoffset */
	ZstdCompressionChunkerIterator_iter, /* tp_iter */
	(iternextfunc)ZstdCompressionChunkerIterator_iternext, /* tp_iternext */
	0,                               /* 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 */
	0,                               /* tp_init */
	0,                               /* tp_alloc */
	PyType_GenericNew,              /* tp_new */
};

PyDoc_STRVAR(ZstdCompressionChunker__doc__,
	"Compress chunks iteratively into exact chunk sizes.\n"
);

static void ZstdCompressionChunker_dealloc(ZstdCompressionChunker* self) {
	PyBuffer_Release(&self->inBuffer);
	self->input.src = NULL;

	PyMem_Free(self->output.dst);
	self->output.dst = NULL;

	Py_XDECREF(self->compressor);

	PyObject_Del(self);
}

static ZstdCompressionChunkerIterator* ZstdCompressionChunker_compress(ZstdCompressionChunker* self, PyObject* args, PyObject* kwargs) {
	static char* kwlist[] = {
		"data",
		NULL
	};

	ZstdCompressionChunkerIterator* result;

	if (self->finished) {
		PyErr_SetString(ZstdError, "cannot call compress() after compression finished");
		return NULL;
	}

	if (self->inBuffer.obj) {
		PyErr_SetString(ZstdError,
			"cannot perform operation before consuming output from previous operation");
		return NULL;
	}

#if PY_MAJOR_VERSION >= 3
	if (!PyArg_ParseTupleAndKeywords(args, kwargs, "y*:compress",
#else
	if (!PyArg_ParseTupleAndKeywords(args, kwargs, "s*:compress",
#endif
		kwlist, &self->inBuffer)) {
		return NULL;
	}

	if (!PyBuffer_IsContiguous(&self->inBuffer, 'C') || self->inBuffer.ndim > 1) {
		PyErr_SetString(PyExc_ValueError,
			"data buffer should be contiguous and have at most one dimension");
		PyBuffer_Release(&self->inBuffer);
		return NULL;
	}

	result = (ZstdCompressionChunkerIterator*)PyObject_CallObject((PyObject*)&ZstdCompressionChunkerIteratorType, NULL);
	if (!result) {
		PyBuffer_Release(&self->inBuffer);
		return NULL;
	}

	self->input.src = self->inBuffer.buf;
	self->input.size = self->inBuffer.len;
	self->input.pos = 0;

	result->chunker = self;
	Py_INCREF(result->chunker);

	result->mode = compressionchunker_mode_normal;

	return result;
}

static ZstdCompressionChunkerIterator* ZstdCompressionChunker_finish(ZstdCompressionChunker* self) {
	ZstdCompressionChunkerIterator* result;

	if (self->finished) {
		PyErr_SetString(ZstdError, "cannot call finish() after compression finished");
		return NULL;
	}

	if (self->inBuffer.obj) {
		PyErr_SetString(ZstdError,
			"cannot call finish() before consuming output from previous operation");
		return NULL;
	}

	result = (ZstdCompressionChunkerIterator*)PyObject_CallObject((PyObject*)&ZstdCompressionChunkerIteratorType, NULL);
	if (!result) {
		return NULL;
	}

	result->chunker = self;
	Py_INCREF(result->chunker);

	result->mode = compressionchunker_mode_finish;

	return result;
}

static ZstdCompressionChunkerIterator* ZstdCompressionChunker_flush(ZstdCompressionChunker* self, PyObject* args, PyObject* kwargs) {
	ZstdCompressionChunkerIterator* result;

	if (self->finished) {
		PyErr_SetString(ZstdError, "cannot call flush() after compression finished");
		return NULL;
	}

	if (self->inBuffer.obj) {
		PyErr_SetString(ZstdError,
			"cannot call flush() before consuming output from previous operation");
		return NULL;
	}

	result = (ZstdCompressionChunkerIterator*)PyObject_CallObject((PyObject*)&ZstdCompressionChunkerIteratorType, NULL);
	if (!result) {
		return NULL;
	}

	result->chunker = self;
	Py_INCREF(result->chunker);

	result->mode = compressionchunker_mode_flush;

	return result;
}

static PyMethodDef ZstdCompressionChunker_methods[] = {
	{ "compress", (PyCFunction)ZstdCompressionChunker_compress, METH_VARARGS | METH_KEYWORDS,
	PyDoc_STR("compress data") },
	{ "finish", (PyCFunction)ZstdCompressionChunker_finish, METH_NOARGS,
	PyDoc_STR("finish compression operation") },
	{ "flush", (PyCFunction)ZstdCompressionChunker_flush, METH_VARARGS | METH_KEYWORDS,
	PyDoc_STR("finish compression operation") },
	{ NULL, NULL }
};

PyTypeObject ZstdCompressionChunkerType = {
	PyVarObject_HEAD_INIT(NULL, 0)
	"zstd.ZstdCompressionChunkerType",  /* tp_name */
	sizeof(ZstdCompressionChunker),     /* tp_basicsize */
	0,                                  /* tp_itemsize */
	(destructor)ZstdCompressionChunker_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 */
	ZstdCompressionChunker__doc__,      /* tp_doc */
	0,                                  /* tp_traverse */
	0,                                  /* tp_clear */
	0,                                  /* tp_richcompare */
	0,                                  /* tp_weaklistoffset */
	0,                                  /* tp_iter */
	0,                                  /* tp_iternext */
	ZstdCompressionChunker_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 */
	0,                                  /* tp_init */
	0,                                  /* tp_alloc */
	PyType_GenericNew,                  /* tp_new */
};

void compressionchunker_module_init(PyObject* module) {
	Py_SET_TYPE(&ZstdCompressionChunkerIteratorType, &PyType_Type);
	if (PyType_Ready(&ZstdCompressionChunkerIteratorType) < 0) {
		return;
	}

	Py_SET_TYPE(&ZstdCompressionChunkerType, &PyType_Type);
	if (PyType_Ready(&ZstdCompressionChunkerType) < 0) {
		return;
	}
}