view contrib/python-zstandard/c-ext/compressobj.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) 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;

PyDoc_STRVAR(ZstdCompressionObj__doc__,
"Perform compression using a standard library compatible API.\n"
);

static void ZstdCompressionObj_dealloc(ZstdCompressionObj* self) {
	PyMem_Free(self->output.dst);
	self->output.dst = NULL;

	Py_XDECREF(self->compressor);

	PyObject_Del(self);
}

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

	Py_buffer source;
	ZSTD_inBuffer input;
	size_t zresult;
	PyObject* result = NULL;
	Py_ssize_t resultSize = 0;

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

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

	if (!PyBuffer_IsContiguous(&source, 'C') || source.ndim > 1) {
		PyErr_SetString(PyExc_ValueError,
			"data buffer should be contiguous and have at most one dimension");
		goto finally;
	}

	input.src = source.buf;
	input.size = source.len;
	input.pos = 0;

	while (input.pos < (size_t)source.len) {
		Py_BEGIN_ALLOW_THREADS
			zresult = ZSTD_compressStream2(self->compressor->cctx, &self->output,
				&input, ZSTD_e_continue);
		Py_END_ALLOW_THREADS

		if (ZSTD_isError(zresult)) {
			PyErr_Format(ZstdError, "zstd compress error: %s", ZSTD_getErrorName(zresult));
			Py_CLEAR(result);
			goto finally;
		}

		if (self->output.pos) {
			if (result) {
				resultSize = PyBytes_GET_SIZE(result);

				if (safe_pybytes_resize(&result, resultSize + self->output.pos)) {
					Py_CLEAR(result);
					goto finally;
				}

				memcpy(PyBytes_AS_STRING(result) + resultSize,
					self->output.dst, self->output.pos);
			}
			else {
				result = PyBytes_FromStringAndSize(self->output.dst, self->output.pos);
				if (!result) {
					goto finally;
				}
			}

			self->output.pos = 0;
		}
	}

	if (NULL == result) {
		result = PyBytes_FromString("");
	}

finally:
	PyBuffer_Release(&source);

	return result;
}

static PyObject* ZstdCompressionObj_flush(ZstdCompressionObj* self, PyObject* args, PyObject* kwargs) {
	static char* kwlist[] = {
		"flush_mode",
		NULL
	};

	int flushMode = compressorobj_flush_finish;
	size_t zresult;
	PyObject* result = NULL;
	Py_ssize_t resultSize = 0;
	ZSTD_inBuffer input;
	ZSTD_EndDirective zFlushMode;

	if (!PyArg_ParseTupleAndKeywords(args, kwargs, "|i:flush", kwlist, &flushMode)) {
		return NULL;
	}

	if (flushMode != compressorobj_flush_finish && flushMode != compressorobj_flush_block) {
		PyErr_SetString(PyExc_ValueError, "flush mode not recognized");
		return NULL;
	}

	if (self->finished) {
		PyErr_SetString(ZstdError, "compressor object already finished");
		return NULL;
	}

	switch (flushMode) {
		case compressorobj_flush_block:
			zFlushMode = ZSTD_e_flush;
			break;

		case compressorobj_flush_finish:
			zFlushMode = ZSTD_e_end;
			self->finished = 1;
			break;

		default:
			PyErr_SetString(ZstdError, "unhandled flush mode");
			return NULL;
	}

	assert(self->output.pos == 0);

	input.src = NULL;
	input.size = 0;
	input.pos = 0;

	while (1) {
		Py_BEGIN_ALLOW_THREADS
		zresult = ZSTD_compressStream2(self->compressor->cctx, &self->output,
			&input, zFlushMode);
		Py_END_ALLOW_THREADS

		if (ZSTD_isError(zresult)) {
			PyErr_Format(ZstdError, "error ending compression stream: %s",
				ZSTD_getErrorName(zresult));
			return NULL;
		}

		if (self->output.pos) {
			if (result) {
				resultSize = PyBytes_GET_SIZE(result);

				if (safe_pybytes_resize(&result, resultSize + self->output.pos)) {
					Py_XDECREF(result);
					return NULL;
				}

				memcpy(PyBytes_AS_STRING(result) + resultSize,
					self->output.dst, self->output.pos);
			}
			else {
				result = PyBytes_FromStringAndSize(self->output.dst, self->output.pos);
				if (!result) {
					return NULL;
				}
			}

			self->output.pos = 0;
		}

		if (!zresult) {
			break;
		}
	}

	if (result) {
		return result;
	}
	else {
		return PyBytes_FromString("");
	}
}

static PyMethodDef ZstdCompressionObj_methods[] = {
	{ "compress", (PyCFunction)ZstdCompressionObj_compress, METH_VARARGS | METH_KEYWORDS,
	PyDoc_STR("compress data") },
	{ "flush", (PyCFunction)ZstdCompressionObj_flush, METH_VARARGS | METH_KEYWORDS,
	PyDoc_STR("finish compression operation") },
	{ NULL, NULL }
};

PyTypeObject ZstdCompressionObjType = {
	PyVarObject_HEAD_INIT(NULL, 0)
	"zstd.ZstdCompressionObj",      /* tp_name */
	sizeof(ZstdCompressionObj),     /* tp_basicsize */
	0,                              /* tp_itemsize */
	(destructor)ZstdCompressionObj_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 */
	ZstdCompressionObj__doc__,      /* tp_doc */
	0,                              /* tp_traverse */
	0,                              /* tp_clear */
	0,                              /* tp_richcompare */
	0,                              /* tp_weaklistoffset */
	0,                              /* tp_iter */
	0,                              /* tp_iternext */
	ZstdCompressionObj_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 compressobj_module_init(PyObject* module) {
	Py_SET_TYPE(&ZstdCompressionObjType, &PyType_Type);
	if (PyType_Ready(&ZstdCompressionObjType) < 0) {
		return;
	}
}