hook: add a 'hashook' function to test for hook existence
Preparing the data for some hooks can be expensive. Add a function to check if
a hook exists so we can skip useless preparation if no hook is configured.
/**
* 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(ZstdCompresssionWriter__doc__,
"""A context manager used for writing compressed output to a writer.\n"
);
static void ZstdCompressionWriter_dealloc(ZstdCompressionWriter* self) {
Py_XDECREF(self->compressor);
Py_XDECREF(self->writer);
PyObject_Del(self);
}
static PyObject* ZstdCompressionWriter_enter(ZstdCompressionWriter* self) {
if (self->entered) {
PyErr_SetString(ZstdError, "cannot __enter__ multiple times");
return NULL;
}
if (self->compressor->mtcctx) {
if (init_mtcstream(self->compressor, self->sourceSize)) {
return NULL;
}
}
else {
if (0 != init_cstream(self->compressor, self->sourceSize)) {
return NULL;
}
}
self->entered = 1;
Py_INCREF(self);
return (PyObject*)self;
}
static PyObject* ZstdCompressionWriter_exit(ZstdCompressionWriter* self, PyObject* args) {
PyObject* exc_type;
PyObject* exc_value;
PyObject* exc_tb;
size_t zresult;
ZSTD_outBuffer output;
PyObject* res;
if (!PyArg_ParseTuple(args, "OOO:__exit__", &exc_type, &exc_value, &exc_tb)) {
return NULL;
}
self->entered = 0;
if ((self->compressor->cstream || self->compressor->mtcctx) && exc_type == Py_None
&& exc_value == Py_None && exc_tb == Py_None) {
output.dst = PyMem_Malloc(self->outSize);
if (!output.dst) {
return PyErr_NoMemory();
}
output.size = self->outSize;
output.pos = 0;
while (1) {
if (self->compressor->mtcctx) {
zresult = ZSTDMT_endStream(self->compressor->mtcctx, &output);
}
else {
zresult = ZSTD_endStream(self->compressor->cstream, &output);
}
if (ZSTD_isError(zresult)) {
PyErr_Format(ZstdError, "error ending compression stream: %s",
ZSTD_getErrorName(zresult));
PyMem_Free(output.dst);
return NULL;
}
if (output.pos) {
#if PY_MAJOR_VERSION >= 3
res = PyObject_CallMethod(self->writer, "write", "y#",
#else
res = PyObject_CallMethod(self->writer, "write", "s#",
#endif
output.dst, output.pos);
Py_XDECREF(res);
}
if (!zresult) {
break;
}
output.pos = 0;
}
PyMem_Free(output.dst);
}
Py_RETURN_FALSE;
}
static PyObject* ZstdCompressionWriter_memory_size(ZstdCompressionWriter* self) {
if (!self->compressor->cstream) {
PyErr_SetString(ZstdError, "cannot determine size of an inactive compressor; "
"call when a context manager is active");
return NULL;
}
return PyLong_FromSize_t(ZSTD_sizeof_CStream(self->compressor->cstream));
}
static PyObject* ZstdCompressionWriter_write(ZstdCompressionWriter* self, PyObject* args) {
const char* source;
Py_ssize_t sourceSize;
size_t zresult;
ZSTD_inBuffer input;
ZSTD_outBuffer output;
PyObject* res;
Py_ssize_t totalWrite = 0;
#if PY_MAJOR_VERSION >= 3
if (!PyArg_ParseTuple(args, "y#:write", &source, &sourceSize)) {
#else
if (!PyArg_ParseTuple(args, "s#:write", &source, &sourceSize)) {
#endif
return NULL;
}
if (!self->entered) {
PyErr_SetString(ZstdError, "compress must be called from an active context manager");
return NULL;
}
output.dst = PyMem_Malloc(self->outSize);
if (!output.dst) {
return PyErr_NoMemory();
}
output.size = self->outSize;
output.pos = 0;
input.src = source;
input.size = sourceSize;
input.pos = 0;
while ((ssize_t)input.pos < sourceSize) {
Py_BEGIN_ALLOW_THREADS
if (self->compressor->mtcctx) {
zresult = ZSTDMT_compressStream(self->compressor->mtcctx,
&output, &input);
}
else {
zresult = ZSTD_compressStream(self->compressor->cstream, &output, &input);
}
Py_END_ALLOW_THREADS
if (ZSTD_isError(zresult)) {
PyMem_Free(output.dst);
PyErr_Format(ZstdError, "zstd compress error: %s", ZSTD_getErrorName(zresult));
return NULL;
}
/* Copy data from output buffer to writer. */
if (output.pos) {
#if PY_MAJOR_VERSION >= 3
res = PyObject_CallMethod(self->writer, "write", "y#",
#else
res = PyObject_CallMethod(self->writer, "write", "s#",
#endif
output.dst, output.pos);
Py_XDECREF(res);
totalWrite += output.pos;
}
output.pos = 0;
}
PyMem_Free(output.dst);
return PyLong_FromSsize_t(totalWrite);
}
static PyObject* ZstdCompressionWriter_flush(ZstdCompressionWriter* self, PyObject* args) {
size_t zresult;
ZSTD_outBuffer output;
PyObject* res;
Py_ssize_t totalWrite = 0;
if (!self->entered) {
PyErr_SetString(ZstdError, "flush must be called from an active context manager");
return NULL;
}
output.dst = PyMem_Malloc(self->outSize);
if (!output.dst) {
return PyErr_NoMemory();
}
output.size = self->outSize;
output.pos = 0;
while (1) {
Py_BEGIN_ALLOW_THREADS
if (self->compressor->mtcctx) {
zresult = ZSTDMT_flushStream(self->compressor->mtcctx, &output);
}
else {
zresult = ZSTD_flushStream(self->compressor->cstream, &output);
}
Py_END_ALLOW_THREADS
if (ZSTD_isError(zresult)) {
PyMem_Free(output.dst);
PyErr_Format(ZstdError, "zstd compress error: %s", ZSTD_getErrorName(zresult));
return NULL;
}
if (!output.pos) {
break;
}
/* Copy data from output buffer to writer. */
if (output.pos) {
#if PY_MAJOR_VERSION >= 3
res = PyObject_CallMethod(self->writer, "write", "y#",
#else
res = PyObject_CallMethod(self->writer, "write", "s#",
#endif
output.dst, output.pos);
Py_XDECREF(res);
totalWrite += output.pos;
}
output.pos = 0;
}
PyMem_Free(output.dst);
return PyLong_FromSsize_t(totalWrite);
}
static PyMethodDef ZstdCompressionWriter_methods[] = {
{ "__enter__", (PyCFunction)ZstdCompressionWriter_enter, METH_NOARGS,
PyDoc_STR("Enter a compression context.") },
{ "__exit__", (PyCFunction)ZstdCompressionWriter_exit, METH_VARARGS,
PyDoc_STR("Exit a compression context.") },
{ "memory_size", (PyCFunction)ZstdCompressionWriter_memory_size, METH_NOARGS,
PyDoc_STR("Obtain the memory size of the underlying compressor") },
{ "write", (PyCFunction)ZstdCompressionWriter_write, METH_VARARGS,
PyDoc_STR("Compress data") },
{ "flush", (PyCFunction)ZstdCompressionWriter_flush, METH_NOARGS,
PyDoc_STR("Flush data and finish a zstd frame") },
{ NULL, NULL }
};
PyTypeObject ZstdCompressionWriterType = {
PyVarObject_HEAD_INIT(NULL, 0)
"zstd.ZstdCompressionWriter", /* tp_name */
sizeof(ZstdCompressionWriter), /* tp_basicsize */
0, /* tp_itemsize */
(destructor)ZstdCompressionWriter_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 */
ZstdCompresssionWriter__doc__, /* tp_doc */
0, /* tp_traverse */
0, /* tp_clear */
0, /* tp_richcompare */
0, /* tp_weaklistoffset */
0, /* tp_iter */
0, /* tp_iternext */
ZstdCompressionWriter_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 compressionwriter_module_init(PyObject* mod) {
Py_TYPE(&ZstdCompressionWriterType) = &PyType_Type;
if (PyType_Ready(&ZstdCompressionWriterType) < 0) {
return;
}
}