##// END OF EJS Templates
revset: lookup descendents for negative arguments to ancestor operator...
revset: lookup descendents for negative arguments to ancestor operator Negative offsets to the `~` operator now search for descendents. The search is aborted when a node has more than one child as we do not have a definition for 'nth child'. Optionally we can introduce such a notion and take the nth child ordered by rev number. The current revset language does provides a short operator for ancestor lookup but not for descendents. This gives user a simple revset to move to the previous changeset, e.g. `hg up '.~1'` but not to the 'next' changeset. With this change userse can now use `.~-1` as a shortcut to move to the next changeset. This fits better into allowing users to specify revisions via revsets and avoiding the need for special `hg next` and `hg prev` operations. The alternative to negative offsets is adding a new operator. We do not have many operators in ascii left that do not require bash escaping (',', '_', and '/' come to mind). If we decide that we should add a more convenient short operator such as ('/', e.g. './1') we can later add it and allow ascendents lookup via negative numbers.

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frameparams.c
132 lines | 4.1 KiB | text/x-c | CLexer
/**
* Copyright (c) 2017-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(FrameParameters__doc__,
"FrameParameters: information about a zstd frame");
FrameParametersObject* get_frame_parameters(PyObject* self, PyObject* args) {
const char* source;
Py_ssize_t sourceSize;
ZSTD_frameParams params;
FrameParametersObject* result = NULL;
size_t zresult;
#if PY_MAJOR_VERSION >= 3
if (!PyArg_ParseTuple(args, "y#:get_frame_parameters",
#else
if (!PyArg_ParseTuple(args, "s#:get_frame_parameters",
#endif
&source, &sourceSize)) {
return NULL;
}
/* Needed for Python 2 to reject unicode */
if (!PyBytes_Check(PyTuple_GET_ITEM(args, 0))) {
PyErr_SetString(PyExc_TypeError, "argument must be bytes");
return NULL;
}
zresult = ZSTD_getFrameParams(&params, (void*)source, sourceSize);
if (ZSTD_isError(zresult)) {
PyErr_Format(ZstdError, "cannot get frame parameters: %s", ZSTD_getErrorName(zresult));
return NULL;
}
if (zresult) {
PyErr_Format(ZstdError, "not enough data for frame parameters; need %zu bytes", zresult);
return NULL;
}
result = PyObject_New(FrameParametersObject, &FrameParametersType);
if (!result) {
return NULL;
}
result->frameContentSize = params.frameContentSize;
result->windowSize = params.windowSize;
result->dictID = params.dictID;
result->checksumFlag = params.checksumFlag ? 1 : 0;
return result;
}
static void FrameParameters_dealloc(PyObject* self) {
PyObject_Del(self);
}
static PyMemberDef FrameParameters_members[] = {
{ "content_size", T_ULONGLONG,
offsetof(FrameParametersObject, frameContentSize), READONLY,
"frame content size" },
{ "window_size", T_UINT,
offsetof(FrameParametersObject, windowSize), READONLY,
"window size" },
{ "dict_id", T_UINT,
offsetof(FrameParametersObject, dictID), READONLY,
"dictionary ID" },
{ "has_checksum", T_BOOL,
offsetof(FrameParametersObject, checksumFlag), READONLY,
"checksum flag" },
{ NULL }
};
PyTypeObject FrameParametersType = {
PyVarObject_HEAD_INIT(NULL, 0)
"FrameParameters", /* tp_name */
sizeof(FrameParametersObject), /* tp_basicsize */
0, /* tp_itemsize */
(destructor)FrameParameters_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, /* tp_flags */
FrameParameters__doc__, /* tp_doc */
0, /* tp_traverse */
0, /* tp_clear */
0, /* tp_richcompare */
0, /* tp_weaklistoffset */
0, /* tp_iter */
0, /* tp_iternext */
0, /* tp_methods */
FrameParameters_members, /* 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 */
0, /* tp_new */
};
void frameparams_module_init(PyObject* mod) {
Py_TYPE(&FrameParametersType) = &PyType_Type;
if (PyType_Ready(&FrameParametersType) < 0) {
return;
}
Py_INCREF(&FrameParametersType);
PyModule_AddObject(mod, "FrameParameters", (PyObject*)&FrameParametersType);
}