Mercurial > hg
view mercurial/dirs.c @ 30761:7283719e2bfd
util: declare wire protocol support of compression engines
This patch implements a new compression engine API allowing
compression engines to declare support for the wire protocol.
Support is declared by returning a compression format string
identifier that will be added to payloads to signal the compression
type of data that follows and default integer priorities of the
engine.
Accessor methods have been added to the compression engine manager
class to facilitate use.
Note that the "none" and "bz2" engines declare wire protocol support
but aren't enabled by default due to their priorities being 0. It
is essentially free from a coding perspective to support these
compression formats, so we do it in case anyone may derive use from
it.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Sat, 24 Dec 2016 13:51:12 -0700 |
parents | 1e5ff5ae1d2b |
children |
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/* dirs.c - dynamic directory diddling for dirstates Copyright 2013 Facebook This software may be used and distributed according to the terms of the GNU General Public License, incorporated herein by reference. */ #define PY_SSIZE_T_CLEAN #include <Python.h> #include "util.h" #ifdef IS_PY3K #define PYLONG_VALUE(o) ((PyLongObject *)o)->ob_digit[1] #else #define PYLONG_VALUE(o) PyInt_AS_LONG(o) #endif /* * This is a multiset of directory names, built from the files that * appear in a dirstate or manifest. * * A few implementation notes: * * We modify Python integers for refcounting, but those integers are * never visible to Python code. * * We mutate strings in-place, but leave them immutable once they can * be seen by Python code. */ typedef struct { PyObject_HEAD PyObject *dict; } dirsObject; static inline Py_ssize_t _finddir(const char *path, Py_ssize_t pos) { while (pos != -1) { if (path[pos] == '/') break; pos -= 1; } return pos; } static int _addpath(PyObject *dirs, PyObject *path) { const char *cpath = PyBytes_AS_STRING(path); Py_ssize_t pos = PyBytes_GET_SIZE(path); PyObject *key = NULL; int ret = -1; /* This loop is super critical for performance. That's why we inline * access to Python structs instead of going through a supported API. * The implementation, therefore, is heavily dependent on CPython * implementation details. We also commit violations of the Python * "protocol" such as mutating immutable objects. But since we only * mutate objects created in this function or in other well-defined * locations, the references are known so these violations should go * unnoticed. The code for adjusting the length of a PyBytesObject is * essentially a minimal version of _PyBytes_Resize. */ while ((pos = _finddir(cpath, pos - 1)) != -1) { PyObject *val; /* It's likely that every prefix already has an entry in our dict. Try to avoid allocating and deallocating a string for each prefix we check. */ if (key != NULL) ((PyBytesObject *)key)->ob_shash = -1; else { /* Force Python to not reuse a small shared string. */ key = PyBytes_FromStringAndSize(cpath, pos < 2 ? 2 : pos); if (key == NULL) goto bail; } /* Py_SIZE(o) refers to the ob_size member of the struct. Yes, * assigning to what looks like a function seems wrong. */ Py_SIZE(key) = pos; ((PyBytesObject *)key)->ob_sval[pos] = '\0'; val = PyDict_GetItem(dirs, key); if (val != NULL) { PYLONG_VALUE(val) += 1; break; } /* Force Python to not reuse a small shared int. */ #ifdef IS_PY3K val = PyLong_FromLong(0x1eadbeef); #else val = PyInt_FromLong(0x1eadbeef); #endif if (val == NULL) goto bail; PYLONG_VALUE(val) = 1; ret = PyDict_SetItem(dirs, key, val); Py_DECREF(val); if (ret == -1) goto bail; Py_CLEAR(key); } ret = 0; bail: Py_XDECREF(key); return ret; } static int _delpath(PyObject *dirs, PyObject *path) { char *cpath = PyBytes_AS_STRING(path); Py_ssize_t pos = PyBytes_GET_SIZE(path); PyObject *key = NULL; int ret = -1; while ((pos = _finddir(cpath, pos - 1)) != -1) { PyObject *val; key = PyBytes_FromStringAndSize(cpath, pos); if (key == NULL) goto bail; val = PyDict_GetItem(dirs, key); if (val == NULL) { PyErr_SetString(PyExc_ValueError, "expected a value, found none"); goto bail; } if (--PYLONG_VALUE(val) <= 0) { if (PyDict_DelItem(dirs, key) == -1) goto bail; } else break; Py_CLEAR(key); } ret = 0; bail: Py_XDECREF(key); return ret; } static int dirs_fromdict(PyObject *dirs, PyObject *source, char skipchar) { PyObject *key, *value; Py_ssize_t pos = 0; while (PyDict_Next(source, &pos, &key, &value)) { if (!PyBytes_Check(key)) { PyErr_SetString(PyExc_TypeError, "expected string key"); return -1; } if (skipchar) { if (!dirstate_tuple_check(value)) { PyErr_SetString(PyExc_TypeError, "expected a dirstate tuple"); return -1; } if (((dirstateTupleObject *)value)->state == skipchar) continue; } if (_addpath(dirs, key) == -1) return -1; } return 0; } static int dirs_fromiter(PyObject *dirs, PyObject *source) { PyObject *iter, *item = NULL; int ret; iter = PyObject_GetIter(source); if (iter == NULL) return -1; while ((item = PyIter_Next(iter)) != NULL) { if (!PyBytes_Check(item)) { PyErr_SetString(PyExc_TypeError, "expected string"); break; } if (_addpath(dirs, item) == -1) break; Py_CLEAR(item); } ret = PyErr_Occurred() ? -1 : 0; Py_DECREF(iter); Py_XDECREF(item); return ret; } /* * Calculate a refcounted set of directory names for the files in a * dirstate. */ static int dirs_init(dirsObject *self, PyObject *args) { PyObject *dirs = NULL, *source = NULL; char skipchar = 0; int ret = -1; self->dict = NULL; if (!PyArg_ParseTuple(args, "|Oc:__init__", &source, &skipchar)) return -1; dirs = PyDict_New(); if (dirs == NULL) return -1; if (source == NULL) ret = 0; else if (PyDict_Check(source)) ret = dirs_fromdict(dirs, source, skipchar); else if (skipchar) PyErr_SetString(PyExc_ValueError, "skip character is only supported " "with a dict source"); else ret = dirs_fromiter(dirs, source); if (ret == -1) Py_XDECREF(dirs); else self->dict = dirs; return ret; } PyObject *dirs_addpath(dirsObject *self, PyObject *args) { PyObject *path; if (!PyArg_ParseTuple(args, "O!:addpath", &PyBytes_Type, &path)) return NULL; if (_addpath(self->dict, path) == -1) return NULL; Py_RETURN_NONE; } static PyObject *dirs_delpath(dirsObject *self, PyObject *args) { PyObject *path; if (!PyArg_ParseTuple(args, "O!:delpath", &PyBytes_Type, &path)) return NULL; if (_delpath(self->dict, path) == -1) return NULL; Py_RETURN_NONE; } static int dirs_contains(dirsObject *self, PyObject *value) { return PyBytes_Check(value) ? PyDict_Contains(self->dict, value) : 0; } static void dirs_dealloc(dirsObject *self) { Py_XDECREF(self->dict); PyObject_Del(self); } static PyObject *dirs_iter(dirsObject *self) { return PyObject_GetIter(self->dict); } static PySequenceMethods dirs_sequence_methods; static PyMethodDef dirs_methods[] = { {"addpath", (PyCFunction)dirs_addpath, METH_VARARGS, "add a path"}, {"delpath", (PyCFunction)dirs_delpath, METH_VARARGS, "remove a path"}, {NULL} /* Sentinel */ }; static PyTypeObject dirsType = { PyVarObject_HEAD_INIT(NULL, 0) }; void dirs_module_init(PyObject *mod) { dirs_sequence_methods.sq_contains = (objobjproc)dirs_contains; dirsType.tp_name = "parsers.dirs"; dirsType.tp_new = PyType_GenericNew; dirsType.tp_basicsize = sizeof(dirsObject); dirsType.tp_dealloc = (destructor)dirs_dealloc; dirsType.tp_as_sequence = &dirs_sequence_methods; dirsType.tp_flags = Py_TPFLAGS_DEFAULT; dirsType.tp_doc = "dirs"; dirsType.tp_iter = (getiterfunc)dirs_iter; dirsType.tp_methods = dirs_methods; dirsType.tp_init = (initproc)dirs_init; if (PyType_Ready(&dirsType) < 0) return; Py_INCREF(&dirsType); PyModule_AddObject(mod, "dirs", (PyObject *)&dirsType); }