~bzr-pqm/bzr/bzr.dev

4679.3.74 by John Arbash Meinel
Revert back to before I started trying to move to pyrex/cython code.
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/* Copyright (C) 2009 Canonical Ltd
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 * 
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 * This program is free software; you can redistribute it and/or modify
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 * it under the terms of the GNU General Public License as published by
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 * the Free Software Foundation; either version 2 of the License, or
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 * (at your option) any later version.
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 *
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 * This program is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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 * GNU General Public License for more details.
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 *
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 * You should have received a copy of the GNU General Public License
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 * along with this program; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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#ifndef _STATIC_TUPLE_H_
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#define _STATIC_TUPLE_H_
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#include <Python.h>
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#include <string.h>
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#define STATIC_TUPLE_HAS_HASH 0
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/* Caching the hash adds memory, but allows us to save a little time during
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 * lookups. TIMEIT hash(key) shows it as
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 *  0.108usec w/ hash
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 *  0.160usec w/o hash
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 * Note that the entries themselves are strings, which already cache their
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 * hashes. So while there is a 1.5:1 difference in the time for hash(), it is
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 * already a function which is quite fast. Probably the only reason we might
4679.3.77 by John Arbash Meinel
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 * want to do so, is if we customized SimpleSet to the point that the item
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 * pointers were exactly certain types, and then accessed table[i]->hash
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 * directly. So far StaticTuple_hash() is fast enough to not warrant the memory
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 * difference.
4679.3.74 by John Arbash Meinel
Revert back to before I started trying to move to pyrex/cython code.
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 */
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/* This defines a single variable-width key.
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 * It is basically the same as a tuple, but
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 * 1) Lighter weight in memory
4679.3.77 by John Arbash Meinel
Some code cleanup passes.
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 * 2) Only supports strings or other static types (that don't reference other
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 *    objects.)
4679.3.74 by John Arbash Meinel
Revert back to before I started trying to move to pyrex/cython code.
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 */
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#define STATIC_TUPLE_INTERNED_FLAG 0x01
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typedef struct {
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    PyObject_HEAD
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    // We could go with unsigned short here, and support 64k width tuples
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    // without any memory impact, might be worthwhile
4679.3.74 by John Arbash Meinel
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    unsigned char size;
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    unsigned char flags;
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    unsigned char _unused0;
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    unsigned char _unused1;
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    // Note that on 64-bit, we actually have 4-more unused bytes
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    // because items will always be aligned to a 64-bit boundary
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#if STATIC_TUPLE_HAS_HASH
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    long hash;
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#endif
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    PyObject *items[0];
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} StaticTuple;
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extern PyTypeObject StaticTuple_Type;
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typedef struct {
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    PyObject_VAR_HEAD
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    PyObject *table[0];
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} KeyIntern;
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#define StaticTuple_SET_ITEM(key, offset, val) \
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    ((((StaticTuple*)(key))->items[(offset)]) = ((PyObject *)(val)))
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#define StaticTuple_GET_ITEM(key, offset) (((StaticTuple*)key)->items[offset])
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#ifdef STATIC_TUPLE_MODULE
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/* Used when compiling _static_tuple_c.c */
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static StaticTuple * StaticTuple_New(Py_ssize_t);
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static StaticTuple * StaticTuple_Intern(StaticTuple *self);
4739.4.1 by John Arbash Meinel
Implement StaticTuple.from_sequence()
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static StaticTuple * StaticTuple_FromSequence(PyObject *);
4679.3.74 by John Arbash Meinel
Revert back to before I started trying to move to pyrex/cython code.
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#define StaticTuple_CheckExact(op) (Py_TYPE(op) == &StaticTuple_Type)
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#else
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/* Used as the foreign api */
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#include "_import_c_api.h"
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static StaticTuple *(*StaticTuple_New)(Py_ssize_t);
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static StaticTuple *(*StaticTuple_Intern)(StaticTuple *);
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Implement StaticTuple.from_sequence()
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static StaticTuple *(*StaticTuple_FromSequence)(PyObject *);
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static PyTypeObject *_p_StaticTuple_Type;
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#define StaticTuple_CheckExact(op) (Py_TYPE(op) == _p_StaticTuple_Type)
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static int (*_StaticTuple_CheckExact)(PyObject *);
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/* Return -1 and set exception on error, 0 on success */
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static int
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import_static_tuple_c(void)
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{
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    struct function_description functions[] = {
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        {"StaticTuple_New", (void **)&StaticTuple_New,
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            "StaticTuple *(Py_ssize_t)"},
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        {"StaticTuple_Intern", (void **)&StaticTuple_Intern,
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            "StaticTuple *(StaticTuple *)"},
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        {"StaticTuple_FromSequence", (void **)&StaticTuple_FromSequence,
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            "StaticTuple *(PyObject *)"},
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        {"_StaticTuple_CheckExact", (void **)&_StaticTuple_CheckExact,
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            "int(PyObject *)"},
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        {NULL}};
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    struct type_description types[] = {
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        {"StaticTuple", &_p_StaticTuple_Type},
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        {NULL}};
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    return _import_extension_module("bzrlib._static_tuple_c",
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        functions, types);
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}
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#endif // !STATIC_TUPLE_MODULE
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#endif // !_STATIC_TUPLE_H_