py-yajl/ptrstack.h

86 lines
3.1 KiB
C

/*
* Copyright 2009, R. Tyler Ballance <tyler@monkeypox.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. Neither the name of R. Tyler Ballance nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*
* A header only, highly efficient custom pointer stack implementation,
* used in py-yajl to maintain parse state.
*/
#ifndef __PY_YAJL_BYTESTACK_H__
#define __PY_YAJL_BYTESTACK_H__
#include <Python.h>
#include "assert.h"
#define PY_YAJL_PS_INC 128
typedef struct py_yajl_bytestack_t
{
PyObject ** stack;
unsigned int size;
unsigned int used;
} py_yajl_bytestack;
/* initialize a bytestack */
#define py_yajl_ps_init(ops) { \
(ops).stack = NULL; \
(ops).size = 0; \
(ops).used = 0; \
} \
/* initialize a bytestack */
#define py_yajl_ps_free(ops) \
if ((ops).stack) free((ops).stack);
#define py_yajl_ps_current(ops) \
(assert((ops).used > 0), (ops).stack[(ops).used - 1])
#define py_yajl_ps_length(ops) ((ops).used)
#define py_yajl_ps_push(ops, pointer) { \
if (((ops).size - (ops).used) == 0) { \
(ops).size += PY_YAJL_PS_INC; \
(ops).stack = realloc((void *) (ops).stack, sizeof(PyObject *) * (ops).size); \
} \
(ops).stack[((ops).used)++] = (pointer); \
}
/* removes the top item of the stack, returns nothing */
#define py_yajl_ps_pop(ops) { ((ops).used)--; }
#define py_yajl_ps_set(ops, pointer) \
(ops).stack[((ops).used) - 1] = (pointer);
#endif