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Commit	Line	Data
	1	/*
	2	tre-stack.c - Simple stack implementation
	3
	4	This software is released under a BSD-style license.
	5	See the file LICENSE for details and copyright.
	6
	7	*/
	8
	9	#ifdef HAVE_CONFIG_H
	10	#include <config.h>
	11	#endif /* HAVE_CONFIG_H */
	12	#include <stdlib.h>
	13	#include <assert.h>
	14
	15	#include "tre-internal.h"
	16	#include "tre-stack.h"
	17	#include "xmalloc.h"
	18
	19	union tre_stack_item {
	20	void *voidptr_value;
	21	int int_value;
	22	};
	23
	24	struct tre_stack_rec {
	25	int size;
	26	int max_size;
	27	int increment;
	28	int ptr;
	29	union tre_stack_item *stack;
	30	};
	31
	32
	33	tre_stack_t *
	34	tre_stack_new(int size, int max_size, int increment)
	35	{
	36	tre_stack_t *s;
	37
	38	s = xmalloc(sizeof(*s));
	39	if (s != NULL)
	40	{
	41	s->stack = xmalloc(sizeof(s->stack) size);
	42	if (s->stack == NULL)
	43	{
	44	xfree(s);
	45	return NULL;
	46	}
	47	s->size = size;
	48	s->max_size = max_size;
	49	s->increment = increment;
	50	s->ptr = 0;
	51	}
	52	return s;
	53	}
	54
	55	void
	56	tre_stack_destroy(tre_stack_t *s)
	57	{
	58	xfree(s->stack);
	59	xfree(s);
	60	}
	61
	62	int
	63	tre_stack_num_objects(tre_stack_t *s)
	64	{
	65	return s->ptr;
	66	}
	67
	68	static reg_errcode_t
	69	tre_stack_push(tre_stack_t *s, union tre_stack_item value)
	70	{
	71	if (s->ptr < s->size)
	72	{
	73	s->stack[s->ptr] = value;
	74	s->ptr++;
	75	}
	76	else
	77	{
	78	if (s->size >= s->max_size)
	79	{
	80	DPRINT(("tre_stack_push: stack full\n"));
	81	return REG_ESPACE;
	82	}
	83	else
	84	{
	85	union tre_stack_item *new_buffer;
	86	int new_size;
	87	DPRINT(("tre_stack_push: trying to realloc more space\n"));
	88	new_size = s->size + s->increment;
	89	if (new_size > s->max_size)
	90	new_size = s->max_size;
	91	new_buffer = xrealloc(s->stack, sizeof(new_buffer) new_size);
	92	if (new_buffer == NULL)
	93	{
	94	DPRINT(("tre_stack_push: realloc failed.\n"));
	95	return REG_ESPACE;
	96	}
	97	DPRINT(("tre_stack_push: realloc succeeded.\n"));
	98	assert(new_size > s->size);
	99	s->size = new_size;
	100	s->stack = new_buffer;
	101	tre_stack_push(s, value);
	102	}
	103	}
	104	return REG_OK;
	105	}
	106
	107	#define define_pushf(typetag, type) \
	108	declare_pushf(typetag, type) { \
	109	union tre_stack_item item; \
	110	item.typetag ## _value = value; \
	111	return tre_stack_push(s, item); \
	112	}
	113
	114	define_pushf(int, int)
	115	define_pushf(voidptr, void *)
	116
	117	#define define_popf(typetag, type) \
	118	declare_popf(typetag, type) { \
	119	return s->stack[--s->ptr].typetag ## _value; \
	120	}
	121
	122	define_popf(int, int)
	123	define_popf(voidptr, void *)
	124
	125	/* EOF */