/* * This file is part of LibParserUtils. * Licensed under the MIT License, *                http://www.opensource.org/licenses/mit-license.php * Copyright 2008 John-Mark Bell <jmb@netsurf-browser.org> */ #if defined PLAN9#include <limits.h>#define INT32_MAX INT_MAX#endif #include <inttypes.h>#include <string.h> #include <parserutils/utils/stack.h> /** * Stack object */struct parserutils_stack{	size_t item_size;		/**< Size of an item in the stack */	size_t chunk_size;		/**< Size of a stack chunk */	size_t items_allocated;		/**< Number of slots allocated */	int32_t current_item;		/**< Index of current item */	void *items;			/**< Items in stack */ 	parserutils_alloc alloc;	/**< Memory (de)allocation function */	void *pw;			/**< Client-specific data */}; /** * Create a stack * * \param item_size   Length, in bytes, of an item in the stack * \param chunk_size  Number of stack slots in a chunk * \param alloc       Memory (de)allocation function * \param pw          Pointer to client-specific private data * \param stack       Pointer to location to receive stack instance * \return PARSERUTILS_OK on success, *         PARSERUTILS_BADPARM on bad parameters *         PARSERUTILS_NOMEM on memory exhaustion */parserutils_error parserutils_stack_create(size_t item_size, size_t chunk_size,		parserutils_alloc alloc, void *pw, parserutils_stack **stack){	parserutils_stack *s; 	if (item_size == 0 || chunk_size == 0 || alloc == NULL || stack == NULL)		return PARSERUTILS_BADPARM; 	s = alloc(NULL, sizeof(parserutils_stack), pw);	if (s == NULL)		return PARSERUTILS_NOMEM; 	s->items = alloc(NULL, item_size * chunk_size, pw);	if (s->items == NULL) {		alloc(s, 0, pw);		return PARSERUTILS_NOMEM;	} 	s->item_size = item_size;	s->chunk_size = chunk_size;	s->items_allocated = chunk_size;	s->current_item = -1; 	s->alloc = alloc;	s->pw = pw; 	*stack = s; 	return PARSERUTILS_OK;} /** * Destroy a stack instance * * \param stack  The stack to destroy * \return PARSERUTILS_OK on success, appropriate error otherwise. */parserutils_error parserutils_stack_destroy(parserutils_stack *stack){	if (stack == NULL)		return PARSERUTILS_BADPARM; 	stack->alloc(stack->items, 0, stack->pw);	stack->alloc(stack, 0, stack->pw); 	return PARSERUTILS_OK;} /** * Push an item onto the stack * * \param stack  The stack to push onto * \param item   The item to push * \return PARSERUTILS_OK on success, appropriate error otherwise */parserutils_error parserutils_stack_push(parserutils_stack *stack, 		const void *item){	int32_t slot; 	if (stack == NULL || item == NULL)		return PARSERUTILS_BADPARM; 	/* Ensure we'll get a valid slot */	if (stack->current_item < -1 || stack->current_item == INT32_MAX)		return PARSERUTILS_INVALID; 	slot = stack->current_item + 1; 	if ((size_t) slot >= stack->items_allocated) {		void *temp = stack->alloc(stack->items,				(stack->items_allocated + stack->chunk_size) *				stack->item_size, stack->pw);		if (temp == NULL)			return PARSERUTILS_NOMEM; 		stack->items = temp;		stack->items_allocated += stack->chunk_size;	} 	memcpy((uint8_t *) stack->items + (slot * stack->item_size), 			item, stack->item_size);	stack->current_item = slot; 	return PARSERUTILS_OK;} /** * Pop an item off a stack * * \param stack  The stack to pop from * \param item   Pointer to location to receive popped item, or NULL * \return PARSERUTILS_OK on success, appropriate error otherwise. */parserutils_error parserutils_stack_pop(parserutils_stack *stack, void *item){	if (stack == NULL)		return PARSERUTILS_BADPARM; 	if (stack->current_item < 0)		return PARSERUTILS_INVALID; 	if (item != NULL) {		memcpy(item, (uint8_t *) stack->items + 				(stack->current_item * stack->item_size), 				stack->item_size);	} 	stack->current_item -= 1; 	return PARSERUTILS_OK;} /** * Retrieve a pointer to the current item on the stack * * \param stack  The stack to inspect * \return Pointer to item on stack, or NULL if none */void *parserutils_stack_get_current(parserutils_stack *stack){	if (stack == NULL || stack->current_item < 0)		return NULL; 	return (uint8_t *) stack->items + 			(stack->current_item * stack->item_size);} #ifndef NDEBUG#include <stdio.h> extern void parserutils_stack_dump(parserutils_stack *stack, const char *prefix,		void (*printer)(void *item)); void parserutils_stack_dump(parserutils_stack *stack, const char *prefix,		void (*printer)(void *item)){	int32_t i; 	if (stack == NULL || printer == NULL)		return; 	for (i = 0; i <= stack->current_item; i++) {		printf("%s %d: ", prefix != NULL ? prefix : "", i);		printer((uint8_t *) stack->items + (i * stack->item_size));		printf("\n");	}} #endif