tesseract/vs2008/include/leptonica/stack.h

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/*====================================================================*
- Copyright (C) 2001 Leptonica. All rights reserved.
- This software is distributed in the hope that it will be
- useful, but with NO WARRANTY OF ANY KIND.
- No author or distributor accepts responsibility to anyone for the
- consequences of using this software, or for whether it serves any
- particular purpose or works at all, unless he or she says so in
- writing. Everyone is granted permission to copy, modify and
- redistribute this source code, for commercial or non-commercial
- purposes, with the following restrictions: (1) the origin of this
- source code must not be misrepresented; (2) modified versions must
- be plainly marked as such; and (3) this notice may not be removed
- or altered from any source or modified source distribution.
*====================================================================*/
#ifndef LEPTONICA_STACK_H
#define LEPTONICA_STACK_H
/*
* stack.h
*
* Expandable pointer stack for arbitrary void* data.
*
* The L_Stack is an array of void * ptrs, onto which arbitrary
* objects can be stored. At any time, the number of
* stored objects is stack->n. The object at the bottom
* of the stack is at array[0]; the object at the top of
* the stack is at array[n-1]. New objects are added
* to the top of the stack, at the first available location,
* which is array[n]. Objects are removed from the top of the
* stack. When an attempt is made to remove an object from an
* empty stack, the result is null. When the stack becomes
* filled, so that n = nalloc, the size is doubled.
*
* The auxiliary stack can be used to store and remove
* objects for re-use. It must be created by a separate
* call to pstackCreate(). [Just imagine the chaos if
* pstackCreate() created the auxiliary stack!]
* pstackDestroy() checks for the auxiliary stack and removes it.
*/
/* Note that array[n] is the first null ptr in the array */
struct L_Stack
{
l_int32 nalloc; /* size of ptr array */
l_int32 n; /* number of stored elements */
void **array; /* ptr array */
struct L_Stack *auxstack; /* auxiliary stack */
};
typedef struct L_Stack L_STACK;
#endif /* LEPTONICA_STACK_H */