/ocr/ocrservice/jni/hydrogen/include/leptonica/stack.h

 1/*====================================================================*
 2 -  Copyright (C) 2001 Leptonica.  All rights reserved.
 3 -  This software is distributed in the hope that it will be
 4 -  useful, but with NO WARRANTY OF ANY KIND.
 5 -  No author or distributor accepts responsibility to anyone for the
 6 -  consequences of using this software, or for whether it serves any
 7 -  particular purpose or works at all, unless he or she says so in
 8 -  writing.  Everyone is granted permission to copy, modify and
 9 -  redistribute this source code, for commercial or non-commercial
10 -  purposes, with the following restrictions: (1) the origin of this
11 -  source code must not be misrepresented; (2) modified versions must
12 -  be plainly marked as such; and (3) this notice may not be removed
13 -  or altered from any source or modified source distribution.
14 *====================================================================*/
15
16#ifndef  LEPTONICA_STACK_H
17#define  LEPTONICA_STACK_H
18
19/*
20 *  stack.h
21 *
22 *       Expandable pointer stack for arbitrary void* data.
23 *
24 *       The L_Stack is an array of void * ptrs, onto which arbitrary
25 *       objects can be stored.  At any time, the number of
26 *       stored objects is stack->n.  The object at the bottom
27 *       of the stack is at array[0]; the object at the top of
28 *       the stack is at array[n-1].  New objects are added
29 *       to the top of the stack, at the first available location,
30 *       which is array[n].  Objects are removed from the top of the
31 *       stack.  When an attempt is made to remove an object from an
32 *       empty stack, the result is null.   When the stack becomes
33 *       filled, so that n = nalloc, the size is doubled.
34 *
35 *       The auxiliary stack can be used to store and remove
36 *       objects for re-use.  It must be created by a separate
37 *       call to pstackCreate().  [Just imagine the chaos if
38 *       pstackCreate() created the auxiliary stack!]   
39 *       pstackDestroy() checks for the auxiliary stack and removes it.
40 */
41
42
43    /* Note that array[n] is the first null ptr in the array */
44struct L_Stack
45{
46    l_int32          nalloc;       /* size of ptr array              */
47    l_int32          n;            /* number of stored elements      */
48    void           **array;        /* ptr array                      */
49    struct L_Stack  *auxstack;     /* auxiliary stack                */
50};
51typedef struct L_Stack  L_STACK;
52
53
54#endif /*  LEPTONICA_STACK_H */
55