ccextractor/windows/libs/include/queue.h
2016-12-23 18:01:12 +03:00

78 lines
3.4 KiB
C

/*====================================================================*
- Copyright (C) 2001 Leptonica. All rights reserved.
-
- 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.
-
- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- ``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 ANY
- CONTRIBUTORS 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.
*====================================================================*/
#ifndef LEPTONICA_QUEUE_H
#define LEPTONICA_QUEUE_H
/*!
* \file queue.h
*
* <pre>
* Expandable pointer queue for arbitrary void* data.
*
* The L_Queue is a fifo that implements a queue of void* pointers.
* It can be used to hold a queue of any type of struct.
*
* Internally, it maintains two counters:
* nhead: location of head (in ptrs) from the beginning
* of the array.
* nelem: number of ptr elements stored in the queue.
*
* The element at the head of the queue, which is the next to
* be removed, is array[nhead]. The location at the tail of the
* queue to which the next element will be added is
* array[nhead + nelem].
*
* As items are added to the queue, nelem increases.
* As items are removed, nhead increases and nelem decreases.
* Any time the tail reaches the end of the allocated array,
* all the pointers are shifted to the left, so that the head
* is at the beginning of the array.
* If the array becomes more than 3/4 full, it doubles in size.
*
* The auxiliary stack can be used in a wrapper for re-using
* items popped from the queue. It is not made by default.
*
* For further implementation details, see queue.c.
* </pre>
*/
/*! Expandable pointer queue for arbitrary void* data */
struct L_Queue
{
l_int32 nalloc; /*!< size of allocated ptr array */
l_int32 nhead; /*!< location of head (in ptrs) from the */
/*!< beginning of the array */
l_int32 nelem; /*!< number of elements stored in the queue */
void **array; /*!< ptr array */
struct L_Stack *stack; /*!< auxiliary stack */
};
typedef struct L_Queue L_QUEUE;
#endif /* LEPTONICA_QUEUE_H */