--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/leptonica/src/queue.h	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,77 @@
+/*====================================================================*
+ -  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 */