tesseract/cutil/oldheap.cpp
2010-07-27 13:23:23 +00:00

327 lines
9.6 KiB
C++

/******************************************************************************
** Filename: heap.c
** Purpose: Routines for managing heaps (smallest at root)
** Author: Dan Johnson
** History: 3/13/89, DSJ, Created.
**
** (c) Copyright Hewlett-Packard Company, 1988.
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
** http://www.apache.org/licenses/LICENSE-2.0
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
******************************************************************************/
/*-----------------------------------------------------------------------------
Include Files and Type Defines
-----------------------------------------------------------------------------*/
#include "oldheap.h"
#include "freelist.h"
#include "danerror.h"
#include "emalloc.h"
#include <stdio.h>
#define FATHER(N) ((N)>>1)
#define LEFTSON(N) ((N)<<1)
#define RIGHTSON(N) ((N)<<1 + 1)
/*-----------------------------------------------------------------------------
Public Code
-----------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
/**
* This routine creates and initializes a new heap data
* structure containing Size elements. In actuality, Size + 1
* elements are allocated. The first element, element 0, is
* unused, this makes the index arithmetic easier.
*
* Globals:
* - None
*
* @param Size maximum number of entries in the heap
* @return Pointer to the new heap.
* @note Exceptions: None
* @note History: 3/13/89, DSJ, Created.
*/
HEAP *MakeHeap(int Size) {
HEAP *NewHeap;
NewHeap = (HEAP *) Emalloc (sizeof (HEAP) + Size * sizeof (HEAPENTRY));
NewHeap->Size = Size;
NewHeap->FirstFree = 1;
return (NewHeap);
} /* MakeHeap */
/*---------------------------------------------------------------------------*/
/**
* This routine removes the top item on the heap and places
* its contents into Key and Data.
*
* Globals:
* - None
*
* @param Heap ptr to heap whose top is to be removed and returned
* @param Key place to put key of top heap item
* @param Data place to put data of top heap item
*
* @return OK if top entry returned, EMPTY if heap is empty
* @note Exceptions: None
* @note History: 5/10/91, DSJ, Created (Modified from GetTopOfHeap).
*/
int HeapPop(HEAP *Heap, FLOAT32 *Key, void *out_ptr) {
inT32 Hole;
FLOAT32 HoleKey;
inT32 Son;
void **Data = (void **) out_ptr;
if (Heap->FirstFree <= 1)
return (EMPTY);
*Key = Heap->Entry[1].Key;
*Data = Heap->Entry[1].Data;
Heap->FirstFree--;
/* imagine the hole at the root is filled with the last entry in the heap */
HoleKey = Heap->Entry[Heap->FirstFree].Key;
Hole = 1;
/* while hole has 2 sons */
while ((Son = LEFTSON (Hole)) < Heap->FirstFree) {
/* find the son with the smallest key */
if (Heap->Entry[Son].Key > Heap->Entry[Son + 1].Key)
Son++;
/* if key for hole is greater than key for son, sift hole down */
if (HoleKey > Heap->Entry[Son].Key) {
Heap->Entry[Hole].Key = Heap->Entry[Son].Key;
Heap->Entry[Hole].Data = Heap->Entry[Son].Data;
Hole = Son;
}
else
break;
}
Heap->Entry[Hole].Key = HoleKey;
Heap->Entry[Hole].Data = Heap->Entry[Heap->FirstFree].Data;
return (OK);
} /* HeapPop */
/**
* HeapPopWorst
*
* Remove the largest item from the heap.
*
* @param Heap ptr to heap whose top is to be removed and returned
* @param Key place to put key of top heap item
* @param Data place to put data of top heap item
*/
int HeapPopWorst(HEAP *Heap, FLOAT32 *Key, void *out_ptr) {
inT32 Index; /*current index */
inT32 Hole;
FLOAT32 HoleKey;
inT32 Father;
void *HoleData;
void **Data = (void **) out_ptr;
if (Heap->FirstFree <= 1)
return (EMPTY);
HoleKey = Heap->Entry[1].Key;
Hole = 1;
Heap->FirstFree--;
for (Index = Heap->FirstFree, Father = FATHER (Index); Index > Father;
Index--)
if (Heap->Entry[Index].Key > HoleKey) {
/*find biggest */
HoleKey = Heap->Entry[Index].Key;
Hole = Index;
}
*Key = HoleKey;
*Data = Heap->Entry[Hole].Data;
HoleKey = Heap->Entry[Heap->FirstFree].Key;
Heap->Entry[Hole].Key = HoleKey;
HoleData = Heap->Entry[Heap->FirstFree].Data;
Heap->Entry[Hole].Data = HoleData;
/* now sift last entry to its rightful place */
Father = FATHER (Hole); /*father of hole */
while (Hole > 1 && Heap->Entry[Father].Key > HoleKey) {
/*swap entries */
Heap->Entry[Hole].Key = Heap->Entry[Father].Key;
Heap->Entry[Hole].Data = Heap->Entry[Father].Data;
Heap->Entry[Father].Data = HoleData;
Heap->Entry[Father].Key = HoleKey;
Hole = Father;
Father = FATHER (Hole);
}
return (OK);
} /* HeapPop */
/*---------------------------------------------------------------------------*/
/**
* This routine stores Data into Heap and associates it
* with Key. The heap is
* maintained in such a way that the item with the lowest key
* is always at the top of the heap.
*
* Globals:
* - None
*
* @param Heap ptr to heap to store new item in
* @param Key numeric key associated with new item
* @param Data ptr to data contents of new item
*
* @note Exceptions:
* - HEAPFULL error if heap size is exceeded
*
* @note History: 5/10/91, DSJ, Created (Modified version of HeapStore).
*/
void HeapPush(HEAP *Heap, FLOAT32 Key, void *Data) {
inT32 Item;
inT32 Father;
if (Heap->FirstFree > Heap->Size)
DoError (HEAPFULL, "Heap size exceeded");
Item = Heap->FirstFree;
Heap->FirstFree++;
while (Item != 1) {
Father = FATHER (Item);
if (Heap->Entry[Father].Key > Key) {
Heap->Entry[Item].Key = Heap->Entry[Father].Key;
Heap->Entry[Item].Data = Heap->Entry[Father].Data;
Item = Father;
}
else
break;
}
Heap->Entry[Item].Key = Key;
Heap->Entry[Item].Data = Data;
} /* HeapPush */
/*---------------------------------------------------------------------------*/
/**
* This routine stores Entry into Heap. The heap is
* maintained in such a way that the item with the lowest key
* is always at the top of the heap.
*
* Globals:
* - None
*
* @param Heap ptr to heap to store new item in
* @param Entry ptr to item to be stored in Heap
* @note Exceptions:
* - HEAPFULL error if heap size is exceeded
* @note History: 3/13/89, DSJ, Created.
*/
void HeapStore(HEAP *Heap, HEAPENTRY *Entry) {
inT32 Item;
inT32 Father;
if (Heap->FirstFree > Heap->Size)
DoError (HEAPFULL, "Heap size exceeded");
Item = Heap->FirstFree;
Heap->FirstFree++;
while (Item != 1) {
Father = FATHER (Item);
if (Heap->Entry[Father].Key > Entry->Key) {
Heap->Entry[Item].Key = Heap->Entry[Father].Key;
Heap->Entry[Item].Data = Heap->Entry[Father].Data;
Item = Father;
}
else
break;
}
Heap->Entry[Item].Key = Entry->Key;
Heap->Entry[Item].Data = Entry->Data;
} /* HeapStore */
/*---------------------------------------------------------------------------*/
/**
* This routine removes the top item on the heap and copies its
* contents into Entry.
*
* @param Heap ptr to heap whose top is to be removed and returned
* @param Entry ptr to heap entry to be filled with top entry on Heap
*
* Globals:
* - None
*
* @return OK if top entry returned, EMPTY if heap is empty
* @note Exceptions: None
* @note History: 3/13/89, DSJ, Created.
*/
int GetTopOfHeap(HEAP *Heap, HEAPENTRY *Entry) {
inT32 Hole;
FLOAT32 HoleKey;
inT32 Son;
if (Heap->FirstFree <= 1)
return (EMPTY);
Entry->Key = Heap->Entry[1].Key;
Entry->Data = Heap->Entry[1].Data;
Heap->FirstFree--;
/* imagine the hole at the root is filled with the last entry in the heap */
HoleKey = Heap->Entry[Heap->FirstFree].Key;
Hole = 1;
/* while hole has 2 sons */
while ((Son = LEFTSON (Hole)) < Heap->FirstFree) {
/* find the son with the smallest key */
if (Heap->Entry[Son].Key > Heap->Entry[Son + 1].Key)
Son++;
/* if key for hole is greater than key for son, sift hole down */
if (HoleKey > Heap->Entry[Son].Key) {
Heap->Entry[Hole].Key = Heap->Entry[Son].Key;
Heap->Entry[Hole].Data = Heap->Entry[Son].Data;
Hole = Son;
}
else
break;
}
Heap->Entry[Hole].Key = HoleKey;
Heap->Entry[Hole].Data = Heap->Entry[Heap->FirstFree].Data;
return (OK);
} /* GetTopOfHeap */
/*---------------------------------------------------------------------------*/
/**
* This routine is similar to FreeHeap in that it
* deallocates the memory consumed by the heap. However, it
* also calls Deallocator for each item in the heap so that
* this data is also deallocated.
*
* @param Heap heap whose data is to be freed
* @param Deallocator function to be used to deallocate data
*
* Globals:
* - None
*
* @note Exceptions: none
* @note History: Tue May 15 08:52:04 1990, DSJ, Created.
*/
void FreeHeapData(HEAP *Heap, void_dest destructor) {
HEAPENTRY Entry;
while (GetTopOfHeap (Heap, &Entry) != EMPTY)
destructor (Entry.Data);
FreeHeap(Heap);
} /* FreeHeapData */