haiku/headers/build/os/support/List.h
Rene Gollent 0c8bdbafd5 Revamp BList somewhat to further optimize the resizing behavior.
We now keep track of a lower bound as to when the list should scale
itself back down. When increasing the list size, we double the current,
with the lower bound set to 1/4 of the current size, not allowing it to
go any smaller than the block size. These combined allow us to do very
cheap tests to see if an operation requires a resize at all, and minimize
how often the list actually needs to be resized, since the difference in upper
and lower bounds prevents bouncing back and forth between a size in the case
of adding/removing an item while close to a boundary. All in all this should
make BList noticably more scalable when doing large numbers of add/remove
operations.



git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25946 a95241bf-73f2-0310-859d-f6bbb57e9c96
2008-06-12 21:30:28 +00:00

99 lines
3.1 KiB
C++

//------------------------------------------------------------------------------
// Copyright (c) 2001-2002, OpenBeOS
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//
// File Name: List.h
// Author(s): The Storage kit Team
// Description: BList class provides storage for pointers.
// Not thread safe..
//------------------------------------------------------------------------------
#ifndef _BE_LIST_H
#define _BE_LIST_H
#include <SupportDefs.h>
/*----- BList class --------------------------------------*/
class BList {
public:
BList(int32 count = 20);
BList(const BList& anotherList);
virtual ~BList();
BList& operator =(const BList &);
/* Adding and removing items. */
bool AddItem(void *item, int32 index);
bool AddItem(void *item);
bool AddList(const BList *list, int32 index);
bool AddList(const BList *list);
bool RemoveItem(void *item);
void *RemoveItem(int32 index);
bool RemoveItems(int32 index, int32 count);
bool ReplaceItem(int32 index, void *newItem);
void MakeEmpty();
/* Reordering items. */
void SortItems(int (*compareFunc)(const void *, const void *));
bool SwapItems(int32 indexA, int32 indexB);
bool MoveItem(int32 fromIndex, int32 toIndex);
/* Retrieving items. */
void *ItemAt(int32 index) const;
void *FirstItem() const;
/* Be careful when using this function, since it doesn't */
/* check if the index you pass is valid, and can lead to */
/* unexpected results when it isn't. */
void *ItemAtFast(int32) const;
void *LastItem() const;
void *Items() const;
/* Querying the list. */
bool HasItem(void *item) const;
int32 IndexOf(void *item) const;
int32 CountItems() const;
bool IsEmpty() const;
/* Iterating over the list. */
void DoForEach(bool (*func)(void *));
void DoForEach(bool (*func)(void *, void *), void *arg2);
/*----- Private or reserved ---------------*/
private:
virtual void _ReservedList1();
virtual void _ReservedList2();
// return type differs from BeOS version
bool _ResizeArray(int32 count);
private:
void** fObjectList;
int32 fPhysicalSize;
int32 fItemCount;
int32 fBlockSize;
int32 fResizeThreshold;
uint32 _reserved[1];
};
#endif // _BE_LIST_H