haiku/headers/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

70 lines
1.6 KiB
C++

/*
* Copyright 2001-2007, Haiku, Inc. All Rights Reserved.
* Distributed under the terms of the MIT License.
*/
#ifndef _BE_LIST_H
#define _BE_LIST_H
#include <SupportDefs.h>
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();
// Reorder items
void SortItems(int (*compareFunc)(const void*, const void*));
bool SwapItems(int32 indexA, int32 indexB);
bool MoveItem(int32 fromIndex, int32 toIndex);
// Retrieve items
void* ItemAt(int32 index) const;
void* FirstItem() const;
void* ItemAtFast(int32) const;
// does not check the array bounds!
void* LastItem() const;
void* Items() const;
// Query
bool HasItem(void* item) const;
int32 IndexOf(void* item) const;
int32 CountItems() const;
bool IsEmpty() const;
// Iteration
void DoForEach(bool (*func)(void* item));
void DoForEach(bool (*func)(void* item, void* arg2), void *arg2);
private:
virtual void _ReservedList1();
virtual void _ReservedList2();
bool _ResizeArray(int32 count);
private:
void** fObjectList;
int32 fPhysicalSize;
int32 fItemCount;
int32 fBlockSize;
int32 fResizeThreshold;
uint32 _reserved[1];
};
#endif // _BE_LIST_H