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qtermwidget-packaging/lib/BlockArray.h

131 lines
3.1 KiB

/*
This file is part of Konsole, an X terminal.
Copyright (C) 2000 by Stephan Kulow <coolo@kde.org>
Rewritten for QT4 by e_k <e_k at users.sourceforge.net>, Copyright (C)2008
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA.
*/
#ifndef BLOCKARRAY_H
#define BLOCKARRAY_H
#include <unistd.h>
//#error Do not use in KDE 2.1
#define BlockSize (1 << 12)
#define ENTRIES ((BlockSize - sizeof(size_t) ) / sizeof(unsigned char))
namespace Konsole {
struct Block {
Block() {
size = 0;
}
unsigned char data[ENTRIES];
size_t size;
};
// ///////////////////////////////////////////////////////
class BlockArray {
public:
/**
* Creates a history file for holding
* maximal size blocks. If more blocks
* are requested, then it drops earlier
* added ones.
*/
BlockArray();
/// destructor
~BlockArray();
/**
* adds the Block at the end of history.
* This may drop other blocks.
*
* The ownership on the block is transfered.
* An unique index number is returned for accessing
* it later (if not yet dropped then)
*
* Note, that the block may be dropped completely
* if history is turned off.
*/
size_t append(Block * block);
/**
* gets the block at the index. Function may return
* 0 if the block isn't available any more.
*
* The returned block is strictly readonly as only
* maped in memory - and will be invalid on the next
* operation on this class.
*/
const Block * at(size_t index);
/**
* reorders blocks as needed. If newsize is null,
* the history is emptied completely. The indices
* returned on append won't change their semantic,
* but they may not be valid after this call.
*/
bool setHistorySize(size_t newsize);
size_t newBlock();
Block * lastBlock() const;
/**
* Convenient function to set the size in KBytes
* instead of blocks
*/
bool setSize(size_t newsize);
size_t len() const {
return length;
}
bool has(size_t index) const;
size_t getCurrent() const {
return current;
}
private:
void unmap();
void increaseBuffer();
void decreaseBuffer(size_t newsize);
size_t size;
// current always shows to the last inserted block
size_t current;
size_t index;
Block * lastmap;
size_t lastmap_index;
Block * lastblock;
int ion;
size_t length;
};
}
#endif