assemblingbuffer.cc

来自「Linux下比较早的基于命令行的DVD播放器」· CC 代码 · 共 72 行

//
// Copyright (c) 2003 by Istv醤 V醨adi
//
// This file is part of dxr3Player, a DVD player written specifically 
// for the DXR3 (aka Hollywood+) decoder card.

// 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

//------------------------------------------------------------------------------

#include "AssemblingBuffer.h"

#include <cstring>
#include <cassert>

//------------------------------------------------------------------------------

size_t AssemblingBuffer::getLength(const unsigned char* buffer)
{
    size_t length = buffer[0];
    length <<= 8;
    length  |= buffer[1];

    return length;
}

//------------------------------------------------------------------------------

size_t AssemblingBuffer::add(const unsigned char* source, size_t length)
{
    assert(!isEmpty() || length>=2);

    size_t totalLength = 
        isEmpty() ? getLength(source) : getLength(data);

    if (isEmpty()) {
        data = new unsigned char[totalLength];
    }

    size_t toAdd = length;
    size_t needToAdd = totalLength - addedBytes;
    if (toAdd>needToAdd) toAdd = needToAdd;

    memcpy(data + addedBytes, source, toAdd);
    addedBytes += toAdd;
    
    return toAdd;
}

//------------------------------------------------------------------------------

void AssemblingBuffer::reset()
{
    delete[] data;
    data = 0;
    addedBytes = 0;
}

//------------------------------------------------------------------------------