/*------------------------------------------------------------------------------ | |
* Copyright (C) 2003-2006 Jos van den Oever | |
* | |
* Distributable under the terms of either the Apache License (Version 2.0) or | |
* the GNU Lesser General Public License, as specified in the COPYING file. | |
------------------------------------------------------------------------------*/ | |
/* This file is part of Strigi Desktop Search | |
* | |
* Copyright (C) 2006 Jos van den Oever <jos@vandenoever.info> | |
* | |
* This library is free software; you can redistribute it and/or | |
* modify it under the terms of the GNU Library General Public | |
* License as published by the Free Software Foundation; either | |
* version 2 of the License, or (at your option) any later version. | |
* | |
* This library 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 | |
* Library General Public License for more details. | |
* | |
* You should have received a copy of the GNU Library General Public License | |
* along with this library; see the file COPYING.LIB. If not, write to | |
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, | |
* Boston, MA 02110-1301, USA. | |
*/ | |
#ifndef SUBINPUTSTREAM_H | |
#define SUBINPUTSTREAM_H | |
#include "streambase.h" | |
namespace jstreams { | |
template<class T> | |
class SubInputStream : public StreamBase<T> { | |
private: | |
const int64_t offset; | |
StreamBase<T> *input; | |
public: | |
SubInputStream(StreamBase<T> *input, int64_t size=-1); | |
int32_t read(const T*& start, int32_t min, int32_t max); | |
int64_t reset(int64_t newpos); | |
int64_t skip(int64_t ntoskip); | |
}; | |
template<class T> | |
SubInputStream<T>::SubInputStream(StreamBase<T> *i, int64_t length) | |
: offset(i->getPosition()), input(i) { | |
assert(length >= -1); | |
// printf("substream offset: %lli\n", offset); | |
StreamBase<T>::size = length; | |
} | |
template<class T> | |
int32_t SubInputStream<T>::read(const T*& start, int32_t min, int32_t max) { | |
if (StreamBase<T>::size != -1) { | |
const int64_t left = StreamBase<T>::size - StreamBase<T>::position; | |
if (left == 0) { | |
return -1; | |
} | |
// restrict the amount of data that can be read | |
if (max <= 0 || max > left) { | |
max = (int32_t)left; | |
} | |
if (min > max) min = max; | |
if (left < min) min = (int32_t)left; | |
} | |
int32_t nread = input->read(start, min, max); | |
if (nread < -1) { | |
fprintf(stderr, "substream too short.\n"); | |
StreamBase<T>::status = Error; | |
StreamBase<T>::error = input->getError(); | |
} else if (nread < min) { | |
if (StreamBase<T>::size == -1) { | |
StreamBase<T>::status = Eof; | |
if (nread > 0) { | |
StreamBase<T>::position += nread; | |
StreamBase<T>::size = StreamBase<T>::position; | |
} | |
} else { | |
// fprintf(stderr, "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! nread %i min %i max %i size %lli\n", nread, min, max, size); | |
// fprintf(stderr, "pos %lli parentpos %lli\n", position, input->getPosition()); | |
// fprintf(stderr, "status: %i error: %s\n", input->getStatus(), input->getError()); | |
// we expected data but didn't get enough so that's an error | |
StreamBase<T>::status = Error; | |
StreamBase<T>::error = "Premature end of stream\n"; | |
nread = -2; | |
} | |
} else { | |
StreamBase<T>::position += nread; | |
if (StreamBase<T>::position == StreamBase<T>::size) { | |
StreamBase<T>::status = Eof; | |
} | |
} | |
return nread; | |
} | |
template<class T> | |
int64_t SubInputStream<T>::reset(int64_t newpos) { | |
// fprintf(stderr, "subreset pos: %lli newpos: %lli offset: %lli\n", position, | |
// newpos, offset); | |
StreamBase<T>::position = input->reset(newpos + offset); | |
if (StreamBase<T>::position < offset) { | |
printf("###########\n"); | |
StreamBase<T>::status = Error; | |
StreamBase<T>::error = input->getError(); | |
} else { | |
StreamBase<T>::position -= offset; | |
StreamBase<T>::status = input->getStatus(); | |
} | |
return StreamBase<T>::position; | |
} | |
template<class T> | |
int64_t SubInputStream<T>::skip(int64_t ntoskip) { | |
// printf("subskip pos: %lli ntoskip: %lli offset: %lli\n", position, ntoskip, offset); | |
if (StreamBase<T>::size == StreamBase<T>::position) { | |
StreamBase<T>::status = Eof; | |
return -1; | |
} | |
if (StreamBase<T>::size != -1) { | |
const int64_t left = StreamBase<T>::size - StreamBase<T>::position; | |
// restrict the amount of data that can be skipped | |
if (ntoskip > left) { | |
ntoskip = left; | |
} | |
} | |
int64_t skipped = input->skip(ntoskip); | |
if (input->getStatus() == Error) { | |
StreamBase<T>::status = Error; | |
StreamBase<T>::error = input->getError(); | |
} else { | |
StreamBase<T>::position += skipped; | |
if (StreamBase<T>::position == StreamBase<T>::size) { | |
StreamBase<T>::status = Eof; | |
} | |
} | |
return skipped; | |
} | |
} //end namespace jstreams | |
#endif |