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/*
* Copyright (C) 2001-2005 Jacek Sieka, arnetheduck on gmail point com
*
* 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.
*/
#ifndef _FILTERED_FILE
#define _FILTERED_FILE
#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000
#include "Streams.h"
template<class Filter, bool managed>
class CalcOutputStream : public OutputStream {
public:
using OutputStream::write;
CalcOutputStream(OutputStream* aStream) : s(aStream) { }
virtual ~CalcOutputStream() throw() { if(managed) delete s; }
size_t flush() throw(Exception) {
return s->flush();
}
size_t write(const void* buf, size_t len) throw(Exception) {
filter(buf, len);
return s->write(buf, len);
}
const Filter& getFilter() const { return filter; }
private:
OutputStream* s;
Filter filter;
};
template<class Filter, bool managed>
class CalcInputStream : public InputStream {
public:
CalcInputStream(InputStream* aStream) : s(aStream) { }
virtual ~CalcInputStream() throw() { if(managed) delete s; }
size_t read(void* buf, size_t& len) throw(Exception) {
size_t x = s->read(buf, len);
filter(buf, x);
return x;
}
const Filter& getFilter() const { return filter; }
private:
InputStream* s;
Filter filter;
};
template<class Filter, bool manage>
class FilteredOutputStream : public OutputStream {
public:
using OutputStream::write;
FilteredOutputStream(OutputStream* aFile) : f(aFile), flushed(false) { }
~FilteredOutputStream() throw() { if(manage) delete f; }
size_t flush() throw(Exception) {
if(flushed)
return 0;
flushed = true;
size_t written = 0;
for(;;) {
size_t n = BUF_SIZE;
size_t zero = 0;
bool more = filter(NULL, zero, buf, n);
written += f->write(buf, n);
if(!more)
break;
}
return written + f->flush();
}
size_t write(const void* wbuf, size_t len) throw(Exception) {
if(flushed)
throw Exception("No filtered writes after flush");
u_int8_t* wb = (u_int8_t*)wbuf;
size_t written = 0;
while(len > 0) {
size_t n = BUF_SIZE;
size_t m = len;
bool more = filter(wb, m, buf, n);
wb += m;
len -= m;
written += f->write(buf, n);
if(!more) {
if(len > 0) {
throw Exception("Garbage data after end of stream");
}
flushed = true;
return written;
}
}
return written;
}
private:
enum { BUF_SIZE = 64*1024 };
OutputStream* f;
Filter filter;
u_int8_t buf[BUF_SIZE];
bool flushed;
};
template<class Filter, bool managed>
class FilteredInputStream : public InputStream {
public:
FilteredInputStream(InputStream* aFile) : f(aFile), pos(0), valid(0), more(true) { }
virtual ~FilteredInputStream() throw() { if(managed) delete f; }
/**
* Read data through filter, keep calling until len returns 0.
* @param rbuf Data buffer
* @param len Buffer size on entry, bytes actually read on exit
* @return Length of data in buffer
*/
size_t read(void* rbuf, size_t& len) throw(Exception) {
u_int8_t* rb = (u_int8_t*)rbuf;
size_t totalRead = 0;
size_t totalProduced = 0;
while(more && totalProduced < len) {
size_t curRead = BUF_SIZE;
if(valid == 0) {
dcassert(pos == 0);
valid = f->read(buf, curRead);
totalRead += curRead;
}
size_t n = len - totalProduced;
size_t m = valid - pos;
more = filter(buf + pos, m, rb, n);
pos += m;
if(pos == valid) {
valid = pos = 0;
}
totalProduced += n;
rb += n;
}
len = totalRead;
return totalProduced;
}
private:
enum { BUF_SIZE = 64*1024 };
InputStream* f;
Filter filter;
u_int8_t buf[BUF_SIZE];
size_t pos;
size_t valid;
bool more;
};
#endif // _FILTERED_FILE
/**
* @file
* $Id: FilteredFile.h,v 1.2 2005/08/21 14:03:43 olof Exp $
*/
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