vmime/vmime/utility/parserInputStreamAdapter.hpp
2012-07-30 11:23:23 +02:00

174 lines
4.3 KiB
C++

//
// VMime library (http://www.vmime.org)
// Copyright (C) 2002-2012 Vincent Richard <vincent@vincent-richard.net>
//
// 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 3 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.
//
// Linking this library statically or dynamically with other modules is making
// a combined work based on this library. Thus, the terms and conditions of
// the GNU General Public License cover the whole combination.
//
#ifndef VMIME_UTILITY_PARSERINPUTSTREAMADAPTER_HPP_INCLUDED
#define VMIME_UTILITY_PARSERINPUTSTREAMADAPTER_HPP_INCLUDED
#include "vmime/utility/seekableInputStream.hpp"
#include <cstring>
namespace vmime {
namespace utility {
/** An adapter class used for parsing from an input stream.
*/
class parserInputStreamAdapter : public seekableInputStream
{
public:
/** @param is input stream to wrap
*/
parserInputStreamAdapter(ref <seekableInputStream> inputStream);
ref <seekableInputStream> getUnderlyingStream();
bool eof() const;
void reset();
size_type read(value_type* const data, const size_type count);
void seek(const size_type pos)
{
m_stream->seek(pos);
}
size_type skip(const size_type count)
{
return m_stream->skip(count);
}
size_type getPosition() const
{
return m_stream->getPosition();
}
/** Get the byte at the current position without updating the
* current position.
*
* @return byte at the current position
*/
value_type peekByte() const
{
const size_type initialPos = m_stream->getPosition();
try
{
value_type buffer[1];
const size_type readBytes = m_stream->read(buffer, 1);
m_stream->seek(initialPos);
return (readBytes == 1 ? buffer[0] : static_cast <value_type>(0));
}
catch (...)
{
m_stream->seek(initialPos);
throw;
}
}
/** Get the byte at the current position and advance current
* position by one byte.
*
* @return byte at the current position
*/
value_type getByte()
{
value_type buffer[1];
const size_type readBytes = m_stream->read(buffer, 1);
return (readBytes == 1 ? buffer[0] : static_cast <value_type>(0));
}
/** Check whether the bytes following the current position match
* the specified bytes. Position is not updated.
*
* @param bytes bytes to compare
* @param length number of bytes
* @return true if the next bytes match the pattern, false otherwise
*/
bool matchBytes(const value_type* bytes, const size_type length) const
{
const size_type initialPos = m_stream->getPosition();
try
{
value_type buffer[32];
const size_type readBytes = m_stream->read(buffer, length);
m_stream->seek(initialPos);
return readBytes == length &&
::memcmp(bytes, buffer, length) == 0;
}
catch (...)
{
m_stream->seek(initialPos);
throw;
}
}
const string extract(const size_type begin, const size_type end) const;
/** Skips bytes matching a predicate from the current position.
* The current position is updated to the next following byte
* which does not match the predicate.
*
* @param pred predicate
* @param endPosition stop at this position (or at end of the stream,
* whichever comes first)
* @return number of bytes skipped
*/
template <typename PREDICATE>
size_type skipIf(PREDICATE pred, const size_type endPosition)
{
const size_type initialPos = getPosition();
size_type pos = initialPos;
while (!m_stream->eof() && pos < endPosition && pred(getByte()))
++pos;
m_stream->seek(pos);
return pos - initialPos;
}
size_type findNext(const std::string& token, const size_type startPosition = 0);
private:
mutable ref <seekableInputStream> m_stream;
};
} // utility
} // vmime
#endif // VMIME_UTILITY_PARSERINPUTSTREAMADAPTER_HPP_INCLUDED