//
// VMime library (http://www.vmime.org)
// Copyright (C) 2002 Vincent Richard <vincent@vmime.org>
//
// 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_FILTEREDSTREAM_HPP_INCLUDED
#define VMIME_UTILITY_FILTEREDSTREAM_HPP_INCLUDED
#include <algorithm>
#include "vmime/utility/inputStream.hpp"
#include "vmime/utility/outputStream.hpp"
namespace vmime {
namespace utility {
/** A stream whose input is filtered.
*/
class VMIME_EXPORT filteredInputStream : public inputStream {
public:
virtual size_t getBlockSize();
/** Return a reference to the stream being filtered.
*
* @return stream being filtered
*/
virtual inputStream& getPreviousInputStream() = 0;
};
/** A stream whose output is filtered.
*/
class VMIME_EXPORT filteredOutputStream : public outputStream {
public:
virtual size_t getBlockSize();
/** Return a reference to the stream being filtered.
*
* @return destination stream for filtered data
*/
virtual outputStream& getNextOutputStream() = 0;
};
/** A filtered input stream which replaces "\n.."
* sequences with "\n." sequences.
*/
class VMIME_EXPORT dotFilteredInputStream : public filteredInputStream {
public:
/** Construct a new filter for the specified input stream.
*
* @param is stream from which to read data to be filtered
*/
dotFilteredInputStream(inputStream& is);
inputStream& getPreviousInputStream();
bool eof() const;
void reset();
size_t read(byte_t* const data, const size_t count);
size_t skip(const size_t count);
private:
inputStream& m_stream;
byte_t m_previousChar2; // (N - 1)th character of previous buffer
byte_t m_previousChar1; // (N)th (last) character of previous buffer
};
/** A filtered output stream which replaces "\n."
* sequences with "\n.." sequences.
*/
class VMIME_EXPORT dotFilteredOutputStream : public filteredOutputStream {
public:
/** Construct a new filter for the specified output stream.
*
* @param os stream into which write filtered data
*/
dotFilteredOutputStream(outputStream& os);
outputStream& getNextOutputStream();
void flush();
size_t getBlockSize();
protected:
void writeImpl(const byte_t* const data, const size_t count);
private:
outputStream& m_stream;
byte_t m_previousChar;
bool m_start;
};
/** A filtered output stream which replaces CRLF sequences
* with single LF characters.
*/
class VMIME_EXPORT CRLFToLFFilteredOutputStream : public filteredOutputStream {
public:
/** Construct a new filter for the specified output stream.
*
* @param os stream into which write filtered data
*/
CRLFToLFFilteredOutputStream(outputStream& os);
outputStream& getNextOutputStream();
void flush();
size_t getBlockSize();
protected:
void writeImpl(const byte_t* const data, const size_t count);
private:
outputStream& m_stream;
byte_t m_previousChar;
};
/** A filtered output stream which replaces CR or LF characters
* with CRLF sequences.
*/
class VMIME_EXPORT LFToCRLFFilteredOutputStream : public filteredOutputStream {
public:
/** Construct a new filter for the specified output stream.
*
* @param os stream into which write filtered data
*/
LFToCRLFFilteredOutputStream(outputStream& os);
outputStream& getNextOutputStream();
void flush();
size_t getBlockSize();
protected:
void writeImpl(const byte_t* const data, const size_t count);
private:
outputStream& m_stream;
byte_t m_previousChar;
};
/** A filtered input stream which stops when a specified sequence
* is found (eof() method will return 'true').
*/
template <int COUNT>
class VMIME_EXPORT stopSequenceFilteredInputStream : public filteredInputStream {
public:
/** Construct a new filter for the specified input stream.
*
* @param is stream from which to read data to be filtered
* @param sequence sequence on which to stop
*/
stopSequenceFilteredInputStream(inputStream& is, const byte_t* sequence)
: m_stream(is),
m_sequence(sequence),
m_found(0),
m_eof(false) {
}
/** Construct a new filter for the specified input stream.
*
* @param is stream from which to read data to be filtered
* @param sequence sequence on which to stop
*/
stopSequenceFilteredInputStream(inputStream& is, const char* sequence)
: m_stream(is),
m_sequence(reinterpret_cast <const byte_t*>(sequence)),
m_found(0),
m_eof(false) {
}
inputStream& getPreviousInputStream() {
return m_stream;
}
bool eof() const {
return m_found == COUNT || m_eof;
}
void reset() {
m_found = 0;
m_stream.reset();
}
size_t read(byte_t* const data, const size_t count) {
// Read buffer must be at least 'COUNT' size + 1 byte
if (eof() || count <= COUNT) {
return 0;
}
if (m_stream.eof()) {
if (m_found != 0) {
const size_t found = m_found;
for (size_t f = 0 ; f < found ; ++f) {
data[f] = m_sequence[f];
}
m_found = 0;
m_eof = true;
return found;
} else {
m_eof = true;
return 0;
}
}
size_t read = m_stream.read(data, count - COUNT);
byte_t* end = data + read;
byte_t* pos = data;
while (pos < end) {
// Very simple case, search for the whole sequence
if (m_found == 0) {
while (pos < end) {
pos = std::find(pos, end, m_sequence[0]);
if (pos == end) {
return read;
}
m_found = 1;
++pos;
while (pos < end && m_found < COUNT && m_sequence[m_found] == *pos) {
++m_found;
++pos;
}
// Didn't found whole sequence
if (m_found != COUNT) {
// We reached the end of the buffer
if (pos == end) {
return read - m_found;
// Common prefix but not whole sequence
} else {
m_found = 0;
}
// Whole sequence found
} else {
// End of stream
return pos - data - m_found;
}
}
// More complex case: search for a sequence which has begun
// in a previous buffer
} else {
// Search for the end of the previously started sequence
while (pos < end && m_found < COUNT && m_sequence[m_found] == *pos) {
++m_found;
++pos;
}
if (m_found != COUNT) {
// End of buffer
if (pos == end) {
// No data: this buffer is a sub-sequence of the
// searched sequence
return 0;
// Common prefix
} else {
// We have to reinject the incomplete sequence into
// the stream data
// -- shift right data
const size_t n = pos - data;
byte_t* newEnd = data + read + m_found - n;
byte_t* oldEnd = data + read;
for (size_t i = 0 ; i < read - n ; ++i) {
--newEnd;
--oldEnd;
*newEnd = *oldEnd;
}
// -- copy the prefix just before data
for (size_t f = 0 ; f < m_found ; ++f) {
data[f] = m_sequence[f];
}
read += m_found - n;
end += m_found - n;
m_found = 0;
}
} else {
return 0; // no more data
}
}
}
return read;
}
size_t skip(const size_t /* count */) {
// Not supported
return 0;
}
private:
inputStream& m_stream;
const byte_t* m_sequence;
size_t m_found;
bool m_eof;
};
template <>
size_t stopSequenceFilteredInputStream <1>::read(byte_t* const data, const size_t count);
} // utility
} // vmime
#endif // VMIME_UTILITY_FILTEREDSTREAM_HPP_INCLUDED
