/* -*- mode:c++;c-basic-offset:2 -*- */
/* --------------------------------------------------------------------
* Filename:
* src/mime-inputsource.h
*
* Description:
* The base class of the MIME input source
* --------------------------------------------------------------------
* Copyright 2002-2005 Andreas Aardal Hanssen
*
* 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 Street #330, Boston, MA 02111-1307, USA.
* --------------------------------------------------------------------
*/
#ifndef mime_inputsource_h_included
#define mime_inputsource_h_included
#include "autoconfig.h"
// Data source for MIME parser
// Note about large files: we might want to change the unsigned int
// used for offsets into an off_t for intellectual satisfaction, but
// in the context of recoll, we could only get into trouble if a
// *single message* exceeded 2GB, which seems rather unlikely. When
// parsing a mailbox files, we read each message in memory and use the
// stream input source (from a memory buffer, no file offsets). When
// parsing a raw message file, it's only one message.
#include <string.h>
#include "safeunistd.h"
#include <iostream>
namespace Binc {
class MimeInputSource {
public:
// Note that we do NOT take ownership of fd, won't close it on delete
inline MimeInputSource(int fd, unsigned int start = 0);
virtual inline ~MimeInputSource(void);
virtual inline ssize_t fillRaw(char *raw, size_t nbytes);
virtual inline void reset(void);
virtual inline bool fillInputBuffer(void);
inline void seek(unsigned int offset);
inline bool getChar(char *c);
inline void ungetChar(void);
inline int getFileDescriptor(void) const;
inline unsigned int getOffset(void) const;
private:
int fd;
char data[16384];
unsigned int offset;
unsigned int tail;
unsigned int head;
unsigned int start;
char lastChar;
};
inline MimeInputSource::MimeInputSource(int fd, unsigned int start)
{
this->fd = fd;
this->start = start;
offset = 0;
tail = 0;
head = 0;
lastChar = '\0';
memset(data, '\0', sizeof(data));
seek(start);
}
inline MimeInputSource::~MimeInputSource(void)
{
}
inline ssize_t MimeInputSource::fillRaw(char *raw, size_t nbytes)
{
return read(fd, raw, nbytes);
}
inline bool MimeInputSource::fillInputBuffer(void)
{
char raw[4096];
ssize_t nbytes = fillRaw(raw, 4096);
if (nbytes <= 0) {
// FIXME: If ferror(crlffile) we should log this.
return false;
}
for (ssize_t i = 0; i < nbytes; ++i) {
const char c = raw[i];
if (c == '\r') {
if (lastChar == '\r') {
data[tail++ & (0x4000-1)] = '\r';
data[tail++ & (0x4000-1)] = '\n';
}
} else if (c == '\n') {
data[tail++ & (0x4000-1)] = '\r';
data[tail++ & (0x4000-1)] = '\n';
} else {
if (lastChar == '\r') {
data[tail++ & (0x4000-1)] = '\r';
data[tail++ & (0x4000-1)] = '\n';
}
data[tail++ & (0x4000-1)] = c;
}
lastChar = c;
}
return true;
}
inline void MimeInputSource::reset(void)
{
offset = head = tail = 0;
lastChar = '\0';
if (fd != -1)
lseek(fd, 0, SEEK_SET);
}
inline void MimeInputSource::seek(unsigned int seekToOffset)
{
if (offset > seekToOffset)
reset();
char c;
int n = 0;
while (seekToOffset > offset) {
if (!getChar(&c))
break;
++n;
}
}
inline bool MimeInputSource::getChar(char *c)
{
if (head == tail && !fillInputBuffer())
return false;
*c = data[head++ & (0x4000-1)];
++offset;
return true;
}
inline void MimeInputSource::ungetChar()
{
--head;
--offset;
}
inline int MimeInputSource::getFileDescriptor(void) const
{
return fd;
}
inline unsigned int MimeInputSource::getOffset(void) const
{
return offset;
}
///////////////////////////////////
class MimeInputSourceStream : public MimeInputSource {
public:
inline MimeInputSourceStream(istream& s, unsigned int start = 0);
virtual inline ssize_t fillRaw(char *raw, size_t nb);
virtual inline void reset(void);
private:
istream& s;
};
inline MimeInputSourceStream::MimeInputSourceStream(istream& si,
unsigned int start)
: MimeInputSource(-1, start), s(si)
{
}
inline ssize_t MimeInputSourceStream::fillRaw(char *raw, size_t nb)
{
// Why can't streams tell how many characters were actually read
// when hitting eof ?
std::streampos st = s.tellg();
s.seekg(0, ios::end);
std::streampos lst = s.tellg();
s.seekg(st);
size_t nbytes = size_t(lst - st);
if (nbytes > nb) {
nbytes = nb;
}
if (nbytes <= 0) {
return (ssize_t)-1;
}
s.read(raw, nbytes);
return static_cast<ssize_t>(nbytes);
}
inline void MimeInputSourceStream::reset(void)
{
MimeInputSource::reset();
s.seekg(0);
}
}
#endif