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/* This file is part of Strigi Desktop Search
*
* Copyright (C) 2007 Alexandr Goncearenco <neksa@neksa.net>
*
* 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.
*/
#include <strigi/sdfinputstream.h>
#include <strigi/subinputstream.h>
#include <iostream>
#include <sstream>
#include <cstring>
using namespace std;
using namespace Strigi;
const string SdfInputStream::delimiter("$$$$");
const string SdfInputStream::label("V2000");
SdfInputStream::SdfInputStream(InputStream* input)
: SubStreamProvider(input), substream(0), entrynumber(0),
previousStartOfDelimiter(0) {
m_searcher.setQuery(delimiter);
}
SdfInputStream::~SdfInputStream() {
if (substream && substream != m_entrystream) {
delete substream;
}
}
/**
* Return a pointer that points past the current line. The line can end on
* either \r, \n, or \r\n.
* If the pointer would point past then end of the buffer or the line is longer
* than 80 bytes, NULL is returned.
**/
const char*
skip80Line(const char* data, int32_t size) {
if (size <= 0) return 0;
// EOL can be at position 80
int max = min(size, 81);
int i;
for (i=0; i<max && data[i] != '\n' && data[i] != '\r'; ++i) {
}
if (i == max) return 0;
if (data[i] == '\n') return (i+1 < size) ?data+i+1 :0;
// data[i] is known to be '\r' by now
if (i+1 < size && data[i+1] != '\n') return data+i+1;
// data[i+1] is known to be '\n' by now
return (i+2 < size) ?data+i+2 :0;
}
bool
SdfInputStream::checkHeader(const char* data, int32_t datasize) {
if (datasize <= 10) return false;
// the fourth line must contain the string "V2000"
// skip three lines of at most 80 bytes
const char* thisLine = 0;
const char* nextLine = data;
for (int i=0; i<4 && nextLine != 0; ++i) {
thisLine = nextLine;
nextLine = skip80Line(thisLine, datasize - (int32_t)(thisLine - data));
}
static const KmpSearcher searcher(label);
if (nextLine != 0) {
nextLine = searcher.search(thisLine, (int32_t)(nextLine - thisLine));
}
return nextLine != 0;
}
InputStream*
SdfInputStream::nextEntry() {
if (m_status != Ok) return 0;
m_input->reset(previousStartOfDelimiter);
int32_t nread = 0;
// read anything that's left over in the previous substream
if (substream) {
substream->reset(0);
const char* dummy;
while (substream->status() == Ok) {
substream->read(dummy, 1, 0);
}
if (substream->status() == Error) {
m_status = Error;
}
if (substream && substream != m_entrystream) {
delete substream;
}
substream = 0;
delete m_entrystream;
m_entrystream = 0;
m_input->reset(previousStartOfDelimiter);
// eat delimiter and following newlines
if (m_input->status() == Ok) {
nread = m_input->read(dummy, 4, 4);
if (nread == 4 && strncmp(dummy, delimiter.c_str(), 4) == 0) {
m_input->read(dummy, 1, 1);
while (m_input->status() == Ok && (
strncmp(dummy, "\n", 1) == 0
|| strncmp(dummy, "\r", 1) == 0)) {
m_input->read(dummy, 1, 1);
}
}
}
}
// make sure it is not a MOL
// we can not check it in checkHeader due to low header size limit
// There is only one way to destinguish between MOL and SD:
// MOL does not have $$$$ delimiter. Return no entries if it is a MOL.
const char* start;
const char* end;
int32_t total = 0;
const int64_t pos = m_input->position();
int64_t len=0;
while (m_input->status() == Ok) {
nread = m_input->read(start, 1024, 0);
if (nread > 0) {
end = m_searcher.search(start, nread);
if (end) {
len = end - start + total;
break;
}
total += nread;
}
}
if (m_input->status() == Error) {
m_status = Error;
m_entrystream = 0;
return 0;
}
m_input->reset(pos);
if (len > 0) {
// this stream is an SD
substream = new SubInputStream(m_input, len);
previousStartOfDelimiter = m_input->position() + len;
m_entryinfo.type = EntryInfo::File;
m_entryinfo.size = len;
m_entryinfo.filename.assign("Molecule");
entrynumber++;
ostringstream o;
o << entrynumber;
m_entryinfo.filename.append(o.str());
m_entrystream = substream;
return m_entrystream;
} else {
// this stream is a MOL itself, not an SD
m_status = Eof;
m_entrystream = 0;
return 0;
}
}
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