125 lines
5 KiB
C++
125 lines
5 KiB
C++
/* Copyright (C) 2004 J.F.Dockes
|
|
* 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 _MH_EXECM_H_INCLUDED_
|
|
#define _MH_EXECM_H_INCLUDED_
|
|
|
|
#include "mh_exec.h"
|
|
#include "execmd.h"
|
|
|
|
/**
|
|
* Turn external document into internal one by executing an external filter.
|
|
*
|
|
* The command to execute, and its parameters, are stored in the "params"
|
|
* which is built in mimehandler.cpp out of data from the mimeconf file.
|
|
*
|
|
* This version uses persistent filters which can handle multiple requests
|
|
* without exiting (both multiple files and multiple documents per file),
|
|
* with a simple question/response protocol.
|
|
*
|
|
* The data is exchanged in TLV fashion, in a way that should be
|
|
* usable in most script languages. The basic unit of data has one line
|
|
* with a data type and a count (both ASCII), followed by the data. A
|
|
* 'message' is made of one or several units or tags and ends with one empty
|
|
* line.
|
|
*
|
|
* Example from recollindex (the message begins before 'Filename' and has
|
|
* 'Filename' and 'Ipath' tags):
|
|
*
|
|
Filename: 24
|
|
/my/home/mail/somefolderIpath: 2
|
|
22
|
|
|
|
<Message ends here: because of the empty line after '22'
|
|
|
|
*
|
|
* Example answer, with 'Mimetype' and 'Data' tags
|
|
*
|
|
Mimetype: 10
|
|
text/plainData: 10
|
|
0123456789
|
|
|
|
<Message ends here because of empty line
|
|
|
|
*
|
|
* This format is both extensible and reasonably easy to parse.
|
|
* While it's more fitted for python or perl on the script side, it
|
|
* should even be sort of usable from the shell (e.g.: use dd to read
|
|
* the counted data). Most alternatives would need data encoding in
|
|
* some cases.
|
|
*
|
|
* Higher level dialog:
|
|
* The C++ program is the master and sends request messages to the script.
|
|
* Both sides of the communication should be prepared to receive and discard
|
|
* unknown tags.
|
|
* The messages normally have the following tags:
|
|
* - Filename: the file to process. This can be empty meaning that we
|
|
* are requesting the next document in the current file.
|
|
* - Ipath: this will be present only if we are requesting a specific
|
|
* subdocument inside a container file (typically for preview, at query
|
|
* time). Absent during indexing (ipaths are generated and sent back from
|
|
* the script)
|
|
* - Mimetype: this is the mime type for the (possibly container) file.
|
|
* Can be useful to filters which handle multiple types, like rclaudio.
|
|
*
|
|
* The script answers with messages having the following fields:
|
|
* - Document: translated document data.
|
|
* - Ipath: ipath for the returned document. Can be used at query time to
|
|
* extract a specific subdocument for preview. Not present or empty for
|
|
* non-container files and for the "self" document of a container.
|
|
* - Mimetype: mime type for the returned data.
|
|
* This is optional. For multi-document filters, if mimetype is
|
|
* not present in the answer, the ipath must be a file-name-like
|
|
* string which will be used to divine the mime type (this is used
|
|
* typically with archives like Zip or Tar). If this fails,
|
|
* the document will be handled as unknown type and the contents won't
|
|
* be indexed. When neither ipath nor mimetype are present the default
|
|
* is to attempt to treat the document as HTML.
|
|
* - Charset: for document types for which it makes sense, and if the filter
|
|
* has the information.
|
|
* - Eofnow: empty field: no document is returned and we're at eof.
|
|
* - Eofnext: empty field: file ends after the doc returned by this message.
|
|
* - SubdocError: no subdoc returned by this request, but file goes on.
|
|
* - FileError: error, stop for this file.
|
|
*/
|
|
class MimeHandlerExecMultiple : public MimeHandlerExec {
|
|
/////////
|
|
// Things not reset by "clear()", additionally to those in MimeHandlerExec
|
|
ExecCmd m_cmd;
|
|
/////// End un-cleared stuff.
|
|
|
|
public:
|
|
MimeHandlerExecMultiple(RclConfig *cnf, const string& mt)
|
|
: MimeHandlerExec(cnf, mt)
|
|
{}
|
|
// No resources to clean up, the ExecCmd destructor does it.
|
|
virtual ~MimeHandlerExecMultiple() {}
|
|
virtual bool set_document_file(const string &file_path) {
|
|
m_filefirst = true;
|
|
return MimeHandlerExec::set_document_file(file_path);
|
|
}
|
|
virtual bool next_document();
|
|
|
|
// skip_to and clear inherited from MimeHandlerExec
|
|
|
|
private:
|
|
bool startCmd();
|
|
bool readDataElement(string& name, string& data);
|
|
bool m_filefirst;
|
|
int m_maxmemberkb;
|
|
};
|
|
|
|
#endif /* _MH_EXECM_H_INCLUDED_ */
|