/* Copyright (C) 2012 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 _FETCHER_H_INCLUDED_
#define _FETCHER_H_INCLUDED_
#include <sys/stat.h>
#include <string>
#include "rcldoc.h"
class RclConfig;
/**
* Definition for a generic method to retrieve the data
* for a document designated by its index data (udi/ipath/url).
* This is used to retrieve the data for previewing. The
* actual implementation is specific to the kind of backend (file
* system, beagle cache, others in the future ?), and of course may
* share code with the indexing-time functions from the specific backend.
*/
class DocFetcher {
public:
/** A RawDoc is the data for a source document either as a memory
block, or pointed to by a file name */
struct RawDoc {
enum RawDocKind {RDK_FILENAME, RDK_DATA};
RawDocKind kind;
std::string data; // Doc data or file name
struct stat st; // Only used if RDK_FILENAME
};
/**
* Return the data for the requested document, either as a
* file-system file or as a memory object (maybe stream too in the
* future?)
* @param cnf the global config
* @param idoc the data gathered from the index for this doc (udi/ipath)
* @param out we may return either a file name or the document data.
*/
virtual bool fetch(RclConfig* cnf, const Rcl::Doc& idoc, RawDoc& out) = 0;
/**
* Return the signature for the requested document. This is used for
* up-to-date tests performed out of indexing (e.g.: verifying that a
* document is not stale before previewing it).
* @param cnf the global config
* @param idoc the data gathered from the index for this doc (udi/ipath)
* @param sig output.
*/
virtual bool makesig(RclConfig* cnf, const Rcl::Doc& idoc, string& sig) = 0;
virtual ~DocFetcher() {}
};
/** Returns an appropriate fetcher object given the backend string identifier */
DocFetcher *docFetcherMake(const Rcl::Doc& idoc);
#endif /* _FETCHER_H_INCLUDED_ */