recoll/src/internfile/mh_exec.cpp

/* Copyright (C) 2005 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.
 */
#include "cstr.h"
#include "execmd.h"
#include "mh_exec.h"
#include "mh_html.h"
#include "debuglog.h"
#include "cancelcheck.h"
#include "smallut.h"
#include "md5.h"
#include "rclconfig.h"

#include <sys/types.h>
#include <sys/wait.h>

#ifndef NO_NAMESPACES
using namespace std;
#endif /* NO_NAMESPACES */

// This is called periodically by ExeCmd when it is waiting for data,
// or when it does receive some. We may choose to interrupt the
// command.
class MEAdv : public ExecCmdAdvise {
public:
    MEAdv(int maxsecs) : m_filtermaxseconds(maxsecs) {m_start = time(0L);}
    void newData(int n) {
        LOGDEB1(("MHExec:newData(%d)\n", n));
        if (m_filtermaxseconds > 0 && 
            time(0L) - m_start > m_filtermaxseconds) {
            LOGERR(("MimeHandlerExec: filter timeout (%d S)\n",
                    m_filtermaxseconds));
            CancelCheck::instance().setCancel();
        }
        // If a cancel request was set by the signal handler (or by us
        // just above), this will raise an exception. Another approach
        // would be to call ExeCmd::setCancel().
	CancelCheck::instance().checkCancel();
    }
    time_t m_start;
    int m_filtermaxseconds;
};


bool MimeHandlerExec::skip_to_document(const string& ipath) 
{
    LOGDEB(("MimeHandlerExec:skip_to_document: [%s]\n", ipath.c_str()));
    m_ipath = ipath;
    return true;
}

// Execute an external program to translate a file from its native
// format to text or html.
bool MimeHandlerExec::next_document()
{
    if (m_havedoc == false)
	return false;
    m_havedoc = false;
    if (missingHelper) {
	LOGDEB(("MimeHandlerExec::next_document(): helper known missing\n"));
	return false;
    }

    int filtermaxseconds = 900;
    m_config->getConfParam("filtermaxseconds", &filtermaxseconds);

    if (params.empty()) {
	// Hu ho
	LOGERR(("MimeHandlerExec::mkDoc: empty params\n"));
	m_reason = "RECFILTERROR BADCONFIG";
	return false;
    }

    // Command name
    string cmd = params.front();
    
    // Build parameter vector: delete cmd name and add the file name
    vector<string>myparams(params.begin() + 1, params.end());
    myparams.push_back(m_fn);
    if (!m_ipath.empty())
	myparams.push_back(m_ipath);

    // Execute command, store the output
    string& output = m_metaData[cstr_dj_keycontent];
    output.erase();
    ExecCmd mexec;
    MEAdv adv(filtermaxseconds);
    mexec.setAdvise(&adv);
    mexec.putenv(m_forPreview ? "RECOLL_FILTER_FORPREVIEW=yes" :
		"RECOLL_FILTER_FORPREVIEW=no");

    int status;
    try {
        status = mexec.doexec(cmd, myparams, 0, &output);
    } catch (CancelExcept) {
	LOGERR(("MimeHandlerExec: cancelled\n"));
        status = 0x110f;
    }

    if (status) {
	LOGERR(("MimeHandlerExec: command status 0x%x for %s\n", 
		status, cmd.c_str()));
	if (WIFEXITED(status) && WEXITSTATUS(status) == 127) {
	    // That's how execmd signals a failed exec (most probably
	    // a missing command). Let'hope no filter uses the same value as
	    // an exit status... Disable myself permanently and signal the 
	    // missing cmd.
	    missingHelper = true;
	    m_reason = string("RECFILTERROR HELPERNOTFOUND ") + cmd;
	} else if (output.find("RECFILTERROR") == 0) {
	    // If the output string begins with RECFILTERROR, then it's 
	    // interpretable error information out from a recoll script
	    m_reason = output;
	    list<string> lerr;
	    stringToStrings(output, lerr);
	    if (lerr.size() > 2) {
		list<string>::iterator it = lerr.begin();
		it++;
		if (*it == "HELPERNOTFOUND") {
		    // No use trying again and again to execute this filter, 
		    // it won't work.
		    missingHelper = true;
		}
	    }		    
	}
	return false;
    }

    finaldetails();
    return true;
}

void MimeHandlerExec::handle_cs(const string& mt, const string& icharset)
{
    string charset(icharset);

    // cfgFilterOutputCharset comes from the mimeconf filter
    // definition line and defaults to UTF-8 if empty. If the value is
    // "default", we use the default input charset value defined in
    // recoll.conf (which may vary depending on directory)
    if (charset.empty()) {
	charset = cfgFilterOutputCharset.empty() ? cstr_utf8 : 
	    cfgFilterOutputCharset;
	if (!stringlowercmp("default", charset)) {
	    charset = m_dfltInputCharset;
	}
    }
    m_metaData[cstr_dj_keyorigcharset] = charset;

    // If this is text/plain transcode_to/check utf-8
    if (!mt.compare(cstr_textplain)) {
	(void)txtdcode("mh_exec/m");
    } else {
	m_metaData[cstr_dj_keycharset] = charset;
    }
}

void MimeHandlerExec::finaldetails()
{
    // The default output mime type is html, but it may be defined
    // otherwise in the filter definition.
    m_metaData[cstr_dj_keymt] = cfgFilterOutputMtype.empty() ? "text/html" : 
	cfgFilterOutputMtype;

    if (!m_forPreview) {
	string md5, xmd5, reason;
	if (MD5File(m_fn, md5, &reason)) {
	    m_metaData[cstr_dj_keymd5] = MD5HexPrint(md5, xmd5);
	} else {
	    LOGERR(("MimeHandlerExec: cant compute md5 for [%s]: %s\n", 
		    m_fn.c_str(), reason.c_str()));
	}
    }

    handle_cs(m_metaData[cstr_dj_keymt]);
}