view base/HelperExecPath.h @ 1752:6d09d68165a4 by-id

Further review of ById: make IDs only available when adding a model to the ById store, not by querying the item directly. This means any id encountered in the wild must have been added to the store at some point (even if later released), which simplifies reasoning about lifecycles

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*
    Sonic Visualiser
    An audio file viewer and annotation editor.
    Centre for Digital Music, Queen Mary, University of London.
    This file copyright 2006-2016 Chris Cannam and QMUL.
    
    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.  See the file
    COPYING included with this distribution for more information.
*/

#ifndef SV_HELPER_EXEC_PATH_H
#define SV_HELPER_EXEC_PATH_H

#include <QStringList>

/**
 * Class to find helper executables that have been installed alongside
 * the application. There may be more than one executable available
 * with a given base name, because it's possible to have more than one
 * implementation of a given service. For example, a plugin helper or
 * scanner may exist in both 32-bit and 64-bit variants.
 *
 * This class encodes both the expected locations of helper
 * executables, and the expected priority between different
 * implementations (e.g. preferring the architecture that matches that
 * of the host).
 */
class HelperExecPath
{
public:
    enum SearchType {
        NativeArchitectureOnly,
        AllInstalled
    };
    
    HelperExecPath(SearchType type) : m_type(type) { }
    
    /**
     * Find a helper executable with the given base name in the bundle
     * directory or installation location, if one exists, and return
     * its full path. Equivalent to calling getHelperExecutables() and
     * taking the first result from the returned list (or "" if empty).
     */
    QString getHelperExecutable(QString basename);

    struct HelperExec {
        QString executable;
        QString tag;
    };
    
    /**
     * Find all helper executables with the given base name in the
     * bundle directory or installation location, and return their
     * full paths in order of priority. The "tag" string contains an
     * identifier for the location or architecture of the helper, for
     * example "32", "64", "js" etc. An empty tag signifies a default
     * helper that matches the application's architecture.
     */
    QList<HelperExec> getHelperExecutables(QString basename);

    /**
     * Return the list of directories searched for helper
     * executables.
     */
    QStringList getHelperDirPaths();
    
    /**
     * Return the list of executable paths examined in the search for
     * the helper executable with the given basename.
     */
    QStringList getHelperCandidatePaths(QString basename);

private:
    SearchType m_type;
    QList<HelperExec> search(QString, QStringList &);
    QStringList getTags();
};

#endif