Add a IDeviceLister interface.

This will be used on OSes that make it painfull to list devices, be it
because of permissions or lack of APIs or anything else.

Makefile.am

@@ -55,6 +55,7 @@ libmedialibrary_la_SOURCES = \
 	src/discoverer/DiscovererWorker.cpp \
 	src/discoverer/FsDiscoverer.cpp \
 	src/factory/FileSystem.cpp \
+	src/factory/DeviceListerFactory.cpp \
 	src/filesystem/common/CommonFile.cpp \
 	src/logging/IostreamLogger.cpp \
 	src/logging/Logger.cpp \
@@ -107,11 +108,13 @@ noinst_HEADERS = \
 	src/discoverer/DiscovererWorker.h \
 	src/discoverer/FsDiscoverer.h \
 	src/factory/FileSystem.h \
+	src/factory/DeviceListerFactory.h \
 	src/File.h \
 	src/filesystem/common/CommonFile.h \
 	src/filesystem/unix/Device.h \
 	src/filesystem/unix/Directory.h \
 	src/filesystem/unix/File.h \
+	src/filesystem/unix/DeviceLister.h \
 	src/filesystem/win32/Directory.h \
 	src/filesystem/win32/File.h \
 	src/Folder.h \
@@ -155,7 +158,9 @@ libmedialibrary_la_SOURCES += \
 	src/filesystem/unix/File.cpp
 if HAVE_LINUX
 libmedialibrary_la_SOURCES += \
-	src/filesystem/unix/Device.cpp
+	src/filesystem/unix/Device.cpp \
+	src/filesystem/unix/DeviceLister.cpp \
+	$(NULL)
 endif
 if HAVE_DARWIN
 libmedialibrary_macos_la_SOURCES = \

include/IDeviceLister.h

+/*****************************************************************************
+ * Media Library
+ *****************************************************************************
+ * Copyright (C) 2015 Hugo Beauzée-Luyssen, Videolabs
+ *
+ * Authors: Hugo Beauzée-Luyssen<hugo@beauzee.fr>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#pragma once
+
+#include <tuple>
+#include <vector>
+
+namespace medialibrary
+{
+
+class IDeviceListerCb
+{
+public:
+    virtual ~IDeviceListerCb() = default;
+    /**
+     * @brief onDevicePlugged Shall be invoked when a known device gets plugged
+     * @param uuid The device UUID
+     * @param mountpoint The device new mountpoint
+     */
+    virtual void onDevicePlugged( const std::string& uuid, const std::string& mountpoint ) = 0;
+    /**
+     * @brief onDeviceUnplugged Shall be invoked when a known device gets unplugged
+     * @param uuid The device UUID
+     */
+    virtual void onDeviceUnplugged( const std::string& uuid ) = 0;
+};
+
+class IDeviceLister
+{
+public:
+    virtual ~IDeviceLister() = default;
+    /**
+     * @brief devices Returns a tuple containing:
+     * - The device UUID
+     * - The device mountpoint
+     * - A 'removable' state, being true if the device can be removed, false otherwise.
+     * @return
+     */
+    virtual std::vector<std::tuple<std::string, std::string, bool>> devices() const = 0;
+};
+}

include/medialibrary/IMediaLibrary.h

@@ -220,6 +220,20 @@ class IMediaLibrary
         virtual void resumeBackgroundOperations() = 0;
         virtual void reload() = 0;
         virtual void reload( const std::string& entryPoint ) = 0;
+
+        /**
+         * @brief setDeviceLister Sets a device lister.
+         * This is meant for OSes with complicated/impossible to achieve device listing (due to
+         * missing APIs, permissions problems...)
+         * @param lister A device lister
+         * @return In case of successfull registration, this will return a IDeviceListerCb, which
+         * can be used to signal changes related to the devices available. This callback is owned by
+         * the medialibrary, and must *NOT* be released by the application.
+         * In case of failure, nullptr will be returned.
+         *
+         * This must be called *before* initialize()
+         */
+        virtual IDeviceListerCb* setDeviceLister( DeviceListerPtr lister ) = 0;
 };
 
 }

include/medialibrary/Types.h

@@ -44,6 +44,8 @@ class ILogger;
 class IArtist;
 class IPlaylist;
 class IMediaLibraryCb;
+class IDeviceLister;
+class IDeviceListerCb;
 
 using AlbumPtr = std::shared_ptr<IAlbum>;
 using AlbumTrackPtr = std::shared_ptr<IAlbumTrack>;
@@ -59,6 +61,7 @@ using PlaylistPtr = std::shared_ptr<IPlaylist>;
 using ShowEpisodePtr = std::shared_ptr<IShowEpisode>;
 using ShowPtr = std::shared_ptr<IShow>;
 using VideoTrackPtr = std::shared_ptr<IVideoTrack>;
+using DeviceListerPtr = std::shared_ptr<IDeviceLister>;
 
 }
 

src/MediaLibrary.cpp

@@ -59,6 +59,8 @@
 #include "metadata_services/vlc/VLCThumbnailer.h"
 #include "metadata_services/MetadataParser.h"
 
+// FileSystem
+#include "factory/DeviceListerFactory.h"
 #include "factory/FileSystem.h"
 
 namespace medialibrary
@@ -195,8 +197,14 @@ bool MediaLibrary::validateSearchPattern( const std::string& pattern )
 
 bool MediaLibrary::initialize( const std::string& dbPath, const std::string& thumbnailPath, IMediaLibraryCb* mlCallback )
 {
+    if ( m_deviceLister == nullptr )
+    {
+        m_deviceLister = factory::createDeviceLister();
+        if ( m_deviceLister == nullptr )
+            return false;
+    }
     if ( m_fsFactory == nullptr )
-        m_fsFactory.reset( new factory::FileSystemFactory );
+        m_fsFactory.reset( new factory::FileSystemFactory( m_deviceLister ) );
     Folder::setFileSystemFactory( m_fsFactory );
     if ( mkdir( thumbnailPath.c_str(), S_IRWXU ) != 0 )
     {
@@ -582,6 +590,12 @@ std::shared_ptr<ModificationNotifier> MediaLibrary::getNotifier() const
     return m_modificationNotifier;
 }
 
+IDeviceListerCb* MediaLibrary::setDeviceLister( DeviceListerPtr lister )
+{
+    m_deviceLister = lister;
+    return static_cast<IDeviceListerCb*>( this );
+}
+
 void MediaLibrary::discover( const std::string &entryPoint )
 {
     if ( m_discoverer != nullptr )
@@ -621,4 +635,12 @@ void MediaLibrary::setLogger( ILogger* logger )
     Log::SetLogger( logger );
 }
 
+void MediaLibrary::onDevicePlugged( const std::string&, const std::string& )
+{
+}
+
+void MediaLibrary::onDeviceUnplugged( const std::string& )
+{
+}
+
 }

src/MediaLibrary.h

@@ -27,6 +27,8 @@
 #include "logging/Logger.h"
 #include "Settings.h"
 
+#include <IDeviceLister.h>
+
 namespace medialibrary
 {
 
@@ -55,7 +57,7 @@ class IFile;
 class IDirectory;
 }
 
-class MediaLibrary : public IMediaLibrary
+class MediaLibrary : public IMediaLibrary, public IDeviceListerCb
 {
     public:
         MediaLibrary();
@@ -125,6 +127,8 @@ class MediaLibrary : public IMediaLibrary
         IMediaLibraryCb* getCb() const;
         std::shared_ptr<ModificationNotifier> getNotifier() const;
 
+        virtual IDeviceListerCb* setDeviceLister( DeviceListerPtr lister ) override;
+
     public:
         static const uint32_t DbModelVersion;
 
@@ -141,11 +145,17 @@ class MediaLibrary : public IMediaLibrary
         void registerEntityHooks();
         static bool validateSearchPattern( const std::string& pattern );
 
+        // Mark IDeviceListerCb callbacks as private. They must be invoked through the interface.
+    private:
+        virtual void onDevicePlugged(const std::string& uuid, const std::string& mountpoint) override;
+        virtual void onDeviceUnplugged(const std::string& uuid) override;
+
     protected:
         std::unique_ptr<SqliteConnection> m_dbConnection;
         std::shared_ptr<factory::IFileSystem> m_fsFactory;
         std::string m_thumbnailPath;
         IMediaLibraryCb* m_callback;
+        DeviceListerPtr m_deviceLister;
 
         // Keep the parser as last field.
         // The parser holds a (raw) pointer to the media library. When MediaLibrary's destructor gets called

src/factory/DeviceListerFactory.cpp

+/*****************************************************************************
+ * Media Library
+ *****************************************************************************
+ * Copyright (C) 2015 Hugo Beauzée-Luyssen, Videolabs
+ *
+ * Authors: Hugo Beauzée-Luyssen<hugo@beauzee.fr>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#include "DeviceListerFactory.h"
+
+#if defined(__linux__) && !defined(__ANDROID__)
+#include "filesystem/unix/DeviceLister.h"
+#endif
+
+medialibrary::DeviceListerPtr medialibrary::factory::createDeviceLister()
+{
+#if defined(__linux__) && !defined(__ANDROID__)
+    return std::make_shared<fs::DeviceLister>();
+#endif
+    return nullptr;
+}

src/factory/DeviceListerFactory.h

+/*****************************************************************************
+ * Media Library
+ *****************************************************************************
+ * Copyright (C) 2015 Hugo Beauzée-Luyssen, Videolabs
+ *
+ * Authors: Hugo Beauzée-Luyssen<hugo@beauzee.fr>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#pragma once
+
+#include "medialibrary/Types.h"
+
+namespace medialibrary
+{
+namespace factory
+{
+DeviceListerPtr createDeviceLister();
+}
+}

src/factory/FileSystem.cpp

@@ -42,6 +42,11 @@ namespace medialibrary
 namespace factory
 {
 
+FileSystemFactory::FileSystemFactory( DeviceListerPtr lister )
+{
+    fs::Device::setDeviceLister( lister );
+}
+
 std::shared_ptr<fs::IDirectory> FileSystemFactory::createDirectory( const std::string& path )
 {
     std::lock_guard<std::mutex> lock( m_mutex );
@@ -68,7 +73,6 @@ std::shared_ptr<fs::IDevice> FileSystemFactory::createDevice( const std::string&
 
 void FileSystemFactory::refresh()
 {
-    fs::Device::populateCache();
     std::lock_guard<std::mutex> lock( m_mutex );
     m_dirs.clear();
 }

src/factory/FileSystem.h

@@ -23,6 +23,7 @@
 #pragma once
 
 #include "factory/IFileSystem.h"
+#include "medialibrary/Types.h"
 
 #include <mutex>
 #include <string>
@@ -36,6 +37,7 @@ namespace factory
     class FileSystemFactory : public IFileSystem
     {
     public:
+        FileSystemFactory( DeviceListerPtr lister );
         virtual std::shared_ptr<fs::IDirectory> createDirectory( const std::string& path ) override;
         virtual std::shared_ptr<fs::IDevice> createDevice( const std::string& uuid ) override;
         virtual void refresh() override;

src/filesystem/unix/Device.cpp

@@ -22,17 +22,8 @@
 
 #include "Device.h"
 #include "Directory.h"
-#include "utils/Filename.h"
 #include "logging/Logger.h"
-
-#include <algorithm>
-#include <cstring>
-#include <cstdio>
-#include <dirent.h>
-#include <limits.h>
-#include <mntent.h>
-#include <unistd.h>
-#include <sys/types.h>
+#include "IDeviceLister.h"
 
 namespace
 {
@@ -50,9 +41,8 @@ namespace medialibrary
 namespace fs
 {
 
-Device::DeviceMap Device::Devices;
-Device::MountpointMap Device::Mountpoints;
-Device::DeviceCacheMap Device::DeviceCache;
+Cache<Device::DeviceCacheMap> Device::DeviceCache;
+DeviceListerPtr Device::DeviceLister;
 
 Device::Device( const std::string& uuid, const std::string& mountpoint, bool isRemovable )
     : m_uuid( uuid )
@@ -86,8 +76,9 @@ const std::string&Device::mountpoint() const
 
 std::shared_ptr<IDevice> Device::fromPath( const std::string& path )
 {
+    auto lock = DeviceCache.lock();
     std::shared_ptr<IDevice> res;
-    for ( const auto& p : DeviceCache )
+    for ( const auto& p : DeviceCache.get() )
     {
         if ( path.find( p.second->mountpoint() ) == 0 )
         {
@@ -100,197 +91,40 @@ std::shared_ptr<IDevice> Device::fromPath( const std::string& path )
 
 std::shared_ptr<IDevice> Device::fromUuid( const std::string& uuid )
 {
-    auto it = DeviceCache.find( uuid );
-    if ( it != end( DeviceCache ) )
+    auto lock = DeviceCache.lock();
+
+    auto it = DeviceCache.get().find( uuid );
+    if ( it != end( DeviceCache.get() ) )
         return it->second;
     return nullptr;
 }
 
-bool Device::populateCache()
+void Device::setDeviceLister( DeviceListerPtr lister )
 {
-    Devices = listDevices();
-    Mountpoints = listMountpoints();
-    DeviceCache = populateDeviceCache();
-    return true;
+    auto lock = DeviceCache.lock();
+    DeviceLister = lister;
+    refreshDeviceCacheLocked();
 }
 
-Device::DeviceMap Device::listDevices()
+void Device::refreshDeviceCache()
 {
-    static const std::vector<std::string> deviceBlacklist = { "loop", "dm-" };
-    const std::string devPath = "/dev/disk/by-uuid/";
-    // Don't use fs::Directory to iterate, as it resolves the symbolic links automatically.
-    // We need the link name & what it points to.
-    std::unique_ptr<DIR, int(*)(DIR*)> dir( opendir( devPath.c_str() ), &closedir );
-    if ( dir == nullptr )
-    {
-        std::stringstream err;
-        err << "Failed to open /dev/disk/by-uuid: " << strerror(errno);
-        throw std::runtime_error( err.str() );
-    }
-    DeviceMap res;
-    dirent* result = nullptr;
-
-    while ( ( result = readdir( dir.get() ) ) != nullptr )
-    {
-        if ( strcmp( result->d_name, "." ) == 0 ||
-             strcmp( result->d_name, ".." ) == 0 )
-        {
-            continue;
-        }
-        std::string path = devPath + result->d_name;
-        char linkPath[PATH_MAX] = {};
-        if ( readlink( path.c_str(), linkPath, PATH_MAX ) < 0 )
-        {
-            std::stringstream err;
-            err << "Failed to resolve uuid -> device link: "
-                << result->d_name << " (" << strerror(errno) << ')';
-            throw std::runtime_error( err.str() );
-        }
-        auto deviceName = utils::file::fileName( linkPath );
-        if ( std::find_if( begin( deviceBlacklist ), end( deviceBlacklist ), [&deviceName]( const std::string& pattern ) {
-                return deviceName.length() >= pattern.length() && deviceName.find( pattern ) == 0;
-            }) != end( deviceBlacklist ) )
-            continue;
-        auto uuid = result->d_name;
-        LOG_INFO( "Discovered device ", deviceName, " -> {", uuid, '}' );
-        res[deviceName] = uuid;
-    }
-    return res;
-}
-
-Device::MountpointMap Device::listMountpoints()
-{
-    static const std::vector<std::string> allowedFsType = { "vfat", "exfat", "sdcardfs", "fuse",
-                                                            "ntfs", "fat32", "ext3", "ext4", "esdfs" };
-    MountpointMap res;
-    errno = 0;
-    mntent* s;
-#ifndef __ANDROID__
-    char buff[512];
-    mntent smnt;
-    FILE* f = setmntent("/etc/mtab", "r");
-    if ( f == nullptr )
-        throw std::runtime_error( "Failed to read /etc/mtab" );
-    std::unique_ptr<FILE, int(*)(FILE*)> fPtr( f, &endmntent );
-    while ( getmntent_r( f, &smnt, buff, sizeof(buff) ) != nullptr )
-    {
-        s = &smnt;
-#else
-    FILE* f = fopen( "/proc/mounts", "r" );
-    std::unique_ptr<FILE, int(*)(FILE*)> fPtr( f, &fclose );
-    while ( ( s = getmntent( f ) ) )
-    {
-#endif
-        if ( std::find( begin( allowedFsType ), end( allowedFsType ), s->mnt_type ) == end( allowedFsType ) )
-            continue;
-        auto deviceName = s->mnt_fsname;
-        LOG_INFO( "Discovered mountpoint ", deviceName, " mounted on ", s->mnt_dir, " (", s->mnt_type, ')' );
-        res[deviceName] = s->mnt_dir;
-        errno = 0;
-    }
-    if ( errno != 0 )
-    {
-        LOG_ERROR( "Failed to read mountpoints: ", strerror( errno ) );
-    }
-    return res;
+    auto lock = DeviceCache.lock();
+    refreshDeviceCacheLocked();
 }
 
-Device::DeviceCacheMap Device::populateDeviceCache()
+void Device::refreshDeviceCacheLocked()
 {
-    Device::DeviceCacheMap res;
-    for ( const auto& p : Mountpoints )
-    {
-        const auto& devicePath = p.first;
-        auto deviceName = utils::file::fileName( devicePath );
-        const auto& mountpoint = p.second;
-        auto it = Devices.find( deviceName );
-        std::string uuid;
-        if ( it != end( Devices ) )
-            uuid = it->second;
-        else
-        {
-#ifndef __ANDROID__
-            deviceName = deviceFromDeviceMapper( devicePath );
-            it = Devices.find( deviceName );
-            if ( it != end( Devices ) )
-                uuid = it->second;
-            else
-#endif
-            {
-                LOG_ERROR( "Failed to resolve mountpoint ", mountpoint, " to any known device" );
-                continue;
-            }
-        }
-        auto removable = isRemovable( deviceName, mountpoint );
-        LOG_INFO( "Adding device to cache: {", uuid, "} mounted on ", mountpoint, " Removable: ", removable );
-        res[uuid] = std::make_shared<DeviceBuilder>( uuid, mountpoint, removable );
-    }
-    return res;
-}
-
-std::string Device::deviceFromDeviceMapper( const std::string& devicePath )
-{
-    if ( devicePath.find( "/dev/mapper" ) != 0 )
-        return {};
-    char linkPath[PATH_MAX];
-    if ( readlink( devicePath.c_str(), linkPath, PATH_MAX ) < 0 )
-    {
-        std::stringstream err;
-        err << "Failed to resolve device -> mapper link: "
-            << devicePath << " (" << strerror(errno) << ')';
-        throw std::runtime_error( err.str() );
-    }
-    const auto dmName = utils::file::fileName( linkPath );
-    std::string dmSlavePath = "/sys/block/" + dmName + "/slaves";
-    std::unique_ptr<DIR, int(*)(DIR*)> dir( opendir( dmSlavePath.c_str() ), &closedir );
-    std::string res;
-    if ( dir == nullptr )
-        return {};
-    dirent* result;
-    while ( ( result = readdir( dir.get() ) ) != nullptr )
-    {
-        if ( strcmp( result->d_name, "." ) == 0 ||
-             strcmp( result->d_name, ".." ) == 0 )
-        {
-            continue;
-        }
-        if ( res.empty() == true )
-            res = result->d_name;
-        else
-            LOG_WARN( "More than one slave for device mapper ", linkPath );
-    }
-    LOG_INFO( "Device mapper ", dmName, " maps to ", res );
-    return res;
-}
-
-bool Device::isRemovable( const std::string& deviceName, const std::string& mountpoint )
-{
-#ifndef TIZEN
-    (void)mountpoint;
-    std::stringstream removableFilePath;
-    removableFilePath << "/sys/block/" << deviceName << "/removable";
-    std::unique_ptr<FILE, int(*)(FILE*)> removableFile( fopen( removableFilePath.str().c_str(), "r" ), &fclose );
-    // Assume the file isn't removable by default
-    if ( removableFile != nullptr )
-    {
-        char buff;
-        if ( fread(&buff, sizeof(buff), 1, removableFile.get() ) != 1 )
-            return buff == '1';
-        return false;
-    }
-#else
-    (void)deviceName;
-    static const std::vector<std::string> SDMountpoints = { "/opt/storage/sdcard" };
-    auto it = std::find_if( begin( SDMountpoints ), end( SDMountpoints ), [mountpoint]( const std::string& pattern ) {
-        return mountpoint.length() >= pattern.length() && mountpoint.find( pattern ) == 0;
-    });
-    if ( it != end( SDMountpoints ) )
+    if ( DeviceCache.isCached() == false )
+        DeviceCache = DeviceCacheMap{};
+    DeviceCache.get().clear();
+    auto devices = DeviceLister->devices();
+    for ( const auto& d : devices )
     {
-        LOG_INFO( "Considering mountpoint ", mountpoint, " a removable SDCard" );
-        return true;
+        const auto& uuid = std::get<0>( d );
+        const auto& mountpoint = std::get<1>( d );
+        const auto removable = std::get<2>( d );
+        DeviceCache.get().emplace( uuid, std::make_shared<DeviceBuilder>( uuid, mountpoint, removable ) );
     }
-#endif
-    return false;
 }
 
 }

src/filesystem/unix/Device.h

@@ -23,6 +23,9 @@
 #pragma once
 
 #include "filesystem/IDevice.h"
+#include "medialibrary/Types.h"
+#include "utils/Cache.h"
+
 #include <memory>
 #include <unordered_map>
 
@@ -34,10 +37,6 @@ namespace fs
 
 class Device : public IDevice
 {
-    // Device name / UUID map
-    using DeviceMap = std::unordered_map<std::string, std::string>;
-    // Device path / Mountpoints map
-    using MountpointMap = std::unordered_map<std::string, std::string>;
     // UUID -> Device instance map
     using DeviceCacheMap = std::unordered_map<std::string, std::shared_ptr<IDevice>>;
 
@@ -52,22 +51,19 @@ public:
     ///
     static std::shared_ptr<IDevice> fromPath( const std::string& path );
     static std::shared_ptr<IDevice> fromUuid( const std::string& uuid );
-    static bool populateCache();
+
+    static void setDeviceLister( DeviceListerPtr lister );
+    static void refreshDeviceCache();
 
 protected:
     Device( const std::string& uuid, const std::string& mountpoint, bool isRemovable );
 
 private:
-    static DeviceMap listDevices();
-    static MountpointMap listMountpoints();
-    static DeviceCacheMap populateDeviceCache();
-    static std::string deviceFromDeviceMapper( const std::string& devicePath );
-    static bool isRemovable( const std::string& deviceName, const std::string& mountpoint );
+    static void refreshDeviceCacheLocked();
 
 private:
-    static DeviceMap Devices;
-    static MountpointMap Mountpoints;
-    static DeviceCacheMap DeviceCache;
+    static Cache<DeviceCacheMap> DeviceCache;
+    static DeviceListerPtr DeviceLister;
 
 private:
     std::string m_uuid;

src/filesystem/unix/DeviceLister.cpp

+/*****************************************************************************
+ * Media Library
+ *****************************************************************************
+ * Copyright (C) 2015 Hugo Beauzée-Luyssen, Videolabs
+ *
+ * Authors: Hugo Beauzée-Luyssen<hugo@beauzee.fr>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include "DeviceLister.h"
+#include "logging/Logger.h"
+#include "utils/Filename.h"
+
+#include <dirent.h>
+#include <mntent.h>
+#include <sys/types.h>
+#include <vector>
+#include <memory>
+#include <cerrno>
+#include <sstream>
+#include <cstdio>
+#include <algorithm>
+#include <cstring>
+#include <limits.h>
+#include <unistd.h>
+
+namespace medialibrary
+{
+namespace fs
+{
+
+DeviceLister::DeviceMap DeviceLister::listDevices() const
+{
+    static const std::vector<std::string> deviceBlacklist = { "loop", "dm-" };
+    const std::string devPath = "/dev/disk/by-uuid/";
+    // Don't use fs::Directory to iterate, as it resolves the symbolic links automatically.
+    // We need the link name & what it points to.
+    std::unique_ptr<DIR, int(*)(DIR*)> dir( opendir( devPath.c_str() ), &closedir );
+    if ( dir == nullptr )
+    {
+        std::stringstream err;
+        err << "Failed to open /dev/disk/by-uuid: " << strerror(errno);
+        throw std::runtime_error( err.str() );
+    }
+    DeviceMap res;
+    dirent* result = nullptr;
+
+    while ( ( result = readdir( dir.get() ) ) != nullptr )
+    {
+        if ( strcmp( result->d_name, "." ) == 0 ||
+             strcmp( result->d_name, ".." ) == 0 )
+        {
+            continue;
+        }
+        std::string path = devPath + result->d_name;
+        char linkPath[PATH_MAX] = {};