TrackRef = Track Location + Track ID

build/depends.py

@@ -957,6 +957,7 @@ def sources(self, build):
                    "track/tracknumbers.cpp",
                    "track/trackmetadata.cpp",
                    "track/trackmetadatataglib.cpp",
+                   "track/trackref.cpp",
 
                    "mixer/auxiliary.cpp",
                    "mixer/baseplayer.cpp",

src/library/scanner/importfilestask.cpp

@@ -1,6 +1,7 @@
 #include "library/scanner/importfilestask.h"
 
 #include "library/scanner/libraryscanner.h"
+#include "track/trackref.h"
 #include "util/timer.h"
 
 ImportFilesTask::ImportFilesTask(LibraryScanner* pScanner,
@@ -29,27 +30,27 @@ void ImportFilesTask::run() {
             return;
         }
 
-        const QString filePath(fileInfo.filePath());
-        //qDebug() << "ImportFilesTask::run" << filePath;
+        const QString trackLocation(TrackRef::location(fileInfo));
+        //qDebug() << "ImportFilesTask::run" << trackLocation;
 
         // If the file does not exist in the database then add it. If it
         // does then it is either in the user's library OR the user has
         // "removed" the track via "Right-Click -> Remove". These tracks
         // stay in the library, but their mixxx_deleted column is 1.
-        if (m_scannerGlobal->trackExistsInDatabase(filePath)) {
+        if (m_scannerGlobal->trackExistsInDatabase(trackLocation)) {
             // If the track is in the database, mark it as existing. This code gets
             // executed when other files in the same directory have changed (the
             // directory hash has changed).
-            emit(trackExists(filePath));
+            emit(trackExists(trackLocation));
         } else {
             if (!fileInfo.exists()) {
                 qWarning() << "ImportFilesTask: Skipping inaccessible file"
-                        << filePath;
+                        << trackLocation;
                 continue;
             }
-            qDebug() << "Importing track" << filePath;
+            qDebug() << "Importing track" << trackLocation;
 
-            emit(addNewTrack(filePath));
+            emit(addNewTrack(trackLocation));
         }
     }
     // Insert or update the hash in the database.

src/test/trackreftest.cpp

@@ -0,0 +1,82 @@
+#include <gtest/gtest.h>
+
+#include <QDir>
+#include <QTemporaryFile>
+#include <QtDebug>
+
+#include "track/trackref.h"
+
+namespace {
+
+class TrackRefTest : public testing::Test {
+  protected:
+
+    TrackRefTest()
+      : m_tempFile("TrackRefTest.tmp"),
+        m_tempFileDir(QDir::tempPath()),
+        m_tempFileName(m_tempFile.fileName()),
+        m_tempFileInfo(m_tempFileDir, m_tempFileName),
+        m_validTrackId(123) {
+    }
+
+    virtual void SetUp() {
+        ASSERT_TRUE(m_validTrackId.isValid());
+        ASSERT_FALSE(m_invalidTrackId.isValid());
+    }
+
+    virtual void TearDown() {
+    }
+
+    static void verifyFileInfo(const TrackRef& actual, const QFileInfo& fileInfo) {
+        EXPECT_TRUE(actual.hasLocation());
+        EXPECT_EQ(TrackRef::location(fileInfo), actual.getLocation());
+        EXPECT_TRUE(actual.hasCanonicalLocation());
+        EXPECT_EQ(TrackRef::canonicalLocation(fileInfo), actual.getCanonicalLocation());
+    }
+
+    const QTemporaryFile m_tempFile;
+    const QDir m_tempFileDir;
+    const QString m_tempFileName;
+    const QFileInfo m_tempFileInfo;
+    const TrackId m_validTrackId;
+    const TrackId m_invalidTrackId;
+};
+
+TEST_F(TrackRefTest, DefaultConstructor) {
+    TrackRef actual;
+
+    EXPECT_FALSE(actual.hasLocation());
+    EXPECT_FALSE(actual.hasCanonicalLocation());
+    EXPECT_FALSE(actual.hasId());
+}
+
+TEST_F(TrackRefTest, FromFileInfoWithId) {
+    const TrackRef actual(
+            TrackRef::fromFileInfo(m_tempFileInfo, m_validTrackId));
+
+    verifyFileInfo(actual, m_tempFileInfo);
+    EXPECT_TRUE(actual.hasId());
+    EXPECT_EQ(m_validTrackId, actual.getId());
+}
+
+TEST_F(TrackRefTest, FromFileInfoWithoutId) {
+    const TrackRef actual(
+            TrackRef::fromFileInfo(m_tempFileInfo));
+
+    verifyFileInfo(actual, m_tempFileInfo);
+    EXPECT_FALSE(actual.hasId());
+    EXPECT_EQ(m_invalidTrackId, actual.getId());
+}
+
+TEST_F(TrackRefTest, CopyAndSetId) {
+    const TrackRef withoutId(
+            TrackRef::fromFileInfo(m_tempFileInfo));
+
+    const TrackRef actual(withoutId, m_validTrackId);
+
+    verifyFileInfo(actual, m_tempFileInfo);
+    EXPECT_TRUE(actual.hasId());
+    EXPECT_EQ(m_validTrackId, actual.getId());
+}
+
+}  // namespace

src/track/trackref.cpp

@@ -0,0 +1,28 @@
+#include "track/trackref.h"
+
+
+bool TrackRef::verifyConsistency() const {
+    DEBUG_ASSERT_AND_HANDLE(hasLocation() || !hasCanonicalLocation()) {
+        return false;
+    }
+    DEBUG_ASSERT_AND_HANDLE(hasLocation() || !hasId()) {
+        return false;
+    }
+    return true;
+}
+
+std::ostream& operator<<(std::ostream& os, const TrackRef& trackRef) {
+    return os << '[' << trackRef.getLocation().toStdString()
+            << " | " << trackRef.getCanonicalLocation().toStdString()
+            << " | " << trackRef.getId()
+            << ']';
+
+}
+
+QDebug operator<<(QDebug debug, const TrackRef& trackRef) {
+    debug.nospace() << '[' << trackRef.getLocation()
+                    << " | " << trackRef.getCanonicalLocation()
+                    << " | " << trackRef.getId()
+                    << ']';
+    return debug.space();
+}

src/track/trackref.h

@@ -0,0 +1,132 @@
+#ifndef TRACKREF_H
+#define TRACKREF_H
+
+
+#include <QFileInfo>
+
+#include "track/trackid.h"
+
+
+// A track in the library is identified by a location and an id.
+// The location is mandatory to identify the file, whereas the id
+// only exists after the track has been inserted into the database.
+//
+// This class is intended to be used as a simple, almost immutable
+// value object. Only the id can be set once.
+class TrackRef {
+public:
+    // All file-related track properties are snapshots from the provided
+    // QFileInfo. Obtaining them might involve accessing the file system
+    // and should be used consciously! The QFileInfo class does some
+    // caching behind the scenes.
+    // Please note that the canonical location of QFileInfo may change at
+    // any time, when the underlying file system structure is modified.
+    // It becomes empty if the file is deleted.
+    static QString location(const QFileInfo& fileInfo) {
+        return fileInfo.absoluteFilePath();
+    }
+    static QString canonicalLocation(const QFileInfo& fileInfo) {
+        return fileInfo.canonicalFilePath();
+    }
+
+    // Converts a QFileInfo and an optional TrackId into a TrackRef. This
+    // involves obtaining the file-related track properties from QFileInfo
+    // (see above) and should used consciously!
+    static TrackRef fromFileInfo(
+            const QFileInfo& fileInfo,
+            TrackId id = TrackId()) {
+        return TrackRef(
+                location(fileInfo),
+                canonicalLocation(fileInfo),
+                id);
+    }
+
+    // Default constructor
+    TrackRef() {
+        DEBUG_ASSERT(verifyConsistency());
+    }
+    // Regular copy constructor
+    TrackRef(const TrackRef& other) = default;
+    // Custom copy constructor:  Creates a copy of an existing TrackRef,
+    // but overwrite the TrackId with a custom value.
+    TrackRef(
+            const TrackRef& other,
+            TrackId id)
+        : m_location(other.m_location),
+          m_canonicalLocation(other.m_canonicalLocation),
+          m_id(id) {
+        DEBUG_ASSERT(verifyConsistency());
+    }
+
+    // The human-readable identifier of a track in Mixxx. The location is
+    // immutable and the starting point for accessing a track's file.
+    const QString& getLocation() const {
+        return m_location;
+    }
+    bool hasLocation() const {
+        return !getLocation().isEmpty();
+    }
+
+    // The unique identifier of a track's file at runtime and used
+    // for caching. The canonical location is empty for inexistent
+    // files.
+    const QString& getCanonicalLocation() const {
+        return m_canonicalLocation;
+    }
+    bool hasCanonicalLocation() const {
+        return !getCanonicalLocation().isEmpty();
+    }
+
+    // The primary key of a track in the Mixxx library. The id must only
+    // be set once after inserting into or after loading from the database.
+    // Tracks that have not been stored in the database don't have an id.
+    const TrackId& getId() const {
+        return m_id;
+    }
+    bool hasId() const {
+        return getId().isValid();
+    }
+
+    bool isValid() const {
+        return hasId() || hasCanonicalLocation();
+    }
+protected:
+    // Initializing constructor
+    TrackRef(
+            const QString& location,
+            const QString& canonicalLocation,
+            TrackId id = TrackId())
+        : m_location(location),
+          m_canonicalLocation(canonicalLocation),
+          m_id(id) {
+        DEBUG_ASSERT(verifyConsistency());
+    }
+
+private:
+    bool verifyConsistency() const;
+
+    QString m_location;
+    QString m_canonicalLocation;
+    TrackId m_id;
+};
+
+inline
+bool operator==(const TrackRef& lhs, const TrackRef& rhs) {
+    return (lhs.getId() == rhs.getId()) &&
+            (lhs.getLocation() == rhs.getLocation()) &&
+            (lhs.getCanonicalLocation() == rhs.getCanonicalLocation());
+}
+
+inline
+bool operator!=(const TrackRef& lhs, const TrackRef& rhs) {
+    return !(lhs == rhs);
+}
+
+Q_DECLARE_METATYPE(TrackRef)
+
+std::ostream& operator<<(std::ostream& os, const TrackRef& trackRef);
+
+QDebug operator<<(QDebug debug, const TrackRef& trackRef);
+
+
+#endif // TRACKREF_H

src/trackinfoobject.cpp

@@ -5,16 +5,14 @@
 
 #include "trackinfoobject.h"
 
-#include "library/coverartutils.h"
-#include "soundsourceproxy.h"
 #include "track/beatfactory.h"
 #include "track/keyfactory.h"
 #include "track/keyutils.h"
 #include "track/trackmetadatataglib.h"
+#include "track/trackref.h"
 #include "util/assert.h"
 #include "util/compatibility.h"
 #include "util/time.h"
-#include "util/xml.h"
 
 
 namespace {
@@ -155,15 +153,15 @@ QString TrackInfoObject::getLocation() const {
     // (copy-on write). But operating on a single instance of QFileInfo
     // might not be thread-safe due to internal caching!
     QMutexLocker lock(&m_qMutex);
-    return m_fileInfo.absoluteFilePath();
+    return TrackRef::location(m_fileInfo);
 }
 
 QString TrackInfoObject::getCanonicalLocation() const {
     // Copying QFileInfo is thread-safe due to "implicit sharing"
     // (copy-on write). But operating on a single instance of QFileInfo
     // might not be thread-safe due to internal caching!
     QMutexLocker lock(&m_qMutex);
-    return m_fileInfo.canonicalFilePath();
+    return TrackRef::canonicalLocation(m_fileInfo);
 }
 
 QString TrackInfoObject::getDirectory() const {

src/trackinfoobject.h

@@ -62,8 +62,6 @@ class TrackInfoObject : public QObject {
     Q_PROPERTY(int duration READ getDuration WRITE setDuration)
     Q_PROPERTY(QString durationFormatted READ getDurationText STORED false)
 
-    TrackId getId() const;
-
     QFileInfo getFileInfo() const {
         // Copying a QFileInfo is thread-safe (implicit sharing), no locking needed.
         return m_fileInfo;
@@ -73,6 +71,8 @@ class TrackInfoObject : public QObject {
         return m_pSecurityToken;
     }
 
+    TrackId getId() const;
+
     // Accessors for various stats of the file on disk.
     // Returns absolute path to the file, including the filename.
     QString getLocation() const;

src/widget/wtracktableview.cpp

@@ -5,24 +5,26 @@
 #include <QDrag>
 #include <QShortcut>
 
-#include "widget/wwidget.h"
+#include "widget/wtracktableview.h"
+
+#include "widget/wcoverartmenu.h"
 #include "widget/wskincolor.h"
 #include "widget/wtracktableviewheader.h"
+#include "widget/wwidget.h"
 #include "library/coverartcache.h"
 #include "library/librarytablemodel.h"
 #include "library/trackcollection.h"
+#include "library/dlgtrackinfo.h"
+#include "track/trackref.h"
 #include "trackinfoobject.h"
 #include "controlobject.h"
 #include "controlobjectslave.h"
-#include "widget/wtracktableview.h"
-#include "library/dlgtrackinfo.h"
 #include "soundsourceproxy.h"
 #include "mixer/playermanager.h"
-#include "util/dnd.h"
-#include "util/time.h"
 #include "preferences/dialog/dlgpreflibrary.h"
 #include "waveform/guitick.h"
-#include "widget/wcoverartmenu.h"
+#include "util/dnd.h"
+#include "util/time.h"
 #include "util/assert.h"
 
 WTrackTableView::WTrackTableView(QWidget * parent,
@@ -1167,8 +1169,7 @@ void WTrackTableView::dropEvent(QDropEvent * event) {
 
         QList<QString> fileLocationList;
         foreach (const QFileInfo& fileInfo, fileList) {
-            // TODO(uklotzde): Replace with TrackRef::location()
-            fileLocationList.append(fileInfo.absoluteFilePath());
+            fileLocationList.append(TrackRef::location(fileInfo));
         }
 
         // Drag-and-drop from an external application