Drop file-engine abstraction from public API

This abstraction imposed serious performance penalties and is being
dropped from the public API.

In particular, by allowing file names to be arbitrarily hijacked by
different file engines, and requiring engines to be instantiated in
order to decide, it imposed unnecessary overhead on all file operations.

Another flaw in the design with direct impact on performance is how
engines have no way to provide (or retain) additional information
obtained when querying the filesystem. In many places this has meant
repeated operations on the file system, where useful information is
immediately discarded to be queried again subsequently.

For Qt 4.8 a major refactoring of the code base took place to allow
bypassing the file-engine abstraction in select places, with
considerable performance gains observed. In Qt 5 it is expected we'll be
able to take this further, reaping even more benefits, but the
abstraction has to go.

[Dropping this now does not preclude that virtual file systems make an
appearance in Qt at a later point in Qt 5's lifecycle. Hopefully with a
new and improved abstraction.]

Forward declarations for QFileExtension(Result) were dropped, as the
classes were never used or defined.

Tests using "internalized" classes will only fully run on developer
builds. QFSFileEngine was removed altogether from exception safety test,
as it isn't its intent to test internal API.

Change-Id: Ie910e6c2628be202ea9e05366b091d6d529b246b
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Lars Knoll <lars.knoll@nokia.com>

12 files changed, 75 insertions, 16 deletions

diff --git a/tests/auto/corelib/io/io.pro b/tests/auto/corelib/io/io.pro
index 095aa7a77d..84a885f5b6 100644
--- a/tests/auto/corelib/io/io.pro
+++ b/tests/auto/corelib/io/io.pro
@@ -30,6 +30,7 @@ SUBDIRS=\
 }
 
 !contains(QT_CONFIG, private_tests): SUBDIRS -= \
+    qabstractfileengine \
     qfileinfo
 
 win32:!contains(QT_CONFIG, private_tests): SUBDIRS -= \
diff --git a/tests/auto/corelib/io/qabstractfileengine/qabstractfileengine.pro b/tests/auto/corelib/io/qabstractfileengine/qabstractfileengine.pro
index d7565b5429..641bb7341b 100644
--- a/tests/auto/corelib/io/qabstractfileengine/qabstractfileengine.pro
+++ b/tests/auto/corelib/io/qabstractfileengine/qabstractfileengine.pro
@@ -1,5 +1,5 @@
 CONFIG += testcase
 TARGET = tst_qabstractfileengine
-QT = core testlib
+QT = core-private core testlib
 SOURCES = tst_qabstractfileengine.cpp
 RESOURCES += qabstractfileengine.qrc
diff --git a/tests/auto/corelib/io/qabstractfileengine/tst_qabstractfileengine.cpp b/tests/auto/corelib/io/qabstractfileengine/tst_qabstractfileengine.cpp
index 776ad4d0a7..c6ccc9308a 100644
--- a/tests/auto/corelib/io/qabstractfileengine/tst_qabstractfileengine.cpp
+++ b/tests/auto/corelib/io/qabstractfileengine/tst_qabstractfileengine.cpp
@@ -39,8 +39,8 @@
 **
 ****************************************************************************/
 
-#include <QtCore/QAbstractFileEngine>
-#include <QtCore/QFSFileEngine>
+#include <QtCore/private/qabstractfileengine_p.h>
+#include <QtCore/private/qfsfileengine_p.h>
 
 #include <QtCore/QMutex>
 #include <QtCore/QMutexLocker>
diff --git a/tests/auto/corelib/io/qdir/qdir.pro b/tests/auto/corelib/io/qdir/qdir.pro
index 14f2d8812a..94ee14b51e 100644
--- a/tests/auto/corelib/io/qdir/qdir.pro
+++ b/tests/auto/corelib/io/qdir/qdir.pro
@@ -1,6 +1,6 @@
 CONFIG += testcase parallel_test
 TARGET = tst_qdir
-QT = core testlib
+QT = core core-private testlib
 SOURCES = tst_qdir.cpp
 RESOURCES += qdir.qrc
 
diff --git a/tests/auto/corelib/io/qdir/tst_qdir.cpp b/tests/auto/corelib/io/qdir/tst_qdir.cpp
index 6a48d7e60f..04967d8313 100644
--- a/tests/auto/corelib/io/qdir/tst_qdir.cpp
+++ b/tests/auto/corelib/io/qdir/tst_qdir.cpp
@@ -49,6 +49,7 @@
 #include <qstringlist.h>
 
 #if (defined(Q_OS_WIN) && !defined(Q_OS_WINCE))
+#include <QtCore/private/qfsfileengine_p.h>
 #include "../../../network-settings.h"
 #endif
 
@@ -471,6 +472,7 @@ void tst_QDir::exists_data()
 #if (defined(Q_OS_WIN) && !defined(Q_OS_WINCE))
     QTest::newRow("This drive should exist") <<  "C:/" << true;
     // find a non-existing drive and check if it does not exist
+#ifdef QT_BUILD_INTERNAL
     QFileInfoList drives = QFSFileEngine::drives();
     QStringList driveLetters;
     for (int i = 0; i < drives.count(); ++i) {
@@ -487,6 +489,7 @@ void tst_QDir::exists_data()
         QTest::newRow("This drive should not exist") <<  driv << false;
     }
 #endif
+#endif
 }
 
 void tst_QDir::exists()
diff --git a/tests/auto/corelib/io/qdiriterator/qdiriterator.pro b/tests/auto/corelib/io/qdiriterator/qdiriterator.pro
index cfb3201c43..ef59fc48e3 100644
--- a/tests/auto/corelib/io/qdiriterator/qdiriterator.pro
+++ b/tests/auto/corelib/io/qdiriterator/qdiriterator.pro
@@ -1,6 +1,6 @@
 CONFIG += testcase parallel_test
 TARGET = tst_qdiriterator
-QT = core testlib
+QT = core-private core testlib
 SOURCES = tst_qdiriterator.cpp
 RESOURCES += qdiriterator.qrc
 
diff --git a/tests/auto/corelib/io/qdiriterator/tst_qdiriterator.cpp b/tests/auto/corelib/io/qdiriterator/tst_qdiriterator.cpp
index d5d490dc29..37d3e1ab68 100644
--- a/tests/auto/corelib/io/qdiriterator/tst_qdiriterator.cpp
+++ b/tests/auto/corelib/io/qdiriterator/tst_qdiriterator.cpp
@@ -48,6 +48,8 @@
 #include <qfileinfo.h>
 #include <qstringlist.h>
 
+#include <QtCore/private/qfsfileengine_p.h>
+
 #if defined(Q_OS_VXWORKS)
 #define Q_NO_SYMLINKS
 #endif
@@ -454,6 +456,7 @@ void tst_QDirIterator::stopLinkLoop()
     // The goal of this test is only to ensure that the test above don't malfunction
 }
 
+#ifdef QT_BUILD_INTERNAL
 class EngineWithNoIterator : public QFSFileEngine
 {
 public:
@@ -473,13 +476,18 @@ public:
         return new EngineWithNoIterator(fileName);
     }
 };
+#endif
 
 void tst_QDirIterator::engineWithNoIterator()
 {
+#ifdef QT_BUILD_INTERNAL
     EngineWithNoIteratorHandler handler;
 
     QDir("entrylist").entryList();
     QVERIFY(true); // test that the above line doesn't crash
+#else
+    QSKIP("This test requires -developer-build.");
+#endif
 }
 
 void tst_QDirIterator::absoluteFilePathsFromRelativeIteratorPath()
diff --git a/tests/auto/corelib/io/qfile/test/test.pro b/tests/auto/corelib/io/qfile/test/test.pro
index 2611ff39bd..dab5e4a3a5 100644
--- a/tests/auto/corelib/io/qfile/test/test.pro
+++ b/tests/auto/corelib/io/qfile/test/test.pro
@@ -1,5 +1,5 @@
 CONFIG += testcase
-QT = core network testlib
+QT = core-private core network testlib
 TARGET = ../tst_qfile
 SOURCES = ../tst_qfile.cpp
 RESOURCES += ../qfile.qrc ../rename-fallback.qrc ../copy-fallback.qrc
diff --git a/tests/auto/corelib/io/qfile/tst_qfile.cpp b/tests/auto/corelib/io/qfile/tst_qfile.cpp
index d1a0debf4d..87d2cf83f7 100644
--- a/tests/auto/corelib/io/qfile/tst_qfile.cpp
+++ b/tests/auto/corelib/io/qfile/tst_qfile.cpp
@@ -42,13 +42,15 @@
 #include <QtTest/QtTest>
 #include <qplatformdefs.h>
 
-#include <QAbstractFileEngine>
-#include <QFSFileEngine>
 #include <QCoreApplication>
 #include <QDebug>
 #include <QDir>
 #include <QFile>
 #include <QFileInfo>
+
+#include <private/qabstractfileengine_p.h>
+#include <private/qfsfileengine_p.h>
+
 #if !defined(Q_OS_WINCE)
 #include <QHostInfo>
 #endif
@@ -70,7 +72,6 @@
 # include <sys/statfs.h>
 #elif defined(Q_OS_WINCE)
 # include <qplatformdefs.h>
-# include <private/qfsfileengine_p.h>
 #endif
 
 #include <stdio.h>
@@ -1943,6 +1944,7 @@ void tst_QFile::longFileName()
     QVERIFY(QFile::remove(newName));
 }
 
+#ifdef QT_BUILD_INTERNAL
 class MyEngine : public QAbstractFileEngine
 {
 public:
@@ -1998,6 +2000,7 @@ public:
         return new MyEngine(2);
     }
 };
+#endif
 
 void tst_QFile::fileEngineHandler()
 {
@@ -2006,6 +2009,7 @@ void tst_QFile::fileEngineHandler()
     QFile file("ole.bull");
     QCOMPARE(file.size(), qint64(0));
 
+#ifdef QT_BUILD_INTERNAL
     // Instantiating our handler will enable the new engine.
     MyHandler handler;
     file.setFileName("ole.bull");
@@ -2015,9 +2019,10 @@ void tst_QFile::fileEngineHandler()
     MyHandler2 handler2;
     file.setFileName("ole.bull");
     QCOMPARE(file.size(), qint64(125));
-
+#endif
 }
 
+#ifdef QT_BUILD_INTERNAL
 class MyRecursiveHandler : public QAbstractFileEngineHandler
 {
 public:
@@ -2032,13 +2037,18 @@ public:
         return 0;
     }
 };
+#endif
 
 void tst_QFile::useQFileInAFileHandler()
 {
+#ifdef QT_BUILD_INTERNAL
     // This test should not dead-lock
     MyRecursiveHandler handler;
     QFile file(":!tst_qfile.cpp");
     QVERIFY(file.exists());
+#else
+    QSKIP("This test requires -developer-build.");
+#endif
 }
 
 void tst_QFile::getCharFF()
diff --git a/tests/auto/other/exceptionsafety_objects/tst_exceptionsafety_objects.cpp b/tests/auto/other/exceptionsafety_objects/tst_exceptionsafety_objects.cpp
index 71a70384fc..a426a90976 100644
--- a/tests/auto/other/exceptionsafety_objects/tst_exceptionsafety_objects.cpp
+++ b/tests/auto/other/exceptionsafety_objects/tst_exceptionsafety_objects.cpp
@@ -166,7 +166,6 @@ void tst_ExceptionSafety_Objects::objects_data()
     NEWROW(QObject);
     NEWROW(QBuffer);
     NEWROW(QFile);
-    NEWROW(QFSFileEngine);
     NEWROW(QProcess);
     NEWROW(QSettings);
     NEWROW(QThread);
diff --git a/tests/benchmarks/corelib/io/qfile/main.cpp b/tests/benchmarks/corelib/io/qfile/main.cpp
index 3d16921b7f..02922e0bbd 100644
--- a/tests/benchmarks/corelib/io/qfile/main.cpp
+++ b/tests/benchmarks/corelib/io/qfile/main.cpp
@@ -41,10 +41,11 @@
 
 #include <QDebug>
 #include <QTemporaryFile>
-#include <QFSFileEngine>
 #include <QString>
 #include <QDirIterator>
 
+#include <private/qfsfileengine_p.h>
+
 #include <qtest.h>
 
 #include <stdio.h>
@@ -79,7 +80,9 @@ Q_OBJECT
 public:
     enum BenchmarkType {
         QFileBenchmark = 1,
+#ifdef QT_BUILD_INTERNAL
         QFSFileEngineBenchmark,
+#endif
         Win32Benchmark,
         PosixBenchmark,
         QFileFromPosixBenchmark
@@ -173,7 +176,14 @@ void tst_qfile::cleanupTestCase()
 }
 
 void tst_qfile::readBigFile_QFile() { readBigFile(); }
-void tst_qfile::readBigFile_QFSFileEngine() { readBigFile(); }
+void tst_qfile::readBigFile_QFSFileEngine()
+{
+#ifdef QT_BUILD_INTERNAL
+    readBigFile();
+#else
+    QSKIP("This test requires -developer-build.");
+#endif
+}
 void tst_qfile::readBigFile_posix() 
 { 
     readBigFile(); 
@@ -191,10 +201,15 @@ void tst_qfile::readBigFile_QFile_data()
 
 void tst_qfile::readBigFile_QFSFileEngine_data()
 {
+#ifdef QT_BUILD_INTERNAL
     readBigFile_data(QFSFileEngineBenchmark, QIODevice::NotOpen, QIODevice::NotOpen);
     readBigFile_data(QFSFileEngineBenchmark, QIODevice::NotOpen, QIODevice::Unbuffered);
     readBigFile_data(QFSFileEngineBenchmark, QIODevice::Text, QIODevice::NotOpen);
     readBigFile_data(QFSFileEngineBenchmark, QIODevice::Text, QIODevice::Unbuffered);
+#else
+    QTest::addColumn<int>("dummy");
+    QTest::newRow("Test will be skipped") << -1;
+#endif
 }
 
 void tst_qfile::readBigFile_posix_data()
@@ -255,6 +270,7 @@ void tst_qfile::readBigFile()
             file.close();
         }
         break;
+#ifdef QT_BUILD_INTERNAL
         case(QFSFileEngineBenchmark): {
             QFSFileEngine fse(filename);
             fse.open(QIODevice::ReadOnly|textMode|bufferedMode);
@@ -266,6 +282,7 @@ void tst_qfile::readBigFile()
             fse.close();
         }
         break;
+#endif
         case(PosixBenchmark): {
             QByteArray data = filename.toLocal8Bit();
             const char* cfilename = data.constData();
@@ -317,7 +334,9 @@ void tst_qfile::seek_data()
 {
     QTest::addColumn<tst_qfile::BenchmarkType>("testType");
     QTest::newRow("QFile") << QFileBenchmark;
+#ifdef QT_BUILD_INTERNAL
     QTest::newRow("QFSFileEngine") << QFSFileEngineBenchmark;
+#endif
     QTest::newRow("Posix FILE*") << PosixBenchmark;
 #ifdef Q_OS_WIN
     QTest::newRow("Win32 API") << Win32Benchmark;
@@ -343,6 +362,7 @@ void tst_qfile::seek()
             file.close();
         }
         break;
+#ifdef QT_BUILD_INTERNAL
         case(QFSFileEngineBenchmark): {
             QFSFileEngine fse(filename);
             fse.open(QIODevice::ReadOnly);
@@ -353,6 +373,7 @@ void tst_qfile::seek()
             fse.close();
         }
         break;
+#endif
         case(PosixBenchmark): {
             QByteArray data = filename.toLocal8Bit();
             const char* cfilename = data.constData();
@@ -396,7 +417,9 @@ void tst_qfile::open_data()
 {
     QTest::addColumn<tst_qfile::BenchmarkType>("testType");
     QTest::newRow("QFile") << QFileBenchmark;
+#ifdef QT_BUILD_INTERNAL
     QTest::newRow("QFSFileEngine") << QFSFileEngineBenchmark;
+#endif
     QTest::newRow("Posix FILE*") << PosixBenchmark;
     QTest::newRow("QFile from FILE*") << QFileFromPosixBenchmark;
 #ifdef Q_OS_WIN
@@ -419,6 +442,7 @@ void tst_qfile::open()
             }
         }
         break;
+#ifdef QT_BUILD_INTERNAL
         case(QFSFileEngineBenchmark): {
             QBENCHMARK {
                 QFSFileEngine fse(filename);
@@ -427,7 +451,7 @@ void tst_qfile::open()
             }
         }
         break;
-
+#endif
         case(PosixBenchmark): {
             // ensure we don't account toLocal8Bit()
             QByteArray data = filename.toLocal8Bit();
@@ -477,7 +501,14 @@ void tst_qfile::open()
 
 
 void tst_qfile::readSmallFiles_QFile() { readSmallFiles(); }
-void tst_qfile::readSmallFiles_QFSFileEngine() { readSmallFiles(); }
+void tst_qfile::readSmallFiles_QFSFileEngine()
+{
+#ifdef QT_BUILD_INTERNAL
+    readSmallFiles();
+#else
+    QSKIP("This test requires -developer-build.");
+#endif
+}
 void tst_qfile::readSmallFiles_posix() 
 {
     readSmallFiles(); 
@@ -498,10 +529,15 @@ void tst_qfile::readSmallFiles_QFile_data()
 
 void tst_qfile::readSmallFiles_QFSFileEngine_data()
 {
+#ifdef QT_BUILD_INTERNAL
     readSmallFiles_data(QFSFileEngineBenchmark, QIODevice::NotOpen, QIODevice::NotOpen);
     readSmallFiles_data(QFSFileEngineBenchmark, QIODevice::NotOpen, QIODevice::Unbuffered);
     readSmallFiles_data(QFSFileEngineBenchmark, QIODevice::Text, QIODevice::NotOpen);
     readSmallFiles_data(QFSFileEngineBenchmark, QIODevice::Text, QIODevice::Unbuffered);
+#else
+    QTest::addColumn<int>("dummy");
+    QTest::newRow("Test will be skipped") << -1;
+#endif
 }
 
 void tst_qfile::readSmallFiles_posix_data()
@@ -606,6 +642,7 @@ void tst_qfile::readSmallFiles()
             }
         }
         break;
+#ifdef QT_BUILD_INTERNAL
         case(QFSFileEngineBenchmark): {
             QList<QFSFileEngine*> fileList;
             Q_FOREACH(QString file, files) {
@@ -626,6 +663,7 @@ void tst_qfile::readSmallFiles()
             }
         }
         break;
+#endif
         case(PosixBenchmark): {
             QList<FILE*> fileList;
             Q_FOREACH(QString file, files) {
diff --git a/tests/benchmarks/corelib/io/qfile/qfile.pro b/tests/benchmarks/corelib/io/qfile/qfile.pro
index 933469071d..5f7b9af73f 100644
--- a/tests/benchmarks/corelib/io/qfile/qfile.pro
+++ b/tests/benchmarks/corelib/io/qfile/qfile.pro
@@ -1,6 +1,6 @@
 TEMPLATE = app
 TARGET = tst_bench_qfile
-QT = core testlib
+QT = core core-private testlib
 win32: DEFINES+= _CRT_SECURE_NO_WARNINGS
 
 SOURCES += main.cpp