Enable disk caching on Windows

In order to enable the disk cache we need to replace the QFile::map
usage with direct win32 file API calls in order to create executable
file mappings. The files opened with QFile lack GENERIC_EXECUTE in
the open flags.

The code remains disabled on WinRT for now.

Change-Id: I7d12267755a9de0344ac087b2ff67140531d9df0
Reviewed-by: Maurice Kalinowski <maurice.kalinowski@qt.io>

5 files changed, 131 insertions, 53 deletions

diff --git a/src/qml/compiler/compiler.pri b/src/qml/compiler/compiler.pri
index e80c0236a3..e49f5c40a5 100644
--- a/src/qml/compiler/compiler.pri
+++ b/src/qml/compiler/compiler.pri
@@ -41,5 +41,6 @@ SOURCES += \
     $$PWD/qv4compilationunitmapper.cpp
 
 unix: SOURCES += $$PWD/qv4compilationunitmapper_unix.cpp
+else: SOURCES += $$PWD/qv4compilationunitmapper_win.cpp
 
 }
diff --git a/src/qml/compiler/qv4compilationunitmapper.cpp b/src/qml/compiler/qv4compilationunitmapper.cpp
index 084137f17f..b53b7cf784 100644
--- a/src/qml/compiler/qv4compilationunitmapper.cpp
+++ b/src/qml/compiler/qv4compilationunitmapper.cpp
@@ -86,44 +86,4 @@ bool CompilationUnitMapper::verifyHeader(const CompiledData::Unit *header, const
     return true;
 }
 
-#if  !defined(Q_OS_UNIX)
-CompiledData::Unit *CompilationUnitMapper::open(const QString &sourcePath, QString *errorString)
-{
-    close();
-
-    f.setFileName(sourcePath + QLatin1Char('c'));
-    if (!f.open(QIODevice::ReadOnly)) {
-        *errorString = f.errorString();
-        return nullptr;
-    }
-
-    CompiledData::Unit header;
-    qint64 bytesRead = f.read(reinterpret_cast<char *>(&header), sizeof(header));
-
-    if (bytesRead != sizeof(header)) {
-        *errorString = QStringLiteral("File too small for the header fields");
-        return nullptr;
-    }
-
-    if (!verifyHeader(&header, sourcePath, errorString))
-        return nullptr;
-
-    // Data structure and qt version matched, so now we can access the rest of the file safely.
-
-    dataPtr = f.map(/*offset*/0, f.size());
-    if (!dataPtr) {
-        *errorString = f.errorString();
-        return nullptr;
-    }
-
-    return reinterpret_cast<CompiledData::Unit*>(dataPtr);
-}
-
-void CompilationUnitMapper::close()
-{
-    f.close();
-    dataPtr = nullptr;
-}
-#endif // !defined(Q_OS_UNIX)
-
 QT_END_NAMESPACE
diff --git a/src/qml/compiler/qv4compilationunitmapper_p.h b/src/qml/compiler/qv4compilationunitmapper_p.h
index 119111ccd6..69007f4618 100644
--- a/src/qml/compiler/qv4compilationunitmapper_p.h
+++ b/src/qml/compiler/qv4compilationunitmapper_p.h
@@ -76,8 +76,6 @@ private:
 
 #if defined(Q_OS_UNIX)
     size_t length;
-#else
-    QFile f;
 #endif
     void *dataPtr;
 };
diff --git a/src/qml/compiler/qv4compilationunitmapper_win.cpp b/src/qml/compiler/qv4compilationunitmapper_win.cpp
new file mode 100644
index 0000000000..d58c46c090
--- /dev/null
+++ b/src/qml/compiler/qv4compilationunitmapper_win.cpp
@@ -0,0 +1,129 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qv4compilationunitmapper_p.h"
+
+#include "qv4compileddata_p.h"
+#include <private/qdeferredcleanup_p.h>
+#include <QFileInfo>
+#include <QDateTime>
+#include <qt_windows.h>
+
+QT_BEGIN_NAMESPACE
+
+using namespace QV4;
+
+CompiledData::Unit *CompilationUnitMapper::open(const QString &sourcePath, QString *errorString)
+{
+    close();
+
+    // ### TODO: fix up file encoding/normalization/unc handling once QFileSystemEntry
+    // is exported from QtCore.
+    const QString cacheFileName = sourcePath + QLatin1Char('c');
+    HANDLE handle =
+#if defined(Q_OS_WINRT)
+        CreateFile2(reinterpret_cast<const wchar_t*>(cacheFileName.constData()),
+                   GENERIC_READ | GENERIC_EXECUTE, FILE_SHARE_READ,
+                   OPEN_EXISTING, nullptr);
+#else
+        CreateFile(reinterpret_cast<const wchar_t*>(cacheFileName.constData()),
+                   GENERIC_READ | GENERIC_EXECUTE, FILE_SHARE_READ,
+                   nullptr, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL,
+                   nullptr);
+#endif
+    if (handle == INVALID_HANDLE_VALUE) {
+        *errorString = qt_error_string(GetLastError());
+        return nullptr;
+    }
+
+    QDeferredCleanup fileHandleCleanup([handle]{
+        CloseHandle(handle);
+    });
+
+#if defined(Q_OS_WINRT)
+    *errorString = QStringLiteral("Compilation unit mapping not supported on WinRT yet");
+    return nullptr;
+#else
+    CompiledData::Unit header;
+    DWORD bytesRead;
+    if (!ReadFile(handle, reinterpret_cast<char *>(&header), sizeof(header), &bytesRead, nullptr)) {
+        *errorString = qt_error_string(GetLastError());
+        return false;
+    }
+
+    if (bytesRead != sizeof(header)) {
+        *errorString = QStringLiteral("File too small for the header fields");
+        return nullptr;
+    }
+
+    if (!verifyHeader(&header, sourcePath, errorString))
+        return nullptr;
+
+    // Data structure and qt version matched, so now we can access the rest of the file safely.
+
+    HANDLE fileMappingHandle = CreateFileMapping(handle, 0, PAGE_EXECUTE_READ, 0, 0, 0);
+    if (!fileMappingHandle) {
+        *errorString = qt_error_string(GetLastError());
+        return false;
+    }
+
+    QDeferredCleanup mappingCleanup([fileMappingHandle]{
+        CloseHandle(fileMappingHandle);
+    });
+
+    dataPtr = MapViewOfFile(fileMappingHandle, FILE_MAP_READ | FILE_MAP_EXECUTE, 0, 0, 0);
+    if (!dataPtr) {
+        *errorString = qt_error_string(GetLastError());
+        return nullptr;
+    }
+
+    return reinterpret_cast<CompiledData::Unit*>(dataPtr);
+#endif
+}
+
+void CompilationUnitMapper::close()
+{
+#if !defined(Q_OS_WINRT)
+    if (dataPtr != nullptr)
+        UnmapViewOfFile(dataPtr);
+#endif
+    dataPtr = nullptr;
+}
+
+QT_END_NAMESPACE
diff --git a/src/qml/qml/qqmltypeloader.cpp b/src/qml/qml/qqmltypeloader.cpp
index a151f50a00..4fa69d22bb 100644
--- a/src/qml/qml/qqmltypeloader.cpp
+++ b/src/qml/qml/qqmltypeloader.cpp
@@ -104,22 +104,12 @@
 #endif
 
 DEFINE_BOOL_CONFIG_OPTION(dumpErrors, QML_DUMP_ERRORS);
-DEFINE_BOOL_CONFIG_OPTION(_disableDiskCache, QML_DISABLE_DISK_CACHE);
+DEFINE_BOOL_CONFIG_OPTION(disableDiskCache, QML_DISABLE_DISK_CACHE);
 DEFINE_BOOL_CONFIG_OPTION(forceDiskCache, QML_FORCE_DISK_CACHE);
 
 Q_DECLARE_LOGGING_CATEGORY(DBG_DISK_CACHE)
 Q_LOGGING_CATEGORY(DBG_DISK_CACHE, "qt.qml.diskcache")
 
-static bool disableDiskCache()
-{
-    return _disableDiskCache()
-           // ### FIXME: Fix crashes on Windows with mmap'ed code.
-#if defined(Q_OS_WIN)
-           || true
-#endif
-           ;
-}
-
 QT_BEGIN_NAMESPACE
 
 namespace {