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>

1 files changed, 129 insertions, 0 deletions

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