1 files changed, 105 insertions, 0 deletions
diff --git a/src/qml/jsruntime/qv4compilationunitmapper_win.cpp b/src/qml/jsruntime/qv4compilationunitmapper_win.cpp
new file mode 100644
index 0000000000..73096207b4
--- /dev/null
+++ b/src/qml/jsruntime/qv4compilationunitmapper_win.cpp
@@ -0,0 +1,105 @@
+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+#include "qv4compilationunitmapper_p.h"
+
+#include <private/qv4compileddata_p.h>
+
+#include <QtCore/qdatetime.h>
+#include <QtCore/qfileinfo.h>
+#include <QtCore/qscopeguard.h>
+
+#include <qt_windows.h>
+
+QT_BEGIN_NAMESPACE
+
+using namespace QV4;
+
+CompiledData::Unit *CompilationUnitMapper::open(const QString &cacheFileName, const QDateTime &sourceTimeStamp, QString *errorString)
+{
+    close();
+
+    // ### TODO: fix up file encoding/normalization/unc handling once QFileSystemEntry
+    // is exported from QtCore.
+    HANDLE handle =
+        CreateFile(reinterpret_cast<const wchar_t*>(cacheFileName.constData()),
+                   GENERIC_READ | GENERIC_EXECUTE, FILE_SHARE_READ,
+                   nullptr, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL,
+                   nullptr);
+    if (handle == INVALID_HANDLE_VALUE) {
+        *errorString = qt_error_string(GetLastError());
+        return nullptr;
+    }
+
+    auto fileHandleCleanup = qScopeGuard([handle]{
+        CloseHandle(handle);
+    });
+
+    CompiledData::Unit header;
+    DWORD bytesRead;
+    if (!ReadFile(handle, reinterpret_cast<char *>(&header), sizeof(header), &bytesRead, nullptr)) {
+        *errorString = qt_error_string(GetLastError());
+        return nullptr;
+    }
+
+    if (bytesRead != sizeof(header)) {
+        *errorString = QStringLiteral("File too small for the header fields");
+        return nullptr;
+    }
+
+    if (!header.verifyHeader(sourceTimeStamp, errorString))
+        return nullptr;
+
+    // Data structure and qt version matched, so now we can access the rest of the file safely.
+
+    /* Error out early on file corruption. We assume we can read header.unitSize bytes
+       later (even before verifying the checksum), potentially causing out-of-bound
+       reads
+       Also, no need to wait until checksum verification if we know beforehand
+       that the cached unit is bogus
+    */
+    LARGE_INTEGER fileSize;
+    if (!GetFileSizeEx(handle, &fileSize)) {
+        *errorString = QStringLiteral("Could not determine file size");
+        return nullptr;
+    }
+    if (header.unitSize != fileSize.QuadPart) {
+        *errorString = QStringLiteral("Potential file corruption, file too small");
+        return nullptr;
+    }
+
+
+    HANDLE fileMappingHandle = CreateFileMapping(handle, 0, PAGE_READONLY, 0, 0, 0);
+    if (!fileMappingHandle) {
+        *errorString = qt_error_string(GetLastError());
+        return nullptr;
+    }
+
+    auto mappingCleanup = qScopeGuard([fileMappingHandle]{
+        CloseHandle(fileMappingHandle);
+    });
+
+    dataPtr = MapViewOfFile(fileMappingHandle, FILE_MAP_READ, 0, 0, 0);
+    if (!dataPtr) {
+        *errorString = qt_error_string(GetLastError());
+        return nullptr;
+    }
+
+    return reinterpret_cast<CompiledData::Unit*>(dataPtr);
+}
+
+void CompilationUnitMapper::close()
+{
+    if (dataPtr != nullptr) {
+        // Do not unmap cache files that are built with the StaticData flag. That's the majority of
+        // them and it's necessary to benefit from the QString literal optimization. There might
+        // still be QString instances around that point into that memory area. The memory is backed
+        // on the disk, so the kernel is free to release the pages and all that remains is the
+        // address space allocation.
+        if (!(reinterpret_cast<CompiledData::Unit*>(dataPtr)->flags & CompiledData::Unit::StaticData))
+            UnmapViewOfFile(dataPtr);
+    }
+    dataPtr = nullptr;
+}
+
+QT_END_NAMESPACE