Qt/QML edition

windows/winfile.cpp

@@ -0,0 +1,193 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ * Copyright (C) 2020 Raspberry Pi (Trading) Limited
+ */
+
+#include "winfile.h"
+#include <QDebug>
+#include <QThread>
+
+WinFile::WinFile(QObject *parent)
+    : QObject(parent), _locked(false), _h(INVALID_HANDLE_VALUE)
+{
+
+}
+
+WinFile::~WinFile()
+{
+    if (isOpen())
+        close();
+}
+
+void WinFile::setFileName(const QString &name)
+{
+    _name = name;
+}
+
+bool WinFile::open(QIODevice::OpenMode)
+{
+    QByteArray n = _name.toLatin1();
+
+    for (int attempt = 0; attempt < 20; attempt++)
+    {
+        _h = CreateFileA(n.data(), GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
+        if (_h != INVALID_HANDLE_VALUE)
+            break;
+
+        qDebug() << "Error opening device. Retrying...";
+        QThread::msleep(100);
+    }
+
+    // Try with FILE_SHARE_WRITE
+    if (_h == INVALID_HANDLE_VALUE)
+        _h = CreateFileA(n.data(), GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);;
+
+    if (_h == INVALID_HANDLE_VALUE)
+    {
+        _lasterror = qt_error_string();
+        qDebug() << "Error opening:" << _lasterror;
+        return false;
+    }
+
+    return true;
+}
+
+void WinFile::close()
+{
+    if (!isOpen())
+        return;
+
+    if (_locked)
+    {
+        unlockVolume();
+    }
+
+    CloseHandle(_h);
+    _h = INVALID_HANDLE_VALUE;
+}
+
+bool WinFile::isOpen()
+{
+    return _h != INVALID_HANDLE_VALUE;
+}
+
+qint64 WinFile::write(const char *data, qint64 maxSize)
+{
+    DWORD bytesWritten;
+
+    if (maxSize % 512)
+        qDebug() << "write: NOT SECTOR ALIGNED";
+
+    if (!WriteFile(_h, data, maxSize, &bytesWritten, NULL))
+    {
+        _lasterror = qt_error_string();
+        return -1;
+    }
+
+    return bytesWritten;
+}
+
+qint64 WinFile::read(char *data, qint64 maxSize)
+{
+    DWORD bytesRead;
+
+    if (!ReadFile(_h, data, maxSize, &bytesRead, NULL))
+    {
+        _lasterror = qt_error_string();
+        return -1;
+    }
+
+    return bytesRead;
+}
+
+bool WinFile::seek(qint64 pos)
+{
+    LARGE_INTEGER current;
+    LARGE_INTEGER offset;
+    offset.QuadPart = pos;
+    if (!SetFilePointerEx(_h, offset, &current, FILE_BEGIN))
+    {
+        _lasterror = qt_error_string();
+        qDebug() << "Error seeking:" << _lasterror;
+        return false;
+    }
+
+    return true;
+}
+
+qint64 WinFile::pos()
+{
+    LARGE_INTEGER current;
+    LARGE_INTEGER offset;
+    offset.QuadPart = 0;
+    if (!SetFilePointerEx(_h, offset, &current, FILE_CURRENT))
+    {
+        _lasterror = qt_error_string();
+        return 0;
+    }
+
+    return qint64(current.QuadPart);
+}
+
+HANDLE WinFile::handle()
+{
+    return _h;
+}
+
+QString WinFile::errorString() const
+{
+    return _lasterror;
+}
+
+bool WinFile::flush()
+{
+    if (!FlushFileBuffers(_h))
+    {
+        _lasterror = qt_error_string();
+        return false;
+    }
+
+    return true;
+}
+
+bool WinFile::lockVolume()
+{
+    DWORD bytesRet;
+    DeviceIoControl(_h, FSCTL_ALLOW_EXTENDED_DASD_IO, NULL, 0, NULL, 0, &bytesRet, NULL);
+    for (int attempt = 0; attempt < 20; attempt++)
+    {
+        qDebug() << "Locking volume" << _name;
+
+        if (DeviceIoControl(_h, FSCTL_LOCK_VOLUME, NULL, 0, NULL, 0, &bytesRet, NULL))
+        {
+            _locked = true;
+            qDebug() << "Locked volume";
+            return true;
+        }
+
+        qDebug() << "FSCTL_LOCK_VOLUME failed. Retrying in 0.1 sec";
+        QThread::msleep(100);
+    }
+
+    qDebug() << "Giving up locking volume";
+    return false;
+}
+
+bool WinFile::unlockVolume()
+{
+    if (!_locked)
+        return true;
+
+    DWORD bytesRet;
+    if (DeviceIoControl(_h, FSCTL_UNLOCK_VOLUME, NULL, 0, NULL, 0, &bytesRet, NULL))
+    {
+        _locked = false;
+        qDebug() << "Unlocked volume";
+        return true;
+    }
+    else
+    {
+        qDebug() << "FSCTL_UNLOCK_VOLUME failed";
+        return false;
+    }
+}