WingHexExplorer2/ShareMemoryDrv/sharedmemory.cpp

115 lines
3.3 KiB
C++

/*==============================================================================
** Copyright (C) 2024-2027 WingSummer
**
** This program is free software: you can redistribute it and/or modify it under
** the terms of the GNU Affero General Public License as published by the Free
** Software Foundation, version 3.
**
** This program is distributed in the hope that it will be useful, but WITHOUT
** ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
** FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
** details.
**
** You should have received a copy of the GNU Affero General Public License
** along with this program. If not, see <https://www.gnu.org/licenses/>.
** =============================================================================
*/
#include "sharedmemory.h"
#include <QDebug>
SharedMemory::SharedMemory(const QString &key, OpenMode mode, QObject *parent)
: WingHex::WingIODevice(parent), m_key(key), m_mode(mode),
m_sharedMemory(key) {
if (m_mode == WriteOnly) {
if (!m_sharedMemory.create(1024)) {
qWarning() << "Unable to create shared memory segment.";
}
}
}
SharedMemory::~SharedMemory() {
if (m_sharedMemory.isAttached()) {
m_sharedMemory.unlock();
m_sharedMemory.detach();
}
}
bool SharedMemory::open(OpenMode mode) {
if ((m_mode == ReadOnly && !(mode & QIODevice::ReadOnly)) ||
(m_mode == WriteOnly && !(mode & QIODevice::WriteOnly))) {
return false;
}
if (m_mode == ReadOnly && !m_sharedMemory.attach()) {
qWarning() << "Unable to attach to shared memory segment.";
return false;
}
QSharedMemory::AccessMode m;
if (mode == ReadOnly) {
m = QSharedMemory::AccessMode::ReadOnly;
} else {
m = QSharedMemory::AccessMode::ReadWrite;
}
if (m_sharedMemory.attach(m)) {
m_sharedMemory.lock(); // Lock memory for reading or writing safely
return QIODevice::open(mode);
}
return false;
}
bool SharedMemory::keepSize() const { return true; }
void SharedMemory::close() {
m_sharedMemory.unlock();
m_sharedMemory.detach();
QIODevice::close();
}
qint64 SharedMemory::readData(char *data, qint64 maxSize) {
if (m_mode == WriteOnly) {
return -1; // Writing is not allowed in this mode
}
if (maxSize <= 0) {
return -1;
}
const char *sharedMemoryData =
static_cast<const char *>(m_sharedMemory.constData());
// Copy the data from shared memory
qint64 dataSize = qMin(maxSize, m_sharedMemory.size());
memcpy(data, sharedMemoryData, dataSize);
return dataSize;
}
qint64 SharedMemory::writeData(const char *data, qint64 maxSize) {
if (m_mode == ReadOnly) {
return -1; // Reading is not allowed in this mode
}
if (maxSize <= 0) {
return -1;
}
// Ensure the shared memory is large enough
if (maxSize > m_sharedMemory.size()) {
qWarning() << "Data exceeds shared memory size.";
return -1;
}
// Copy data to the shared memory
char *sharedMemoryData = static_cast<char *>(m_sharedMemory.data());
memcpy(sharedMemoryData, data, maxSize);
return maxSize;
}
qint64 SharedMemory::size() const { return m_sharedMemory.size(); }