SingleApplicationMessage the core of the v4.0 communication

singleapplicationmessage.cpp

@@ -0,0 +1,86 @@
+// Copyright (c) Itay Grudev 2023
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// Permission is not granted to use this software or any of the associated files
+// as sample data for the purposes of building machine learning models.
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+#include "singleapplicationmessage.h"
+
+#include <QIODevice>
+
+SingleApplicationMessage::SingleApplicationMessage()
+    : invalid( true )
+{
+}
+
+SingleApplicationMessage::SingleApplicationMessage( MessageType type, quint16 instanceId, QByteArray content )
+    : type( type ), instanceId( instanceId ), content( content ), invalid( false )
+{}
+
+SingleApplicationMessage::SingleApplicationMessage( QByteArray message )
+    : invalid( false )
+{
+        QDataStream dataStream( &message, QIODevice::ReadOnly );
+        qsizetype messageLength;
+        quint16 messageChecksum;
+
+        dataStream >> type;
+        dataStream >> instanceId;
+        dataStream >> messageLength;
+        if( (qsizetype)(message.size() - sizeof(type) - sizeof(messageLength) - sizeof(quint16)) < messageLength ){
+            invalid = true;
+            return;
+        }
+        content = QByteArray( messageLength, Qt::Uninitialized );
+        dataStream.readRawData( content.data(), messageLength );
+        dataStream >> messageChecksum;
+
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+        const quint16 computedChecksum = qChecksum(QByteArray(message.constData(), static_cast<quint32>(message.length() - sizeof(quint16))));
+#else
+        const quint16 computedChecksum = qChecksum(message.constData(), static_cast<quint32>(message.length() - sizeof(quint16)));
+#endif
+
+        if( messageChecksum != computedChecksum )
+            invalid = true;
+    }
+
+SingleApplicationMessage:: operator QByteArray()
+{
+    QByteArray message;
+    QDataStream dataStream( &message, QIODevice::WriteOnly );
+
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 6, 0))
+    dataStream.setVersion(QDataStream::Qt_5_6);
+#endif
+
+    dataStream << static_cast<quint8>( type );
+    dataStream << instanceId;
+    dataStream << (qsizetype)content.size();
+    dataStream << content;
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+    quint16 checksum = qChecksum( QByteArray( message.constData(), static_cast<quint32>( message.length())));
+#else
+    quint16 checksum = qChecksum( message.constData(), static_cast<quint32>( messageMsg.length()));
+#endif
+    dataStream << checksum;
+
+    return message;
+}

singleapplicationmessage.h

@@ -0,0 +1,69 @@
+// Copyright (c) Itay Grudev 2023
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// Permission is not granted to use this software or any of the associated files
+// as sample data for the purposes of building machine learning models.
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+#ifndef SINGLEAPPLICATIONMESSAGE_H
+#define SINGLEAPPLICATIONMESSAGE_H
+
+#include <QByteArray>
+
+struct SingleApplicationMessage {
+    enum MessageType : quint8 {
+        Acknowledge,
+        NewInstance,
+        Message,
+    };
+
+    MessageType type;
+    quint16 instanceId;
+    QByteArray content;
+    bool invalid;
+
+    /**
+     * @brief Create an unitialized SingleApplicationMessage
+     * The message is initialized with invalid = true
+     */
+    SingleApplicationMessage();
+
+    /**
+     * @brief Create a SingleApplicationMessage
+     * @param type
+     * @param instanceId
+     * @param content
+     */
+    SingleApplicationMessage( MessageType type, quint16 instanceId, QByteArray content );
+
+    /**
+     * @brief Create a SingleApplicationMessage from a QByteArray containing a message
+     * @param message
+     */
+    SingleApplicationMessage( QByteArray message );
+
+    /**
+     * @brief Convert a SingleApplicationMessage to a QByteArray
+     * @return QByteArray
+     */
+    operator QByteArray();
+};
+
+
+#endif // SINGLEAPPLICATIONMESSAGE_H