File indexing completed on 2024-05-12 05:26:01

 /*
  * Copyright (C) 2019 Christian Mollekopf <mollekopf@kolabsys.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) version 3, or any
  * later version accepted by the membership of KDE e.V. (or its
  * successor approved by the membership of KDE e.V.), which shall
  * act as a proxy defined in Section 6 of version 3 of the license.
  *
  * This library 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
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
  */
 #pragma once
 
 #include "sink_export.h"
 #include <QObject>
 #include <QByteArrayList>
 #include <string>
 #include <functional>
 #include <QString>
 #include <KAsync/Async>
 #include "storage.h"
 
 /**
  * A persistent FIFO message queue.
  */
 class SINK_EXPORT MessageQueue : public QObject
 {
     Q_OBJECT
 public:
     enum ErrorCodes
     {
         NoMessageFound
     };
     class Error
     {
     public:
         Error(const QByteArray &s, int c, const QByteArray &m) : store(s), message(m), code(c)
         {
         }
         QByteArray store;
         QByteArray message;
         int code;
     };
 
     MessageQueue(const QString &storageRoot, const QString &name);
     ~MessageQueue();
 
     QString name() const;
 
     void startTransaction();
     void enqueue(void const *msg, size_t size);
     void enqueue(const QByteArray &value);
     // Dequeue a message. This will return a new message everytime called.
     // Call the result handler with a success response to remove the message from the store.
     // TODO track processing progress to avoid processing the same message with the same preprocessor twice?
     void dequeue(const std::function<void(void *ptr, int size, std::function<void(bool success)>)> &resultHandler, const std::function<void(const Error &error)> &errorHandler);
     KAsync::Job<void> dequeueBatch(int maxBatchSize, const std::function<KAsync::Job<void>(const QByteArray &)> &resultHandler);
     bool isEmpty();
 
 public slots:
     void commit();
 
 signals:
     void messageReady();
     void drained();
 
 private slots:
     void processRemovals();
 
 private:
     Q_DISABLE_COPY(MessageQueue);
     Sink::Storage::DataStore mStorage;
     Sink::Storage::DataStore::Transaction mWriteTransaction;
     qint64 mReplayedRevision;
     QString mName;
 };