Issue #15 Classes for sharing the history of log messages

src/blackmisc/loghistory.cpp

@@ -0,0 +1,41 @@
+/* Copyright (C) 2020
+ * swift Project Community / Contributors
+ *
+ * This file is part of swift project. It is subject to the license terms in the LICENSE file found in the top-level
+ * directory of this distribution. No part of swift project, including this file, may be copied, modified, propagated,
+ * or distributed except according to the terms contained in the LICENSE file.
+ */
+
+//! \file
+
+#include "blackmisc/loghistory.h"
+#include "blackmisc/loghandler.h"
+
+namespace BlackMisc
+{
+    CLogHistory::CLogHistory(QObject *parent) : CListJournal(parent)
+    {
+    }
+
+    CLogHistorySource::CLogHistorySource(QObject *parent) : CListMutator(parent)
+    {
+        connect(CLogHandler::instance(), &CLogHandler::localMessageLogged, this, [this](auto&&... args)
+        {
+            this->addElement(args...);
+        });
+    }
+
+    CLogHistoryReplica::CLogHistoryReplica(QObject* parent) : CListObserver(parent)
+    {
+    }
+
+    void CLogHistoryReplica::onElementAdded(const CStatusMessage &msg)
+    {
+        emit elementAdded(msg);
+    }
+
+    void CLogHistoryReplica::onElementsReplaced(const CStatusMessageList &msgs)
+    {
+        emit elementsReplaced(msgs);
+    }
+}

src/blackmisc/loghistory.h

@@ -0,0 +1,75 @@
+/* Copyright (C) 2020
+ * swift Project Community / Contributors
+ *
+ * This file is part of swift project. It is subject to the license terms in the LICENSE file found in the top-level
+ * directory of this distribution. No part of swift project, including this file, may be copied, modified, propagated,
+ * or distributed except according to the terms contained in the LICENSE file.
+ */
+
+//! \file
+
+#ifndef BLACKMISC_LOGHISTORY_H
+#define BLACKMISC_LOGHISTORY_H
+
+#include "blackmisc/sharedstate/datalink.h"
+#include "blackmisc/sharedstate/listjournal.h"
+#include "blackmisc/sharedstate/listmutator.h"
+#include "blackmisc/sharedstate/listobserver.h"
+#include "blackmisc/statusmessagelist.h"
+#include "blackmisc/logpattern.h"
+#include <QObject>
+
+namespace BlackMisc
+{
+    /*!
+     * Records all log messages to a list that persists for the lifetime of the application.
+     */
+    class BLACKMISC_EXPORT CLogHistory : public SharedState::CListJournal<CStatusMessageList>
+    {
+        Q_OBJECT
+        BLACK_SHARED_STATE_CHANNEL("swift.log.history")
+
+    public:
+        //! Constructor.
+        CLogHistory(QObject *parent = nullptr);
+    };
+
+    /*!
+     * Allows distributed insertion of log messages into a central CLogHistory.
+     */
+    class BLACKMISC_EXPORT CLogHistorySource : public SharedState::CListMutator<CStatusMessageList>
+    {
+        Q_OBJECT
+        BLACK_SHARED_STATE_CHANNEL("swift.log.history")
+
+    public:
+        //! Constructor.
+        CLogHistorySource(QObject *parent = nullptr);
+    };
+
+    /*!
+     * Allows distributed access to the log messages of a central CLogHistory.
+     */
+    class BLACKMISC_EXPORT CLogHistoryReplica : public SharedState::CListObserver<CStatusMessageList, CLogPattern>
+    {
+        Q_OBJECT
+        BLACK_SHARED_STATE_CHANNEL("swift.log.history")
+
+    public:
+        //! Constructor.
+        CLogHistoryReplica(QObject *parent = nullptr);
+
+    signals:
+        //! Signal emitted for each new log message.
+        void elementAdded(const BlackMisc::CStatusMessage &msg);
+
+        //! Signal emitted when the whole history is updated wholesale.
+        void elementsReplaced(const BlackMisc::CStatusMessageList &msgs);
+
+    private:
+        virtual void onElementAdded(const CStatusMessage &msg) override final;
+        virtual void onElementsReplaced(const CStatusMessageList &msgs) override final;
+    };
+}
+
+#endif

src/blackmisc/logpattern.cpp

@@ -328,7 +328,7 @@ namespace BlackMisc
         QString categories = m_strings.values().join("|"); // clazy:exclude=container-anti-pattern
         switch (m_strategy)
         {
-        case Everything: strategy = "none"; break;
+        case Everything: strategy = "all"; break;
         case ExactMatch: strategy = "exact match:" + categories; break;
         case AnyOf: strategy = "any of:" + categories; break;
         case AllOf: strategy = "all of:" + categories; break;

src/blackmisc/logpattern.h

@@ -93,6 +93,9 @@ namespace BlackMisc
         //! Returns true if the given message matches this pattern.
         bool match(const CStatusMessage &message) const;
 
+        //! This class acts as a SharedState filter when stored in a CVariant.
+        bool matches(const CVariant &message) const { return match(message.to<CStatusMessage>()); }
+
         //! Returns true if this pattern is a proper subset of the other pattern.
         //! \see     https://en.wikipedia.org/wiki/Proper_subset
         //! \details Pattern A is a proper subset of pattern B iff pattern B would match every category which pattern A matches,