refs #338 CLogHandler filtering messages using CLogPattern instead of the old prefix-based approach.

src/blackmisc/loghandler.cpp

@@ -8,6 +8,7 @@
  */
 
 #include "loghandler.h"
+#include "algorithm.h"
 #include <QCoreApplication>
 #include <QMetaMethod>
 
@@ -43,27 +44,34 @@ namespace BlackMisc
         qInstallMessageHandler(m_oldHandler);
     }
 
-    CLogCategoryHandler *CLogHandler::handlerForCategoryPrefix(const QString &category)
+    CLogPatternHandler *CLogHandler::handlerForPattern(const CLogPattern &pattern)
     {
         Q_ASSERT(thread() == QThread::currentThread());
 
-        if (! m_categoryPrefixHandlers.contains(category))
+        auto finder = [ & ](const PatternPair &pair) { return pair.first == pattern; };
+        auto comparator = [](const PatternPair &a, const PatternPair &b) { return a.first.isProperSubsetOf(b.first); };
+
+        auto it = std::find_if(m_patternHandlers.begin(), m_patternHandlers.end(), finder);
+        if (it == m_patternHandlers.end())
         {
-            m_categoryPrefixHandlers[category] = new CLogCategoryHandler(this, m_enableFallThrough);
-
+            auto *handler = new CLogPatternHandler(this, m_enableFallThrough);
+            topologicallySortedInsert(m_patternHandlers, PatternPair(pattern, handler), comparator);
+            return handler;
+        }
+        else
+        {
+            return (*it).second;
         }
-
-        return m_categoryPrefixHandlers[category];
     }
 
-    QList<CLogCategoryHandler *> CLogHandler::handlersForCategories(const CLogCategoryList &categories) const
+    QList<CLogPatternHandler *> CLogHandler::handlersForMessage(const CStatusMessage &message) const
     {
-        QList<CLogCategoryHandler *> m_handlers;
-        for (auto i = m_categoryPrefixHandlers.begin(); i != m_categoryPrefixHandlers.end(); ++i)
+        QList<CLogPatternHandler *> m_handlers;
+        for (const auto &pair : m_patternHandlers)
         {
-            if (categories.anyStartWith(i.key()))
+            if (pair.first.match(message))
             {
-                m_handlers.push_back(i.value());
+                m_handlers.push_back(pair.second);
             }
         }
         return m_handlers;
@@ -74,13 +82,13 @@ namespace BlackMisc
         Q_ASSERT(thread() == QThread::currentThread());
 
         m_enableFallThrough = enable;
-        for (auto *handler : m_categoryPrefixHandlers.values())
+        for (const auto &pair : m_patternHandlers)
         {
-            handler->enableConsoleOutput(enable);
+            pair.second->enableConsoleOutput(enable);
         }
     }
 
-    bool CLogHandler::isFallThroughEnabled(const QList<CLogCategoryHandler *> &handlers) const
+    bool CLogHandler::isFallThroughEnabled(const QList<CLogPatternHandler *> &handlers) const
     {
         for (const auto *handler : handlers)
         {
@@ -108,7 +116,7 @@ namespace BlackMisc
     {
         collectGarbage();
 
-        auto handlers = handlersForCategories(statusMessage.getCategories());
+        auto handlers = handlersForMessage(statusMessage);
 
         if (isFallThroughEnabled(handlers))
         {

src/blackmisc/loghandler.h

@@ -12,13 +12,14 @@
 
 //! \file
 
+#include "logpattern.h"
 #include "statusmessage.h"
 #include <QObject>
 #include <QMap>
 
 namespace BlackMisc
 {
-    class CLogCategoryHandler;
+    class CLogPatternHandler;
 
     /*!
      * Class for subscribing to log messages.
@@ -41,9 +42,9 @@ namespace BlackMisc
         //! Tell the CLogHandler to install itself with qInstallMessageHandler.
         void install();
 
-        //! Return a category handler for subscribing to all messages with a category starting with the given prefix.
+        //! Return a pattern handler for subscribing to all messages which match the given pattern.
         //! \warning This must only be called from the main thread.
-        CLogCategoryHandler *handlerForCategoryPrefix(const QString &prefix);
+        CLogPatternHandler *handlerForPattern(const CLogPattern &pattern);
 
     signals:
         //! Emitted when a message is logged in this process.
@@ -67,34 +68,38 @@ namespace BlackMisc
         void collectGarbage();
         QtMessageHandler m_oldHandler = nullptr;
         bool m_enableFallThrough = true;
-        bool isFallThroughEnabled(const QList<CLogCategoryHandler *> &handlers) const;
-        QMap<QString, CLogCategoryHandler *> m_categoryPrefixHandlers;
-        QList<CLogCategoryHandler *> handlersForCategories(const CLogCategoryList &categories) const;
+        bool isFallThroughEnabled(const QList<CLogPatternHandler *> &handlers) const;
+        using PatternPair = std::pair<CLogPattern, CLogPatternHandler *>;
+        QList<PatternPair> m_patternHandlers;
+        QList<CLogPatternHandler *> handlersForMessage(const CStatusMessage &message) const;
     };
 
     /*!
-     * A class for subscribing to log messages in particular categories.
-     * \sa CLogHandler::handlerForCategory
+     * A class for subscribing to log messages which match particular patterns.
+     * \see CLogHandler::handlerForPattern
      */
-    class CLogCategoryHandler : public QObject
+    class CLogPatternHandler : public QObject
     {
         Q_OBJECT
 
     public slots:
         /*!
-         * Enable or disable the default Qt handler for messages in relevant categories.
-         * This can override the setting of the parent CLogHandler.
+         * Enable or disable the default Qt handler for messages which match the relevant pattern.
+         *
+         * The setting of this property in one CLogPatternHandler can override the setting in another
+         * CLogPatternHandler or the base CLogHandler, if this handler's pattern is a subset of the
+         * other handler's pattern. Which is to say, more specific patterns can override less specific patterns.
          */
         void enableConsoleOutput(bool enable) { Q_ASSERT(thread() == QThread::currentThread()); m_enableFallThrough = enable; }
 
     signals:
         /*!
-         * Emitted when a message is logged in a relevant category.
+         * Emitted when a message is logged which matches the relevant pattern.
          *
-         * When all slots are disconnected from this signal, the CLogCategoryHandler could be deleted.
+         * When all slots are disconnected from this signal, the CLogPatternHandler could be deleted.
          *
-         * Note that if a message matches more that one category handler, then this signal will be emitted for all of them,
-         * so if a slot is connected to all of them then it will be called multiple times. Use the methods
+         * Note that if a message matches more that one handler's pattern, then this signal will be emitted for all of
+         * those handlers, so if a slot is connected to all of them then it will be called multiple times. Use the methods
          * CStatusMessage::markAsHandledBy() and CStatusMessage::wasHandledBy() to detect this case in the slot and avoid
          * multiple handlings of the same message. Caveat: for this to work, the slot must take its argument by non-const
          * reference, and be connected by Qt::DirectConnection (i.e. the receiver is in the same thread as the CLogHandler).
@@ -103,7 +108,7 @@ namespace BlackMisc
 
     private:
         friend class CLogHandler;
-        CLogCategoryHandler(QObject *parent, bool enableFallThrough) : QObject(parent), m_enableFallThrough(enableFallThrough) {}
+        CLogPatternHandler(QObject *parent, bool enableFallThrough) : QObject(parent), m_enableFallThrough(enableFallThrough) {}
         bool m_enableFallThrough;
 
         bool canBeDeleted()