From 8599c4d371139dc0d4444b128792cd499129d349 Mon Sep 17 00:00:00 2001
From: Christian Mollekopf <chrigi_1@fastmail.fm>
Date: Thu, 4 Feb 2016 18:39:18 +0100
Subject: Filter debug output by program name and area

---
 common/log.cpp | 56 ++++++++++++++++++++++++++++++++++++++++++++++----------
 common/log.h   | 18 +++++++++++++++++-
 2 files changed, 63 insertions(+), 11 deletions(-)

diff --git a/common/log.cpp b/common/log.cpp
index 85a55c0..0f011b1 100644
--- a/common/log.cpp
+++ b/common/log.cpp
@@ -142,23 +142,56 @@ Sink::Log::DebugLevel Sink::Log::debugOutputLevel()
     return debugLevelFromName(qgetenv("SINKDEBUGLEVEL"));
 }
 
+void Sink::Log::setFilter(const QByteArrayList &filter)
+{
+    qputenv("SINKDEBUGFILTER", filter.join(','));
+}
+
+void Sink::Log::setAreas(const QByteArrayList &filter)
+{
+    qputenv("SINKDEBUGAREAS", filter.join(','));
+}
+
+static QByteArray getProgramName()
+{
+    if (QCoreApplication::instance()) {
+        return QCoreApplication::instance()->applicationName().toLocal8Bit();
+    } else {
+        return "<unknown program name>";
+    }
+}
+
+static bool containsItemStartingWith(const QByteArray &pattern, const QByteArrayList &list)
+{
+    for (const auto &item : list) {
+        if (pattern.startsWith(item)) {
+            return true;
+        }
+    }
+    return false;
+}
+
 QDebug Sink::Log::debugStream(DebugLevel debugLevel, int line, const char* file, const char* function, const char* debugArea)
 {
+    static NullStream nullstream;
     DebugLevel debugOutputLevel = debugLevelFromName(qgetenv("SINKDEBUGLEVEL"));
     if (debugLevel < debugOutputLevel) {
-        static NullStream stream;
-        return QDebug(&stream);
+        return QDebug(&nullstream);
     }
 
-    static DebugStream stream;
-    QDebug debug(&stream);
+    auto areas = qgetenv("SINKDEBUGAREAS").split(',');
+    if (debugArea && !areas.isEmpty()) {
+        if (!containsItemStartingWith(debugArea, areas)) {
+            return QDebug(&nullstream);
+        }
+    }
+    static QByteArray programName = getProgramName();
 
-    static QByteArray programName;
-    if (programName.isEmpty()) {
-        if (QCoreApplication::instance())
-            programName = QCoreApplication::instance()->applicationName().toLocal8Bit();
-        else
-            programName = "<unknown program name>";
+    auto filter = qgetenv("SINKDEBUGFILTER").split(',');
+    if (!filter.isEmpty() && !filter.contains(programName)) {
+        if (!containsItemStartingWith(programName, filter)) {
+            return QDebug(&nullstream);
+        }
     }
 
     QString prefix;
@@ -221,6 +254,9 @@ QDebug Sink::Log::debugStream(DebugLevel debugLevel, int line, const char* file,
     }
     output += ": ";
 
+    static DebugStream stream;
+    QDebug debug(&stream);
+
     debug.noquote().nospace() << output;
 
     return debug;
diff --git a/common/log.h b/common/log.h
index 564c574..c643f84 100644
--- a/common/log.h
+++ b/common/log.h
@@ -16,15 +16,31 @@ enum DebugLevel {
 QByteArray SINKCOMMON_EXPORT debugLevelName(DebugLevel debugLevel);
 DebugLevel SINKCOMMON_EXPORT debugLevelFromName(const QByteArray &name);
 
+/**
+ * Sets the debug output level.
+ *
+ * Everything below is ignored.
+ */
 void SINKCOMMON_EXPORT setDebugOutputLevel(DebugLevel);
 DebugLevel SINKCOMMON_EXPORT debugOutputLevel();
 
+/// Set debug areas that should be logged
+void SINKCOMMON_EXPORT setAreas(const QByteArrayList &areas);
+
+/**
+ * Set an application name filter.
+ *
+ * Note: In case of resources the identifier is the application name.
+ */
+void SINKCOMMON_EXPORT setFilter(const QByteArrayList &filter);
+
+
 QDebug SINKCOMMON_EXPORT debugStream(DebugLevel debugLevel, int line, const char* file, const char* function, const char* debugArea = 0);
 
 }
 }
 
-#define DEBUG_AREA 0
+#define DEBUG_AREA nullptr
 
 #define Trace_() Sink::Log::debugStream(Sink::Log::DebugLevel::Trace, __LINE__, __FILE__, Q_FUNC_INFO)
 #define Log_() Sink::Log::debugStream(Sink::Log::DebugLevel::Log, __LINE__, __FILE__, Q_FUNC_INFO)
-- 
cgit v1.2.3