New bif log_set_buf() to set the buffering state for a stream.

TODO.logging

@@ -1,18 +1,19 @@
 List of the things not implemented yet:
 
-    - Dynamic path function.
     - Cluster-style remote_print
     - Rotation support
-    - Flushing support
     - Spawning writers in separate threads (not clear if we want that initially).
     - Not sure if the logging does the right thing with &optional and
       &default values. Needs testing.
     - Seems we could do some of the filter-related type checks
       currently done dynamically at startup via a TraversalCallback.
+	- LogMgs' error handling
+	- Put script function/constants into namespace.
+	- Cleanup code.
 
 There's probably more missing.
 
-Question:
+Questions:
 
     * Is giving the record column twice to create_stream too
 	  redundant? (once directly, and once via the event)::

src/LogMgr.cc

@@ -76,6 +76,19 @@ LogMgr::~LogMgr()
 		delete *s;
 	}
 
+LogMgr::Stream* LogMgr::FindStream(EnumVal* stream_id)
+	{
+	unsigned int idx = stream_id->AsEnum();
+
+	if ( idx >= streams.size() || ! streams[idx] )
+		{
+		run_time("unknown log stream");
+		return 0;
+		}
+
+	return streams[idx];
+	}
+
 bool LogMgr::CreateStream(EnumVal* stream_id, RecordType* columns, EventHandlerPtr handler)
 	{
 	// TODO: Should check that the record has only supported types.
@@ -182,15 +195,9 @@ bool LogMgr::AddFilter(EnumVal* stream_id, RecordVal* fval)
 		return false;
 		}
 
-	unsigned int i = stream_id->AsEnum();
+	Stream* stream = FindStream(stream_id);
-
+	if ( ! stream )
-	if ( i >= streams.size() || ! streams[i] )
-		{
-		run_time("unknown log stream");
 		return false;
-		}
-
-	Stream* stream = streams[i];
 
 	// Find the right writer type.
 	int writer = 0;
@@ -317,15 +324,9 @@ bool LogMgr::AddFilter(EnumVal* stream_id, RecordVal* fval)
 
 bool LogMgr::RemoveFilter(EnumVal* stream_id, StringVal* filter)
 	{
-	unsigned int idx = stream_id->AsEnum();
+	Stream* stream = FindStream(stream_id);
-
+	if ( ! stream )
-	if ( idx >= streams.size() || ! streams[idx] )
-		{
-		run_time("unknown log stream");
 		return false;
-		}
-
-	Stream* stream = streams[idx];
 
 	string name = filter->AsString()->CheckString();
 
@@ -348,15 +349,9 @@ bool LogMgr::RemoveFilter(EnumVal* stream_id, StringVal* filter)
 
 bool LogMgr::Write(EnumVal* stream_id, RecordVal* columns)
 	{
-	unsigned int idx = stream_id->AsEnum();
+	Stream* stream = FindStream(stream_id);
-
+	if ( ! stream )
-	if ( idx >= streams.size() || ! streams[idx] )
-		{
-		run_time("unknown log stream");
 		return false;
-		}
-
-	Stream* stream = streams[idx];
 
 	columns = columns->CoerceTo(stream->columns);
 
@@ -538,9 +533,21 @@ LogVal** LogMgr::RecordToFilterVals(Filter* filter, RecordVal* columns)
 	return vals;
 	}
 
+bool LogMgr::SetBuf(EnumVal* stream_id, bool enabled)
+	{
+	Stream* stream = FindStream(stream_id);
+	if ( ! stream )
+		return false;
+
+	for ( list<Filter*>::iterator i = stream->filters.begin(); i != stream->filters.end(); ++i )
+		{
+		for ( Filter::WriterMap::iterator j = (*i)->writers.begin(); j != (*i)->writers.end(); j++ )
+			j->second->SetBuf(enabled);
+		}
+
+	return true;
+	}
 
 void LogMgr::Error(LogWriter* writer, const char* msg)
 	{
-#if 0
-#endif
 	}

src/LogMgr.h

@@ -59,6 +59,7 @@ public:
     bool AddFilter(EnumVal* stream_id, RecordVal* filter);
     bool RemoveFilter(EnumVal* stream_id, StringVal* filter);
     bool Write(EnumVal* stream_id, RecordVal* columns);
+	bool SetBuf(EnumVal* stream_id, bool enabled); // Changes the state for all writers for that stream.
 
 protected:
     friend class LogWriter;
@@ -74,6 +75,7 @@ private:
 
 	bool TraverseRecord(Filter* filter, RecordType* rt, TableVal* include, TableVal* exclude, string path, list<int> indices);
 	LogVal** RecordToFilterVals(Filter* filter, RecordVal* columns);
+	Stream* FindStream(EnumVal* stream_id);
 
 	vector<Stream *> streams; // Indexed by stream enum.
 };

src/LogWriter.cc

@@ -6,6 +6,7 @@ LogWriter::LogWriter()
 	{
 	buf = 0;
 	buf_len = 1024;
+	buffering = true;
 	}
 
 LogWriter::~LogWriter()
@@ -37,6 +38,16 @@ void LogWriter::Finish()
 	DoFinish();
 	}
 
+bool LogWriter::SetBuf(bool enabled)
+	{
+	if ( enabled == buffering )
+		// No change.
+		return true;
+
+	buffering = enabled;
+	return DoSetBuf(enabled);
+	}
+
 const char* LogWriter::Fmt(const char* format, ...)
 	{
 	if ( ! buf )

src/LogWriter.h

@@ -36,6 +36,9 @@ public:
 	// performed.
 	void Finish();
 
+	// Sets the buffering status for the writer, if the writer supports 
+	bool SetBuf(bool enabled);
+
 protected:
 
     //// Methods for Writers to override.
@@ -50,15 +53,17 @@ protected:
     // should be reported via Error().
     virtual bool DoWrite(int num_fields, LogField** fields, LogVal** vals) = 0;
 
-	// Called when the flushing status for this writer is changed. If
+	// Called when the buffering status for this writer is changed. If
-	// flushing is enabled, the writer should attempt to write out
+	// buffering is disabled, the writer should attempt to write out
 	// information as quickly as possible even if that may have an
-	// performance impact. If disabled (which the writer should assume to be
+	// performance impact. If enabled (which the writer should assume to be
 	// the default), then it can buffer things up as necessary and write out
-	// in a way optimized for performance.
+	// in a way optimized for performance. The current buffering state can
+	// alse be queried via IsBuf().
 	//
-	// A writer may ignore flushing if it doesn't fit with its semantics.
+	// A writer may ignore buffering if it doesn't fit with its semantics.
-	virtual void DoSetFlushing(bool enabled) = 0;
+	// Still return true in that case.
+	virtual bool DoSetBuf(bool enabled) = 0;
 
 	// Called when a log output is to be rotated. Most directly, this only
 	// applies to writers outputting files, thoug a writer may also trigger
@@ -91,6 +96,9 @@ protected:
 	// A thread-safe version of fmt().
 	const char* Fmt(const char* format, ...);
 
+	// Returns the current buffering state.
+	bool IsBuf()	{ return buffering; }
+
     // Reports an error.
     void Error(const char *msg);
 
@@ -104,6 +112,7 @@ private:
     string path;
     int num_fields;
     LogField** fields;
+	bool buffering;
 
 	// For Fmt().
 	char* buf;

src/LogWriterAscii.cc

@@ -125,6 +125,9 @@ bool LogWriterAscii::DoWrite(int num_fields, LogField** fields, LogVal** vals)
 		return false;
 		}
 
+	if ( IsBuf() )
+		fflush(file);
+
 	return true;
 	}
 
@@ -133,8 +136,10 @@ bool LogWriterAscii::DoRotate(string rotated_path)
 	return true;
 	}
 
-void LogWriterAscii::DoSetFlushing(bool enabled)
+bool LogWriterAscii::DoSetBuf(bool enabled)
 	{
+	// Nothing to do.
+	return true;
 	}
 
 

src/LogWriterAscii.h

@@ -17,7 +17,7 @@ public:
 protected:
     virtual bool DoInit(string path, int num_fields, LogField** fields);
     virtual bool DoWrite(int num_fields, LogField** fields, LogVal** vals);
-	virtual void DoSetFlushing(bool enabled);
+	virtual bool DoSetBuf(bool enabled);
 	virtual bool DoRotate(string rotated_path);
     virtual void DoFinish();
 

src/bro.bif

@@ -548,6 +548,12 @@ function log_write%(id: Log_ID, columns: any%) : bool
 	return new Val(result, TYPE_BOOL);
     %}
 
+function log_set_buf%(id: Log_ID, buffered: bool%): bool
+	%{
+	bool result = log_mgr->SetBuf(id->AsEnumVal(), buffered);
+	return new Val(result, TYPE_BOOL);
+	%}
+
 function record_type_to_vector%(rt: string%): string_vec
 	%{
 	VectorVal* result =