Adding a dummy log writer WRITER_NONE that just discards everything.

This can be handy when oen doesn't want any output but still get
access to filter functionality, including rotation; and also for
general testing.

src/CMakeLists.txt

@@ -335,6 +335,7 @@ set(bro_SRCS
     LogMgr.cc
     LogWriter.cc
     LogWriterAscii.cc
+    LogWriterNone.cc
     Login.cc
     MIME.cc
     NCP.cc

src/LogMgr.cc

@@ -9,6 +9,7 @@
 #include "Net.h"
 
 #include "LogWriterAscii.h"
+#include "LogWriterNone.h"
 
 // Structure describing a log writer type.
 struct LogWriterDefinition {
@@ -20,6 +21,7 @@ struct LogWriterDefinition {
 
 // Static table defining all availabel log writers.
 LogWriterDefinition log_writers[] = {
+	{ BifEnum::Log::WRITER_NONE,  "None", 0, LogWriterNone::Instantiate },
 	{ BifEnum::Log::WRITER_ASCII, "Ascii", 0, LogWriterAscii::Instantiate },
 
 	// End marker, don't touch.

src/LogWriterNone.cc

@@ -0,0 +1,16 @@
+
+#include "LogWriterNone.h"
+
+bool LogWriterNone::DoRotate(string rotated_path, double open,
+			      double close, bool terminating)
+	{
+	if ( ! FinishedRotation(string("/dev/null"), Path(), open, close, terminating))
+		{
+		Error(Fmt("error rotating %s", Path().c_str()));
+		return false;
+		}
+
+	return true;
+	}
+
+

src/LogWriterNone.h

@@ -0,0 +1,30 @@
+// See the file "COPYING" in the main distribution directory for copyright.
+//
+// Dummy log writer that just discards everything (but still pretends to rotate).
+
+#ifndef LOGWRITERNONE_H
+#define LOGWRITERNONE_H
+
+#include "LogWriter.h"
+
+class LogWriterNone : public LogWriter {
+public:
+	LogWriterNone()	{}
+	~LogWriterNone()	{};
+
+	static LogWriter* Instantiate()	{ return new LogWriterNone; }
+
+protected:
+	virtual bool DoInit(string path, int num_fields,
+			    const LogField* const * fields)	{ return true; }
+
+	virtual bool DoWrite(int num_fields, const LogField* const * fields,
+			     LogVal** vals)	{ return true; }
+	virtual bool DoSetBuf(bool enabled)	{ return true; }
+	virtual bool DoRotate(string rotated_path, double open, double close,
+			      bool terminating);
+	virtual bool DoFlush()	{ return true; }
+	virtual void DoFinish()	{}
+};
+
+#endif

src/types.bif

@@ -159,6 +159,7 @@ module Log;
 
 enum Writer %{
 	WRITER_DEFAULT,
+	WRITER_NONE,
 	WRITER_ASCII,
 %}