Defined a simple file format to store debug event streams as generated by the

system profiling interface and added classes BDebugEvent{Input,Ouput}Stream for
reading/writing those files.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30244 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/debug/DebugEventStream.h

@@ -0,0 +1,83 @@
+/*
+ * Copyright 2009, Ingo Weinhold, [email protected].
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef _DEBUG_EVENT_STREAM_H
+#define _DEBUG_EVENT_STREAM_H
+
+#include <SupportDefs.h>
+
+#include <system_profiler_defs.h>
+
+
+class BDataIO;
+
+
+struct debug_event_stream_header {
+	char	signature[32];
+	uint32	version;
+	uint32	flags;
+	uint32	event_mask;
+};
+
+
+// signature and version
+#define B_DEBUG_EVENT_STREAM_SIGNATURE	"Haiku debug events"
+#define B_DEBUG_EVENT_STREAM_VERSION	1
+
+
+// flags
+enum {
+	B_DEBUG_EVENT_STREAM_FLAG_HOST_ENDIAN		= 0x00000001,
+	B_DEBUG_EVENT_STREAM_FLAG_SWAPPED_ENDIAN	= 0x01000000,
+
+	B_DEBUG_EVENT_STREAM_FLAG_ZIPPED			= 0x00000002
+};
+
+
+class BDebugEventInputStream {
+public:
+								BDebugEventInputStream();
+								~BDebugEventInputStream();
+
+			status_t			SetTo(BDataIO* stream);
+			void				Unset();
+
+			ssize_t				ReadNextEvent(
+									const system_profiler_event_header**
+										_header);
+
+private:
+			ssize_t				_Read(void* buffer, size_t size);
+			status_t			_GetData(size_t size);
+
+private:
+			BDataIO*			fStream;
+			uint32				fFlags;
+			uint32				fEventMask;
+			uint8*				fBuffer;
+			size_t				fBufferCapacity;
+			size_t				fBufferSize;
+			size_t				fBufferPosition;
+};
+
+
+class BDebugEventOutputStream {
+public:
+								BDebugEventOutputStream();
+								~BDebugEventOutputStream();
+
+			status_t			SetTo(BDataIO* stream, uint32 flags,
+									uint32 eventMask);
+			void				Unset();
+
+			status_t 			Write(const void* buffer, size_t size);
+			status_t			Flush();
+
+private:
+			BDataIO*			fStream;
+			uint32				fFlags;
+};
+
+
+#endif	// _DEBUG_EVENT_STREAM_H