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, ingo_weinhold@gmx.de.
+ * 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

src/kits/debug/DebugEventStream.cpp

@@ -0,0 +1,269 @@
+/*
+ * Copyright 2009, Ingo Weinhold, ingo_weinhold@gmx.de.
+ * Distributed under the terms of the MIT License.
+ */
+
+#include <DebugEventStream.h>
+
+#include <stdlib.h>
+#include <string.h>
+
+#include <DataIO.h>
+
+
+#define INPUT_BUFFER_SIZE	(128 * 1024)
+
+
+BDebugEventInputStream::BDebugEventInputStream()
+	:
+	fStream(NULL),
+	fFlags(0),
+	fEventMask(0),
+	fBuffer(NULL),
+	fBufferCapacity(0),
+	fBufferSize(0),
+	fBufferPosition(0)
+{
+}
+
+
+BDebugEventInputStream::~BDebugEventInputStream()
+{
+	Unset();
+
+	free(fBuffer);
+}
+
+
+status_t
+BDebugEventInputStream::SetTo(BDataIO* stream)
+{
+	Unset();
+
+	// set the new values
+	if (stream == NULL)
+		return B_BAD_VALUE;
+
+	fStream = stream;
+
+	// allocate a buffer
+	if (fBuffer == NULL) {
+		fBuffer = (uint8*)malloc(INPUT_BUFFER_SIZE);
+		if (fBuffer == NULL) {
+			Unset();
+			return B_NO_MEMORY;
+		}
+
+		fBufferCapacity = INPUT_BUFFER_SIZE;
+		fBufferSize = 0;
+	}
+
+	fBufferPosition = 0;
+
+	// read the header
+	debug_event_stream_header header;
+	ssize_t bytesRead = _Read(&header, sizeof(header));
+	if (bytesRead < 0) {
+		Unset();
+		return bytesRead;
+	}
+	if ((size_t)bytesRead != sizeof(header)) {
+		Unset();
+		return B_BAD_DATA;
+	}
+
+	// check the header
+	if (strlcpy(header.signature, B_DEBUG_EVENT_STREAM_SIGNATURE,
+			sizeof(header.signature)) != 0
+		|| header.version != B_DEBUG_EVENT_STREAM_VERSION
+		|| (header.flags & B_DEBUG_EVENT_STREAM_FLAG_HOST_ENDIAN) == 0) {
+		// TODO: Support non-host endianess!
+		Unset();
+		return B_BAD_DATA;
+	}
+
+	fFlags = header.flags;
+	fEventMask = header.event_mask;
+
+	return B_OK;
+}
+
+
+void
+BDebugEventInputStream::Unset()
+{
+	fStream = NULL;
+	fFlags = 0;
+	fEventMask = 0;
+}
+
+
+ssize_t
+BDebugEventInputStream::ReadNextEvent(
+	const system_profiler_event_header** _header)
+{
+	// get the next header
+	status_t error = _GetData(sizeof(system_profiler_event_header));
+	if (error != B_OK) {
+		if (error == B_BAD_DATA && fBufferSize == 0)
+			return B_ENTRY_NOT_FOUND;
+		return error;
+	}
+
+	system_profiler_event_header* header
+		= (system_profiler_event_header*)(fBuffer + fBufferPosition);
+
+	// get the data
+	size_t size = header->size;
+	size_t totalSize = sizeof(system_profiler_event_header) + size;
+	if (header->size > 0) {
+		error = _GetData(totalSize);
+		if (error != B_OK)
+			return error;
+	}
+
+	// header might have moved when getting the data
+	header = (system_profiler_event_header*)(fBuffer + fBufferPosition);
+
+	// skip the event in the buffer
+	fBufferSize -= totalSize;
+	fBufferPosition += totalSize;
+
+	*_header = header;
+	return size;
+}
+
+
+ssize_t
+BDebugEventInputStream::_Read(void* _buffer, size_t size)
+{
+	uint8* buffer = (uint8*)_buffer;
+	size_t totalBytesRead = 0;
+	ssize_t bytesRead = 0;
+
+	while (size > 0 && (bytesRead = fStream->Read(buffer, size)) > 0) {
+		totalBytesRead += bytesRead;
+		buffer += bytesRead;
+		size -= bytesRead;
+	}
+
+	if (bytesRead < 0)
+		return bytesRead;
+
+	return totalBytesRead;
+}
+
+
+status_t
+BDebugEventInputStream::_GetData(size_t size)
+{
+	if (fBufferSize >= size)
+		return B_OK;
+
+	if (size > fBufferCapacity)
+		return B_BUFFER_OVERFLOW;
+
+	// move remaining data to the start of the buffer
+	if (fBufferSize > 0 && fBufferPosition > 0) {
+		memmove(fBuffer, fBuffer + fBufferPosition, fBufferSize);
+		fBufferPosition = 0;
+	}
+
+	// read more data
+	ssize_t bytesRead = _Read(fBuffer + fBufferPosition,
+		fBufferCapacity - fBufferSize);
+	if (bytesRead < 0)
+		return bytesRead;
+
+	fBufferSize += bytesRead;
+
+	return fBufferSize >= size ? B_OK : B_BAD_DATA;
+}
+
+
+// #pragma mark - BDebugEventOutputStream
+
+
+BDebugEventOutputStream::BDebugEventOutputStream()
+	:
+	fStream(NULL),
+	fFlags(0)
+{
+}
+
+
+BDebugEventOutputStream::~BDebugEventOutputStream()
+{
+	Unset();
+}
+
+
+status_t
+BDebugEventOutputStream::SetTo(BDataIO* stream, uint32 flags, uint32 eventMask)
+{
+	Unset();
+
+	// set the new values
+	if (stream == NULL)
+		return B_BAD_VALUE;
+
+	fStream = stream;
+	fFlags = /*(flags & B_DEBUG_EVENT_STREAM_FLAG_ZIPPED)
+		|*/ B_DEBUG_EVENT_STREAM_FLAG_HOST_ENDIAN;
+		// TODO: Support zipped data!
+
+	// init and write the header
+	debug_event_stream_header header;
+	memset(header.signature, 0, sizeof(header.signature));
+	strlcpy(header.signature, B_DEBUG_EVENT_STREAM_SIGNATURE,
+		sizeof(header.signature));
+	header.version = B_DEBUG_EVENT_STREAM_VERSION;
+	header.flags = fFlags;
+	header.event_mask = eventMask;
+
+	ssize_t written = fStream->Write(&header, sizeof(header));
+	if (written < 0) {
+		Unset();
+		return written;
+	}
+	if ((size_t)written != sizeof(header)) {
+		Unset();
+		return B_FILE_ERROR;
+	}
+
+	return B_OK;
+}
+
+
+void
+BDebugEventOutputStream::Unset()
+{
+	Flush();
+	fStream = NULL;
+	fFlags = 0;
+}
+
+
+status_t
+BDebugEventOutputStream::Write(const void* buffer, size_t size)
+{
+	if (size == 0)
+		return B_OK;
+	if (buffer == NULL)
+		return B_BAD_VALUE;
+
+	ssize_t written = fStream->Write(buffer, size);
+	if (written < 0)
+		return written;
+	if ((size_t)written != size)
+		return B_FILE_ERROR;
+
+	return B_OK;
+}
+
+
+status_t
+BDebugEventOutputStream::Flush()
+{
+	return B_OK;
+}

src/kits/debug/Jamfile

@@ -12,9 +12,12 @@ SEARCH_SOURCE += [ FDirName $(SUBDIR) arch $(TARGET_ARCH) ] ;
 
 SharedLibrary libdebug.so :
 	debug_support.cpp
+	DebugEventStream.cpp
 	Image.cpp
 	SymbolLookup.cpp
 
 	# architecture specific
 	arch_debug_support.cpp
+
+	: be
 ;