Cleanup logfileHeader in DefaultEntryLogger

[AnonHxy]

Descriptions of the changes in this PR:

Motivation

Cleanup logfileHeader in DefaultEntryLogger. There is no place to invoke DefaultEntryLogger#logfileHeader to write, and the logfileHeader has moved to EntryLoggerAllocator:

bookkeeper/bookkeeper-server/src/main/java/org/apache/bookkeeper/bookie/EntryLoggerAllocator.java

Line 66 in a842f3e

final ByteBuf logfileHeader = Unpooled.buffer(DefaultEntryLogger.LOGFILE_HEADER_SIZE);

bookkeeper/bookkeeper-server/src/main/java/org/apache/bookkeeper/bookie/EntryLoggerAllocator.java

Lines 79 to 87 in a842f3e

	// Initialize the entry log header buffer. This cannot be a static object
	// since in our unit tests, we run multiple Bookies and thus EntryLoggers
	// within the same JVM. All of these Bookie instances access this header
	// so there can be race conditions when entry logs are rolled over and
	// this header buffer is cleared before writing it into the new logChannel.
	logfileHeader.writeBytes("BKLO".getBytes(UTF_8));
	logfileHeader.writeInt(DefaultEntryLogger.HEADER_CURRENT_VERSION);
	logfileHeader.writerIndex(DefaultEntryLogger.LOGFILE_HEADER_SIZE);

bookkeeper/bookkeeper-server/src/main/java/org/apache/bookkeeper/bookie/EntryLoggerAllocator.java

Lines 170 to 171 in a842f3e

	logfileHeader.readerIndex(0);
	logChannel.write(logfileHeader);

Changes

Cleanup logfileHeader in DefaultEntryLogger

[hangc0276]

@AnonHxy Please rebase the master, thanks.

[AnonHxy]

@AnonHxy Please rebase the master, thanks.

Done @hangc0276 @zymap PTAL