Package org.iq80.leveldb.impl

Class LogReader

java.lang.Object

org.iq80.leveldb.impl.LogReader

public class LogReader
extends Object

Field Summary

Fields

Modifier and Type	Field	Description
private final SliceOutput	blockScratch	Scratch buffer for current block.
private SliceInput	currentBlock	The current block records are being read from.
private Slice	currentChunk	Current chunk which is sliced from the current block.
private long	endOfBufferOffset	Offset of the first location past the end of buffer.
private boolean	eof	Have we read to the end of the file?
private final FileChannel	fileChannel
private final long	initialOffset	Offset at which to start looking for the first record to return
private long	lastRecordOffset	Offset of the last record returned by readRecord.
private final LogMonitor	monitor
private final DynamicSliceOutput	recordScratch	Scratch buffer in which the next record is assembled.
private final boolean	verifyChecksums

Constructor Summary

Constructors

Constructor	Description
LogReader(FileChannel fileChannel, LogMonitor monitor, boolean verifyChecksums, long initialOffset)

Method Summary

Modifier and Type	Method	Description
long	getLastRecordOffset()
boolean	readNextBlock()
private LogChunkType	readNextChunk()	Return type, or one of the preceding special values
Slice	readRecord()
private void	reportCorruption(long bytes, String reason)	Reports corruption to the monitor.
private void	reportDrop(long bytes, Throwable reason)	Reports dropped bytes to the monitor.
private boolean	skipToInitialBlock()	Skips all blocks that are completely before "initial_offset_".

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

fileChannel

private final FileChannel fileChannel

monitor

private final LogMonitor monitor

verifyChecksums

private final boolean verifyChecksums

initialOffset

private final long initialOffset

Offset at which to start looking for the first record to return

eof

private boolean eof

Have we read to the end of the file?

lastRecordOffset

private long lastRecordOffset

Offset of the last record returned by readRecord.

endOfBufferOffset

private long endOfBufferOffset

Offset of the first location past the end of buffer.

recordScratch

private final DynamicSliceOutput recordScratch

Scratch buffer in which the next record is assembled.

blockScratch

private final SliceOutput blockScratch

Scratch buffer for current block. The currentBlock is sliced off the underlying buffer.

currentBlock

private SliceInput currentBlock

The current block records are being read from.

currentChunk

private Slice currentChunk

Current chunk which is sliced from the current block.

Constructor Details

LogReader

public LogReader(FileChannel fileChannel,
 LogMonitor monitor,
 boolean verifyChecksums,
 long initialOffset)

Method Details

getLastRecordOffset

public long getLastRecordOffset()

skipToInitialBlock

private boolean skipToInitialBlock()

Skips all blocks that are completely before "initial_offset_".

Handles reporting corruption

Returns:

true on success.

readRecord

public Slice readRecord()

readNextChunk

private LogChunkType readNextChunk()

Return type, or one of the preceding special values

readNextBlock

public boolean readNextBlock()

reportCorruption

private void reportCorruption(long bytes,
 String reason)

Reports corruption to the monitor. The buffer must be updated to remove the dropped bytes prior to invocation.

reportDrop

private void reportDrop(long bytes,
 Throwable reason)

Reports dropped bytes to the monitor. The buffer must be updated to remove the dropped bytes prior to invocation.