Package org.apache.hadoop.hbase.io.hfile.bucket

Class PersistentIOEngine

java.lang.Object

org.apache.hadoop.hbase.io.hfile.bucket.PersistentIOEngine

All Implemented Interfaces:

IOEngine

Direct Known Subclasses:

FileIOEngine, FileMmapIOEngine

@Private
public abstract class PersistentIOEngine
extends Object
implements IOEngine

A class implementing PersistentIOEngine interface supports file integrity verification for BucketCache which use persistent IOEngine

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static class	PersistentIOEngine.DuFileCommand

Field Summary

Fields

Modifier and Type	Field	Description
private static final PersistentIOEngine.DuFileCommand	DU
protected final String[]	filePaths
private static final org.slf4j.Logger	LOG

Constructor Summary

Constructors

Constructor	Description
PersistentIOEngine(String... filePaths)

Method Summary

Modifier and Type	Method	Description
protected byte[]	calculateChecksum(String algorithm)	Using an encryption algorithm to calculate a checksum, the default encryption algorithm is MD5
private static long	getFileSize(String filePath)	Using Linux command du to get file's real size
protected void	verifyFileIntegrity(byte[] persistentChecksum, String algorithm)	Verify cache files's integrity

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.hadoop.hbase.io.hfile.bucket.IOEngine

isPersistent, read, shutdown, sync, usesSharedMemory, write, write

Field Details

LOG

private static final org.slf4j.Logger LOG

DU

private static final PersistentIOEngine.DuFileCommand DU

filePaths

protected final String[] filePaths

Constructor Details

PersistentIOEngine

public PersistentIOEngine(String... filePaths)

Method Details

verifyFileIntegrity

protected void verifyFileIntegrity(byte[] persistentChecksum,
 String algorithm)
                            throws IOException

Verify cache files's integrity

Parameters:

algorithm - the backingMap persistence path

Throws:

IOException

calculateChecksum

protected byte[] calculateChecksum(String algorithm)

Using an encryption algorithm to calculate a checksum, the default encryption algorithm is MD5

Returns:

the checksum which is convert to HexString

Throws:

IOException - something happened like file not exists

NoSuchAlgorithmException - no such algorithm

getFileSize

private static long getFileSize(String filePath)
                         throws IOException

Using Linux command du to get file's real size

Parameters:

filePath - the file

Returns:

file's real size

Throws:

IOException - something happened like file not exists