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

类 FileIOEngine

java.lang.Object

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

所有已实现的接口:

IOEngine, PersistentIOEngine

@InterfaceAudience.Private
public class FileIOEngine
extends Object
implements PersistentIOEngine

IO engine that stores data to a file on the local file system.

字段概要

字段

限定符和类型	字段和说明
static String	FILE_DELIMITER

构造器概要

构造器

构造器和说明
FileIOEngine(long capacity, String... filePaths)

方法概要

方法

限定符和类型	方法和说明
byte[]	calculateChecksum(String algorithm) Using an encryption algorithm to calculate a checksum, the default encryption algorithm is MD5
boolean	isPersistent() File IO engine is always able to support persistent storage for the cache
int	read(ByteBuffer dstBuffer, long offset) Transfers data from file to the given byte buffer
void	shutdown() Close the file
void	sync() Sync the data to file after writing
String	toString()
boolean	verifyFileIntegrity(byte[] persistentChecksum, String algorithm) Verify cache files's integrity
void	write(ByteBuffer srcBuffer, long offset) Transfers data from the given byte buffer to file

从类继承的方法 java.lang.Object

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

字段详细资料

FILE_DELIMITER

public static final String FILE_DELIMITER

另请参阅:

常量字段值

构造器详细资料

FileIOEngine

public FileIOEngine(long capacity,
            String... filePaths)
             throws IOException

抛出:

IOException

方法详细资料

verifyFileIntegrity

public boolean verifyFileIntegrity(byte[] persistentChecksum,
                          String algorithm)

从接口复制的说明: PersistentIOEngine

Verify cache files's integrity

指定者:

verifyFileIntegrity 在接口中 PersistentIOEngine

参数:

persistentChecksum - the persistent checksum

algorithm - which algorithm to calculate checksum

返回:

true if verify successfully

toString

public String toString()

覆盖:

toString 在类中 Object

isPersistent

public boolean isPersistent()

File IO engine is always able to support persistent storage for the cache

指定者:

isPersistent 在接口中 IOEngine

返回:

true

read

public int read(ByteBuffer dstBuffer,
       long offset)
         throws IOException

Transfers data from file to the given byte buffer

指定者:

read 在接口中 IOEngine

参数:

dstBuffer - the given byte buffer into which bytes are to be written

offset - The offset in the file where the first byte to be read

返回:

number of bytes read

抛出:

IOException

write

public void write(ByteBuffer srcBuffer,
         long offset)
           throws IOException

Transfers data from the given byte buffer to file

指定者:

write 在接口中 IOEngine

参数:

srcBuffer - the given byte buffer from which bytes are to be read

offset - The offset in the file where the first byte to be written

抛出:

IOException

sync

public void sync()
          throws IOException

Sync the data to file after writing

指定者:

sync 在接口中 IOEngine

抛出:

IOException

shutdown

public void shutdown()

Close the file

指定者:

shutdown 在接口中 IOEngine

calculateChecksum

public byte[] calculateChecksum(String algorithm)

从接口复制的说明: PersistentIOEngine

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

指定者:

calculateChecksum 在接口中 PersistentIOEngine

参数:

algorithm - which algorithm to calculate checksum

返回:

the checksum which is convert to HexString