Package org.apache.hadoop.hdfs.protocol

Enum BlockType

java.lang.Object

java.lang.Enum<BlockType>

org.apache.hadoop.hdfs.protocol.BlockType

All Implemented Interfaces:

java.io.Serializable, java.lang.Comparable<BlockType>

public enum BlockType
extends java.lang.Enum<BlockType>

Type of a block. Previously, all blocks were replicated (contiguous). Then Erasure Coded blocks (striped) were implemented. BlockTypes are currently defined by the highest bit in the block id. If this bit is set, then the block is striped. Further extensions may claim the second bit s.t. the highest two bits are set. e.g. 0b00 == contiguous 0b10 == striped 0b11 == possible further extension block type.

Enum Constant Summary

Enum Constants

Enum Constant	Description
CONTIGUOUS
STRIPED

Method Summary

Modifier and Type	Method	Description
static BlockType	fromBlockId(long blockId)	Parse a BlockId to find the BlockType Note: the old block id generation algorithm was based on a pseudo random number generator, so there may be legacy blocks that make this conversion unreliable.
static BlockType	valueOf(java.lang.String name)	Returns the enum constant of this type with the specified name.
static BlockType[]	values()	Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

CONTIGUOUS

public static final BlockType CONTIGUOUS

STRIPED

public static final BlockType STRIPED

Method Detail

values

public static BlockType[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (BlockType c : BlockType.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static BlockType valueOf(java.lang.String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

java.lang.IllegalArgumentException - if this enum type has no constant with the specified name

java.lang.NullPointerException - if the argument is null

fromBlockId

public static BlockType fromBlockId(long blockId)

Parse a BlockId to find the BlockType Note: the old block id generation algorithm was based on a pseudo random number generator, so there may be legacy blocks that make this conversion unreliable.