Package com.google.common.hash

Class AbstractCompositeHashFunction

java.lang.Object

com.google.common.hash.AbstractHashFunction

com.google.common.hash.AbstractCompositeHashFunction

All Implemented Interfaces:

HashFunction

Direct Known Subclasses:

Hashing.ConcatenatedHashFunction

abstract class AbstractCompositeHashFunction
extends AbstractHashFunction

An abstract composition of multiple hash functions. newHasher() delegates to the Hasher objects of the delegate hash functions, and in the end, they are used by makeHash(Hasher[]) that constructs the final HashCode.

Field Summary

Fields

Modifier and Type	Field	Description
(package private) HashFunction[]	functions
private static long	serialVersionUID

Constructor Summary

Constructors

Constructor	Description
AbstractCompositeHashFunction(HashFunction... functions)

Method Summary

Modifier and Type	Method	Description
private Hasher	fromHashers(Hasher[] hashers)
(package private) abstract HashCode	makeHash(Hasher[] hashers)	Constructs a HashCode from the Hasher objects of the functions.
Hasher	newHasher()	Begins a new hash code computation by returning an initialized, stateful Hasher instance that is ready to receive data.
Hasher	newHasher(int expectedInputSize)	Begins a new hash code computation as HashFunction.newHasher(), but provides a hint of the expected size of the input (in bytes).

Methods inherited from class com.google.common.hash.AbstractHashFunction

hashBytes, hashBytes, hashBytes, hashInt, hashLong, hashObject, hashString, hashUnencodedChars

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.google.common.hash.HashFunction

bits

Field Detail

functions

final HashFunction[] functions

serialVersionUID

private static final long serialVersionUID

See Also:

Constant Field Values

Constructor Detail

AbstractCompositeHashFunction

AbstractCompositeHashFunction(HashFunction... functions)

Method Detail

makeHash

abstract HashCode makeHash(Hasher[] hashers)

Constructs a HashCode from the Hasher objects of the functions. Each of them has consumed the entire input and they are ready to output a HashCode. The order of the hashers are the same order as the functions given to the constructor.

newHasher

public Hasher newHasher()

Description copied from interface: HashFunction

Begins a new hash code computation by returning an initialized, stateful Hasher instance that is ready to receive data. Example:

 HashFunction hf = Hashing.md5();
 HashCode hc = hf.newHasher()
     .putLong(id)
     .putBoolean(isActive)
     .hash();
 

newHasher

public Hasher newHasher(int expectedInputSize)

Description copied from interface: HashFunction

Begins a new hash code computation as HashFunction.newHasher(), but provides a hint of the expected size of the input (in bytes). This is only important for non-streaming hash functions (hash functions that need to buffer their whole input before processing any of it).

Specified by:

newHasher in interface HashFunction

Overrides:

newHasher in class AbstractHashFunction

fromHashers

private Hasher fromHashers(Hasher[] hashers)