org.ccnx.ccn.protocol.BloomFilter Class Reference

Implement bloom filter operations. More...

List of all members.

Public Member Functions
	BloomFilter (int estimatedMembers, byte[] seed)
	Constructor.
	BloomFilter ()
	For decoding.
void	insert (byte[] key)
	Insert a key.
boolean	match (byte[] key)
	Test if the bloom filter matches a particular key.
int	size ()
	Returns the value given on creation by estimatedMembers.
byte[]	seed ()
	Get a copy of the seed.
long	getElementLabel ()
	Gets the type of element this is within an exclude filter.
void	decode (XMLDecoder decoder) throws ContentDecodingException
	Decode this object as the top-level item in a new XML document, reading it from a network buffer.
void	encode (XMLEncoder encoder) throws ContentEncodingException
	Encode this object during an ongoing encoding pass; this is what subclasses generally need to know how to implement.
int	compareTo (BloomFilter o)
BloomFilter	clone () throws CloneNotSupportedException
boolean	validate ()
	Make sure all of the necessary fields are filled in prior to attempting to encode.
int	hashCode ()
boolean	equals (Object obj)
Static Public Member Functions
static byte[]	createSeed ()
	Create a seed from random values.

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Detailed Description

Implement bloom filter operations.

Bloom filters are used to exclude keys that are inserted into the filter

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Constructor & Destructor Documentation

org.ccnx.ccn.protocol.BloomFilter.BloomFilter	(	int	estimatedMembers,
		byte[]	seed
	)

Constructor.

Parameters:

	estimatedMembers	The performance of the bloom filter can be improved by accurately estimating the number of members that will be inserted into it. Too low a number will increase the likelihood of false positives. Too high a number will cause the filter to be larger than necessary, impacting performance. It is better for this number to be too low than too high.
	seed	Random seed data must be of length 4

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Member Function Documentation

static byte [] org.ccnx.ccn.protocol.BloomFilter.createSeed

(

)

[static]

Create a seed from random values.

Returns:

the seed

void org.ccnx.ccn.protocol.BloomFilter.decode

(

XMLDecoder

decoder

)

throws ContentDecodingException [virtual]

Decode this object as the top-level item in a new XML document, reading it from a network buffer.

Reads document start and end. Assumes default encoding.

Parameters:

buf

input stream to read from

Exceptions:

ContentDecodingException

if there is an error decoding the content Decode this object as the top-level item in a new XML document, reading it from a network buffer. Reads document start and end.

Parameters:

	buf	input stream to read from
	codec	the codec to use; must be recognized by XMLCodecFactory

Exceptions:

ContentDecodingException

if there is an error decoding the content

See also:

XMLCodecFactory Decode this object during an ongoing decoding pass; this is what subclasses generally need to know how to implement. Reads just the object itself, higher-level processes have handled start and end document if need be. Allows object to be read using the same code whether it is a top-level element written alone, or nested inside another element.

Parameters:

decoder

the decoder being used; encapsulates state including the codec being used as well as the input source and current offset

Implements org.ccnx.ccn.impl.encoding.GenericXMLEncodable.

void org.ccnx.ccn.protocol.BloomFilter.encode

(

XMLEncoder

encoder

)

throws ContentEncodingException [virtual]

Encode this object during an ongoing encoding pass; this is what subclasses generally need to know how to implement.

Writes just the object itself, higher-level processes have handled start and end document if need be. Allows object to be written using the same code whether it is a top-level element written alone, or nested inside another element.

Parameters:

encoder

the encoder being used; encapsulates state including the codec being used as well as the output destination and current offset

Implements org.ccnx.ccn.impl.encoding.GenericXMLEncodable.

void org.ccnx.ccn.protocol.BloomFilter.insert

(

byte[]

key

)

Insert a key.

Parameters:

key

a key to exclude

boolean org.ccnx.ccn.protocol.BloomFilter.match

(

byte[]

key

)

[virtual]

Test if the bloom filter matches a particular key.

Note - a negative result means the key was definitely not set, but a positive result only means the key was likely set.

Parameters:

key

key to test

Returns:

false if not set

Implements org.ccnx.ccn.protocol.Exclude.Filler.

byte [] org.ccnx.ccn.protocol.BloomFilter.seed

(

)

Get a copy of the seed.

Returns:

copy of seed

int org.ccnx.ccn.protocol.BloomFilter.size

(

)

Returns the value given on creation by estimatedMembers.

See also:

BloomFilter.BloomFilter

Returns:

the estimated members of this filter

boolean org.ccnx.ccn.protocol.BloomFilter.validate

(

)

[virtual]

Make sure all of the necessary fields are filled in prior to attempting to encode.

All implementations of encode(XMLEncoder) should call this for their classes prior to encoding.

Returns:

true if object is valid and can be encoded, false if there is a problem; for example mandatory fields are uninitialized

Implements org.ccnx.ccn.impl.encoding.GenericXMLEncodable.

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The documentation for this class was generated from the following file:

• src/org/ccnx/ccn/protocol/BloomFilter.java