Class FixedLeafTree

java.lang.Object

io.crums.util.mrkl.Tree

io.crums.util.mrkl.FixedLeafTree

public class FixedLeafTree
extends Tree

A more compact Tree appropriate if the leaves are fixed-width and it'all fits under 2 gigabytes.

See Also:

• treeDataLength(int, int, int)

Field Summary

Fields

Modifier and Type	Field	Description
static final int	MIN_ALGO_WIDTH
static final int	MIN_LEAF_WIDTH

Fields inherited from class io.crums.util.mrkl.Tree

BRANCH_PAD, LEAF_PAD

Constructor Summary

Constructors

Modifier	Constructor	Description
	FixedLeafTree(int leaves, String algo, byte[] data, int algoWidth, int leafWidth)	Creates a new instance.
protected	FixedLeafTree(FixedLeafTree copy)	Copy constructor.

Method Summary

Modifier and Type	Method	Description
byte[]	data(int level, int index)	Returns [a copy of] the data for the node at the specified coordinates.
ByteBuffer	dataBlock()	Returns entire data block.
protected ByteBuffer	extraBlock()	Returns the data beyond the standard definition of the tree.
static boolean	fitsModelCapacity(int leaves, int algoWidth, int leafWidth)
int	hashWidth()
int	leafWidth()	Returns the fixed-size leaf width.
ByteBuffer	leavesBlock()	Returns the leaves' data block.
static int	treeDataLength(int leaves, int algoWidth, int leafWidth)	Returns the number of bytes needed to encode the state of the tree, or -1 if that number exceeds the maximum int Java allows.

Methods inherited from class io.crums.util.mrkl.Tree

appendToStringDetail, getHashAlgo, hash, hashAlgoWidth, hashInternals, hashInternals, hashLeaves, hashLeaves, hashUncommon, hashUncommon, idx, isLeafWidthFixed, isOmniWidth, proof, root, toString

Methods inherited from class java.lang.Object

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

Field Details

MIN_ALGO_WIDTH

public static final int MIN_ALGO_WIDTH

See Also:

• Constant Field Values

MIN_LEAF_WIDTH

public static final int MIN_LEAF_WIDTH

See Also:

• Constant Field Values

Constructor Details

FixedLeafTree

public FixedLeafTree(int leaves,
 String algo,
 byte[] data,
 int algoWidth,
 int leafWidth)
              throws IllegalArgumentException

Creates a new instance.

Parameters:

leaves - number of leaf nodes in the tree

algo - hash algo used for the trees internal nodes

data - node data in serial form (interpreted by next parameters)

algoWidth - number of bytes in the hash generated by algo

leafWidth - number of bytes in a leaf node

Throws:

IllegalArgumentException

FixedLeafTree

protected FixedLeafTree(FixedLeafTree copy)

Copy constructor.

Method Details

data

public byte[] data(int level,
 int index)

Description copied from class: Tree

Returns [a copy of] the data for the node at the specified coordinates. For internal nodes, this is just the node's hash, which is computed from the hash of its child nodes; for leaf nodes, the node's data may generally be anything, but more often than not it's the hash of a source object.

Specified by:

data in class Tree

See Also:

• Node.data()

leafWidth

public int leafWidth()

Returns the fixed-size leaf width.

Specified by:

leafWidth in class Tree

Returns:

in bytes

dataBlock

public ByteBuffer dataBlock()

Returns entire data block.

Returns:

a new read-only view of the entire block.

leavesBlock

public ByteBuffer leavesBlock()

Returns the leaves' data block.

Returns:

a new read-only view of leaves' block.

extraBlock

protected ByteBuffer extraBlock()

Returns the data beyond the standard definition of the tree. This is a view of whatever bytes remain in the data block after the tree definition.

Returns:

possibly empty extra block

hashWidth

public int hashWidth()

fitsModelCapacity

public static boolean fitsModelCapacity(int leaves,
 int algoWidth,
 int leafWidth)

treeDataLength

public static int treeDataLength(int leaves,
 int algoWidth,
 int leafWidth)

Returns the number of bytes needed to encode the state of the tree, or -1 if that number exceeds the maximum int Java allows.