com.linkedin.feathr.common.featurizeddataset

Class BaseDenseTensorIterator

java.lang.Object

com.linkedin.feathr.common.featurizeddataset.BaseDenseTensorIterator

All Implemented Interfaces:

ReadableTuple, TensorIterator

public abstract class BaseDenseTensorIterator
extends java.lang.Object
implements TensorIterator

The base for custom iterators over dense tensors of ranks 1+. Encapsulates the logic for traversing nested collections, so that it can be shared between e.g. Avro and Spark representations. Examples:

• A regular tensor of the shape [2, 3]. Numbering of positions: [ [0, 1, 2], [3, 4, 5] ]. The sequence of indices: [(0, 0), (0, 1), (0, 2), (1, 0), (1, 1), (1, 2)].
• A ragged tensor of rank 2. Numbering of positions: [ [0, 1], [], [2, 3, 4] ] The sequence of indices: [(0, 0), (0, 1), (2, 0), (2, 1), (2, 2)].

Subclasses are expected to cache their current path through the tree of nested collections. There are as many collections in the cache as the rank of the tensor, starting from the root and ending with the level containing leaves/values: cache[0] = root cache[1] = cache[0][_indices[0]] ... cache[rank] = cache[rank-1][_indices[rank-1]] = current value

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	BaseDenseTensorIterator(BaseDenseTensorIterator original)
protected	BaseDenseTensorIterator(int rank)

Method Summary

Modifier and Type	Method and Description
protected abstract boolean	cache(int level, int childIndex) Fill the level of cache from the childIndex child of the level-1.
protected abstract void	cacheRoot() Fill the 0th level of cache with the root.
int	getFlatIndex()
protected int	getIndex(int dimension)
protected int	getRank()
boolean	isValid()
void	next() Move iterator to the next row.
void	start() Rewinds the iterator to the beginning of its range.

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.linkedin.feathr.common.tensor.TensorIterator

getBoolean, getBytes, getCopy, getDouble, getString, getTensorData, getTypes, getValue

Methods inherited from interface com.linkedin.feathr.common.tensor.ReadableTuple

getFloat, getInt, getLong

Constructor Detail

BaseDenseTensorIterator

protected BaseDenseTensorIterator(int rank)

BaseDenseTensorIterator

protected BaseDenseTensorIterator(BaseDenseTensorIterator original)

Method Detail

getRank

protected final int getRank()

getFlatIndex

public final int getFlatIndex()

getIndex

protected final int getIndex(int dimension)

cache

protected abstract boolean cache(int level,
                                 int childIndex)

Fill the level of cache from the childIndex child of the level-1.

Returns:

false if j is out of range.

cacheRoot

protected abstract void cacheRoot()

Fill the 0th level of cache with the root.

start

public void start()

Description copied from interface: TensorIterator

Rewinds the iterator to the beginning of its range.

Specified by:

start in interface TensorIterator

isValid

public boolean isValid()

Specified by:

isValid in interface TensorIterator

Returns:

if the iterator is still within its range.

next

public void next()

Description copied from interface: TensorIterator

Move iterator to the next row.

Specified by:

next in interface TensorIterator