org.nd4j.linalg.cache.TadDescriptor Maven / Gradle / Ivy
package org.nd4j.linalg.cache;
import lombok.Data;
import lombok.extern.slf4j.Slf4j;
import org.nd4j.linalg.api.buffer.DataBuffer;
import org.nd4j.linalg.api.ndarray.INDArray;
import org.nd4j.linalg.api.shape.Shape;
import java.util.Arrays;
/**
* This is utility class, made to compare TADs for caching purposes.
*
* Idea: for any given INDArray with any specific shape,
* TAD for specific dimension will always be the same.
* So it can be reused as much as we want.
*
* Of note here is that when used as a key,
* we preserve immutability of the shape buffer
* in the ndarray by copying the values with
* {@link TadDescriptor#dataBufferToArray(DataBuffer)}
*
*
* @author [email protected]
*/
@Slf4j
@Data
public class TadDescriptor {
private int dimensionLength;
private int[] dimension;
private int[] shape;
/**
* Pass in an ndarray to get the databuffer
* and the appropriate dimensions
* @param array the array to pass in
* to get the shape info from
* @param dimension the dimensions for the TAD
*/
public TadDescriptor(INDArray array, int[] dimension) {
this.dimensionLength = dimension == null ? 0 : dimension.length;
this.dimension = dimension;
// TODO: change this to fill shapeInfo
this.shape = dataBufferToArray(array.shapeInfoDataBuffer());
}
/**
* Obtain the values from the shape buffer
* for the array
* @param buffer the buffer to get the values from
* @return the int array version of this data buffer
*/
public static int[] dataBufferToArray(DataBuffer buffer) {
int rank = buffer.getInt(0);
int ret[] = new int[Shape.shapeInfoLength(rank)];
ret[0] = rank;
for (int e = 1; e < Shape.shapeInfoLength(rank); e++) {
ret[e] = buffer.getInt(e);
}
return ret;
}
}