Package org.neo4j.gds.core.compression.common

Class AdjacencyCompression

java.lang.Object

org.neo4j.gds.core.compression.common.AdjacencyCompression

public final class AdjacencyCompression
extends java.lang.Object

Method Summary

Modifier and Type	Method	Description
static int	applyDeltaEncoding(long[] data, int length, long[][] unsortedWeights, long[][] sortedWeights, org.neo4j.gds.core.Aggregation[] aggregations, boolean noAggregation)
static int	applyDeltaEncoding(long[] data, int length, org.neo4j.gds.core.Aggregation aggregation)
static int	applyDeltaEncoding(LongArrayBuffer data, long[][] weights, long[][] sortedWeights, org.neo4j.gds.core.Aggregation[] aggregations, boolean noAggregation)
static int	applyDeltaEncoding(LongArrayBuffer data, org.neo4j.gds.core.Aggregation aggregation)
static int	compress(long[] data, byte[] out, int length)
static int	compress(long[] data, int offset, int length, byte[] out)
static long	compress(long[] data, int offset, int length, long ptr)
static int	compress(LongArrayBuffer data, byte[] out)
static long[]	decompress(byte[] compressed, int numberOfValues)
static long	decompress(int numberOfValues, long ptr, long[] into, int offset)
static long	decompressAndPrefixSum(int numberOfValues, long previousValue, long ptr, long[] into, int offset)
static long	deltaDecode(long[] deltas, int length, long first)	Decodes delta encoded values based on a given initial value.
static byte[]	deltaEncodeAndCompress(long[] values, int offset, int length, org.neo4j.gds.core.Aggregation aggregation)
static int	deltaEncodeSortedValues(long[] values, int offset, int length, org.neo4j.gds.core.Aggregation aggregation)
static byte[]	ensureBufferSize(LongArrayBuffer data, byte[] out)
static void	prefixSumDeltaEncodedValues(long[] values, int length)
static void	zigZagUncompressFrom(long[] into, byte[] targets, int compressedValues, int limit, AdjacencyCompressor.ValueMapper mapper)
static void	zigZagUncompressFrom(LongArrayBuffer into, byte[] targets, int compressedValues, int limit, AdjacencyCompressor.ValueMapper mapper)	Decompress the given array into the given into.

Methods inherited from class java.lang.Object

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

Method Detail

zigZagUncompressFrom

public static void zigZagUncompressFrom(LongArrayBuffer into,
                                        byte[] targets,
                                        int compressedValues,
                                        int limit,
                                        AdjacencyCompressor.ValueMapper mapper)

Decompress the given array into the given into. After this, LongArrayBuffer.length will reflect the number of decompressed values that are in the LongArrayBuffer.buffer.

zigZagUncompressFrom

public static void zigZagUncompressFrom(long[] into,
                                        byte[] targets,
                                        int compressedValues,
                                        int limit,
                                        AdjacencyCompressor.ValueMapper mapper)

applyDeltaEncoding

public static int applyDeltaEncoding(LongArrayBuffer data,
                                     org.neo4j.gds.core.Aggregation aggregation)

applyDeltaEncoding

public static int applyDeltaEncoding(long[] data,
                                     int length,
                                     org.neo4j.gds.core.Aggregation aggregation)

applyDeltaEncoding

public static int applyDeltaEncoding(LongArrayBuffer data,
                                     long[][] weights,
                                     long[][] sortedWeights,
                                     org.neo4j.gds.core.Aggregation[] aggregations,
                                     boolean noAggregation)

applyDeltaEncoding

public static int applyDeltaEncoding(long[] data,
                                     int length,
                                     long[][] unsortedWeights,
                                     long[][] sortedWeights,
                                     org.neo4j.gds.core.Aggregation[] aggregations,
                                     boolean noAggregation)

ensureBufferSize

public static byte[] ensureBufferSize(LongArrayBuffer data,
                                      byte[] out)

compress

public static int compress(LongArrayBuffer data,
                           byte[] out)

compress

public static int compress(long[] data,
                           byte[] out,
                           int length)

compress

public static int compress(long[] data,
                           int offset,
                           int length,
                           byte[] out)

compress

public static long compress(long[] data,
                            int offset,
                            int length,
                            long ptr)

deltaEncodeAndCompress

public static byte[] deltaEncodeAndCompress(long[] values,
                                            int offset,
                                            int length,
                                            org.neo4j.gds.core.Aggregation aggregation)

decompress

public static long[] decompress(byte[] compressed,
                                int numberOfValues)

decompressAndPrefixSum

public static long decompressAndPrefixSum(int numberOfValues,
                                          long previousValue,
                                          long ptr,
                                          long[] into,
                                          int offset)

decompress

public static long decompress(int numberOfValues,
                              long ptr,
                              long[] into,
                              int offset)

deltaEncodeSortedValues

public static int deltaEncodeSortedValues(long[] values,
                                          int offset,
                                          int length,
                                          org.neo4j.gds.core.Aggregation aggregation)

deltaDecode

public static long deltaDecode(long[] deltas,
                               int length,
                               long first)

Decodes delta encoded values based on a given initial value.

A little faster due to manual unrolling. Inspired be Lemire.

Parameters:

deltas - delta encoded values

length - number of values to decode

first - the first decoded value

Returns:

the last decoded value

prefixSumDeltaEncodedValues

public static void prefixSumDeltaEncodedValues(long[] values,
                                               int length)