Package org.apache.druid.frame.read

Class FrameReaderUtils

java.lang.Object

org.apache.druid.frame.read.FrameReaderUtils

public class FrameReaderUtils
extends Object

Utility methods used by various entities that read data from Frame objects.

Constructor Summary

Constructors

Constructor	Description
FrameReaderUtils()

Method Summary

Modifier and Type	Method	Description
static int	compareByteArraysUnsigned(byte[] array1, int position1, int length1, byte[] array2, int position2, int length2)	Compares two byte arrays using unsigned byte ordering.
static int	compareMemoryToByteArrayUnsigned(org.apache.datasketches.memory.Memory memory, long position1, long length1, byte[] array, int position2, int length2)	Compares Memory with a byte array using unsigned byte ordering.
static int	compareMemoryUnsigned(org.apache.datasketches.memory.Memory memory1, long position1, long length1, org.apache.datasketches.memory.Memory memory2, long position2, long length2)	Compares two Memory ranges using unsigned byte ordering.
static Supplier<MemoryRange<org.apache.datasketches.memory.Memory>>	makeRowMemorySupplier(ColumnSelectorFactory columnSelectorFactory, RowSignature expectedSignature)	Returns a direct row memory supplier if mayBeAbleToSelectRowMemory(org.apache.druid.segment.ColumnSelectorFactory), otherwise returns null.
static ByteBuffer	readByteBuffer(org.apache.datasketches.memory.Memory memory, long dataStart, int dataLength)	Returns a ByteBuffer containing data from the provided Memory.

Methods inherited from class java.lang.Object

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

Constructor Detail

FrameReaderUtils

public FrameReaderUtils()

Method Detail

readByteBuffer

public static ByteBuffer readByteBuffer(org.apache.datasketches.memory.Memory memory,
                                        long dataStart,
                                        int dataLength)

Returns a ByteBuffer containing data from the provided Memory. The ByteBuffer is always newly created, so it is OK to change its position, limit, etc. However, it may point directly to the backing memory of the Memory object, so it is not OK to write to its contents.

makeRowMemorySupplier

@Nullable
public static Supplier<MemoryRange<org.apache.datasketches.memory.Memory>> makeRowMemorySupplier(ColumnSelectorFactory columnSelectorFactory,
                                                                                                 RowSignature expectedSignature)

Returns a direct row memory supplier if mayBeAbleToSelectRowMemory(org.apache.druid.segment.ColumnSelectorFactory), otherwise returns null. Note that even if the returned supplier is nonnull, it is still possible for the supplied MemoryRange to be null. Callers must check for this.

Parameters:

columnSelectorFactory - frame column selector factory

expectedSignature - expected signature of the target frame

compareMemoryUnsigned

public static int compareMemoryUnsigned(org.apache.datasketches.memory.Memory memory1,
                                        long position1,
                                        long length1,
                                        org.apache.datasketches.memory.Memory memory2,
                                        long position2,
                                        long length2)

Compares two Memory ranges using unsigned byte ordering. Different from Memory.compareTo(long, long, org.apache.datasketches.memory.Memory, long, long), which uses signed ordering.

compareMemoryToByteArrayUnsigned

public static int compareMemoryToByteArrayUnsigned(org.apache.datasketches.memory.Memory memory,
                                                   long position1,
                                                   long length1,
                                                   byte[] array,
                                                   int position2,
                                                   int length2)

Compares Memory with a byte array using unsigned byte ordering.

compareByteArraysUnsigned

public static int compareByteArraysUnsigned(byte[] array1,
                                            int position1,
                                            int length1,
                                            byte[] array2,
                                            int position2,
                                            int length2)

Compares two byte arrays using unsigned byte ordering.