Class SegmentsUtil


  • public class SegmentsUtil
    extends Object
    Util for data format segments calc.
    • Field Detail

      • LITTLE_ENDIAN

        public static final boolean LITTLE_ENDIAN
        Constant that flags the byte order.
    • Constructor Detail

      • SegmentsUtil

        public SegmentsUtil()
    • Method Detail

      • allocateReuseBytes

        public static byte[] allocateReuseBytes​(int length)
        Allocate bytes that is only for temporary usage, it should not be stored in somewhere else. Use a ThreadLocal to reuse bytes to avoid overhead of byte[] new and gc.

        If there are methods that can only accept a byte[], instead of a MemorySegment[] parameter, we can allocate a reuse bytes and copy the MemorySegment data to byte[], then call the method. Such as String deserialization.

      • allocateReuseChars

        public static char[] allocateReuseChars​(int length)
      • copyToBytes

        public static byte[] copyToBytes​(MemorySegment[] segments,
                                         int offset,
                                         int numBytes)
        Copy segments to a new byte[].
        Parameters:
        segments - Source segments.
        offset - Source segments offset.
        numBytes - the number bytes to copy.
      • copyToBytes

        public static byte[] copyToBytes​(MemorySegment[] segments,
                                         int offset,
                                         byte[] bytes,
                                         int bytesOffset,
                                         int numBytes)
        Copy segments to target byte[].
        Parameters:
        segments - Source segments.
        offset - Source segments offset.
        bytes - target byte[].
        bytesOffset - target byte[] offset.
        numBytes - the number bytes to copy.
      • copyMultiSegmentsToBytes

        public static void copyMultiSegmentsToBytes​(MemorySegment[] segments,
                                                    int offset,
                                                    byte[] bytes,
                                                    int bytesOffset,
                                                    int numBytes)
      • copyToUnsafe

        public static void copyToUnsafe​(MemorySegment[] segments,
                                        int offset,
                                        Object target,
                                        int pointer,
                                        int numBytes)
        Copy segments to target unsafe pointer.
        Parameters:
        segments - Source segments.
        offset - The position where the bytes are started to be read from these memory segments.
        target - The unsafe memory to copy the bytes to.
        pointer - The position in the target unsafe memory to copy the chunk to.
        numBytes - the number bytes to copy.
      • copyToView

        public static void copyToView​(MemorySegment[] segments,
                                      int offset,
                                      int sizeInBytes,
                                      DataOutputView target)
                               throws IOException
        Copy bytes of segments to output view. Note: It just copies the data in, not include the length.
        Parameters:
        segments - source segments
        offset - offset for segments
        sizeInBytes - size in bytes
        target - target output view
        Throws:
        IOException
      • copyFromBytes

        public static void copyFromBytes​(MemorySegment[] segments,
                                         int offset,
                                         byte[] bytes,
                                         int bytesOffset,
                                         int numBytes)
        Copy target segments from source byte[].
        Parameters:
        segments - target segments.
        offset - target segments offset.
        bytes - source byte[].
        bytesOffset - source byte[] offset.
        numBytes - the number bytes to copy.
      • getBytes

        public static byte[] getBytes​(MemorySegment[] segments,
                                      int baseOffset,
                                      int sizeInBytes)
        Maybe not copied, if want copy, please use copyTo.
      • equals

        public static boolean equals​(MemorySegment[] segments1,
                                     int offset1,
                                     MemorySegment[] segments2,
                                     int offset2,
                                     int len)
        Equals two memory segments regions.
        Parameters:
        segments1 - Segments 1
        offset1 - Offset of segments1 to start equaling
        segments2 - Segments 2
        offset2 - Offset of segments2 to start equaling
        len - Length of the equaled memory region
        Returns:
        true if equal, false otherwise
      • hashByWords

        public static int hashByWords​(MemorySegment[] segments,
                                      int offset,
                                      int numBytes)
        hash segments to int, numBytes must be aligned to 4 bytes.
        Parameters:
        segments - Source segments.
        offset - Source segments offset.
        numBytes - the number bytes to hash.
      • hash

        public static int hash​(MemorySegment[] segments,
                               int offset,
                               int numBytes)
        hash segments to int.
        Parameters:
        segments - Source segments.
        offset - Source segments offset.
        numBytes - the number bytes to hash.
      • bitUnSet

        public static void bitUnSet​(MemorySegment segment,
                                    int baseOffset,
                                    int index)
        unset bit.
        Parameters:
        segment - target segment.
        baseOffset - bits base offset.
        index - bit index from base offset.
      • bitSet

        public static void bitSet​(MemorySegment segment,
                                  int baseOffset,
                                  int index)
        set bit.
        Parameters:
        segment - target segment.
        baseOffset - bits base offset.
        index - bit index from base offset.
      • bitGet

        public static boolean bitGet​(MemorySegment segment,
                                     int baseOffset,
                                     int index)
        read bit.
        Parameters:
        segment - target segment.
        baseOffset - bits base offset.
        index - bit index from base offset.
      • bitUnSet

        public static void bitUnSet​(MemorySegment[] segments,
                                    int baseOffset,
                                    int index)
        unset bit from segments.
        Parameters:
        segments - target segments.
        baseOffset - bits base offset.
        index - bit index from base offset.
      • bitSet

        public static void bitSet​(MemorySegment[] segments,
                                  int baseOffset,
                                  int index)
        set bit from segments.
        Parameters:
        segments - target segments.
        baseOffset - bits base offset.
        index - bit index from base offset.
      • bitGet

        public static boolean bitGet​(MemorySegment[] segments,
                                     int baseOffset,
                                     int index)
        read bit from segments.
        Parameters:
        segments - target segments.
        baseOffset - bits base offset.
        index - bit index from base offset.
      • getBoolean

        public static boolean getBoolean​(MemorySegment[] segments,
                                         int offset)
        get boolean from segments.
        Parameters:
        segments - target segments.
        offset - value offset.
      • setBoolean

        public static void setBoolean​(MemorySegment[] segments,
                                      int offset,
                                      boolean value)
        set boolean from segments.
        Parameters:
        segments - target segments.
        offset - value offset.
      • getByte

        public static byte getByte​(MemorySegment[] segments,
                                   int offset)
        get byte from segments.
        Parameters:
        segments - target segments.
        offset - value offset.
      • setByte

        public static void setByte​(MemorySegment[] segments,
                                   int offset,
                                   byte value)
        set byte from segments.
        Parameters:
        segments - target segments.
        offset - value offset.
      • getInt

        public static int getInt​(MemorySegment[] segments,
                                 int offset)
        get int from segments.
        Parameters:
        segments - target segments.
        offset - value offset.
      • setInt

        public static void setInt​(MemorySegment[] segments,
                                  int offset,
                                  int value)
        set int from segments.
        Parameters:
        segments - target segments.
        offset - value offset.
      • getLong

        public static long getLong​(MemorySegment[] segments,
                                   int offset)
        get long from segments.
        Parameters:
        segments - target segments.
        offset - value offset.
      • setLong

        public static void setLong​(MemorySegment[] segments,
                                   int offset,
                                   long value)
        set long from segments.
        Parameters:
        segments - target segments.
        offset - value offset.
      • getShort

        public static short getShort​(MemorySegment[] segments,
                                     int offset)
        get short from segments.
        Parameters:
        segments - target segments.
        offset - value offset.
      • setShort

        public static void setShort​(MemorySegment[] segments,
                                    int offset,
                                    short value)
        set short from segments.
        Parameters:
        segments - target segments.
        offset - value offset.
      • getFloat

        public static float getFloat​(MemorySegment[] segments,
                                     int offset)
        get float from segments.
        Parameters:
        segments - target segments.
        offset - value offset.
      • setFloat

        public static void setFloat​(MemorySegment[] segments,
                                    int offset,
                                    float value)
        set float from segments.
        Parameters:
        segments - target segments.
        offset - value offset.
      • getDouble

        public static double getDouble​(MemorySegment[] segments,
                                       int offset)
        get double from segments.
        Parameters:
        segments - target segments.
        offset - value offset.
      • setDouble

        public static void setDouble​(MemorySegment[] segments,
                                     int offset,
                                     double value)
        set double from segments.
        Parameters:
        segments - target segments.
        offset - value offset.
      • find

        public static int find​(MemorySegment[] segments1,
                               int offset1,
                               int numBytes1,
                               MemorySegment[] segments2,
                               int offset2,
                               int numBytes2)
        Find equal segments2 in segments1.
        Parameters:
        segments1 - segs to find.
        segments2 - sub segs.
        Returns:
        Return the found offset, return -1 if not find.