Package org.apache.hadoop.yarn.server.timeline

Class GenericObjectMapper

java.lang.Object
org.apache.hadoop.yarn.server.timeline.GenericObjectMapper
@Private @Unstable public class GenericObjectMapper extends Object
A utility class providing methods for serializing and deserializing objects. The write(Object) and read(byte[]) methods are used by the LeveldbTimelineStore to store and retrieve arbitrary JSON, while the writeReverseOrderedLong(long) and readReverseOrderedLong(byte[], int) methods are used to sort entities in descending start time order.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final com.fasterxml.jackson.databind.ObjectReader
    OBJECT_READER
     
    static final com.fasterxml.jackson.databind.ObjectWriter
    OBJECT_WRITER
     

  • Constructor Summary

    Constructors
    Constructor
    Description
    GenericObjectMapper()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    static Object
    read(byte[] b)
    Deserializes an Object from a byte array created with write(Object).
    static Object
    read(byte[] b, int offset)
    Deserializes an Object from a byte array at a specified offset, assuming the bytes were created with write(Object).
    static long
    readReverseOrderedLong(byte[] b, int offset)
    Reads 8 bytes from an array starting at the specified offset and converts them to a long.
    static byte[]
    write(Object o)
    Serializes an Object into a byte array.
    static byte[]
    writeReverseOrderedLong(long l)
    Converts a long to a 8-byte array so that lexicographic ordering of the produced byte arrays sort the longs in descending order.
    static byte[]
    writeReverseOrderedLong(long l, byte[] b, int offset)
     

    Methods inherited from class java.lang.Object

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

  • Field Details

    • OBJECT_READER

      public static final com.fasterxml.jackson.databind.ObjectReader OBJECT_READER

    • OBJECT_WRITER

      public static final com.fasterxml.jackson.databind.ObjectWriter OBJECT_WRITER

  • Constructor Details

    • GenericObjectMapper

      public GenericObjectMapper()

  • Method Details

    • write

      public static byte[] write(Object o) throws IOException
      Serializes an Object into a byte array. Along with read(byte[]), can be used to serialize an Object and deserialize it into an Object of the same type without needing to specify the Object's type, as long as it is one of the JSON-compatible objects understood by ObjectMapper.
      Parameters:
      o - An Object
      Returns:
      A byte array representation of the Object
      Throws:
      IOException - if there is a write error

    • read

      public static Object read(byte[] b) throws IOException
      Deserializes an Object from a byte array created with write(Object).
      Parameters:
      b - A byte array
      Returns:
      An Object
      Throws:
      IOException - if there is a read error

    • read

      public static Object read(byte[] b, int offset) throws IOException
      Deserializes an Object from a byte array at a specified offset, assuming the bytes were created with write(Object).
      Parameters:
      b - A byte array
      offset - Offset into the array
      Returns:
      An Object
      Throws:
      IOException - if there is a read error

    • writeReverseOrderedLong

      public static byte[] writeReverseOrderedLong(long l)
      Converts a long to a 8-byte array so that lexicographic ordering of the produced byte arrays sort the longs in descending order.
      Parameters:
      l - A long
      Returns:
      A byte array

    • writeReverseOrderedLong

      public static byte[] writeReverseOrderedLong(long l, byte[] b, int offset)

    • readReverseOrderedLong

      public static long readReverseOrderedLong(byte[] b, int offset)
      Reads 8 bytes from an array starting at the specified offset and converts them to a long. The bytes are assumed to have been created with writeReverseOrderedLong(long).
      Parameters:
      b - A byte array
      offset - An offset into the byte array
      Returns:
      A long