Package org.terrier.structures

Class SimpleBitIndexPointer

  • All Implemented Interfaces:
    org.apache.hadoop.io.Writable, BitFilePosition, BitIndexPointer, Pointer
    public class SimpleBitIndexPointer
extends java.lang.Object
implements BitIndexPointer, org.apache.hadoop.io.Writable
    An implementation of a BitIndexPointer. Records a pointer in a BitIndex structure - i.e. a file number (0-31), a byte offset (long), a bit offset (0-8), and a number of entries (positive int).
    Since:
    3.0
    Author:
    Craig Macdonald

    • Constructor Summary

      Constructors 
      Constructor Description
      SimpleBitIndexPointer()
      Construct an instance of the class.
      SimpleBitIndexPointer​(byte fileId, long byteOffset, byte bitOffset, int numEntries)
      Construct an instance of the class with
      SimpleBitIndexPointer​(long byteOffset, byte bitOffset, int numEntries)
      Construct an instance of the class with

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      byte getFileNumber()
      Returns the file number (byte value in the 0-31 range)
      int getNumberOfEntries()
      Return the number of "things" that this pointer refers to.
      long getOffset()
      Return the number of bytes offset.
      byte getOffsetBits()
      Return the number of bits offset.
      java.lang.String pointerToString()
      Returns a textual representation of the pointer alone
      void readFields​(java.io.DataInput arg0)
      Populate this pointer from DataInput source
      void setBitIndexPointer​(BitIndexPointer pointer)
      Update this pointer to reflect the same values as the specified pointer
      void setFileNumber​(byte fileId)
      Set the file number.
      void setNumberOfEntries​(int count)
      Set the number of "things" that the pointer refers to.
      void setOffset​(long _bytes, byte _bits)
      Set the offset in number of bytes and number of bits.
      void setOffset​(BitFilePosition pos)
      Sets the bit file position within this object to that represented by the specified bit file position.
      void setPointer​(Pointer p)
      Sets the pointer within this object to that represented by the specified pointer.
      java.lang.String toString()
      Debug friendly output of this pointer
      void write​(java.io.DataOutput arg0)
      Write this pointer to DataOutput

      • Methods inherited from class java.lang.Object

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

    • Constructor Detail

      • SimpleBitIndexPointer

        public SimpleBitIndexPointer()
        Construct an instance of the class.

      • SimpleBitIndexPointer

        public SimpleBitIndexPointer​(byte fileId,
                             long byteOffset,
                             byte bitOffset,
                             int numEntries)
        Construct an instance of the class with
        Parameters:
        fileId -
        byteOffset -
        bitOffset -
        numEntries -

      • SimpleBitIndexPointer

        public SimpleBitIndexPointer​(long byteOffset,
                             byte bitOffset,
                             int numEntries)
        Construct an instance of the class with
        Parameters:
        byteOffset -
        bitOffset -
        numEntries -

    • Method Detail

      • getNumberOfEntries

        public int getNumberOfEntries()
        Return the number of "things" that this pointer refers to.
        Specified by:
        getNumberOfEntries in interface Pointer
        Returns:
        the number of "things" that this pointer refers to.

      • setNumberOfEntries

        public void setNumberOfEntries​(int count)
        Set the number of "things" that the pointer refers to.
        Specified by:
        setNumberOfEntries in interface Pointer
        Parameters:
        count - the number of "things" that the pointer refers to.

      • getOffsetBits

        public byte getOffsetBits()
        Return the number of bits offset.
        Specified by:
        getOffsetBits in interface BitFilePosition
        Returns:
        the number of bits offset.

      • getFileNumber

        public byte getFileNumber()
        Returns the file number (byte value in the 0-31 range)
        Specified by:
        getFileNumber in interface BitIndexPointer
        Returns:
        the file number (byte value in the 0-31 range)

      • setFileNumber

        public void setFileNumber​(byte fileId)
        Set the file number.
        Specified by:
        setFileNumber in interface BitIndexPointer
        Parameters:
        fileId - the file number.

      • getOffset

        public long getOffset()
        Return the number of bytes offset.
        Specified by:
        getOffset in interface BitFilePosition
        Returns:
        the number of bytes offset.

      • setOffset

        public void setOffset​(long _bytes,
                      byte _bits)
        Set the offset in number of bytes and number of bits.
        Specified by:
        setOffset in interface BitFilePosition
        Parameters:
        _bytes - the number of bytes to set.
        _bits - the number of bits to set.

      • setBitIndexPointer

        public void setBitIndexPointer​(BitIndexPointer pointer)
        Update this pointer to reflect the same values as the specified pointer
        Specified by:
        setBitIndexPointer in interface BitIndexPointer
        Parameters:
        pointer - the pointer to use to set the byte offset, bit offset and file number parameters.

      • setOffset

        public void setOffset​(BitFilePosition pos)
        Sets the bit file position within this object to that represented by the specified bit file position.
        Specified by:
        setOffset in interface BitFilePosition
        Parameters:
        pos - other bit file position to update the bit file position in this object.

      • readFields

        public void readFields​(java.io.DataInput arg0)
                throws java.io.IOException
        Populate this pointer from DataInput source
        Specified by:
        readFields in interface org.apache.hadoop.io.Writable
        Throws:
        java.io.IOException

      • write

        public void write​(java.io.DataOutput arg0)
           throws java.io.IOException
        Write this pointer to DataOutput
        Specified by:
        write in interface org.apache.hadoop.io.Writable
        Throws:
        java.io.IOException

      • toString

        public java.lang.String toString()
        Debug friendly output of this pointer
        Overrides:
        toString in class java.lang.Object

      • pointerToString

        public java.lang.String pointerToString()
        Returns a textual representation of the pointer alone
        Specified by:
        pointerToString in interface Pointer

      • setPointer

        public void setPointer​(Pointer p)
        Sets the pointer within this object to that represented by the specified pointer.
        Specified by:
        setPointer in interface Pointer
        Parameters:
        p - other pointer to update the pointer in this object.