Class SemiExternalGammaList

java.lang.Object
java.util.AbstractCollection<Long>
it.unimi.dsi.fastutil.longs.AbstractLongCollection
it.unimi.dsi.fastutil.longs.AbstractLongList
it.unimi.dsi.util.SemiExternalGammaList
All Implemented Interfaces:
it.unimi.dsi.fastutil.longs.LongCollection, it.unimi.dsi.fastutil.longs.LongIterable, it.unimi.dsi.fastutil.longs.LongList, it.unimi.dsi.fastutil.longs.LongStack, it.unimi.dsi.fastutil.Stack<Long>, Comparable<List<? extends Long>>, Iterable<Long>, Collection<Long>, List<Long>, SequencedCollection<Long>
public class SemiExternalGammaList extends it.unimi.dsi.fastutil.longs.AbstractLongList
Provides semi-external random access to a list of γ-encoded integers.

This class is a semi-external LongList that MG4J uses to access files containing frequencies.

Instead, this class accesses frequencies in their compressed forms, and provides entry points for random access to each long. At construction time, entry points are computed with a certain step, which is the number of longs accessible from each entry point, or, equivalently, the maximum number of longs that will be necessary to read to access a given long.

Warning: This class is not thread safe, and needs to be synchronised to be used in a multithreaded environment.

Author:
Fabien Campagne, Sebastiano Vigna

  • Nested Class Summary

    Nested classes/interfaces inherited from class it.unimi.dsi.fastutil.longs.AbstractLongList

    it.unimi.dsi.fastutil.longs.AbstractLongList.LongRandomAccessSubList, it.unimi.dsi.fastutil.longs.AbstractLongList.LongSubList

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final int
    DEFAULT_STEP
     

  • Constructor Summary

    Constructors
    Constructor
    Description
    SemiExternalGammaList(InputBitStream longs)
    Creates a new semi-external list.
    SemiExternalGammaList(InputBitStream longs, int step, int numLongs)
    Creates a new semi-external list.

  • Method Summary

    Modifier and Type
    Method
    Description
    final long
    getLong(int index)
     
    int
    size()
     

    Methods inherited from class it.unimi.dsi.fastutil.longs.AbstractLongList

    add, add, addAll, addAll, addAll, addAll, addElements, addElements, clear, compareTo, contains, ensureIndex, ensureRestrictedIndex, equals, forEach, getElements, hashCode, indexOf, iterator, lastIndexOf, listIterator, listIterator, peekLong, popLong, push, rem, removeElements, removeLong, replaceAll, set, setElements, size, subList, toArray, toLongArray, topLong, toString

    Methods inherited from class it.unimi.dsi.fastutil.longs.AbstractLongCollection

    add, contains, containsAll, containsAll, forEach, remove, removeAll, removeAll, removeIf, retainAll, retainAll, toLongArray

    Methods inherited from class AbstractCollection

    isEmpty, toArray, toArray

    Methods inherited from class Object

    clone, finalize, getClass, notify, notifyAll, wait, wait, wait

    Methods inherited from interface Collection

    toArray

    Methods inherited from interface List

    addFirst, addLast, containsAll, getFirst, getLast, isEmpty, removeAll, removeFirst, removeLast, retainAll, reversed, toArray, toArray

    Methods inherited from interface it.unimi.dsi.fastutil.longs.LongCollection

    containsAll, longIterator, longParallelStream, longSpliterator, longStream, parallelStream, removeAll, removeIf, removeIf, removeIf, retainAll, spliterator, stream, toLongArray

    Methods inherited from interface it.unimi.dsi.fastutil.longs.LongIterable

    forEach, forEach

    Methods inherited from interface it.unimi.dsi.fastutil.longs.LongList

    add, add, addAll, addAll, contains, get, indexOf, lastIndexOf, remove, remove, replaceAll, replaceAll, set, setElements, setElements, sort, sort, spliterator, unstableSort, unstableSort

    Methods inherited from interface it.unimi.dsi.fastutil.longs.LongStack

    peek, pop, push, top

    Methods inherited from interface it.unimi.dsi.fastutil.Stack

    isEmpty

  • Field Details

  • Constructor Details

    • SemiExternalGammaList

      public SemiExternalGammaList(InputBitStream longs, int step, int numLongs) throws IOException
      Creates a new semi-external list.
      Parameters:
      longs - a bit stream containing γ-encoded longs.
      step - the step used to build random-access entry points, or -1 to get DEFAULT_STEP.
      numLongs - the overall number of offsets (i.e., the number of terms).
      Throws:
      IOException

    • SemiExternalGammaList

      public SemiExternalGammaList(InputBitStream longs) throws IOException
      Creates a new semi-external list.

      This quick-and-dirty constructor estimates the number of longs by checking for an EOFException.

      Parameters:
      longs - a bit stream containing γ-encoded longs.
      Throws:
      IOException

  • Method Details