Package edu.hm.hafner.analysis

Class LineRangeList

java.lang.Object
java.util.AbstractCollection<E>
java.util.AbstractList<LineRange>
edu.hm.hafner.analysis.LineRangeList
All Implemented Interfaces:
Serializable, Iterable<LineRange>, Collection<LineRange>, List<LineRange>
public class LineRangeList extends AbstractList<LineRange> implements Serializable
List of LineRange that stores values more efficiently at runtime.

This class thinks of LineRange as two integers (start and end-start), hence a list of LineRange becomes a list of integers. The class then stores those integers in byte[]. Each number is packed to UTF-8 like variable length format. To store a long value N, we first split into 7 bit chunk, and store each 7 bit chunk as a byte, in the little endian order. The last byte gets its 8th bit set to indicate that that's the last byte. Thus in this format, 0x0 gets stored as 0x80, 0x1234 gets stored as {0x34,0xA4(0x24|0x80)}.

This variable length mode stores data most efficiently, since most line numbers are small. Access characteristic gets close to that of LinkedList, since we can only traverse this packed byte[] from the start or from the end.

Author:
Kohsuke Kawaguchi
See Also: