era.mi/src/era/mi/logic/components/Merger.java

   1 package era.mi.logic.components;
   2
   3 import java.util.List;
   4
   5 import era.mi.logic.types.BitVector;
   6 import era.mi.logic.wires.Wire;
   7 import era.mi.logic.wires.Wire.ReadEnd;
   8 import era.mi.logic.wires.Wire.ReadWriteEnd;
   9 import era.mi.logic.wires.WireObserver;
  10
  11 public class Merger implements WireObserver, Component
  12 {
  13         private ReadWriteEnd out;
  14         private ReadEnd[] inputs;
  15         private int[] beginningIndex;
  16
  17         /**
  18          *
  19          * @param union  The output of merging n {@link Wire}s into one. Must have length = a1.length() + a2.length() + ... + an.length().
  20          * @param inputs The inputs to be merged into the union
  21          */
  22         public Merger(ReadWriteEnd union, ReadEnd... inputs)
  23         {
  24                 this.inputs = inputs;
  25                 this.out = union;
  26                 this.beginningIndex = new int[inputs.length];
  27
  28                 int length = 0;
  29                 for (int i = 0; i < inputs.length; i++)
  30                 {
  31                         beginningIndex[i] = length;
  32                         length += inputs[i].length();
  33                         inputs[i].addObserver(this);
  34                 }
  35
  36                 if (length != union.length())
  37                         throw new IllegalArgumentException(
  38                                         "The output of merging n WireArrays into one must have length = a1.length() + a2.length() + ... + an.length().");
  39         }
  40
  41         public ReadEnd getInput(int index)
  42         {
  43                 return inputs[index];
  44         }
  45
  46         public ReadEnd getUnion()
  47         {
  48                 return out;
  49         }
  50
  51         @Override
  52         public void update(ReadEnd initiator, BitVector oldValues)
  53         {
  54                 int index = find(initiator);
  55                 int beginning = beginningIndex[index];
  56                 out.feedSignals(beginning, inputs[index].getValues());
  57         }
  58
  59         private int find(ReadEnd r)
  60         {
  61                 for (int i = 0; i < inputs.length; i++)
  62                         if (inputs[i] == r)
  63                                 return i;
  64                 return -1;
  65         }
  66
  67         public ReadEnd[] getInputs()
  68         {
  69                 return inputs.clone();
  70         }
  71
  72         @Override
  73         public List<ReadEnd> getAllInputs()
  74         {
  75                 return List.of(inputs);
  76         }
  77
  78         @Override
  79         public List<ReadWriteEnd> getAllOutputs()
  80         {
  81                 return List.of(out);
  82         }
  83 }