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