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.WireEnd;
   8 import era.mi.logic.wires.WireObserver;
   9
  10 public class Merger implements WireObserver, Component
  11 {
  12         private WireEnd out;
  13         private WireEnd[] inputs;
  14         private int[] beginningIndex;
  15
  16         /**
  17          *
  18          * @param union  The output of merging n {@link Wire}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(WireEnd union, WireEnd... inputs)
  22         {
  23                 this.inputs = inputs;
  24                 this.out = union;
  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 WireEnd getInput(int index)
  41         {
  42                 return inputs[index];
  43         }
  44
  45         public WireEnd getUnion()
  46         {
  47                 return out;
  48         }
  49
  50         @Override
  51         public void update(Wire initiator, BitVector oldValues)
  52         {
  53                 int index = find(initiator);
  54                 int beginning = beginningIndex[index];
  55                 out.feedSignals(beginning, inputs[index].getValues());
  56         }
  57
  58         private int find(Wire w)
  59         {
  60                 for (int i = 0; i < inputs.length; i++)
  61                         if (inputs[i].getWire() == w)
  62                                 return i;
  63                 return -1;
  64         }
  65
  66         public WireEnd[] getInputs()
  67         {
  68                 return inputs.clone();
  69         }
  70
  71         @Override
  72         public List<WireEnd> getAllInputs()
  73         {
  74                 return List.of(inputs);
  75         }
  76
  77         @Override
  78         public List<WireEnd> getAllOutputs()
  79         {
  80                 return List.of(out);
  81         }
  82 }