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

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