added more doc to Timeline; added functionality to Bit
[Mograsim.git] / era.mi / src / era / mi / logic / wires / WireArray.java
index 370cbbd..add55f7 100644 (file)
@@ -17,346 +17,342 @@ import era.mi.logic.Util;
  */
 public class WireArray
 {
-    private Bit[] values;
-    public final int travelTime;
-    private List<WireArrayObserver> observers = new ArrayList<WireArrayObserver>();
-    public final int length;
-    private List<WireArrayInput> inputs = new ArrayList<WireArrayInput>();
-
-    public WireArray(int length, int travelTime)
-    {
-       if (length < 1)
-           throw new IllegalArgumentException("Tried to create an array of wires with length " + length
-                   + ", but a length of less than 1 makes no sense.");
-       this.length = length;
-       this.travelTime = travelTime;
-       initValues();
-    }
-
-    private void initValues()
-    {
-       values = new Bit[length];
-       for (int i = 0; i < length; i++)
-           values[i] = Bit.Z;
-    }
-
-    private void recalculateSingleInput()
-    {
-       WireArrayInput input = inputs.get(0);
-       if (!Arrays.equals(input.getValues(), values))
+       private Bit[] values;
+       public final int travelTime;
+       private List<WireArrayObserver> observers = new ArrayList<WireArrayObserver>();
+       public final int length;
+       private List<WireArrayInput> inputs = new ArrayList<WireArrayInput>();
+
+       public WireArray(int length, int travelTime)
        {
-           System.arraycopy(input.getValues(), 0, values, 0, length);
-           notifyObservers();
+               if (length < 1)
+                       throw new IllegalArgumentException(String.format("Tried to create an array of wires with length %o, but a length of less than 1 makes no sense.", length));
+               this.length = length;
+               this.travelTime = travelTime;
+               initValues();
        }
-    }
 
-    private void recalculateMultipleInputs()
-    {
-       Iterator<WireArrayInput> it = inputs.iterator();
-       Bit[] newValues = it.next().values.clone();
-
-       while (it.hasNext())
+       private void initValues()
        {
-           WireArrayInput input = it.next();
-           Bit[] bits = input.getValues();
-           for (int i = 0; i < length; i++)
-           {
-               if (Bit.Z.equals(bits[i]) || newValues[i].equals(bits[i]))
-                   continue;
-               else if (Bit.Z.equals(newValues[i]))
-                   newValues[i] = bits[i];
-               else
-                   newValues[i] = Bit.X;
-           }
+               values = Bit.Z.makeArray(length);
        }
 
-       if (!Arrays.equals(newValues, values))
+       private void recalculateSingleInput()
        {
-           notifyObservers();
-           values = newValues;
+               WireArrayInput input = inputs.get(0);
+               if (!Arrays.equals(input.getValues(), values))
+               {
+                       System.arraycopy(input.getValues(), 0, values, 0, length);
+                       notifyObservers();
+               }
        }
-    }
 
-    private void recalculate()
-    {
-       switch (inputs.size())
+       private void recalculateMultipleInputs()
        {
-       case 0:
-           return;
-       case 1:
-           recalculateSingleInput();
-           break;
-       default:
-           recalculateMultipleInputs();
+               Iterator<WireArrayInput> it = inputs.iterator();
+               Bit[] newValues = it.next().inputValues.clone();
+
+               while (it.hasNext())
+               {
+                       WireArrayInput input = it.next();
+                       Bit[] bits = input.getValues();
+                       for (int i = 0; i < length; i++)
+                       {
+                               if (Bit.Z.equals(bits[i]) || newValues[i].equals(bits[i]))
+                                       continue;
+                               else if (Bit.Z.equals(newValues[i]))
+                                       newValues[i] = bits[i];
+                               else
+                                       newValues[i] = Bit.X;
+                       }
+               }
+
+               if (!Arrays.equals(newValues, values))
+               {
+                       notifyObservers();
+                       values = newValues;
+               }
        }
-    }
-
-    /**
-     * The WireArray is interpreted as an unsigned integer with n bits.
-     * 
-     * @return <code>true</code> if all bits are either <code>Bit.ONE</code> or
-     *         <code>Bit.ZERO</code> (they do not all have to have the same value),
-     *         not <code>Bit.X</code> or <code>Bit.Z</code>. <code>false</code> is
-     *         returned otherwise.
-     * 
-     * @author Fabian Stemmler
-     */
-    public boolean hasNumericValue()
-    {
-       for (Bit b : values)
+
+       private void recalculate()
        {
-           if (b != Bit.ZERO && b != Bit.ONE)
-               return false;
+               switch (inputs.size())
+               {
+               case 0:
+                       return;
+               case 1:
+                       recalculateSingleInput();
+                       break;
+               default:
+                       recalculateMultipleInputs();
+               }
        }
-       return true;
-    }
-
-    /**
-     * The WireArray is interpreted as an unsigned integer with n bits.
-     * 
-     * @return The unsigned value of the {@link WireArray}'s bits, where value 0
-     *         corresponds with 2^0, value 1 is 2^1 and so on.
-     * 
-     * @author Fabian Stemmler
-     */
-    public long getUnsignedValue()
-    {
-       long val = 0;
-       long mask = 1;
-       for (int i = 0; i < length; i++)
+
+       /**
+        * The WireArray is interpreted as an unsigned integer with n bits.
+        * 
+        * @return <code>true</code> if all bits are either <code>Bit.ONE</code> or
+        *         <code>Bit.ZERO</code> (they do not all have to have the same value),
+        *         not <code>Bit.X</code> or <code>Bit.Z</code>. <code>false</code> is
+        *         returned otherwise.
+        * 
+        * @author Fabian Stemmler
+        */
+       public boolean hasNumericValue()
        {
-           switch (values[i])
-           {
-           default:
-           case Z:
-           case X:
-               return 0; // TODO: Proper handling for getUnsignedValue(), if not all bits are 1 or 0;
-                         // Random number?
-           case ONE:
-               val |= mask;
-               break;
-           case ZERO:
-           }
-           mask = mask << 1;
+               for (Bit b : values)
+               {
+                       if (b != Bit.ZERO && b != Bit.ONE)
+                               return false;
+               }
+               return true;
        }
-       return val;
-    }
-
-    /**
-     * The WireArray is interpreted as a signed integer with n bits.
-     * 
-     * @return The signed value of the {@link WireArray}'s bits, where value 0
-     *         corresponds with 2^0, value 1 is 2^1 and so on.
-     * 
-     * @author Fabian Stemmler
-     */
-    public long getSignedValue()
-    {
-       long val = getUnsignedValue();
-       long mask = 1 << (length - 1);
-       if ((mask & val) != 0)
+
+       /**
+        * The WireArray is interpreted as an unsigned integer with n bits.
+        * 
+        * @return The unsigned value of the {@link WireArray}'s bits, where value 0
+        *         corresponds with 2^0, value 1 is 2^1 and so on.
+        * 
+        * @author Fabian Stemmler
+        */
+       public long getUnsignedValue()
        {
-           int shifts = 64 - length;
-           return (val << shifts) >> shifts;
+               long val = 0;
+               long mask = 1;
+               for (int i = 0; i < length; i++)
+               {
+                       switch (values[i])
+                       {
+                       default:
+                       case Z:
+                       case X:
+                               return 0; // TODO: Proper handling for getUnsignedValue(), if not all bits are 1 or 0;
+                       // Random number?
+                       case ONE:
+                               val |= mask;
+                               break;
+                       case ZERO:
+                       }
+                       mask = mask << 1;
+               }
+               return val;
        }
-       return val;
-    }
-
-    /**
-     * Included for convenient use on {@link WireArray}s of length 1.
-     * 
-     * @return The value of bit 0.
-     * 
-     * @author Fabian Stemmler
-     */
-    public Bit getValue()
-    {
-       return getValue(0);
-    }
-
-    /**
-     * 
-     * @param index Index of the requested bit.
-     * @return The value of the indexed bit.
-     * 
-     * @author Fabian Stemmler
-     */
-    public Bit getValue(int index)
-    {
-       return values[index];
-    }
-
-    public Bit[] getValues(int start, int end)
-    {
-       int length = end - start;
-       Bit[] bits = new Bit[length];
-       System.arraycopy(values, start, bits, 0, length);
-       return bits;
-    }
-
-    /**
-     * @return An array of length n containing the values of the n bits in the
-     *         {@link WireArray}. Can be safely modified.
-     * 
-     * @author Fabian Stemmler
-     */
-    public Bit[] getValues()
-    {
-       return values.clone();
-    }
-
-    /**
-     * Adds an {@link WireArrayObserver}, who will be notified when the value of the
-     * {@link WireArray} is updated.
-     * 
-     * @param ob The {@link WireArrayObserver} to be notified of changes.
-     * @return true if the given {@link WireArrayObserver} was not already
-     *         registered, false otherwise
-     * 
-     * @author Fabian Stemmler
-     */
-    public boolean addObserver(WireArrayObserver ob)
-    {
-       return observers.add(ob);
-    }
-
-    private void notifyObservers()
-    {
-       for (WireArrayObserver o : observers)
-           o.update(this);
-    }
-
-    /**
-     * Create and register a {@link WireArrayInput} object, which is tied to this
-     * {@link WireArray}.
-     */
-    public WireArrayInput createInput()
-    {
-       return new WireArrayInput(this);
-    }
-
-    private void registerInput(WireArrayInput toRegister)
-    {
-       inputs.add(toRegister);
-    }
-
-    /**
-     * A {@link WireArrayInput} feeds a constant signal into the {@link WireArray}
-     * it is tied to. The combination of all inputs determines the
-     * {@link WireArray}s final value. X dominates all other inputs Z does not
-     * affect the final value, unless there are no other inputs than Z 0 and 1 turn
-     * into X when they are mixed
-     * 
-     * @author Fabian Stemmler
-     */
-    public class WireArrayInput
-    {
-       public final WireArray owner;
-       private Bit[] values;
 
-       private WireArrayInput(WireArray owner)
+       /**
+        * The WireArray is interpreted as a signed integer with n bits.
+        * 
+        * @return The signed value of the {@link WireArray}'s bits, where value 0
+        *         corresponds with 2^0, value 1 is 2^1 and so on.
+        * 
+        * @author Fabian Stemmler
+        */
+       public long getSignedValue()
        {
-           super();
-           this.owner = owner;
-           initValues();
-           owner.registerInput(this);
+               long val = getUnsignedValue();
+               long mask = 1 << (length - 1);
+               if ((mask & val) != 0)
+               {
+                       int shifts = 64 - length;
+                       return (val << shifts) >> shifts;
+               }
+               return val;
        }
 
-       private void initValues()
+       /**
+        * Included for convenient use on {@link WireArray}s of length 1.
+        * 
+        * @return The value of bit 0.
+        * 
+        * @author Fabian Stemmler
+        */
+       public Bit getValue()
        {
-           values = new Bit[length];
-           for (int i = 0; i < length; i++)
-               values[i] = Bit.Z;
+               return getValue(0);
        }
 
        /**
-        * Sets the wires values. This takes up time, as specified by the
-        * {@link WireArray}s travel time.
         * 
-        * @param newValues The new values the wires should take on.
+        * @param index Index of the requested bit.
+        * @return The value of the indexed bit.
         * 
         * @author Fabian Stemmler
         */
-       public void feedSignals(Bit... newValues)
+       public Bit getValue(int index)
+       {
+               return values[index];
+       }
+
+       public Bit[] getValues(int start, int end)
        {
-           if (newValues.length == length)
-           {
-               feedSignals(0, newValues);
-           } else
-               throw new IllegalArgumentException(
-                       "Attempted to input " + newValues.length + " bits instead of " + length + " bits.");
+               int length = end - start;
+               Bit[] bits = new Bit[length];
+               System.arraycopy(values, start, bits, 0, length);
+               return bits;
        }
 
        /**
-        * Sets values of a subarray of wires. This takes up time, as specified by the
-        * {@link WireArray}s travel time.
+        * @return An array of length n containing the values of the n bits in the
+        *         {@link WireArray}. Can be safely modified.
         * 
-        * @param newValues   The new values the wires should take on.
-        * @param startingBit The first index of the subarray of wires.
+        * @author Fabian Stemmler
+        */
+       public Bit[] getValues()
+       {
+               return values.clone();
+       }
+
+       /**
+        * Adds an {@link WireArrayObserver}, who will be notified when the value of the
+        * {@link WireArray} is updated.
+        * 
+        * @param ob The {@link WireArrayObserver} to be notified of changes.
+        * @return true if the given {@link WireArrayObserver} was not already
+        *         registered, false otherwise
         * 
         * @author Fabian Stemmler
         */
-       public void feedSignals(int startingBit, Bit... newValues)
+       public boolean addObserver(WireArrayObserver ob)
        {
-           Simulation.TIMELINE.addEvent((e) -> setValues(startingBit, newValues), travelTime);
+               return observers.add(ob);
        }
 
-       private void setValues(int startingBit, Bit... newValues)
+       private void notifyObservers()
        {
-           int exclLastIndex = startingBit + newValues.length;
-           if (length < exclLastIndex)
-               throw new ArrayIndexOutOfBoundsException("Attempted to input bits from index " + startingBit + " to "
-                       + exclLastIndex + " when there are only " + length + "wires.");
-           if (!Arrays.equals(values, startingBit, exclLastIndex, newValues, 0, newValues.length))
-           {
-               System.arraycopy(newValues, 0, values, startingBit, newValues.length);
-               owner.recalculate();
-           }
+               for (WireArrayObserver o : observers)
+                       o.update(this);
        }
 
-       public Bit[] getValues()
+       /**
+        * Create and register a {@link WireArrayInput} object, which is tied to this
+        * {@link WireArray}.
+        */
+       public WireArrayInput createInput()
+       {
+               return new WireArrayInput(this);
+       }
+
+       private void registerInput(WireArrayInput toRegister)
        {
-           return values.clone();
+               inputs.add(toRegister);
        }
-       
-       public Bit[] wireValuesExcludingMe() 
+
+       /**
+        * A {@link WireArrayInput} feeds a constant signal into the {@link WireArray}
+        * it is tied to. The combination of all inputs determines the
+        * {@link WireArray}s final value. X dominates all other inputs Z does not
+        * affect the final value, unless there are no other inputs than Z 0 and 1 turn
+        * into X when they are mixed
+        * 
+        * @author Fabian Stemmler
+        */
+       public class WireArrayInput
        {
-               Bit[] bits = Util.arrayOfZ(length);
-               for (WireArrayInput wai : inputs) 
+               public final WireArray owner;
+               private Bit[] inputValues;
+
+               private WireArrayInput(WireArray owner)
                {
-                       if(wai == this)
-                               continue;
-                       Util.combineInto(bits, wai.getValues());
+                       super();
+                       this.owner = owner;
+                       initValues();
+                       owner.registerInput(this);
                }
-               return bits;
-       }
 
-       public void clearSignals()
-       {
-           Bit[] bits = new Bit[length];
-           for (int i = 0; i < length; i++)
-               bits[i] = Bit.Z;
-           feedSignals(bits);
+               private void initValues()
+               {
+                       inputValues = Bit.Z.makeArray(length);
+               }
+
+               /**
+                * Sets the wires values. This takes up time, as specified by the
+                * {@link WireArray}s travel time.
+                * 
+                * @param newValues The new values the wires should take on.
+                * 
+                * @author Fabian Stemmler
+                */
+               public void feedSignals(Bit... newValues)
+               {
+                       if (newValues.length == length)
+                       {
+                               feedSignals(0, newValues);
+                       } else
+                               throw new IllegalArgumentException(String.format("Attempted to input %o bits instead of %o bits.", newValues.length, length));
+               }
+
+               /**
+                * Sets values of a subarray of wires. This takes up time, as specified by the
+                * {@link WireArray}s travel time.
+                * 
+                * @param newValues   The new values the wires should take on.
+                * @param startingBit The first index of the subarray of wires.
+                * 
+                * @author Fabian Stemmler
+                */
+               public void feedSignals(int startingBit, Bit... newValues)
+               {
+                       Simulation.TIMELINE.addEvent((e) -> setValues(startingBit, newValues), travelTime);
+               }
+
+               private void setValues(int startingBit, Bit... newValues)
+               {
+                       int exclLastIndex = startingBit + newValues.length;
+                       if (length < exclLastIndex)
+                               throw new ArrayIndexOutOfBoundsException(String.format("Attempted to input bits from index %o to %o when there are only %o wires.", startingBit, exclLastIndex - 1, length));
+                       if (!Arrays.equals(inputValues, startingBit, exclLastIndex, newValues, 0, newValues.length))
+                       {
+                               System.arraycopy(newValues, 0, inputValues, startingBit, newValues.length);
+                               owner.recalculate();
+                       }
+               }
+
+               /**
+                * Returns a copy (safe to modify) of the values the {@link WireArrayInput} is currently feeding into the associated {@link WireArray}.
+                */
+               public Bit[] getValues()
+               {
+                       return inputValues.clone();
+               }
+
+               /**
+                * {@link WireArrayInput} now feeds Z into the associated {@link WireArray}.
+                */
+               public void clearSignals()
+               {
+                       feedSignals(Bit.Z.makeArray(length));
+               }
+
+               public Bit[] wireValuesExcludingMe() 
+               {
+                       Bit[] bits = Bit.Z.makeArray(length);
+                       for (WireArrayInput wai : inputs) 
+                       {
+                               if(wai == this)
+                                       continue;
+                               Util.combineInto(bits, wai.getValues());
+                       }
+                       return bits;
+               }
+               
+               @Override
+               public String toString()
+               {
+                       return Arrays.toString(inputValues);
+               }
        }
 
        @Override
        public String toString()
        {
-           return Arrays.toString(values);
+               return String.format("wire 0x%08x value: %s inputs: %s", hashCode(), Arrays.toString(values), inputs);
+       }
+
+       public static WireArrayInput[] extractInputs(WireArray[] w)
+       {
+               WireArrayInput[] inputs = new WireArrayInput[w.length];
+               for (int i = 0; i < w.length; i++)
+                       inputs[i] = w[i].createInput();
+               return inputs;
        }
-    }
-
-    @Override
-    public String toString()
-    {
-       return String.format("wire 0x%08x value: %s inputs: %s", hashCode(), Arrays.toString(values), inputs);
-    }
-    
-    public static WireArrayInput[] extractInputs(WireArray[] w)
-    {
-       WireArrayInput[] inputs = new WireArrayInput[w.length];
-       for(int i = 0; i < w.length; i++)
-           inputs[i] = w[i].createInput();
-       return inputs;
-    }
 }
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