Merge pull request #80 from aya-lang/feature/perf

Some Performance Optimizations

src/aya/CallStack.java

@@ -3,7 +3,6 @@
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.EmptyStackException;
-import java.util.Stack;
 
 import aya.instruction.variable.GetVariableInstruction;
 
@@ -14,14 +13,17 @@
  */
 public class CallStack {
 
-	public static final CallStackFrame CHECKPOINT = new CallStackFrame(null);
+	private final static int MAX_STACK_DEPTH = 128;
 
 	public static class CallStackFrame {
 		private GetVariableInstruction _instruction;
 		private boolean _is_checkpoint;
 
-
-		public CallStackFrame(GetVariableInstruction instruction) {
+		public CallStackFrame() {
+			reset(null);
+		}
+
+		public void reset(GetVariableInstruction instruction) {
 			_instruction = instruction;
 			_is_checkpoint = instruction == null;
 		}
@@ -38,55 +40,79 @@ public String toString() {
 			}
 		}
 	}
+
 
-	private Stack<CallStackFrame> _stack;
+	private CallStackFrame[] _stack;
+	// Points to the most recently filled stack frame
+	// -1 for empty stack
+	private int _stack_index;
 
 	public CallStack() {
-		_stack = new Stack<CallStackFrame>();
+		_stack = new CallStackFrame[MAX_STACK_DEPTH];
+		for (int i = 0; i < MAX_STACK_DEPTH; i++) {
+			_stack[i] = new CallStackFrame();
+		}
+		_stack_index = -1;
 	}
 
 	public void push(GetVariableInstruction var) {
-		_stack.push(new CallStackFrame(var));
+		if (_stack_index < _stack.length) {
+			_stack_index++;
+			_stack[_stack_index].reset(var);
+		} else {
+			throw new StackOverflowError("Call stack overflow");
+		}
 	}
 
-	public void pop() {
-		_stack.pop();
+	public CallStackFrame pop() {
+		// >= : stack_index is allowed to get to -1 (empty stack)
+		if (_stack_index >= 0) {
+			CallStackFrame frame = _stack[_stack_index];
+			_stack_index--;
+			return frame;
+		} else {
+			throw new EmptyStackException();
+		}
 	}
 
 	public void setCheckpoint() {
-		_stack.push(CHECKPOINT);
+		push(null);
 	}
 
 	public void popCheckpoint() {
-		CallStackFrame csf = _stack.pop();
+		CallStackFrame csf = pop();
 		if (!csf.isCheckpoint()) {
 			throw new RuntimeException("Attempted to pop callstack checkpoint but the top of the stack was " + csf);
 		}
 	}
 
 	public void rollbackCheckpoint() {
 		try {
-			CallStackFrame csf = _stack.pop();
+			CallStackFrame csf = pop();
 			// If this loop throws an exception, there is a bug somewhere that
 			// is either rolling back when there is no checkpoint or removing a checkpoint
 			// when it should not be
 			while (!csf.isCheckpoint()) {
-				csf = _stack.pop();
+				csf = pop();
 			}
 		} catch (EmptyStackException e) {
-			throw new RuntimeException("Failed attempt to rollback chackpoint in call stack");
+			throw new RuntimeException("Failed attempt to rollback checkpoint in call stack");
 		}
 	}
 
 	public void reset() {
-		_stack.clear();
+		_stack_index = -1;
+	}
+
+	public int size() {
+		return _stack_index + 1;
 	}
 
 	public String toString() {
 		StringBuilder sb = new StringBuilder("Function call traceback:\n  Error ");
-		ArrayList<CallStackFrame> stack_list = new ArrayList<CallStackFrame>(_stack.size());
-		for (CallStackFrame l : _stack) stack_list.add(l);
-		Collections.reverse(stack_list);
+		ArrayList<CallStackFrame> stack_list = new ArrayList<CallStackFrame>(size());
+		for (int i = size()-1; i >= 0; i--) { stack_list.add(_stack[i]); }
+
 		for (CallStackFrame l : stack_list)
 		{
 			if (l.isCheckpoint()) continue;
@@ -99,6 +125,7 @@ public String toString() {
 	}
 
 	public boolean isEmpty() {
-		return _stack.isEmpty();
+		// -1 means empty stack
+		return _stack_index < 0;
 	}
 }

src/aya/instruction/variable/GetKeyVariableInstruction.java

@@ -8,7 +8,7 @@
 import aya.obj.dict.Dict;
 import aya.obj.symbol.Symbol;
 import aya.obj.symbol.SymbolConstants;
-import aya.util.Callable;
+import aya.util.Casting;
 
 public class GetKeyVariableInstruction extends GetVariableInstruction {
 
@@ -23,12 +23,14 @@ public void execute(Block b) {
 			Dict dict;
 			dict = (Dict)kv_obj;
 			Obj o = dict.get(variable_);
-			Block callable = Callable.getCallable(o);
-			// If user object function, leave it as the first item on the stack
-			if (dict.pushSelf() && callable != null) {
-				b.push(dict);
+
+			if (o.isa(Obj.BLOCK)) {
+				// If user object function, leave it as the first item on the stack
+				if (dict.pushSelf()) b.push(dict);
+				dumpBlock(Casting.asBlock(o), b);
+			} else {
+				b.push(o);
 			}
-			this.addOrDumpVar(o, b, callable);
 		} else {
 			Dict builtin_dict = Aya.getInstance().getVars().getBuiltinMeta(kv_obj);
 			Dict dict = (Dict)builtin_dict;

src/aya/instruction/variable/GetVariableInstruction.java

@@ -6,7 +6,7 @@
 import aya.obj.Obj;
 import aya.obj.block.Block;
 import aya.obj.symbol.Symbol;
-import aya.util.Callable;
+import aya.util.Casting;
 
 public class GetVariableInstruction extends VariableInstruction {
 
@@ -26,19 +26,19 @@ public void execute(Block b) {
 	 * @param b
 	 */
 	public void addOrDumpVar(Obj o, Block b) {
-		addOrDumpVar(o, b, Callable.getCallable(o));
-	}
-
-	public void addOrDumpVar(Obj o, Block b, Block callable) {
-		if (callable != null) {
-			Aya.getInstance().getCallStack().push(this);
-			b.add(PopCallstackInstruction.INSTANCE);
-			b.getInstructions().addAll(callable.getInstructions().getInstrucionList());
+		if (o.isa(Obj.BLOCK)) {
+			dumpBlock(Casting.asBlock(o), b);
 		} else {
 			b.push(o);
 		}
 	}
-
+
+	public void dumpBlock(Block block_to_dump, Block b) {
+		Aya.getInstance().getCallStack().push(this);
+		b.add(PopCallstackInstruction.INSTANCE);
+		b.getInstructions().addAll(block_to_dump.getInstructions().getInstrucionList());
+	}
+
 	@Override
 	public ReprStream repr(ReprStream stream) {
 		stream.print(variable_.name());

src/aya/obj/dict/Dict.java

@@ -12,7 +12,6 @@
 import aya.obj.block.Block;
 import aya.obj.symbol.Symbol;
 import aya.obj.symbol.SymbolConstants;
-import aya.util.Callable;
 import aya.util.Casting;
 import aya.util.Pair;
 /**
@@ -185,6 +184,10 @@ public ArrayList<Obj> values() {
 		out.addAll(_vars.values());
 		return out;
 	}
+
+	public Obj getOrNullNoMeta(Symbol key) {
+		return _vars.get(key);
+	}
 
 	/////////////
 	// SETTERS //
@@ -344,9 +347,8 @@ private ReprStream dictRepr(ReprStream stream) {
 		if (!stream.isSafeMode()) repr = getFromMetaTableOrNull(SymbolConstants.KEYVAR_REPR);
 
 		if (repr != null) {
-			Block callable = Callable.getCallable(repr);
-			if (callable != null) {
-				Block blk_repr = callable.duplicate();
+			if (repr.isa(Obj.BLOCK)) {
+				Block blk_repr = Casting.asBlock(repr).duplicate();
 				blk_repr.push(this);
 				try {
 					blk_repr.eval();

src/aya/variable/VariableData.java

@@ -187,7 +187,7 @@ public Obj getVar(Symbol var) {
 	private Obj getVarOrNull(Symbol id) {
 		Obj res = null;
 		for(int i = _var_sets.size()-1; i >= 0; i--) {
-			res = _var_sets.get(i).dict.get(id, null);
+			res = _var_sets.get(i).dict.getOrNullNoMeta(id);
 			if(res != null) {
 				return res;
 			}