public static Query fromOM(OMElement queryElement) {
Query query = new Query();
String name =
queryElement.getAttribute(new QName(CEPConstants.CEP_CONF_ATTR_NAME)).getAttributeValue();
query.setName(name);
Iterator iterator = queryElement.getChildrenWithName(new QName(CEPConstants.CEP_CONF_QUERY_IP));
while (iterator != null && iterator.hasNext()) {
OMElement ipElement = (OMElement) iterator.next();
String ip = ipElement.getText();
query.addIP(ip);
}
OMElement expressionElement =
queryElement.getFirstChildWithName(
new QName(CEPConstants.CEP_CONF_NAMESPACE, CEPConstants.CEP_CONF_ELE_EXPRESSION));
if (expressionElement != null) {
query.setExpression(ExpressionHelper.fromOM(expressionElement));
}
OMElement outputOmElement =
queryElement.getFirstChildWithName(
new QName(CEPConstants.CEP_CONF_NAMESPACE, CEPConstants.CEP_CONF_ELE_OUTPUT));
if (expressionElement != null && outputOmElement != null) {
query.setOutput(OutputHelper.fromOM(outputOmElement));
}
return query;
}
public static OMElement queryToOM(Query query) {
OMFactory factory = OMAbstractFactory.getOMFactory();
OMElement queryChild =
factory.createOMElement(
new QName(
CEPConstants.CEP_CONF_NAMESPACE,
CEPConstants.CEP_CONF_ELE_QUERY,
CEPConstants.CEP_CONF_CEP_NAME_SPACE_PREFIX));
Expression queryExpression = query.getExpression();
String queryName = query.getName();
OMElement queryIP = null;
List<String> ipList = query.getIpList();
for (String ip : ipList) {
queryIP = factory.createOMElement(new QName(CEPConstants.CEP_CONF_QUERY_IP));
queryIP.setText(ip);
queryChild.addChild(queryIP);
}
queryChild.addAttribute(CEPConstants.CEP_CONF_ATTR_NAME, queryName, null);
OMElement omQueryExpression = ExpressionHelper.expressionToOM(queryExpression);
queryChild.addChild(omQueryExpression);
if (query.getOutput() != null) {
OMElement queryOutput = OutputHelper.outputToOM(query.getOutput());
queryChild.addChild(queryOutput);
}
return queryChild;
}
@Override
public Object evaluate(String expression) throws Exception {
try {
TypeExpressionHolder.push(clazz);
return helper.evaluate(String.format("$[%s]", expression));
} finally {
TypeExpressionHolder.pop();
}
}
/**
* This method runs through the expression in order to generate the corresponding assembly code.
* At the end of the run, the result is always stored in Register.RAX
*/
public StringBuffer handleExpression(Expression e, Context context) throws Exception {
StringBuffer sb = new StringBuffer();
String lastReg;
if (Parser.DEBUG) System.out.println("\nHandling expression: \"" + this.toString() + "\"");
if (this.right == null) {
// Handle leaf
if (this instanceof Variable) {
if (Parser.DEBUG) System.out.println("\tVariable caught: " + ((Variable) this).getValue());
sb = ExpressionHelper.handleVariable(sb, (Variable) this, Register.RAX, context);
} else if (this instanceof FunctionCall) {
if (Parser.DEBUG)
System.out.println("\tFunction-call caught: " + ((FunctionCall) this).getTag());
sb = ExpressionHelper.handleFunctionCall(sb, (FunctionCall) this, context);
}
return sb;
}
sb.append(this.left.handleExpression(e, context));
if (this.flag != null && this.flag.equals(Flag.UMINUS))
sb.append(ExpressionHelper.asm(Assembly.NEG, Register.RAX));
if (this.right.op != null && this.right.priority == false) {
// Handle expression with three or more operands
if (this.right.left.priority) {
// Handle priority expression first (parentheses).
this.right.left.priority = false;
sb.append(context.virtualPush(Register.RAX.toString()));
sb.append(this.right.left.handleExpression(e, context));
sb.append(context.virtualPop(Register.RDX.toString()));
sb = ExpressionHelper.handleOperation(sb, this.op, Register.RAX, Register.RDX);
sb.append(context.virtualPush(Register.RAX.toString()));
sb.append(this.right.right.handleExpression(e, context));
sb.append(context.virtualPop(Register.RDX.toString()));
sb = ExpressionHelper.handleOperation(sb, this.right.op, Register.RAX, Register.RDX);
} else if (ExpressionHelper.getPrecedence(this.op.toString())
> ExpressionHelper.getPrecedence(this.right.op.toString())) {
// Handle operators of higher precedence first.
if (this.right.left instanceof Variable)
sb =
ExpressionHelper.handleVariable(
sb, (Variable) this.right.left, Register.RDX, context);
else {
sb.append(ExpressionHelper.asm(Assembly.MOV, Register.RAX, Register.RDX));
sb = ExpressionHelper.handleFunctionCall(sb, (FunctionCall) this.right.left, context);
}
sb = ExpressionHelper.handleOperation(sb, this.op, Register.RDX, Register.RAX);
sb.append(context.virtualPush(Register.RAX.toString()));
sb.append(this.right.right.handleExpression(e, context));
sb.append(context.virtualPop(Register.RDX.toString()));
sb = ExpressionHelper.handleOperation(sb, this.right.op, Register.RAX, Register.RDX);
} else {
sb.append(context.virtualPush(Register.RAX.toString()));
sb.append(this.right.handleExpression(e, context));
sb.append(ExpressionHelper.asm(Assembly.MOV, Register.RAX, Register.RDX));
sb.append(context.virtualPop(Register.RAX.toString()));
sb = ExpressionHelper.handleOperation(sb, this.op, Register.RAX, Register.RDX);
}
} else {
// Handle simple node (l op r)
if (this.right.priority) {
sb.append(context.virtualPush(Register.RAX.toString()));
sb.append(this.right.handleExpression(e, context));
sb.append(context.virtualPop(Register.RDX.toString()));
sb = ExpressionHelper.handleOperation(sb, this.op, Register.RAX, Register.RDX);
} else if (this.right instanceof Variable) {
if (((Variable) this.right).getValue() instanceof Integer) {
if (this.right.flag != null && this.right.flag.equals(Flag.UMINUS))
sb =
ExpressionHelper.handleOperation(
sb, this.op, "$-" + ((Variable) this.right).getValue());
else
sb =
ExpressionHelper.handleOperation(
sb, this.op, "$" + ((Variable) this.right).getValue());
} else {
if (((Variable) this.right).index != null)
sb.append(context.virtualPush(Register.RAX.toString()));
sb = ExpressionHelper.handleVariable(sb, (Variable) this.right, Register.RDX, context);
if (((Variable) this.right).index != null) {
sb.append(ExpressionHelper.asm(Assembly.MOV, Register.RAX, Register.RDX));
sb.append(context.virtualPop(Register.RAX.toString()));
}
sb = ExpressionHelper.handleOperation(sb, this.op, Register.RDX, Register.RAX);
}
} else if (this.right instanceof FunctionCall) {
sb.append(context.virtualPush(Register.RAX.toString()));
sb = ExpressionHelper.handleFunctionCall(sb, (FunctionCall) this.right, context);
sb.append(context.virtualPop(Register.RDX.toString()));
sb = ExpressionHelper.handleOperation(sb, this.op, Register.RAX, Register.RDX);
sb.append(ExpressionHelper.asm(Assembly.MOV, Register.RAX, Register.RDX));
}
}
return sb;
}
