/* * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */package sun.tools.jstat;import sun.jvmstat.monitor.*;/** * A class implementing the ExpressionEvaluator to resolve unresolved * symbols in an Expression in the context of the available monitoring data. * This class also performs some minimal optimizations of the expressions, * such as simplification of constant subexpressions. * * @author Brian Doherty * @since 1.5 */public class ExpressionResolver implements ExpressionEvaluator { private static boolean debug = Boolean.getBoolean("ExpressionResolver.debug"); private MonitoredVm vm; ExpressionResolver(MonitoredVm vm) { this.vm = vm; } /* * evaluate the given expression. evaluation in this case means * to resolve the counter names in the expression */ public Object evaluate(Expression e) throws MonitorException { if (e == null) { return null; } if (debug) { System.out.println("Resolving Expression:" + e); } if (e instanceof Identifier) { Identifier id = (Identifier)e; // check if it's already resolved if (id.isResolved()) { return id; } // look it up Monitor m = vm.findByName(id.getName()); if (m == null) { System.err.println("Warning: Unresolved Symbol: " + id.getName() + " substituted NaN"); return new Literal(new Double(Double.NaN)); } if (m.getVariability() == Variability.CONSTANT) { if (debug) { System.out.println("Converting constant " + id.getName() + " to literal with value " + m.getValue()); } return new Literal(m.getValue()); } id.setValue(m); return id; } if (e instanceof Literal) { return e; } Expression l = null; Expression r = null; if (e.getLeft() != null) { l = (Expression)evaluate(e.getLeft()); } if (e.getRight() != null) { r = (Expression)evaluate(e.getRight()); } if (l != null && r != null) { if ((l instanceof Literal) && (r instanceof Literal)) { Literal ll = (Literal)l; Literal rl = (Literal)r; boolean warn = false; Double nan = new Double(Double.NaN); if (ll.getValue() instanceof String) { warn = true; ll.setValue(nan); } if (rl.getValue() instanceof String) { warn = true; rl.setValue(nan); } if (debug && warn) { System.out.println("Warning: String literal in " + "numerical expression: " + "substitutied NaN"); } // perform the operation Number ln = (Number)ll.getValue(); Number rn = (Number)rl.getValue(); double result = e.getOperator().eval(ln.doubleValue(), rn.doubleValue()); if (debug) { System.out.println("Converting expression " + e + " (left = " + ln.doubleValue() + ")" + " (right = " + rn.doubleValue() + ")" + " to literal value " + result); } return new Literal(new Double(result)); } } if (l != null && r == null) { return l; } e.setLeft(l); e.setRight(r); return e; }}
/*
* Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package sun.tools.jstat;
import sun.jvmstat.monitor.*;
/**
* A class implementing the ExpressionEvaluator to resolve unresolved
* symbols in an Expression in the context of the available monitoring data.
* This class also performs some minimal optimizations of the expressions,
* such as simplification of constant subexpressions.
*
* @author Brian Doherty
* @since 1.5
*/
public class ExpressionResolver implements ExpressionEvaluator {
private static boolean debug = Boolean.getBoolean("ExpressionResolver.debug");
private MonitoredVm vm;
ExpressionResolver(MonitoredVm vm) {
this.vm = vm;
}
/*
* evaluate the given expression. evaluation in this case means
* to resolve the counter names in the expression
*/
public Object evaluate(Expression e) throws MonitorException {
if (e == null) {
return null;
}
if (debug) {
System.out.println("Resolving Expression:" + e);
}
if (e instanceof Identifier) {
Identifier id = (Identifier)e;
// check if it's already resolved
if (id.isResolved()) {
return id;
}
// look it up
Monitor m = vm.findByName(id.getName());
if (m == null) {
System.err.println("Warning: Unresolved Symbol: "
+ id.getName() + " substituted NaN");
return new Literal(new Double(Double.NaN));
}
if (m.getVariability() == Variability.CONSTANT) {
if (debug) {
System.out.println("Converting constant " + id.getName()
+ " to literal with value "
+ m.getValue());
}
return new Literal(m.getValue());
}
id.setValue(m);
return id;
}
if (e instanceof Literal) {
return e;
}
Expression l = null;
Expression r = null;
if (e.getLeft() != null) {
l = (Expression)evaluate(e.getLeft());
}
if (e.getRight() != null) {
r = (Expression)evaluate(e.getRight());
}
if (l != null && r != null) {
if ((l instanceof Literal) && (r instanceof Literal)) {
Literal ll = (Literal)l;
Literal rl = (Literal)r;
boolean warn = false;
Double nan = new Double(Double.NaN);
if (ll.getValue() instanceof String) {
warn = true; ll.setValue(nan);
}
if (rl.getValue() instanceof String) {
warn = true; rl.setValue(nan);
}
if (debug && warn) {
System.out.println("Warning: String literal in "
+ "numerical expression: "
+ "substitutied NaN");
}
// perform the operation
Number ln = (Number)ll.getValue();
Number rn = (Number)rl.getValue();
double result = e.getOperator().eval(ln.doubleValue(),
rn.doubleValue());
if (debug) {
System.out.println("Converting expression " + e
+ " (left = " + ln.doubleValue() + ")"
+ " (right = " + rn.doubleValue() + ")"
+ " to literal value " + result);
}
return new Literal(new Double(result));
}
}
if (l != null && r == null) {
return l;
}
e.setLeft(l);
e.setRight(r);
return e;
}
}