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Java Rule Engine for the masses
package org.algorithmx.rules.asm;
// ASM: a very small and fast Java bytecode manipulation framework
// Copyright (c) 2000-2011 INRIA, France Telecom
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 1. Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
// 3. Neither the name of the copyright holders nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
// THE POSSIBILITY OF SUCH DAMAGE.
import java.util.Arrays;
/**
* A constant whose value is computed at runtime, with a bootstrap method.
*
* @author Remi Forax
*/
public final class ConstantDynamic {
/** The constant name (can be arbitrary). */
private final String name;
/** The constant type (must be a field descriptor). */
private final String descriptor;
/** The bootstrap method to use to compute the constant value at runtime. */
private final Handle bootstrapMethod;
/**
* The arguments to pass to the bootstrap method, in order to compute the constant value at
* runtime.
*/
private final Object[] bootstrapMethodArguments;
/**
* Constructs a new {@link ConstantDynamic}.
*
* @param name the constant name (can be arbitrary).
* @param descriptor the constant type (must be a field descriptor).
* @param bootstrapMethod the bootstrap method to use to compute the constant value at runtime.
* @param bootstrapMethodArguments the arguments to pass to the bootstrap method, in order to
* compute the constant value at runtime.
*/
public ConstantDynamic(
final String name,
final String descriptor,
final Handle bootstrapMethod,
final Object... bootstrapMethodArguments) {
this.name = name;
this.descriptor = descriptor;
this.bootstrapMethod = bootstrapMethod;
this.bootstrapMethodArguments = bootstrapMethodArguments;
}
/**
* Returns the name of this constant.
*
* @return the name of this constant.
*/
public String getName() {
return name;
}
/**
* Returns the type of this constant.
*
* @return the type of this constant, as a field descriptor.
*/
public String getDescriptor() {
return descriptor;
}
/**
* Returns the bootstrap method used to compute the value of this constant.
*
* @return the bootstrap method used to compute the value of this constant.
*/
public Handle getBootstrapMethod() {
return bootstrapMethod;
}
/**
* Returns the number of arguments passed to the bootstrap method, in order to compute the value
* of this constant.
*
* @return the number of arguments passed to the bootstrap method, in order to compute the value
* of this constant.
*/
public int getBootstrapMethodArgumentCount() {
return bootstrapMethodArguments.length;
}
/**
* Returns an argument passed to the bootstrap method, in order to compute the value of this
* constant.
*
* @param index an argument index, between 0 and {@link #getBootstrapMethodArgumentCount()}
* (exclusive).
* @return the argument passed to the bootstrap method, with the given index.
*/
public Object getBootstrapMethodArgument(final int index) {
return bootstrapMethodArguments[index];
}
/**
* Returns the arguments to pass to the bootstrap method, in order to compute the value of this
* constant. WARNING: this array must not be modified, and must not be returned to the user.
*
* @return the arguments to pass to the bootstrap method, in order to compute the value of this
* constant.
*/
Object[] getBootstrapMethodArgumentsUnsafe() {
return bootstrapMethodArguments;
}
/**
* Returns the size of this constant.
*
* @return the size of this constant, i.e., 2 for {@code long} and {@code double}, 1 otherwise.
*/
public int getSize() {
char firstCharOfDescriptor = descriptor.charAt(0);
return (firstCharOfDescriptor == 'J' || firstCharOfDescriptor == 'D') ? 2 : 1;
}
@Override
public boolean equals(final Object object) {
if (object == this) {
return true;
}
if (!(object instanceof ConstantDynamic)) {
return false;
}
ConstantDynamic constantDynamic = (ConstantDynamic) object;
return name.equals(constantDynamic.name)
&& descriptor.equals(constantDynamic.descriptor)
&& bootstrapMethod.equals(constantDynamic.bootstrapMethod)
&& Arrays.equals(bootstrapMethodArguments, constantDynamic.bootstrapMethodArguments);
}
@Override
public int hashCode() {
return name.hashCode()
^ Integer.rotateLeft(descriptor.hashCode(), 8)
^ Integer.rotateLeft(bootstrapMethod.hashCode(), 16)
^ Integer.rotateLeft(Arrays.hashCode(bootstrapMethodArguments), 24);
}
@Override
public String toString() {
return name
+ " : "
+ descriptor
+ ' '
+ bootstrapMethod
+ ' '
+ Arrays.toString(bootstrapMethodArguments);
}
}