/*
 * Copyright (c) 2017-2018 The Regents of the University of California
 *
 * 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.
 *
 * 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
 * HOLDER 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.
 */
package edu.berkeley.cs.jqf.fuzz.ei;

import java.util.Arrays;

/**
 * A representation of an execution index sans the counts, equivalent to
 * a call stack.
 *
 * @author Rohan Padhye
 */
public class ExecutionContext {

    private final int[] ec;

    /**
     * Create an execution context by extracting the call stack
     * from an execution index.
     *
     * @param executionIndex the execution index to copy call sites from
     */
    public ExecutionContext(ExecutionIndex executionIndex) {
        int[] ei = executionIndex.ei;

        // Take every even element from the execution index
        ec = new int[ei.length / 2];
        for (int i = 0; i < ec.length; i++) {
            ec[i] = ei[2*i];
        }
    }

    @Override
    public int hashCode() {
        return Arrays.hashCode(ec);
    }

    @Override
    public boolean equals(Object other) {
        if (other != null && other instanceof ExecutionContext) {
            return Arrays.equals(ec, ((ExecutionContext) other).ec);
        } else {
            return false;
        }
    }

    @Override
    public String toString() {
        return Arrays.toString(ec);
    }
}
