/*

 * Copyright (c) 2016, 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 jdk.jshell;

import java.util.Arrays;

import java.util.HashMap;

import java.util.Objects;

import jdk.jshell.spi.ExecutionControl.ClassBytecodes;

/**

 * Tracks the state of a class.

 */

class ClassTracker {

    private final HashMap<String, ClassInfo> map;

    ClassTracker() {

        this.map = new HashMap<>();

    }

    /**

     * Associates a class name, class bytes (current and loaded).

     */

    class ClassInfo {

        // The name of the class

        private final String className;

        // The corresponding compiled class bytes when a load or redefine

        // is started.  May not be the loaded bytes.  May be null.

        private byte[] currentBytes;

        // The class bytes successfully loaded/redefined into the remote VM.

        private byte[] loadedBytes;

        private ClassInfo(String className) {

            this.className = className;

        }

        String getClassName() {

            return className;

        }

        byte[] getLoadedBytes() {

            return loadedBytes;

        }

        byte[] getCurrentBytes() {

            return currentBytes;

        }

        void setCurrentBytes(byte[] bytes) {

            this.currentBytes = bytes;

        }

        void setLoadedBytes(byte[] bytes) {

            this.loadedBytes = bytes;

        }

        boolean isLoaded() {

            return loadedBytes != null;

        }

        boolean isCurrent() {

            return Arrays.equals(currentBytes, loadedBytes);

        }

        ClassBytecodes toClassBytecodes() {

            return new ClassBytecodes(className, currentBytes);

        }

            @Override

        public boolean equals(Object o) {

            return o instanceof ClassInfo

                    && ((ClassInfo) o).className.equals(className);

        }

        @Override

        public int hashCode() {

            return Objects.hashCode(this.className);

        }

    }

    void markLoaded(ClassBytecodes[] cbcs) {

        for (ClassBytecodes cbc : cbcs) {

            get(cbc.name()).setLoadedBytes(cbc.bytecodes());

        }

    }

    void markLoaded(ClassBytecodes[] cbcs, boolean[] isLoaded) {

        for (int i = 0; i < cbcs.length; ++i) {

            if (isLoaded[i]) {

                ClassBytecodes cbc = cbcs[i];

                get(cbc.name()).setLoadedBytes(cbc.bytecodes());

            }

        }

    }

    // Map a class name to the current compiled class bytes.

    void setCurrentBytes(String className, byte[] bytes) {

        ClassInfo ci = get(className);

        ci.setCurrentBytes(bytes);

    }

    // Lookup the ClassInfo by class name, create if it does not exist.

    ClassInfo get(String className) {

        return map.computeIfAbsent(className, ClassInfo::new);

    }

}