src/java.base/share/classes/jdk/internal/jimage/ImageStrings.java - master - githubmirror/panama-vector

src/java.base/share/classes/jdk/internal/jimage/ImageStrings.java

66 строк3 KB

Alan Bateman

8377070: Update jimage format to support classes compiled with preview feature enabled

12 май 2026, 13:09

12 май 2026, 13:094edfc38

/*
 * Copyright (c) 2014, 2026, 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.internal.jimage;

/**
 * @implNote This interface needs to maintain JDK 8 source compatibility.
 *
 * It is used internally in the JDK to implement jimage/jrtfs access,
 * but also compiled and delivered as part of the jrtfs.jar to support access
 * to the jimage file provided by the shipped JDK by tools running on JDK 8.
 */
public interface ImageStrings {
    // String offset constants are useful for efficient classification
    // of location entries without string comparison.
    // They are validated during initialization of ImageStringsWriter.
    //
    // Adding new strings (with larger offsets) is possible without changing
    // the jimage version number, but any change to existing strings must be
    // accompanied by a jimage version number change.

    /** Fixed offset for the empty string in the strings table. */
    int EMPTY_STRING_OFFSET = 0;
    /** Fixed offset for the string "class" in the strings table. */
    int CLASS_STRING_OFFSET = 1;
    /** Fixed offset for the string "modules" in the strings table. */
    int MODULES_STRING_OFFSET = 7;
    /** Fixed offset for the string "packages" in the strings table. */
    int PACKAGES_STRING_OFFSET = 15;

    String get(int offset);

    int add(final String string);

    /**
     * If there's a string at {@code offset} matching in full a substring of
     * {@code string} starting at {@code stringOffset}, return the length
     * of that string. Otherwise returns -1. Optional operation.
     */
    default int match(int offset, String string, int stringOffset) {
        throw new UnsupportedOperationException();
    }

}