| /* |
| * Copyright (c) 2014, 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.tools.jlink.internal; |
| |
| import java.nio.ByteBuffer; |
| import java.util.HashMap; |
| import jdk.internal.jimage.ImageStream; |
| import jdk.internal.jimage.ImageStrings; |
| import jdk.internal.jimage.ImageStringsReader; |
| |
| class ImageStringsWriter implements ImageStrings { |
| private static final int NOT_FOUND = -1; |
| static final int EMPTY_OFFSET = 0; |
| |
| private final HashMap<String, Integer> stringToOffsetMap; |
| private final ImageStream stream; |
| |
| ImageStringsWriter() { |
| this.stringToOffsetMap = new HashMap<>(); |
| this.stream = new ImageStream(); |
| |
| // Reserve 0 offset for empty string. |
| int offset = addString(""); |
| if (offset != 0) { |
| throw new InternalError("Empty string not offset zero"); |
| } |
| |
| // Reserve 1 offset for frequently used ".class". |
| offset = addString("class"); |
| if (offset != 1) { |
| throw new InternalError("'class' string not offset one"); |
| } |
| } |
| |
| private int addString(final String string) { |
| int offset = stream.getPosition(); |
| byte[] bytes = ImageStringsReader.mutf8FromString(string); |
| stream.put(bytes, 0, bytes.length); |
| stream.put('\0'); |
| stringToOffsetMap.put(string, offset); |
| |
| return offset; |
| } |
| |
| @Override |
| public int add(final String string) { |
| int offset = find(string); |
| |
| return offset == NOT_FOUND ? addString(string) : offset; |
| } |
| |
| int find(final String string) { |
| Integer offset = stringToOffsetMap.get(string); |
| |
| return offset != null ? offset : NOT_FOUND; |
| } |
| |
| @Override |
| public String get(int offset) { |
| ByteBuffer buffer = stream.getBuffer(); |
| int capacity = buffer.capacity(); |
| if (offset < 0 || offset >= capacity) { |
| throw new InternalError("String buffer offset out of range"); |
| } |
| int zero = NOT_FOUND; |
| for (int i = offset; i < capacity; i++) { |
| if (buffer.get(i) == '\0') { |
| zero = i; |
| break; |
| } |
| } |
| if (zero == NOT_FOUND) { |
| throw new InternalError("String zero terminator not found"); |
| } |
| int length = zero - offset; |
| byte[] bytes = new byte[length]; |
| int mark = buffer.position(); |
| buffer.position(offset); |
| buffer.get(bytes); |
| buffer.position(mark); |
| |
| return ImageStringsReader.stringFromMUTF8(bytes); |
| } |
| |
| ImageStream getStream() { |
| return stream; |
| } |
| |
| int getSize() { |
| return stream.getSize(); |
| } |
| |
| int getCount() { |
| return stringToOffsetMap.size(); |
| } |
| } |