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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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package jdk.internal.jimage;

import java.io.UTFDataFormatException;
import java.nio.ByteBuffer;
import java.util.Objects;

Implementation Note:This class 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.
/** * @implNote This class 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 class ImageStringsReader implements ImageStrings { public static final int HASH_MULTIPLIER = 0x01000193; public static final int POSITIVE_MASK = 0x7FFFFFFF; private final BasicImageReader reader; ImageStringsReader(BasicImageReader reader) { this.reader = Objects.requireNonNull(reader); } @Override public String get(int offset) { return reader.getString(offset); } @Override public int add(final String string) { throw new InternalError("Can not add strings at runtime"); } public static int hashCode(String s) { return hashCode(s, HASH_MULTIPLIER); } public static int hashCode(String s, int seed) { return unmaskedHashCode(s, seed) & POSITIVE_MASK; } public static int hashCode(String module, String name) { return hashCode(module, name, HASH_MULTIPLIER); } public static int hashCode(String module, String name, int seed) { seed = unmaskedHashCode("/", seed); seed = unmaskedHashCode(module, seed); seed = unmaskedHashCode("/", seed); seed = unmaskedHashCode(name, seed); return seed & POSITIVE_MASK; } public static int unmaskedHashCode(String s, int seed) { int slen = s.length(); byte[] buffer = null; for (int i = 0; i < slen; i++) { char ch = s.charAt(i); int uch = ch & 0xFFFF; if ((uch & ~0x7F) != 0) { if (buffer == null) { buffer = new byte[8]; } int mask = ~0x3F; int n = 0; do { buffer[n++] = (byte)(0x80 | (uch & 0x3F)); uch >>= 6; mask >>= 1; } while ((uch & mask) != 0); buffer[n] = (byte)((mask << 1) | uch); do { seed = (seed * HASH_MULTIPLIER) ^ (buffer[n--] & 0xFF); } while (0 <= n); } else if (uch == 0) { seed = (seed * HASH_MULTIPLIER) ^ (0xC0); seed = (seed * HASH_MULTIPLIER) ^ (0x80); } else { seed = (seed * HASH_MULTIPLIER) ^ (uch); } } return seed; } static int charsFromMUTF8Length(byte[] bytes, int offset, int count) { int length = 0; for (int i = offset; i < offset + count; i++) { byte ch = bytes[i]; if (ch == 0) { break; } if ((ch & 0xC0) != 0x80) { length++; } } return length; } static void charsFromMUTF8(char[] chars, byte[] bytes, int offset, int count) throws UTFDataFormatException { int j = 0; for (int i = offset; i < offset + count; i++) { byte ch = bytes[i]; if (ch == 0) { break; } boolean is_unicode = (ch & 0x80) != 0; int uch = ch & 0x7F; if (is_unicode) { int mask = 0x40; while ((uch & mask) != 0) { ch = bytes[++i]; if ((ch & 0xC0) != 0x80) { throw new UTFDataFormatException("bad continuation 0x" + Integer.toHexString(ch)); } uch = ((uch & ~mask) << 6) | (ch & 0x3F); mask <<= 6 - 1; } if ((uch & 0xFFFF) != uch) { throw new UTFDataFormatException("character out of range \\u" + Integer.toHexString(uch)); } } chars[j++] = (char)uch; } } public static String stringFromMUTF8(byte[] bytes, int offset, int count) { int length = charsFromMUTF8Length(bytes, offset, count); char[] chars = new char[length]; try { charsFromMUTF8(chars, bytes, offset, count); } catch (UTFDataFormatException ex) { throw new InternalError("Attempt to convert non modified UTF-8 byte sequence", ex); } return new String(chars); } public static String stringFromMUTF8(byte[] bytes) { return stringFromMUTF8(bytes, 0, bytes.length); } static int charsFromByteBufferLength(ByteBuffer buffer) { int length = 0; while(buffer.hasRemaining()) { byte ch = buffer.get(); if (ch == 0) { return length; } if ((ch & 0xC0) != 0x80) { length++; } } throw new InternalError("No terminating zero byte for modified UTF-8 byte sequence"); } static void charsFromByteBuffer(char[] chars, ByteBuffer buffer) { int j = 0; while(buffer.hasRemaining()) { byte ch = buffer.get(); if (ch == 0) { return; } boolean is_unicode = (ch & 0x80) != 0; int uch = ch & 0x7F; if (is_unicode) { int mask = 0x40; while ((uch & mask) != 0) { ch = buffer.get(); if ((ch & 0xC0) != 0x80) { throw new InternalError("Bad continuation in " + "modified UTF-8 byte sequence: " + ch); } uch = ((uch & ~mask) << 6) | (ch & 0x3F); mask <<= 6 - 1; } } if ((uch & 0xFFFF) != uch) { throw new InternalError("UTF-32 char in modified UTF-8 " + "byte sequence: " + uch); } chars[j++] = (char)uch; } throw new InternalError("No terminating zero byte for modified UTF-8 byte sequence"); } public static String stringFromByteBuffer(ByteBuffer buffer) { int length = charsFromByteBufferLength(buffer); buffer.rewind(); char[] chars = new char[length]; charsFromByteBuffer(chars, buffer); return new String(chars); } static int mutf8FromStringLength(String s) { int length = 0; int slen = s.length(); for (int i = 0; i < slen; i++) { char ch = s.charAt(i); int uch = ch & 0xFFFF; if ((uch & ~0x7F) != 0) { int mask = ~0x3F; int n = 0; do { n++; uch >>= 6; mask >>= 1; } while ((uch & mask) != 0); length += n + 1; } else if (uch == 0) { length += 2; } else { length++; } } return length; } static void mutf8FromString(byte[] bytes, int offset, String s) { int j = offset; byte[] buffer = null; int slen = s.length(); for (int i = 0; i < slen; i++) { char ch = s.charAt(i); int uch = ch & 0xFFFF; if ((uch & ~0x7F) != 0) { if (buffer == null) { buffer = new byte[8]; } int mask = ~0x3F; int n = 0; do { buffer[n++] = (byte)(0x80 | (uch & 0x3F)); uch >>= 6; mask >>= 1; } while ((uch & mask) != 0); buffer[n] = (byte)((mask << 1) | uch); do { bytes[j++] = buffer[n--]; } while (0 <= n); } else if (uch == 0) { bytes[j++] = (byte)0xC0; bytes[j++] = (byte)0x80; } else { bytes[j++] = (byte)uch; } } } public static byte[] mutf8FromString(String string) { int length = mutf8FromStringLength(string); byte[] bytes = new byte[length]; mutf8FromString(bytes, 0, string); return bytes; } }