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StringDecoderUTF8
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StringDecoderUTF8(Charset, String): void
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isNotContinuation(int): boolean
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isMalformed3(int, int, int): boolean
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isMalformed3_2(int, int): boolean
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isMalformed4(int, int, int): boolean
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isMalformed4_2(int, int): boolean
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isMalformed4_3(int): boolean
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malformedN(byte[], int, int): int
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repl: char
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decode(byte[], int, int): Result
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decode(byte[], int, int, Result): Result
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/*
* Copyright (c) 2015, 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 java.lang;
import java.nio.charset.Charset;
import java.util.Arrays;
import static java.lang.String.LATIN1;
import static java.lang.String.UTF16;
import static java.lang.String.COMPACT_STRINGS;
import static java.lang.Character.isSurrogate;
import static java.lang.Character.highSurrogate;
import static java.lang.Character.lowSurrogate;
import static java.lang.Character.isSupplementaryCodePoint;
import static java.lang.StringUTF16.putChar;
class StringDecoderUTF8 extends StringCoding.StringDecoder {
StringDecoderUTF8(Charset cs, String rcn) {
super(cs, rcn);
}
private static boolean isNotContinuation(int b) {
return (b & 0xc0) != 0x80;
}
private static boolean isMalformed3(int b1, int b2, int b3) {
return (b1 == (byte)0xe0 && (b2 & 0xe0) == 0x80) ||
(b2 & 0xc0) != 0x80 || (b3 & 0xc0) != 0x80;
}
private static boolean isMalformed3_2(int b1, int b2) {
return (b1 == (byte)0xe0 && (b2 & 0xe0) == 0x80) ||
(b2 & 0xc0) != 0x80;
}
private static boolean isMalformed4(int b2, int b3, int b4) {
return (b2 & 0xc0) != 0x80 || (b3 & 0xc0) != 0x80 ||
(b4 & 0xc0) != 0x80;
}
private static boolean isMalformed4_2(int b1, int b2) {
return (b1 == 0xf0 && (b2 < 0x90 || b2 > 0xbf)) ||
(b1 == 0xf4 && (b2 & 0xf0) != 0x80) ||
(b2 & 0xc0) != 0x80;
}
private static boolean isMalformed4_3(int b3) {
return (b3 & 0xc0) != 0x80;
}
// for nb == 3/4
private static int malformedN(byte[] src, int sp, int nb) {
if (nb == 3) {
int b1 = src[sp++];
int b2 = src[sp++]; // no need to lookup b3
return ((b1 == (byte)0xe0 && (b2 & 0xe0) == 0x80) ||
isNotContinuation(b2)) ? 1 : 2;
} else if (nb == 4) { // we don't care the speed here
int b1 = src[sp++] & 0xff;
int b2 = src[sp++] & 0xff;
if (b1 > 0xf4 ||
(b1 == 0xf0 && (b2 < 0x90 || b2 > 0xbf)) ||
(b1 == 0xf4 && (b2 & 0xf0) != 0x80) ||
isNotContinuation(b2))
return 1;
if (isNotContinuation(src[sp++]))
return 2;
return 3;
}
assert false;
return -1;
}
private static char repl = '\ufffd';
StringCoding.Result decode(byte[] src, int sp, int len) {
return decode(src, sp, len, result);
}
static StringCoding.Result decode(byte[] src, int sp, int len,
StringCoding.Result ret) {
int sl = sp + len;
byte[] dst = new byte[len];
int dp = 0;
if (COMPACT_STRINGS) { // Latin1 only loop
while (sp < sl) {
int b1 = src[sp];
if (b1 >= 0) {
dst[dp++] = (byte)b1;
sp++;
continue;
}
if ((b1 == (byte)0xc2 || b1 == (byte)0xc3) &&
sp + 1 < sl) {
int b2 = src[sp + 1];
if (!isNotContinuation(b2)) {
dst[dp++] = (byte)(((b1 << 6) ^ b2)^
(((byte) 0xC0 << 6) ^
((byte) 0x80 << 0)));
sp += 2;
continue;
}
}
// anything not a latin1, including the repl
// we have to go with the utf16
break;
}
if (sp == sl) {
if (dp != dst.length) {
dst = Arrays.copyOf(dst, dp);
}
return ret.with(dst, LATIN1);
}
}
if (dp == 0) {
dst = new byte[len << 1];
} else {
byte[] buf = new byte[len << 1];
StringLatin1.inflate(dst, 0, buf, 0, dp);
dst = buf;
}
while (sp < sl) {
int b1 = src[sp++];
if (b1 >= 0) {
putChar(dst, dp++, (char) b1);
} else if ((b1 >> 5) == -2 && (b1 & 0x1e) != 0) {
if (sp < sl) {
int b2 = src[sp++];
if (isNotContinuation(b2)) {
putChar(dst, dp++, repl);
sp--;
} else {
putChar(dst, dp++, (char)(((b1 << 6) ^ b2)^
(((byte) 0xC0 << 6) ^
((byte) 0x80 << 0))));
}
continue;
}
putChar(dst, dp++, repl);
break;
} else if ((b1 >> 4) == -2) {
if (sp + 1 < sl) {
int b2 = src[sp++];
int b3 = src[sp++];
if (isMalformed3(b1, b2, b3)) {
putChar(dst, dp++, repl);
sp -= 3;
sp += malformedN(src, sp, 3);
} else {
char c = (char)((b1 << 12) ^
(b2 << 6) ^
(b3 ^
(((byte) 0xE0 << 12) ^
((byte) 0x80 << 6) ^
((byte) 0x80 << 0))));
putChar(dst, dp++, isSurrogate(c) ? repl : c);
}
continue;
}
if (sp < sl && isMalformed3_2(b1, src[sp])) {
putChar(dst, dp++, repl);
continue;
}
putChar(dst, dp++, repl);
break;
} else if ((b1 >> 3) == -2) {
if (sp + 2 < sl) {
int b2 = src[sp++];
int b3 = src[sp++];
int b4 = src[sp++];
int uc = ((b1 << 18) ^
(b2 << 12) ^
(b3 << 6) ^
(b4 ^
(((byte) 0xF0 << 18) ^
((byte) 0x80 << 12) ^
((byte) 0x80 << 6) ^
((byte) 0x80 << 0))));
if (isMalformed4(b2, b3, b4) ||
!isSupplementaryCodePoint(uc)) { // shortest form check
putChar(dst, dp++, repl);
sp -= 4;
sp += malformedN(src, sp, 4);
} else {
putChar(dst, dp++, highSurrogate(uc));
putChar(dst, dp++, lowSurrogate(uc));
}
continue;
}
b1 &= 0xff;
if (b1 > 0xf4 ||
sp < sl && isMalformed4_2(b1, src[sp] & 0xff)) {
putChar(dst, dp++, repl);
continue;
}
sp++;
putChar(dst, dp++, repl);
if (sp < sl && isMalformed4_3(src[sp])) {
continue;
}
break;
} else {
putChar(dst, dp++, repl);
}
}
if (dp != len) {
dst = Arrays.copyOf(dst, dp << 1);
}
return ret.with(dst, UTF16);
}
}