/*
 * Copyright (c) 2000, 2018, 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.io.UnsupportedEncodingException;
import java.lang.ref.SoftReference;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.Charset;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.CharsetEncoder;
import java.nio.charset.CharacterCodingException;
import java.nio.charset.CoderResult;
import java.nio.charset.CodingErrorAction;
import java.nio.charset.IllegalCharsetNameException;
import java.nio.charset.MalformedInputException;
import java.nio.charset.UnmappableCharacterException;
import java.nio.charset.UnsupportedCharsetException;
import java.util.Arrays;
import jdk.internal.HotSpotIntrinsicCandidate;
import sun.nio.cs.HistoricallyNamedCharset;
import sun.nio.cs.ArrayDecoder;
import sun.nio.cs.ArrayEncoder;

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;

/**
 * Utility class for string encoding and decoding.
 */

class StringCoding {

 private StringCoding() { }

 /** The cached coders for each thread */
 private static final ThreadLocal<SoftReference<StringDecoder>> decoder =
 new ThreadLocal<>();
 private static final ThreadLocal<SoftReference<StringEncoder>> encoder =
 new ThreadLocal<>();

 private static final Charset ISO_8859_1 = sun.nio.cs.ISO_8859_1.INSTANCE;
 private static final Charset US_ASCII = sun.nio.cs.US_ASCII.INSTANCE;
 private static final Charset UTF_8 = sun.nio.cs.UTF_8.INSTANCE;

 private static <T> T deref(ThreadLocal<SoftReference<T>> tl) {
 SoftReference<T> sr = tl.get();
 if (sr == null)
 return null;
 return sr.get();
 }

 private static <T> void set(ThreadLocal<SoftReference<T>> tl, T ob) {
 tl.set(new SoftReference<>(ob));
 }

 // Trim the given byte array to the given length
 private static byte[] safeTrim(byte[] ba, int len, boolean isTrusted) {
 if (len == ba.length && (isTrusted || System.getSecurityManager() == null))
 return ba;
 else
 return Arrays.copyOf(ba, len);
 }

 private static int scale(int len, float expansionFactor) {
 // We need to perform double, not float, arithmetic; otherwise
 // we lose low order bits when len is larger than 2**24.
 return (int)(len * (double)expansionFactor);
 }

 private static Charset lookupCharset(String csn) {
 if (Charset.isSupported(csn)) {
 try {
 return Charset.forName(csn);
 } catch (UnsupportedCharsetException x) {
 throw new Error(x);
 }
 }
 return null;
 }

 static class Result {
 byte[] value;
 byte coder;

 Result with() {
 coder = COMPACT_STRINGS ? LATIN1 : UTF16;
 value = new byte[0];
 return this;
 }

 Result with(char[] val, int off, int len) {
 if (String.COMPACT_STRINGS) {
 byte[] bs = StringUTF16.compress(val, off, len);
 if (bs != null) {
 value = bs;
 coder = LATIN1;
 return this;
 }
 }
 coder = UTF16;
 value = StringUTF16.toBytes(val, off, len);
 return this;
 }

 Result with(byte[] val, byte coder) {
 this.coder = coder;
 value = val;
 return this;
 }
 }

 @HotSpotIntrinsicCandidate
 public static boolean hasNegatives(byte[] ba, int off, int len) {
 for (int i = off; i < off + len; i++) {
 if (ba[i] < 0) {
 return true;
 }
 }
 return false;
 }

 // -- Decoding --
 static class StringDecoder {
 private final String requestedCharsetName;
 private final Charset cs;
 private final boolean isASCIICompatible;
 private final CharsetDecoder cd;
 protected final Result result;

 StringDecoder(Charset cs, String rcn) {
 this.requestedCharsetName = rcn;
 this.cs = cs;
 this.cd = cs.newDecoder()
 .onMalformedInput(CodingErrorAction.REPLACE)
 .onUnmappableCharacter(CodingErrorAction.REPLACE);
 this.result = new Result();
 this.isASCIICompatible = (cd instanceof ArrayDecoder) &&
 ((ArrayDecoder)cd).isASCIICompatible();
 }

 String charsetName() {
 if (cs instanceof HistoricallyNamedCharset)
 return ((HistoricallyNamedCharset)cs).historicalName();
 return cs.name();
 }

 final String requestedCharsetName() {
 return requestedCharsetName;
 }

 Result decode(byte[] ba, int off, int len) {
 if (len == 0) {
 return result.with();
 }
 // fastpath for ascii compatible
 if (isASCIICompatible && !hasNegatives(ba, off, len)) {
 if (COMPACT_STRINGS) {
 return result.with(Arrays.copyOfRange(ba, off, off + len),
 LATIN1);
 } else {
 return result.with(StringLatin1.inflate(ba, off, len), UTF16);
 }
 }
 int en = scale(len, cd.maxCharsPerByte());
 char[] ca = new char[en];
 if (cd instanceof ArrayDecoder) {
 int clen = ((ArrayDecoder)cd).decode(ba, off, len, ca);
 return result.with(ca, 0, clen);
 }
 cd.reset();
 ByteBuffer bb = ByteBuffer.wrap(ba, off, len);
 CharBuffer cb = CharBuffer.wrap(ca);
 try {
 CoderResult cr = cd.decode(bb, cb, true);
 if (!cr.isUnderflow())
 cr.throwException();
 cr = cd.flush(cb);
 if (!cr.isUnderflow())
 cr.throwException();
 } catch (CharacterCodingException x) {
 // Substitution is always enabled,
 // so this shouldn't happen
 throw new Error(x);
 }
 return result.with(ca, 0, cb.position());
 }
 }

 static Result decode(String charsetName, byte[] ba, int off, int len)
 throws UnsupportedEncodingException
 {
 StringDecoder sd = deref(decoder);
 String csn = (charsetName == null) ? "ISO-8859-1" : charsetName;
 if ((sd == null) || !(csn.equals(sd.requestedCharsetName())
 || csn.equals(sd.charsetName()))) {
 sd = null;
 try {
 Charset cs = lookupCharset(csn);
 if (cs != null) {
 if (cs == UTF_8) {
 return decodeUTF8(ba, off, len, true);
 }
 if (cs == ISO_8859_1) {
 return decodeLatin1(ba, off, len);
 }
 if (cs == US_ASCII) {
 return decodeASCII(ba, off, len);
 }
 sd = new StringDecoder(cs, csn);
 }
 } catch (IllegalCharsetNameException x) {}
 if (sd == null)
 throw new UnsupportedEncodingException(csn);
 set(decoder, sd);
 }
 return sd.decode(ba, off, len);
 }

 static Result decode(Charset cs, byte[] ba, int off, int len) {
 if (cs == UTF_8) {
 return decodeUTF8(ba, off, len, true);
 }
 if (cs == ISO_8859_1) {
 return decodeLatin1(ba, off, len);
 }
 if (cs == US_ASCII) {
 return decodeASCII(ba, off, len);
 }

 // (1)We never cache the "external" cs, the only benefit of creating
 // an additional StringDe/Encoder object to wrap it is to share the
 // de/encode() method. These SD/E objects are short-lived, the young-gen
 // gc should be able to take care of them well. But the best approach
 // is still not to generate them if not really necessary.
 // (2)The defensive copy of the input byte/char[] has a big performance
 // impact, as well as the outgoing result byte/char[]. Need to do the
 // optimization check of (sm==null && classLoader0==null) for both.
 // (3)There might be a timing gap in isTrusted setting. getClassLoader0()
 // is only checked (and then isTrusted gets set) when (SM==null). It is
 // possible that the SM==null for now but then SM is NOT null later
 // when safeTrim() is invoked...the "safe" way to do is to redundant
 // check (... && (isTrusted || SM == null || getClassLoader0())) in trim
 // but it then can be argued that the SM is null when the operation
 // is started...
 CharsetDecoder cd = cs.newDecoder();
 // ascii fastpath
 if ((cd instanceof ArrayDecoder) &&
 ((ArrayDecoder)cd).isASCIICompatible() && !hasNegatives(ba, off, len)) {
 return decodeLatin1(ba, off, len);
 }
 int en = scale(len, cd.maxCharsPerByte());
 if (len == 0) {
 return new Result().with();
 }
 cd.onMalformedInput(CodingErrorAction.REPLACE)
 .onUnmappableCharacter(CodingErrorAction.REPLACE)
 .reset();
 char[] ca = new char[en];
 if (cd instanceof ArrayDecoder) {
 int clen = ((ArrayDecoder)cd).decode(ba, off, len, ca);
 return new Result().with(ca, 0, clen);
 }
 if (cs.getClass().getClassLoader0() != null &&
 System.getSecurityManager() != null) {
 ba = Arrays.copyOfRange(ba, off, off + len);
 off = 0;
 }
 ByteBuffer bb = ByteBuffer.wrap(ba, off, len);
 CharBuffer cb = CharBuffer.wrap(ca);
 try {
 CoderResult cr = cd.decode(bb, cb, true);
 if (!cr.isUnderflow())
 cr.throwException();
 cr = cd.flush(cb);
 if (!cr.isUnderflow())
 cr.throwException();
 } catch (CharacterCodingException x) {
 // Substitution is always enabled,
 // so this shouldn't happen
 throw new Error(x);
 }
 return new Result().with(ca, 0, cb.position());
 }

 static Result decode(byte[] ba, int off, int len) {
 Charset cs = Charset.defaultCharset();
 if (cs == UTF_8) {
 return decodeUTF8(ba, off, len, true);
 }
 if (cs == ISO_8859_1) {
 return decodeLatin1(ba, off, len);
 }
 if (cs == US_ASCII) {
 return decodeASCII(ba, off, len);
 }
 StringDecoder sd = deref(decoder);
 if (sd == null || !cs.name().equals(sd.cs.name())) {
 sd = new StringDecoder(cs, cs.name());
 set(decoder, sd);
 }
 return sd.decode(ba, off, len);
 }

 // -- Encoding --
 private static class StringEncoder {
 private Charset cs;
 private CharsetEncoder ce;
 private final boolean isASCIICompatible;
 private final String requestedCharsetName;
 private final boolean isTrusted;

 private StringEncoder(Charset cs, String rcn) {
 this.requestedCharsetName = rcn;
 this.cs = cs;
 this.ce = cs.newEncoder()
 .onMalformedInput(CodingErrorAction.REPLACE)
 .onUnmappableCharacter(CodingErrorAction.REPLACE);
 this.isTrusted = (cs.getClass().getClassLoader0() == null);
 this.isASCIICompatible = (ce instanceof ArrayEncoder) &&
 ((ArrayEncoder)ce).isASCIICompatible();
 }

 String charsetName() {
 if (cs instanceof HistoricallyNamedCharset)
 return ((HistoricallyNamedCharset)cs).historicalName();
 return cs.name();
 }

 final String requestedCharsetName() {
 return requestedCharsetName;
 }

 byte[] encode(byte coder, byte[] val) {
 // fastpath for ascii compatible
 if (coder == LATIN1 && isASCIICompatible &&
 !hasNegatives(val, 0, val.length)) {
 return Arrays.copyOf(val, val.length);
 }
 int len = val.length >> coder; // assume LATIN1=0/UTF16=1;
 int en = scale(len, ce.maxBytesPerChar());
 byte[] ba = new byte[en];
 if (len == 0) {
 return ba;
 }
 if (ce instanceof ArrayEncoder) {
 int blen = (coder == LATIN1 ) ? ((ArrayEncoder)ce).encodeFromLatin1(val, 0, len, ba)
 : ((ArrayEncoder)ce).encodeFromUTF16(val, 0, len, ba);
 if (blen != -1) {
 return safeTrim(ba, blen, isTrusted);
 }
 }
 char[] ca = (coder == LATIN1 ) ? StringLatin1.toChars(val)
 : StringUTF16.toChars(val);
 ce.reset();
 ByteBuffer bb = ByteBuffer.wrap(ba);
 CharBuffer cb = CharBuffer.wrap(ca, 0, len);
 try {
 CoderResult cr = ce.encode(cb, bb, true);
 if (!cr.isUnderflow())
 cr.throwException();
 cr = ce.flush(bb);
 if (!cr.isUnderflow())
 cr.throwException();
 } catch (CharacterCodingException x) {
 // Substitution is always enabled,
 // so this shouldn't happen
 throw new Error(x);
 }
 return safeTrim(ba, bb.position(), isTrusted);
 }
 }

 static byte[] encode(String charsetName, byte coder, byte[] val)
 throws UnsupportedEncodingException
 {
 StringEncoder se = deref(encoder);
 String csn = (charsetName == null) ? "ISO-8859-1" : charsetName;
 if ((se == null) || !(csn.equals(se.requestedCharsetName())
 || csn.equals(se.charsetName()))) {
 se = null;
 try {
 Charset cs = lookupCharset(csn);
 if (cs != null) {
 if (cs == UTF_8) {
 return encodeUTF8(coder, val, true);
 }
 if (cs == ISO_8859_1) {
 return encode8859_1(coder, val);
 }
 if (cs == US_ASCII) {
 return encodeASCII(coder, val);
 }
 se = new StringEncoder(cs, csn);
 }
 } catch (IllegalCharsetNameException x) {}
 if (se == null) {
 throw new UnsupportedEncodingException (csn);
 }
 set(encoder, se);
 }
 return se.encode(coder, val);
 }

 static byte[] encode(Charset cs, byte coder, byte[] val) {
 if (cs == UTF_8) {
 return encodeUTF8(coder, val, true);
 }
 if (cs == ISO_8859_1) {
 return encode8859_1(coder, val);
 }
 if (cs == US_ASCII) {
 return encodeASCII(coder, val);
 }
 CharsetEncoder ce = cs.newEncoder();
 // fastpath for ascii compatible
 if (coder == LATIN1 && (((ce instanceof ArrayEncoder) &&
 ((ArrayEncoder)ce).isASCIICompatible() &&
 !hasNegatives(val, 0, val.length)))) {
 return Arrays.copyOf(val, val.length);
 }
 int len = val.length >> coder; // assume LATIN1=0/UTF16=1;
 int en = scale(len, ce.maxBytesPerChar());
 byte[] ba = new byte[en];
 if (len == 0) {
 return ba;
 }
 ce.onMalformedInput(CodingErrorAction.REPLACE)
 .onUnmappableCharacter(CodingErrorAction.REPLACE)
 .reset();
 if (ce instanceof ArrayEncoder) {
 int blen = (coder == LATIN1 ) ? ((ArrayEncoder)ce).encodeFromLatin1(val, 0, len, ba)
 : ((ArrayEncoder)ce).encodeFromUTF16(val, 0, len, ba);
 if (blen != -1) {
 return safeTrim(ba, blen, true);
 }
 }
 boolean isTrusted = cs.getClass().getClassLoader0() == null ||
 System.getSecurityManager() == null;
 char[] ca = (coder == LATIN1 ) ? StringLatin1.toChars(val)
 : StringUTF16.toChars(val);
 ByteBuffer bb = ByteBuffer.wrap(ba);
 CharBuffer cb = CharBuffer.wrap(ca, 0, len);
 try {
 CoderResult cr = ce.encode(cb, bb, true);
 if (!cr.isUnderflow())
 cr.throwException();
 cr = ce.flush(bb);
 if (!cr.isUnderflow())
 cr.throwException();
 } catch (CharacterCodingException x) {
 throw new Error(x);
 }
 return safeTrim(ba, bb.position(), isTrusted);
 }

 static byte[] encode(byte coder, byte[] val) {
 Charset cs = Charset.defaultCharset();
 if (cs == UTF_8) {
 return encodeUTF8(coder, val, true);
 }
 if (cs == ISO_8859_1) {
 return encode8859_1(coder, val);
 }
 if (cs == US_ASCII) {
 return encodeASCII(coder, val);
 }
 StringEncoder se = deref(encoder);
 if (se == null || !cs.name().equals(se.cs.name())) {
 se = new StringEncoder(cs, cs.name());
 set(encoder, se);
 }
 return se.encode(coder, val);
 }

 /**
 * Print a message directly to stderr, bypassing all character conversion
 * methods.
 * @param msg message to print
 */
 private static native void err(String msg);

 /* The cached Result for each thread */
 private static final ThreadLocal<StringCoding.Result>
 resultCached = new ThreadLocal<>() {
 protected StringCoding.Result initialValue() {
 return new StringCoding.Result();
 }};

 ////////////////////////// ascii //////////////////////////////

 private static Result decodeASCII(byte[] ba, int off, int len) {
 Result result = resultCached.get();
 if (COMPACT_STRINGS && !hasNegatives(ba, off, len)) {
 return result.with(Arrays.copyOfRange(ba, off, off + len),
 LATIN1);
 }
 byte[] dst = new byte[len<<1];
 int dp = 0;
 while (dp < len) {
 int b = ba[off++];
 putChar(dst, dp++, (b >= 0) ? (char)b : repl);
 }
 return result.with(dst, UTF16);
 }

 private static byte[] encodeASCII(byte coder, byte[] val) {
 if (coder == LATIN1) {
 byte[] dst = new byte[val.length];
 for (int i = 0; i < val.length; i++) {
 if (val[i] < 0) {
 dst[i] = '?';
 } else {
 dst[i] = val[i];
 }
 }
 return dst;
 }
 int len = val.length >> 1;
 byte[] dst = new byte[len];
 int dp = 0;
 for (int i = 0; i < len; i++) {
 char c = StringUTF16.getChar(val, i);
 if (c < 0x80) {
 dst[dp++] = (byte)c;
 continue;
 }
 if (Character.isHighSurrogate(c) && i + 1 < len &&
 Character.isLowSurrogate(StringUTF16.getChar(val, i + 1))) {
 i++;
 }
 dst[dp++] = '?';
 }
 if (len == dp) {
 return dst;
 }
 return Arrays.copyOf(dst, dp);
 }

 ////////////////////////// latin1/8859_1 ///////////////////////////

 private static Result decodeLatin1(byte[] ba, int off, int len) {
 Result result = resultCached.get();
 if (COMPACT_STRINGS) {
 return result.with(Arrays.copyOfRange(ba, off, off + len), LATIN1);
 } else {
 return result.with(StringLatin1.inflate(ba, off, len), UTF16);
 }
 }

 @HotSpotIntrinsicCandidate
 private static int implEncodeISOArray(byte[] sa, int sp,
 byte[] da, int dp, int len) {
 int i = 0;
 for (; i < len; i++) {
 char c = StringUTF16.getChar(sa, sp++);
 if (c > '\u00FF')
 break;
 da[dp++] = (byte)c;
 }
 return i;
 }

 private static byte[] encode8859_1(byte coder, byte[] val) {
 return encode8859_1(coder, val, true);
 }

 private static byte[] encode8859_1(byte coder, byte[] val, boolean doReplace) {
 if (coder == LATIN1) {
 return Arrays.copyOf(val, val.length);
 }
 int len = val.length >> 1;
 byte[] dst = new byte[len];
 int dp = 0;
 int sp = 0;
 int sl = len;
 while (sp < sl) {
 int ret = implEncodeISOArray(val, sp, dst, dp, len);
 sp = sp + ret;
 dp = dp + ret;
 if (ret != len) {
 if (!doReplace) {
 throwUnmappable(sp, 1);
 }
 char c = StringUTF16.getChar(val, sp++);
 if (Character.isHighSurrogate(c) && sp < sl &&
 Character.isLowSurrogate(StringUTF16.getChar(val, sp))) {
 sp++;
 }
 dst[dp++] = '?';
 len = sl - sp;
 }
 }
 if (dp == dst.length) {
 return dst;
 }
 return Arrays.copyOf(dst, dp);
 }

 //////////////////////////////// utf8 ////////////////////////////////////

 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 void throwMalformed(int off, int nb) {
 String msg = "malformed input off : " + off + ", length : " + nb;
 throw new IllegalArgumentException(msg, new MalformedInputException(nb));
 }

 private static void throwMalformed(byte[] val) {
 int dp = 0;
 while (dp < val.length && val[dp] >=0) { dp++; }
 throwMalformed(dp, 1);
 }

 private static void throwUnmappable(int off, int nb) {
 String msg = "malformed input off : " + off + ", length : " + nb;
 throw new IllegalArgumentException(msg, new UnmappableCharacterException(nb));
 }

 private static void throwUnmappable(byte[] val) {
 int dp = 0;
 while (dp < val.length && val[dp] >=0) { dp++; }
 throwUnmappable(dp, 1);
 }

 private static char repl = '\ufffd';

 private static Result decodeUTF8(byte[] src, int sp, int len, boolean doReplace) {
 // ascii-bais, which has a relative impact to the non-ascii-only bytes
 if (COMPACT_STRINGS && !hasNegatives(src, sp, len))
 return resultCached.get().with(Arrays.copyOfRange(src, sp, sp + len),
 LATIN1);
 return decodeUTF8_0(src, sp, len, doReplace);
 }

 private static Result decodeUTF8_0(byte[] src, int sp, int len, boolean doReplace) {
 Result ret = resultCached.get();

 int sl = sp + len;
 int dp = 0;
 byte[] dst = new byte[len];

 if (COMPACT_STRINGS) {
 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)) {
 if (!doReplace) {
 throwMalformed(sp - 1, 1);
 }
 putChar(dst, dp++, repl);
 sp--;
 } else {
 putChar(dst, dp++, (char)(((b1 << 6) ^ b2)^
 (((byte) 0xC0 << 6) ^
 ((byte) 0x80 << 0))));
 }
 continue;
 }
 if (!doReplace) {
 throwMalformed(sp, 1); // underflow()
 }
 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)) {
 if (!doReplace) {
 throwMalformed(sp - 3, 3);
 }
 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))));
 if (isSurrogate(c)) {
 if (!doReplace) {
 throwMalformed(sp - 3, 3);
 }
 putChar(dst, dp++, repl);
 } else {
 putChar(dst, dp++, c);
 }
 }
 continue;
 }
 if (sp < sl && isMalformed3_2(b1, src[sp])) {
 if (!doReplace) {
 throwMalformed(sp - 1, 2);
 }
 putChar(dst, dp++, repl);
 continue;
 }
 if (!doReplace){
 throwMalformed(sp, 1);
 }
 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
 if (!doReplace) {
 throwMalformed(sp - 4, 4);
 }
 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)) {
 if (!doReplace) {
 throwMalformed(sp - 1, 1); // or 2
 }
 putChar(dst, dp++, repl);
 continue;
 }
 if (!doReplace) {
 throwMalformed(sp - 1, 1);
 }
 sp++;
 putChar(dst, dp++, repl);
 if (sp < sl && isMalformed4_3(src[sp])) {
 continue;
 }
 break;
 } else {
 if (!doReplace) {
 throwMalformed(sp - 1, 1);
 }
 putChar(dst, dp++, repl);
 }
 }
 if (dp != len) {
 dst = Arrays.copyOf(dst, dp << 1);
 }
 return ret.with(dst, UTF16);
 }

 private static byte[] encodeUTF8(byte coder, byte[] val, boolean doReplace) {
 if (coder == UTF16)
 return encodeUTF8_UTF16(val, doReplace);

 if (!hasNegatives(val, 0, val.length))
 return Arrays.copyOf(val, val.length);

 int dp = 0;
 byte[] dst = new byte[val.length << 1];
 for (int sp = 0; sp < val.length; sp++) {
 byte c = val[sp];
 if (c < 0) {
 dst[dp++] = (byte)(0xc0 | ((c & 0xff) >> 6));
 dst[dp++] = (byte)(0x80 | (c & 0x3f));
 } else {
 dst[dp++] = c;
 }
 }
 if (dp == dst.length)
 return dst;
 return Arrays.copyOf(dst, dp);
 }

 private static byte[] encodeUTF8_UTF16(byte[] val, boolean doReplace) {
 int dp = 0;
 int sp = 0;
 int sl = val.length >> 1;
 byte[] dst = new byte[sl * 3];
 char c;
 while (sp < sl && (c = StringUTF16.getChar(val, sp)) < '\u0080') {
 // ascii fast loop;
 dst[dp++] = (byte)c;
 sp++;
 }
 while (sp < sl) {
 c = StringUTF16.getChar(val, sp++);
 if (c < 0x80) {
 dst[dp++] = (byte)c;
 } else if (c < 0x800) {
 dst[dp++] = (byte)(0xc0 | (c >> 6));
 dst[dp++] = (byte)(0x80 | (c & 0x3f));
 } else if (Character.isSurrogate(c)) {
 int uc = -1;
 char c2;
 if (Character.isHighSurrogate(c) && sp < sl &&
 Character.isLowSurrogate(c2 = StringUTF16.getChar(val, sp))) {
 uc = Character.toCodePoint(c, c2);
 }
 if (uc < 0) {
 if (doReplace) {
 dst[dp++] = '?';
 } else {
 throwUnmappable(sp - 1, 1); // or 2, does not matter here
 }
 } else {
 dst[dp++] = (byte)(0xf0 | ((uc >> 18)));
 dst[dp++] = (byte)(0x80 | ((uc >> 12) & 0x3f));
 dst[dp++] = (byte)(0x80 | ((uc >> 6) & 0x3f));
 dst[dp++] = (byte)(0x80 | (uc & 0x3f));
 sp++; // 2 chars
 }
 } else {
 // 3 bytes, 16 bits
 dst[dp++] = (byte)(0xe0 | ((c >> 12)));
 dst[dp++] = (byte)(0x80 | ((c >> 6) & 0x3f));
 dst[dp++] = (byte)(0x80 | (c & 0x3f));
 }
 }
 if (dp == dst.length) {
 return dst;
 }
 return Arrays.copyOf(dst, dp);
 }

 ////////////////////// for j.u.z.ZipCoder //////////////////////////

 /*
 * Throws iae, instead of replacing, if malformed or unmappable.
 */
 static String newStringUTF8NoRepl(byte[] src, int off, int len) {
 if (COMPACT_STRINGS && !hasNegatives(src, off, len))
 return new String(Arrays.copyOfRange(src, off, off + len), LATIN1);
 Result ret = decodeUTF8_0(src, off, len, false);
 return new String(ret.value, ret.coder);
 }

 /*
 * Throws iae, instead of replacing, if unmappable.
 */
 static byte[] getBytesUTF8NoRepl(String s) {
 return encodeUTF8(s.coder(), s.value(), false);
 }

 ////////////////////// for j.n.f.Files //////////////////////////

 private static boolean isASCII(byte[] src) {
 return !hasNegatives(src, 0, src.length);
 }

 private static String newStringLatin1(byte[] src) {
 if (COMPACT_STRINGS)
 return new String(src, LATIN1);
 return new String(StringLatin1.inflate(src, 0, src.length), UTF16);
 }

 static String newStringNoRepl(byte[] src, Charset cs) throws CharacterCodingException {
 try {
 return newStringNoRepl1(src, cs);
 } catch (IllegalArgumentException e) {
 //newStringNoRepl1 throws IAE with MalformedInputException or CCE as the cause
 Throwable cause = e.getCause();
 if (cause instanceof MalformedInputException) {
 throw (MalformedInputException)cause;
 }
 throw (CharacterCodingException)cause;
 }
 }

 static String newStringNoRepl1(byte[] src, Charset cs) {
 if (cs == UTF_8) {
 if (COMPACT_STRINGS && isASCII(src))
 return new String(src, LATIN1);
 Result ret = decodeUTF8_0(src, 0, src.length, false);
 return new String(ret.value, ret.coder);
 }
 if (cs == ISO_8859_1) {
 return newStringLatin1(src);
 }
 if (cs == US_ASCII) {
 if (isASCII(src)) {
 return newStringLatin1(src);
 } else {
 throwMalformed(src);
 }
 }

 CharsetDecoder cd = cs.newDecoder();
 // ascii fastpath
 if ((cd instanceof ArrayDecoder) &&
 ((ArrayDecoder)cd).isASCIICompatible() && isASCII(src)) {
 return newStringLatin1(src);
 }
 int len = src.length;
 if (len == 0) {
 return "";
 }
 int en = scale(len, cd.maxCharsPerByte());
 char[] ca = new char[en];
 if (cs.getClass().getClassLoader0() != null &&
 System.getSecurityManager() != null) {
 src = Arrays.copyOf(src, len);
 }
 ByteBuffer bb = ByteBuffer.wrap(src);
 CharBuffer cb = CharBuffer.wrap(ca);
 try {
 CoderResult cr = cd.decode(bb, cb, true);
 if (!cr.isUnderflow())
 cr.throwException();
 cr = cd.flush(cb);
 if (!cr.isUnderflow())
 cr.throwException();
 } catch (CharacterCodingException x) {
 throw new IllegalArgumentException(x); // todo
 }
 Result ret = resultCached.get().with(ca, 0, cb.position());
 return new String(ret.value, ret.coder);
 }

 /*
 * Throws CCE, instead of replacing, if unmappable.
 */
 static byte[] getBytesNoRepl(String s, Charset cs) throws CharacterCodingException {
 try {
 return getBytesNoRepl1(s, cs);
 } catch (IllegalArgumentException e) {
 //getBytesNoRepl1 throws IAE with UnmappableCharacterException or CCE as the cause
 Throwable cause = e.getCause();
 if (cause instanceof UnmappableCharacterException) {
 throw (UnmappableCharacterException)cause;
 }
 throw (CharacterCodingException)cause;
 }
 }

 static byte[] getBytesNoRepl1(String s, Charset cs) {
 byte[] val = s.value();
 byte coder = s.coder();
 if (cs == UTF_8) {
 if (coder == LATIN1 && isASCII(val)) {
 return val;
 }
 return encodeUTF8(coder, val, false);
 }
 if (cs == ISO_8859_1) {
 if (coder == LATIN1) {
 return val;
 }
 return encode8859_1(coder, val, false);
 }
 if (cs == US_ASCII) {
 if (coder == LATIN1) {
 if (isASCII(val)) {
 return val;
 } else {
 throwUnmappable(val);
 }
 }
 }
 CharsetEncoder ce = cs.newEncoder();
 // fastpath for ascii compatible
 if (coder == LATIN1 && (((ce instanceof ArrayEncoder) &&
 ((ArrayEncoder)ce).isASCIICompatible() &&
 isASCII(val)))) {
 return val;
 }
 int len = val.length >> coder; // assume LATIN1=0/UTF16=1;
 int en = scale(len, ce.maxBytesPerChar());
 byte[] ba = new byte[en];
 if (len == 0) {
 return ba;
 }
 if (ce instanceof ArrayEncoder) {
 int blen = (coder == LATIN1 ) ? ((ArrayEncoder)ce).encodeFromLatin1(val, 0, len, ba)
 : ((ArrayEncoder)ce).encodeFromUTF16(val, 0, len, ba);
 if (blen != -1) {
 return safeTrim(ba, blen, true);
 }
 }
 boolean isTrusted = cs.getClass().getClassLoader0() == null ||
 System.getSecurityManager() == null;
 char[] ca = (coder == LATIN1 ) ? StringLatin1.toChars(val)
 : StringUTF16.toChars(val);
 ByteBuffer bb = ByteBuffer.wrap(ba);
 CharBuffer cb = CharBuffer.wrap(ca, 0, len);
 try {
 CoderResult cr = ce.encode(cb, bb, true);
 if (!cr.isUnderflow())
 cr.throwException();
 cr = ce.flush(bb);
 if (!cr.isUnderflow())
 cr.throwException();
 } catch (CharacterCodingException x) {
 throw new IllegalArgumentException(x);
 }
 return safeTrim(ba, bb.position(), isTrusted);
 }
}