--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/java.httpclient/share/classes/java/net/http/WSCharsetToolkit.java	Mon May 09 23:33:09 2016 +0100
@@ -0,0 +1,126 @@
+/*
+ * Copyright (c) 2016, 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
+ */
+package java.net.http;
+
+import java.nio.ByteBuffer;
+import java.nio.CharBuffer;
+import java.nio.charset.CharacterCodingException;
+import java.nio.charset.CharsetDecoder;
+import java.nio.charset.CharsetEncoder;
+import java.nio.charset.CoderResult;
+import java.nio.charset.CodingErrorAction;
+import java.nio.charset.StandardCharsets;
+
+import static java.lang.System.Logger.Level.WARNING;
+import static java.net.http.WSUtils.EMPTY_BYTE_BUFFER;
+import static java.net.http.WSUtils.logger;
+import static java.nio.charset.StandardCharsets.UTF_8;
+
+/*
+ * A collection of tools for UTF-8 coding.
+ */
+final class WSCharsetToolkit {
+
+    private WSCharsetToolkit() { }
+
+    static final class Encoder {
+
+        private final CharsetEncoder encoder = UTF_8.newEncoder();
+
+        ByteBuffer encode(CharBuffer in) throws CharacterCodingException {
+            return encoder.encode(in);
+        }
+
+        // TODO:
+        // ByteBuffer[] encode(CharBuffer in) throws CharacterCodingException {
+        //     return encoder.encode(in);
+        // }
+    }
+
+    static CharBuffer decode(ByteBuffer in) throws CharacterCodingException {
+        return UTF_8.newDecoder().decode(in);
+    }
+
+    static final class Decoder {
+
+        private final CharsetDecoder decoder = StandardCharsets.UTF_8.newDecoder();
+
+        {
+            decoder.onMalformedInput(CodingErrorAction.REPORT);
+            decoder.onUnmappableCharacter(CodingErrorAction.REPORT);
+        }
+
+        private ByteBuffer leftovers = EMPTY_BYTE_BUFFER;
+
+        WSShared<CharBuffer> decode(WSShared<ByteBuffer> in, boolean endOfInput)
+                throws CharacterCodingException {
+            ByteBuffer b;
+            int rem = leftovers.remaining();
+            if (rem != 0) {
+                // TODO: We won't need this wasteful allocation & copying when
+                // JDK-8155222 has been resolved
+                b = ByteBuffer.allocate(rem + in.remaining());
+                b.put(leftovers).put(in.buffer()).flip();
+            } else {
+                b = in.buffer();
+            }
+            CharBuffer out = CharBuffer.allocate(b.remaining());
+            CoderResult r = decoder.decode(b, out, endOfInput);
+            if (r.isError()) {
+                r.throwException();
+            }
+            if (b.hasRemaining()) {
+                leftovers = ByteBuffer.allocate(b.remaining()).put(b).flip();
+            } else {
+                leftovers = EMPTY_BYTE_BUFFER;
+            }
+            // Since it's UTF-8, the assumption is leftovers.remaining() < 4
+            // (i.e. small). Otherwise a shared buffer should be used
+            if (!(leftovers.remaining() < 4)) {
+                logger.log(WARNING,
+                        "The size of decoding leftovers is greater than expected: {0}",
+                        leftovers.remaining());
+            }
+            b.position(b.limit()); // As if we always read to the end
+            in.dispose();
+            // Decoder promises that in the case of endOfInput == true:
+            // "...any remaining undecoded input will be treated as being
+            // malformed"
+            assert !(endOfInput && leftovers.hasRemaining()) : endOfInput + ", " + leftovers;
+            if (endOfInput) {
+                r = decoder.flush(out);
+                decoder.reset();
+                if (r.isOverflow()) {
+                    // FIXME: for now I know flush() does nothing. But the
+                    // implementation of UTF8 decoder might change. And if now
+                    // flush() is a no-op, it is not guaranteed to remain so in
+                    // the future
+                    throw new InternalError("Not yet implemented");
+                }
+            }
+            out.flip();
+            return WSShared.wrap(out);
+        }
+    }
+}