Importing upstream Jetty jetty-9.2.1.v20140609

[gigi.git] / lib / jetty / org / eclipse / jetty / util / Utf8LineParser.java

diff --git a/lib/jetty/org/eclipse/jetty/util/Utf8LineParser.java b/lib/jetty/org/eclipse/jetty/util/Utf8LineParser.java
new file mode 100644 (file)
index 0000000..b54cf41
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+++ b/lib/jetty/org/eclipse/jetty/util/Utf8LineParser.java
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+//
+//  ========================================================================
+//  Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd.
+//  ------------------------------------------------------------------------
+//  All rights reserved. This program and the accompanying materials
+//  are made available under the terms of the Eclipse Public License v1.0
+//  and Apache License v2.0 which accompanies this distribution.
+//
+//      The Eclipse Public License is available at
+//      http://www.eclipse.org/legal/epl-v10.html
+//
+//      The Apache License v2.0 is available at
+//      http://www.opensource.org/licenses/apache2.0.php
+//
+//  You may elect to redistribute this code under either of these licenses.
+//  ========================================================================
+//
+
+package org.eclipse.jetty.util;
+
+import java.nio.ByteBuffer;
+
+import org.eclipse.jetty.util.Utf8Appendable.NotUtf8Exception;
+
+/**
+ * Stateful parser for lines of UTF8 formatted text, looking for <code>"\n"</code> as a line termination character.
+ * <p>
+ * For use with new IO framework that is based on ByteBuffer parsing.
+ */
+public class Utf8LineParser
+{
+    private enum State
+    {
+        START,
+        PARSE,
+        END;
+    }
+
+    private State state;
+    private Utf8StringBuilder utf;
+
+    public Utf8LineParser()
+    {
+        this.state = State.START;
+    }
+
+    /**
+     * Parse a ByteBuffer (could be a partial buffer), and return once a complete line of UTF8 parsed text has been reached.
+     *
+     * @param buf
+     *            the buffer to parse (could be an incomplete buffer)
+     * @return the line of UTF8 parsed text, or null if no line end termination has been reached within the {@link ByteBuffer#remaining() remaining} bytes of
+     *         the provided ByteBuffer. (In the case of a null, a subsequent ByteBuffer with a line end termination should be provided)
+     * @throws NotUtf8Exception
+     *             if the input buffer has bytes that do not conform to UTF8 validation (validation performed by {@link Utf8StringBuilder}
+     */
+    public String parse(ByteBuffer buf)
+    {
+        byte b;
+        while (buf.remaining() > 0)
+        {
+            b = buf.get();
+            if (parseByte(b))
+            {
+                state = State.START;
+                return utf.toString();
+            }
+        }
+        // have not reached end of line (yet)
+        return null;
+    }
+
+    private boolean parseByte(byte b)
+    {
+        switch (state)
+        {
+            case START:
+                utf = new Utf8StringBuilder();
+                state = State.PARSE;
+                return parseByte(b);
+            case PARSE:
+                // not waiting on more UTF sequence parts.
+                if (utf.isUtf8SequenceComplete() && ((b == '\r') || (b == '\n')))
+                {
+                    state = State.END;
+                    return parseByte(b);
+                }
+                utf.append(b);
+                break;
+            case END:
+                if (b == '\n')
+                {
+                    // we've reached the end
+                    state = State.START;
+                    return true;
+                }
+                break;
+        }
+        return false;
+    }
+}