1 files changed, 146 insertions, 0 deletions
diff --git a/java/amqp-1-0-common/src/main/java/org/apache/qpid/amqp_1_0/codec/StringWriter.java b/java/amqp-1-0-common/src/main/java/org/apache/qpid/amqp_1_0/codec/StringWriter.java
new file mode 100644
index 0000000000..39f759e54d
--- /dev/null
+++ b/java/amqp-1-0-common/src/main/java/org/apache/qpid/amqp_1_0/codec/StringWriter.java
@@ -0,0 +1,146 @@
+/*
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ *
+ */
+
+package org.apache.qpid.amqp_1_0.codec;
+
+import java.nio.ByteBuffer;
+import java.nio.charset.Charset;
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+public class StringWriter extends SimpleVariableWidthWriter<String>
+{
+    private static final Charset ENCODING_CHARSET;
+    private static final byte ONE_BYTE_CODE;
+    private static final byte FOUR_BYTE_CODE;
+    static
+    {
+        Charset defaultCharset = Charset.defaultCharset();
+        if(defaultCharset.name().equals("UTF-16") || defaultCharset.name().equals("UTF-16BE"))
+        {
+            ENCODING_CHARSET = defaultCharset;
+            ONE_BYTE_CODE = (byte) 0xa2;
+            FOUR_BYTE_CODE = (byte) 0xb2;
+        }
+        else
+        {
+            ENCODING_CHARSET = Charset.forName("UTF-8");
+            ONE_BYTE_CODE = (byte) 0xa1;
+            FOUR_BYTE_CODE = (byte) 0xb1;
+        }
+    }
+
+    private static final class ValueCache<K,V> extends LinkedHashMap<K,V>
+    {
+        private final int _cacheSize;
+
+        public ValueCache(int cacheSize)
+        {
+            _cacheSize = cacheSize;
+        }
+
+        @Override
+        protected boolean removeEldestEntry(Map.Entry<K, V> eldest)
+        {
+            return size() > _cacheSize;
+        }
+
+        public boolean isFull()
+        {
+            return size() == _cacheSize;
+        }
+    }
+
+    private final ValueCache<String, byte[]> _cachedEncodings = new ValueCache<String, byte[]>(10);
+
+
+    @Override
+    protected byte getFourOctetEncodingCode()
+    {
+        return FOUR_BYTE_CODE;
+    }
+
+    @Override
+    protected byte getSingleOctetEncodingCode()
+    {
+        return ONE_BYTE_CODE;
+    }
+
+    @Override
+    protected byte[] getByteArray(String value)
+    {
+
+        byte[] encoding;
+        boolean isFull = _cachedEncodings.isFull();
+        if(isFull)
+        {
+            encoding = _cachedEncodings.remove(value);
+        }
+        else
+        {
+            encoding = _cachedEncodings.get(value);
+        }
+
+
+        if(encoding == null)
+        {
+            ByteBuffer buf = ENCODING_CHARSET.encode(value);
+            if(buf.hasArray() && buf.arrayOffset() == 0 && buf.limit()==buf.capacity())
+            {
+                encoding = buf.array();
+            }
+            else
+            {
+                byte[] bufArray = new byte[buf.limit()-buf.position()];
+                buf.get(bufArray);
+                encoding = bufArray;
+            }
+            _cachedEncodings.put(value,encoding);
+
+        }
+        else if(isFull)
+        {
+            _cachedEncodings.put(value,encoding);
+        }
+
+        return encoding;
+    }
+
+    @Override
+    protected int getOffset()
+    {
+        return 0;
+    }
+
+    private static Factory<String> FACTORY = new Factory<String>()
+                                            {
+
+                                                public ValueWriter<String> newInstance(Registry registry)
+                                                {
+                                                    return new StringWriter();
+                                                }
+                                            };
+
+    public static void register(ValueWriter.Registry registry)
+    {
+        registry.register(String.class, FACTORY);
+    }
+}
+\ No newline at end of file