| /* |
| * |
| * 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.server.protocol.v1_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); |
| } |
| } |