/*
* Copyright 2013 Rackspace
*
* Licensed 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 com.rackspacecloud.blueflood.io.serializers;
import com.google.protobuf.CodedInputStream;
import com.google.protobuf.CodedOutputStream;
import com.netflix.astyanax.serializers.AbstractSerializer;
import java.io.IOException;
import java.nio.ByteBuffer;
public class StringMetadataSerializer extends AbstractSerializer<String> {
private static final StringMetadataSerializer INSTANCE = new StringMetadataSerializer();
private static final byte STRING = 4; // History: this used to support multiple types.
// However, we never actually used that functionality, and it duplicated a lot of logic
// as is contained in NumericSerializer, without actually being in a compatible [de]serialization format.
// TODO: re-add non-str functionality in a way that does not involve as much code duplication and format incompatibility
public static StringMetadataSerializer get() {
return INSTANCE;
}
@Override
public ByteBuffer toByteBuffer(String o) {
try {
byte[] buf = new byte[computeBufLength(o)];
CodedOutputStream out = CodedOutputStream.newInstance(buf);
writeToOutputStream(o, out);
return ByteBuffer.wrap(buf);
} catch (IOException e) {
throw new RuntimeException("Serialization problems", e);
}
}
// writes object to CodedOutputStream.
private static void writeToOutputStream(Object obj, CodedOutputStream out) throws IOException {
out.writeRawByte(STRING);
out.writeStringNoTag((String)obj);
}
// figure out how much space it will take to encode an object. this makes it so that we only allocate one buffer
// during encode.
private static int computeBufLength(String obj) throws IOException {
return 1 + CodedOutputStream.computeStringSizeNoTag(obj); // 1 for type
}
@Override
public String fromByteBuffer(ByteBuffer byteBuffer) {
CodedInputStream is = CodedInputStream.newInstance(byteBuffer.array());
try {
byte type = is.readRawByte();
if (type == STRING) {
return is.readString();
} else {
throw new IOException("Unexpected first byte. Expected '4' (string). Got '" + type + "'.");
}
} catch (IOException e) {
throw new RuntimeException("IOException during deserialization", e);
}
}
}