com.datastax.dse.driver.internal.core.graph.binary.AbstractDynamicGraphBinaryCustomSerializer Maven / Gradle / Ivy
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* 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 com.datastax.dse.driver.internal.core.graph.binary;
import java.io.IOException;
import org.apache.tinkerpop.gremlin.structure.io.Buffer;
import org.apache.tinkerpop.gremlin.structure.io.binary.GraphBinaryReader;
import org.apache.tinkerpop.gremlin.structure.io.binary.GraphBinaryWriter;
/**
* Convenience class for dynamic types implemented as Custom types in GraphBinary. This class will
* take care of handling {value_length} automatically for implementing classes. {@link
* #writeDynamicCustomValue(Object, Buffer, GraphBinaryWriter)} and {@link
* #readDynamicCustomValue(Buffer, GraphBinaryReader)} only need to handle writing the internal
* components of the custom type.
*
* @param the java type the implementing classes will encode and decode.
*/
public abstract class AbstractDynamicGraphBinaryCustomSerializer
extends AbstractSimpleGraphBinaryCustomSerializer {
protected abstract void writeDynamicCustomValue(T value, Buffer buffer, GraphBinaryWriter context)
throws IOException;
protected abstract T readDynamicCustomValue(Buffer buffer, GraphBinaryReader context)
throws IOException;
@Override
protected T readCustomValue(int valueLength, Buffer buffer, GraphBinaryReader context)
throws IOException {
int initialIndex = buffer.readerIndex();
// read actual custom value
T read = readDynamicCustomValue(buffer, context);
// make sure we didn't read more than what was input as {value_length}
checkValueSize(valueLength, (buffer.readerIndex() - initialIndex));
return read;
}
@Override
protected void writeCustomValue(T value, Buffer buffer, GraphBinaryWriter context)
throws IOException {
// Store the current writer index
final int valueLengthIndex = buffer.writerIndex();
// Write a dummy length that will be overwritten at the end of this method
buffer.writeInt(0);
// Custom type's writer logic
writeDynamicCustomValue(value, buffer, context);
// value_length = diff written - 4 bytes for the dummy length
final int valueLength = buffer.writerIndex() - valueLengthIndex - GraphBinaryUtils.sizeOfInt();
// Go back, write the {value_length} and then reset back the writer index
buffer.markWriterIndex().writerIndex(valueLengthIndex).writeInt(valueLength).resetWriterIndex();
}
}