| /* |
| * 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.datasketches; |
| |
| import java.nio.charset.StandardCharsets; |
| |
| import org.apache.datasketches.memory.Memory; |
| import org.apache.datasketches.memory.WritableMemory; |
| |
| /** |
| * Methods of serializing and deserializing arrays of String. |
| * This class serializes strings in UTF-8 format, which is more compact compared to |
| * {@link ArrayOfUtf16StringsSerDe}. In an extreme case when all strings are in ASCII, |
| * this method is 2 times more compact, but it takes more time to encode and decode |
| * by a factor of 1.5 to 2. |
| * |
| * @author Alexander Saydakov |
| */ |
| public class ArrayOfStringsSerDe extends ArrayOfItemsSerDe<String> { |
| |
| @Override |
| public byte[] serializeToByteArray(final String[] items) { |
| int length = 0; |
| final byte[][] itemsBytes = new byte[items.length][]; |
| for (int i = 0; i < items.length; i++) { |
| itemsBytes[i] = items[i].getBytes(StandardCharsets.UTF_8); |
| length += itemsBytes[i].length + Integer.BYTES; |
| } |
| final byte[] bytes = new byte[length]; |
| final WritableMemory mem = WritableMemory.writableWrap(bytes); |
| long offsetBytes = 0; |
| for (int i = 0; i < items.length; i++) { |
| mem.putInt(offsetBytes, itemsBytes[i].length); |
| offsetBytes += Integer.BYTES; |
| mem.putByteArray(offsetBytes, itemsBytes[i], 0, itemsBytes[i].length); |
| offsetBytes += itemsBytes[i].length; |
| } |
| return bytes; |
| } |
| |
| @Override |
| public String[] deserializeFromMemory(final Memory mem, final int numItems) { |
| final String[] array = new String[numItems]; |
| long offsetBytes = 0; |
| for (int i = 0; i < numItems; i++) { |
| Util.checkBounds(offsetBytes, Integer.BYTES, mem.getCapacity()); |
| final int strLength = mem.getInt(offsetBytes); |
| offsetBytes += Integer.BYTES; |
| final byte[] bytes = new byte[strLength]; |
| Util.checkBounds(offsetBytes, strLength, mem.getCapacity()); |
| mem.getByteArray(offsetBytes, bytes, 0, strLength); |
| offsetBytes += strLength; |
| array[i] = new String(bytes, StandardCharsets.UTF_8); |
| } |
| return array; |
| } |
| |
| } |