text: /*
   * Copyright 2019-present HiveMQ GmbH
   *
   * 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.hivemq.mqtt.message.mqtt5;
  
  import com.google.common.base.Charsets;
  import com.google.common.collect.ImmutableList;
  import com.hivemq.extension.sdk.api.annotations.NotNull;
  import com.hivemq.persistence.local.xodus.XodusUtils;
  import com.hivemq.util.Bytes;
  
  /**
   * @author Lukas Brandl
   */
  public class PropertiesSerializationUtil {
  
      public static int encodedSize(final Mqtt5UserProperties properties) {
          int size = Integer.BYTES; // List size integer
          for (final MqttUserProperty property : properties.asList()) {
              size += XodusUtils.shortLengthStringSize(property.getName());
              size += XodusUtils.shortLengthStringSize(property.getValue());
          }
          return size;
      }
  
      public static int write(@NotNull final Mqtt5UserProperties properties, @NotNull final byte[] bytes, int offset) {
          Bytes.copyIntToByteArray(properties.asList().size(), bytes, offset);
          offset += Integer.BYTES;
          for (final MqttUserProperty property : properties.asList()) {
              offset = XodusUtils.serializeShortLengthString(property.getName(), bytes, offset);
              offset = XodusUtils.serializeShortLengthString(property.getValue(), bytes, offset);
          }
          return offset;
      }
  
      @NotNull
      public static Mqtt5UserProperties read(@NotNull final byte[] bytes, int offset) {
          final int size = Bytes.readInt(bytes, offset);
          offset += Integer.BYTES;
          final ImmutableList.Builder<MqttUserProperty> builder = ImmutableList.builderWithExpectedSize(size);
  
          for (int i = 0; i < size; i++) {
              final int nameLength = Bytes.readUnsignedShort(bytes, offset);
              offset += Short.BYTES;
              final String name = new String(bytes, offset, nameLength, Charsets.UTF_8);
              offset += nameLength;
  
              final int valueLength = Bytes.readUnsignedShort(bytes, offset);
              offset += Short.BYTES;
              final String value = new String(bytes, offset, valueLength, Charsets.UTF_8);
              offset += valueLength;
  
              builder.add(new MqttUserProperty(name, value));
          }
          return Mqtt5UserProperties.of(builder.build());
      }
  }
  