deserialize()

in gremlin-javascript/src/main/javascript/gremlin-javascript/lib/structure/io/binary/internals/VertexPropertySerializer.js [74:173]

• 82 lines of code
• 17 McCabe index (conditional complexity)

  deserialize(buffer, fullyQualifiedFormat = true) {
    let len = 0;
    let cursor = buffer;

    try {
      if (buffer === undefined || buffer === null || !(buffer instanceof Buffer)) {
        throw new Error('buffer is missing');
      }
      if (buffer.length < 1) {
        throw new Error('buffer is empty');
      }

      if (fullyQualifiedFormat) {
        const type_code = cursor.readUInt8();
        len++;
        if (type_code !== this.ioc.DataType.VERTEXPROPERTY) {
          throw new Error('unexpected {type_code}');
        }
        cursor = cursor.slice(1);

        if (cursor.length < 1) {
          throw new Error('{value_flag} is missing');
        }
        const value_flag = cursor.readUInt8();
        len++;
        if (value_flag === 1) {
          return { v: null, len };
        }
        if (value_flag !== 0) {
          throw new Error('unexpected {value_flag}');
        }
        cursor = cursor.slice(1);
      }

      // {id} is a fully qualified typed value composed of {type_code}{type_info}{value_flag}{value}
      let id, id_len;
      try {
        ({ v: id, len: id_len } = this.ioc.anySerializer.deserialize(cursor));
        len += id_len;
      } catch (err) {
        err.message = '{id}: ' + err.message;
        throw err;
      }
      cursor = cursor.slice(id_len);

      // {label} is a String value
      let label, label_len;
      try {
        ({ v: label, len: label_len } = this.ioc.stringSerializer.deserialize(cursor, false));
        len += label_len;
      } catch (err) {
        err.message = '{label}: ' + err.message;
        throw err;
      }
      cursor = cursor.slice(label_len);

      // {value} is a fully qualified typed value composed of {type_code}{type_info}{value_flag}{value}
      let value, value_len;
      try {
        ({ v: value, len: value_len } = this.ioc.anySerializer.deserialize(cursor));
        len += value_len;
      } catch (err) {
        err.message = '{value}: ' + err.message;
        throw err;
      }
      cursor = cursor.slice(value_len);

      // {parent} is a fully qualified typed value composed of {type_code}{type_info}{value_flag}{value} which contains the parent Vertex.
      // Note that as TinkerPop currently send "references" only, this value will always be null.
      let parent_len;
      try {
        ({ len: parent_len } = this.ioc.unspecifiedNullSerializer.deserialize(cursor));
        len += parent_len;
      } catch (err) {
        err.message = '{parent}: ' + err.message;
        throw err;
      }
      // TODO: should we verify that parent is null?
      cursor = cursor.slice(parent_len);

      // {properties} is a fully qualified typed value composed of {type_code}{type_info}{value_flag}{value} which contains properties. Note that as TinkerPop currently send "references" only, this value will always be null.
      let properties, properties_len;
      try {
        ({ v: properties, len: properties_len } = this.ioc.anySerializer.deserialize(cursor));
        len += properties_len;
      } catch (err) {
        err.message = '{properties}: ' + err.message;
        throw err;
      }
      // TODO: should we verify that properties is null?
      cursor = cursor.slice(properties_len);

      // null properties are deserialized into empty lists
      const vp_props = properties ? properties : [];
      const v = new VertexProperty(id, label, value, vp_props);
      return { v, len };
    } catch (err) {
      throw this.ioc.utils.des_error({ serializer: this, args: arguments, cursor, err });
    }
  }