SortedVectorsExample.cs

/*
 * Copyright 2020 James Courtney
 *
 * 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.
 */

using FlatSharp;
using FlatSharp.Attributes;
using System;
using System.Collections.Generic;
using System.Diagnostics;

namespace Samples.SortedVectors
{
    /// <summary>
    /// This example shows how to use FlatSharp to generated sorted vectors. this can be handy in situations where you expect to read and look up data
    /// much more than you expect to write it, since sorting happens each time you serialize. Only Vectors of Tables are eligible to be sorted, and those tables must
    /// have a primitive type key specified. This example uses C# to define everything, but there is an equivalent example in this directory using an FBS file.
    /// </summary>
    public class SortedVectorsExample
    {
        public static void Run()
        {
            UserList userList = new UserList
            {
                Users = new[]
                {
                    new User { FirstName = "Jason", LastName = "Bourne", SSN = "234-56-7890"},
                    new User { FirstName = "James", LastName = "Bond", SSN = "123-45-6789"},
                    new User { FirstName = "Austin", LastName = "Powers", SSN = "International Man of Mystery" }
                }
            };

            byte[] data = new byte[1024];
            int bytesWritten = FlatBufferSerializer.Default.Serialize(userList, data);
            UserList parsedList = FlatBufferSerializer.Default.Parse<UserList>(data);

            foreach (var u in parsedList.Users)
            {
                Console.WriteLine($"{u.FirstName} {u.LastName} {u.SSN}");
            }

            // Similarly, we can use binary search. You're encouraged to use the FlatSharp binary search method
            // since FlatBuffers uses a different string sorting algorithm than .NET does by default. If you must use
            // your own binary search, use FlatBufferStringComparer.
            User user = parsedList.Users.BinarySearchByFlatBufferKey("234-56-7890");
            Debug.Assert(user.LastName == "Bourne");
        }

        [FlatBufferTable]
        public class UserList
        {
            [FlatBufferItem(0, SortedVector = true)]
            public virtual IList<User> Users { get; set; }
        }

        [FlatBufferTable]
        public class User
        {
            [FlatBufferItem(0)]
            public virtual string FirstName { get; set; }

            [FlatBufferItem(1)]
            public virtual string LastName { get; set; }

            [FlatBufferItem(2, Key = true)]
            public virtual string SSN { get; set; }
        }
    }
}