CODEWITHSUNDEEP
c#redisstackexchange.redis
Shane
Shane

Reputation: 4315

How to add Generic List to Redis via StackExchange.Redis?

For example, if I have a model called Customer

public class Customer
    {
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public string Address1 { get; set; }
        public string City { get; set; }
        public string State { get; set; }
    }

Example:

var customers = new List<Customer>();

How would I added a List of Customer? How would I do this?

 using (var redis = ConnectionMultiplexer.Connect(this.redisServer))
            {
                var db = redis.GetDatabase();

                db.SetAdd(key, ?????);
}

I think SetAdd is the right method, but I can't see how to get my generic list of Customer (i.e. List into the format of RedisValue.

Upvotes: 16

Views: 26048

Answers (4)

Andrey Gubal
Andrey Gubal

Reputation: 3479

May be it helps. I also faced the same question at the beginning of my diving into StackExchange.Redis. In my project I created 2 extension methods, which help me serialize/deserialize complex type for Redis database. You may extend them to your needs.

Methods:

    public static class RedisUtils
        {
//Serialize in Redis format:
            public static HashEntry[] ToHashEntries(this object obj)
            {
                PropertyInfo[] properties = obj.GetType().GetProperties();
                return properties.Select(property => new HashEntry(property.Name, property.GetValue(obj).ToString())).ToArray();
            }
    //Deserialize from Redis format
            public static T ConvertFromRedis<T>(this HashEntry[] hashEntries)
            {
                PropertyInfo[] properties = typeof(T).GetProperties();
                var obj = Activator.CreateInstance(typeof(T));
                foreach (var property in properties)
                {
                    HashEntry entry = hashEntries.FirstOrDefault(g => g.Name.ToString().Equals(property.Name));
                    if (entry.Equals(new HashEntry())) continue;
                    property.SetValue(obj, Convert.ChangeType(entry.Value.ToString(), property.PropertyType));
                }
                return (T)obj;
            }
        }

Usage:

var customer = new Customer
{
//Initialization
};

Db.HashSet("customer", customer.ToHashEntries());
Customer result = Db.HashGetAll("customer").ConvertFromRedis<Customer>();

Assert.AreEqual(customer.FirstName, result.FirstName);
Assert.AreEqual(customer.LastName, result.LastName);
Assert.AreEqual(customer.Address1, result.Address1);

Upvotes: 16

Andrey Fedorov
Andrey Fedorov

Reputation: 59

This is an option

public static class StackExchangeRedisExtensions
{

    public static T Get<T>(string key)
    {
        var connect = AzureredisDb.Cache;
        var r = AzureredisDb.Cache.StringGet(key);
        return Deserialize<T>(r);
    }

    public static List<T> GetList<T>(string key)
    {                       
        return (List<T>)Get(key);
    }

    public static void SetList<T>(string key, List<T> list)
    {
        Set(key, list);
    }

    public static object Get(string key)
    {
        return Deserialize<object>(AzureredisDb.Cache.StringGet(key));
    }

    public static void Set(string key, object value)
    {
        AzureredisDb.Cache.StringSet(key, Serialize(value));
    }

    static byte[] Serialize(object o)
    {
        if (o == null)
        {
            return null;
        }

        BinaryFormatter binaryFormatter = new BinaryFormatter();
        using (MemoryStream memoryStream = new MemoryStream())
        {
            binaryFormatter.Serialize(memoryStream, o);
            byte[] objectDataAsStream = memoryStream.ToArray();
            return objectDataAsStream;
        }
    }

    static T Deserialize<T>(byte[] stream)
    {
        if (stream == null)
        {
            return default(T);
        }

        BinaryFormatter binaryFormatter = new BinaryFormatter();
        using (MemoryStream memoryStream = new MemoryStream(stream))
        {
            T result = (T)binaryFormatter.Deserialize(memoryStream);
            return result;
        }
    }
}

AzureredisDb.Cache is СonnectionMultiplexer.Connect and GetDatabase();

Upvotes: 4

von v.
von v.

Reputation: 17118

An improvement to Andrey Gubal's answer, to handle nullable properties or null values:

public static class RedisUtils
{
    //Serialize in Redis format:
    public static HashEntry[] ToHashEntries(this object obj)
    {
        PropertyInfo[] properties = obj.GetType().GetProperties();
        return properties
            .Where(x=> x.GetValue(obj)!=null) // <-- PREVENT NullReferenceException
            .Select(property => new HashEntry(property.Name, property.GetValue(obj)
            .ToString())).ToArray();
    }

    //Deserialize from Redis format
    public static T ConvertFromRedis<T>(this HashEntry[] hashEntries)
    {
        PropertyInfo[] properties = typeof(T).GetProperties();
        var obj = Activator.CreateInstance(typeof(T));
        foreach (var property in properties)
        {
            HashEntry entry = hashEntries.FirstOrDefault(g => g.Name.ToString().Equals(property.Name));
            if (entry.Equals(new HashEntry())) continue;
            property.SetValue(obj, Convert.ChangeType(entry.Value.ToString(), property.PropertyType));
        }
        return (T)obj;
    }
}

Upvotes: 8

Marc Gravell
Marc Gravell

Reputation: 1063944

StackExchange.Redis is a raw client - it talks in Redis terms only. It does not attempt to be an ORM of any kind. It will, however, store any string or byte[] that you care to throw at it - which means you should have your choice of serializers. JSON would be a reasonable default (Jil is awesome), although we tend to use protocol-buffers ourselves (via protobuf-net).

It you intend to use list semantics, I strongly recommend starting with the List* commands - sets have different semantics to lists - sets are unordered and only store unique values; lists preserve order and allow duplicates.

Upvotes: 16

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