Serialization

Since CacheManager version 0.7, serialization of cache values can be configured and extended.

In general, serialization is only used by CacheManager, if the cache handle cannot store the object reference in memory. This is the case for any distributed cache, because in those scenarios, the cache value has to be stored remotely/out of process. For cache handles like the DictionaryCacheHandle or SystemRuntimeCaching, serialization is not needed and doesn't have to be configured at all.

Implementation Detailslink

The ICacheSerializer interface defines the contract for cache item and cache value serialization. Those methods are different, because some cache handles might only have to serialize the cache value itself and not the CacheItem<T>. The redis cache handle, for example, does serialize the value only, and all the meta data is stored within the redis hash.

The object Deserialize(byte[] data, Type target); method takes the target type, which will be the actually Type of the value stored. This is needed in cases where a) the TCacheValue of the cache is e.g. object or b) is an interface or c) maybe the actual Type is a derived class of TCacheValue. In all those scenarios, the actual Type might defer from TCacheValue and would otherwise lead to issues. The actual Type is stored within the CacheItem<TCacheValue> and CacheManager will pass that value to the deserialization method.

Default and Fall-Backlink

The CacheManager.Core package contains only one implementation based on the .NET binary serialization. If nothing else is specified, this one will be used.

Because binary serialization is not available in the .NET core clr, it cannot be used by projects targeting cross platform frameworks. In this case, you have to install e.g. the JSON serializer.

JSON Serializationlink

One alternative to the default serialization uses Json.NET. To use the JSON serializer instead of the binary serializer, you have to install the CacheManager.Serialization.Json Nuget package and configure CacheManager to use it.

Configurationlink

The configuration stores only the Type of the serializer which should be used. The moment a CacheManager instance gets created, this type will be resolved.

By Codelink

As usual, there are extension methods to configure the serializer type. A general one, which allows you to implement and configure your own serializer, and specific ones for the implementations.

// add a custom serializer
var config = new ConfigurationBuilder()
	.WithSerializer(typeof(MySerializer))

// use JSON serializer
var config = new ConfigurationBuilder()
	.WithJsonSerializer();

Via JSON configurationlink

If you use the CacheManager.Microsoft.Extensions.Configuration, you can configure it, too. The following example shows the serializer property only, with all the options:

{
	"$schema" : "http://cachemanager.michaco.net/schemas/cachemanager.json",
	"cacheManagers" : [{
			"serializer" : {
				"knownType" : "Json | Binary",
				"type" : "MyType"
			}
		}
	]
}

Via App-/Web.configlink

The XML configuration schema can also be used to configure the serializer. Therefore, the cache node under managers has an optional property serializerType, which must be defined as assembly qualified type.