JsonVBucketConfig.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Security.Cryptography;
using System.Net;
using System.Web.Script.Serialization;
using Enyim.Caching.Configuration;

namespace Enyim.Caching.Configuration
{
	/// <summary>
	/// Parses a json formatted vbucket config.
	/// </summary>
	public class JsonVBucketConfig : IVBucketConfiguration
	{
		private Func<HashAlgorithm> factory;
		private IPEndPoint[] servers;
		private VBucket[] buckets;

		public JsonVBucketConfig(string json)
		{
			var config = new JavaScriptSerializer().Deserialize<_JsonConfig>(json);

			if (config.numReplicas < 0)
				throw new ArgumentException("Invalid numReplicas: " + config.numReplicas, "json");

			if (hashFactory.TryGetValue(config.hashAlgorithm, out this.factory))
				throw new ArgumentException("Unknown hash algorithm: " + config.hashAlgorithm, "json");

			this.servers = config.serverList.Select(endpoint => ConfigurationHelper.ResolveToEndPoint(endpoint)).ToArray();
			this.buckets = config.vBucketMap.Select((bucket, index) =>
							{
								if (bucket == null || bucket.Length != config.numReplicas + 1)
									throw new ArgumentException("Invalid bucket definition at index " + index, "json");

								return new VBucket(bucket[0], bucket.Skip(1).Take(config.numReplicas)/* .Where(v => v > -1) */.ToArray());
							}).ToArray();
		}

		#region [ _JsonConfig                  ]

		private class _JsonConfig
		{
			public string hashAlgorithm;
			public int numReplicas;
			public string[] serverList;
			public int[][] vBucketMap;
		}

		#endregion
		#region [ IVBucketConfiguration        ]

		HashAlgorithm IVBucketConfiguration.CreateHashAlgorithm()
		{
			return factory();
		}

		IList<IPEndPoint> IVBucketConfiguration.Servers
		{
			get { return this.servers; }
		}

		IList<VBucket> IVBucketConfiguration.Buckets
		{
			get { return this.buckets; }
		}

		#endregion
		#region [ hashFactory                  ]

		private static readonly Dictionary<string, Func<HashAlgorithm>> hashFactory = new Dictionary<string, Func<HashAlgorithm>>(StringComparer.OrdinalIgnoreCase)
		{
			{ String.Empty, () => new HashkitOneAtATime() },
			{ "default", () => new HashkitOneAtATime() },
			{ "crc", () => new HashkitCrc32() },
			{ "fnv1_32", () => new Enyim.FNV1() },
			{ "fnv1_64", () => new Enyim.FNV1a() },
			{ "fnv1a_32", () => new Enyim.FNV64() },
			{ "fnv1a_64", () => new Enyim.FNV64a() },
			{ "murmur", () => new HashkitMurmur() }
		};

		#endregion
	}
}