代码改变世界

C#开源磁盘/内存缓存引擎

2013-07-04 14:33 by 灵感之源, ... 阅读, ... 评论, 收藏, 编辑

前言

昨天写了个 《基于STSdb和fastJson的磁盘/内存缓存》,大家可以先看看。下午用到业务系统时候,觉得可以改进一下,昨晚想了一个晚上,刚才重新实现一下。

更新

1. 增加了对批量处理的支持,写操作速度提升5倍,读操作提升100倍

2. 增加了一个存储provider,可以选择不用STSdb做存储,而用物理文件/Dictionary。

3. 增加了空间回收

4. 增加了对并发的支持

需求

业务系统用的是数据库,数据量大,部分只读或相对稳定业务查询复杂,每次页面加载都要花耗不少时间(不讨论异步),觉得可以做一下高速缓存,譬如用nosql那种key/value快速存取结果

目的

提供一个简单易用的解决缓存方案,可以根据数据的大小缓存到内存或者磁盘。

实现

存取

方法1. 基于STSdb,提供高效的Key/Value存取,支持磁盘/内存,对Key无限制

方法2. 基于直接物理文件/Dictionary。Key必须是基本类型,譬如int/long/uint/ulong/DateTime/string等。

代码

代码比较简单,花了2个小时写的,很多情况没考虑,譬如磁盘空间/内存不足,自动回收过期缓存等,这些留给大家做家庭作业吧。另外,为了发布方便,STSdb和fastJson的代码都合并到一个项目里。

BaseCahce.cs

这是一个抽象基类,提供存取接口。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Com.SuperCache.Engine
{
    public abstract class BaseCache
    {
        protected internal const string KeyExpiration = "Expiration";

        public abstract void Add<K>(string Category, K Key, object Data);
        public abstract void Add<K, V>(string Category, IEnumerable<KeyValuePair<K, V>> Items, DateTime? ExpirationDate);
        public abstract void Add<K>(string Category, K Key, object Data, DateTime? ExpirationDate);
        public abstract List<KeyValuePair<K, V>> Get<K, V>(string Category, IEnumerable<K> Keys);
        public abstract V Get<K, V>(string Category, K Key);
        public abstract void Recycle<K>( string Category, long Count);
    }
}

  

  

CahceEngine.cs

主要调用缓存引擎

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using STSdb4.Database;
using fastJSON;
using System.IO;

namespace Com.SuperCache.Engine
{
    public enum CacheProviders
    {
        Default = 1,
        Raw = 2
    }

    public enum RecycleAlgorithms
    {
        None = 0,
        //LRU = 1,
        MRU = 2
    }

    public enum RecycleModes
    {
        None = 0,
        Passive = 1,
        Active = 2
    }

    public class CacheEngine
    {
        private BaseCache cacheProvider = null;

        public CacheEngine(string DataPath)
            : this(CacheProviders.Default, DataPath, RecycleAlgorithms.None, 0, 0, RecycleModes.None)
        {
        }

        public CacheEngine(CacheProviders Provider, string DataPath, RecycleAlgorithms RecycleAlgorithm, int MaxCount, int Threshold, RecycleModes RecycleMode)
        {
            switch (Provider)
            {
                case CacheProviders.Default:
                    cacheProvider = new STSdbCache(DataPath, RecycleAlgorithm, MaxCount, Threshold, RecycleMode);
                    break;
                case CacheProviders.Raw:
                    cacheProvider = new RawCache(DataPath, RecycleAlgorithm, MaxCount, Threshold, RecycleMode);
                    break;
                default:
                    break;
            }
        }

        public void Add<K>(string Category, K Key, object Data)
        {
            cacheProvider.Add<K>(Category, Key, Data);
        }

        public void Add<K, V>(string Category, IEnumerable<KeyValuePair<K, V>> Items, DateTime? ExpirationDate)
        {
            cacheProvider.Add<K, V>(Category, Items, ExpirationDate);
        }

        public void Add<K>(string Category, K Key, object Data, DateTime? ExpirationDate)
        {
            cacheProvider.Add<K>(Category, Key, Data, ExpirationDate);
        }

        public List<KeyValuePair<K, V>> Get<K, V>(string Category, IEnumerable<K> Keys)
        {
            return cacheProvider.Get<K, V>(Category, Keys);
        }

        public V Get<K, V>(string Category, K Key)
        {
            return cacheProvider.Get<K, V>(Category, Key);
        }

    }
}

  

  

  

STSdbCache.cs

STSdb存储引擎  

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using STSdb4.Database;
using fastJSON;
using System.IO;

namespace Com.SuperCache.Engine
{
    public class STSdbCache : BaseCache
    {
        private const string UsageStat = "SuperCacheUsageStat";
        private string dataPath;
        private static IStorageEngine memoryInstance = null;
        private static object syncRoot = new object();
        private bool isMemory = false;
        private RecycleAlgorithms recycleAlgorithm;
        private int maxCount;
        private int threshold;
        private RecycleModes recycleMode;

        public STSdbCache(string DataPath, RecycleAlgorithms RecycleAlgorithm, int MaxCount, int Threshold, RecycleModes RecycleMode)
        {
            dataPath = DataPath;
            if (!dataPath.EndsWith(Path.DirectorySeparatorChar.ToString()))
                dataPath += Path.DirectorySeparatorChar;

            isMemory = string.IsNullOrEmpty(DataPath);

            recycleAlgorithm = RecycleAlgorithm;
            maxCount = MaxCount;
            threshold = Threshold;
            recycleMode = RecycleMode;
        }

        public override void Add<K>(string Category, K Key, object Data)
        {
            Add(Category, Key, Data, null);
        }

        private IStorageEngine Engine
        {
            get
            {
                if (isMemory)
                {
                    lock (syncRoot)
                    {
                        if (memoryInstance == null)
                            memoryInstance = STSdb.FromMemory();
                    }
                    return memoryInstance;
                }
                else
                    return STSdb.FromFile(GetFile(false), GetFile(true));
            }
        }

        private string GetExpirationTable(string Category)
        {
            return KeyExpiration + "_" + Category;
        }

        public override void Add<K, V>(string Category, IEnumerable<KeyValuePair<K, V>> Items, DateTime? ExpirationDate)
        {
            long count = 0;

            lock (syncRoot)
            {
                var engine = Engine;
                var table = engine.OpenXIndex<K, string>(Category);
                var expiration = engine.OpenXIndex<K, DateTime>(GetExpirationTable(Category));

                //track recycle
                IIndex<K, int> usage = null;
                if (recycleAlgorithm != RecycleAlgorithms.None)
                    usage = engine.OpenXIndex<K, int>(UsageStat);

                Items.ForEach(i =>
                    {
                        var key = i.Key;
                        var data = i.Value;
                        //will only serialize object other than string
                        var result = typeof(V) == typeof(string) ? data as string : JSON.Instance.ToJSON(data);
                        table[key] = result;
                        table.Flush();

                        //specify expiration
                        //default 30 mins to expire from now
                        var expirationDate = ExpirationDate == null || ExpirationDate <= DateTime.Now ? DateTime.Now.AddMinutes(30) : (DateTime)ExpirationDate;
                        expiration[key] = expirationDate;
                        expiration.Flush();

                        //track recycle
                        if (usage != null)
                        {
                            usage[key] = 0;
                            if (recycleMode == RecycleModes.Active)
                                Recycle<K>(Category, usage.Count());
                        }
                    });

                if (usage != null)
                    count = usage.Count();

                engine.Commit();

                //only dispose disk-based engine
                if (!isMemory)
                    engine.Dispose();
            }

            if (recycleMode == RecycleModes.Passive)
                Recycle<K>(Category, count);
        }

        public override void Add<K>(string Category, K Key, object Data, DateTime? ExpirationDate)
        {
            Add<K, object>(Category, new List<KeyValuePair<K, object>> { new KeyValuePair<K, object>(Key, Data) }, ExpirationDate);
        }

        private string GetFile(bool IsData)
        {
            if (!Directory.Exists(dataPath))
                Directory.CreateDirectory(dataPath);
            return dataPath + "SuperCache." + (IsData ? "dat" : "sys");
        }

        public override List<KeyValuePair<K, V>> Get<K, V>(string Category, IEnumerable<K> Keys)
        {
            var result = new List<KeyValuePair<K, V>>();
            lock (syncRoot)
            {
                var engine = Engine;
                var table = engine.OpenXIndex<K, string>(Category);
                var expiration = engine.OpenXIndex<K, DateTime>(GetExpirationTable(Category));
                var isCommitRequired = false;

                //track recycle
                IIndex<K, int> usage = null;
                if (recycleAlgorithm != RecycleAlgorithms.None)
                    usage = engine.OpenXIndex<K, int>(UsageStat);

                Keys.ForEach(key =>
                    {
                        string buffer;
                        V value;
                        if (table.TryGet(key, out buffer))
                        {
                            //will only deserialize object other than string
                            value = typeof(V) == typeof(string) ? (V)(object)buffer : JSON.Instance.ToObject<V>(buffer);
                            bool needUpdate = true;
                            DateTime expirationDate;
                            //get expiration date
                            if (expiration.TryGet(key, out expirationDate))
                            {
                                //expired
                                if (expirationDate < DateTime.Now)
                                {
                                    value = default(V);
                                    table.Delete(key);
                                    table.Flush();
                                    expiration.Delete(key);
                                    expiration.Flush();
                                    isCommitRequired = true;
                                    needUpdate = false;
                                }
                            }

                            //track recycle
                            if (usage != null && needUpdate)
                            {
                                usage[key]++;
                                isCommitRequired = true;
                            }
                        }
                        else
                            value = default(V);

                        result.Add(new KeyValuePair<K, V>(key, value));
                    });

                //only need to commit write actions
                if (isCommitRequired)
                    engine.Commit();

                //only dispose disk-based engine
                if (!isMemory)
                    engine.Dispose();
            }
            return result;
        }

        public override V Get<K, V>(string Category, K Key)
        {
            var buffer = Get<K, V>(Category, new K[] { Key });
            var result = buffer.FirstOrDefault();
            return result.Value;
        }

        public override void Recycle<K>(string Category, long Count)
        {
            if (Count < maxCount)
                return;

            switch (recycleAlgorithm)
            {
                case RecycleAlgorithms.MRU:
                    lock (syncRoot)
                    {
                        var engine = Engine;
                        var table = engine.OpenXIndex<K, string>(Category);
                        var expiration = engine.OpenXIndex<K, DateTime>(GetExpirationTable(Category));
                        var usage = engine.OpenXIndex<K, int>(UsageStat);
                        //find out expired items
                        var expired = expiration.Where(e => e.Value < DateTime.Now);
                        expired.ForEach(e =>
                            {
                                table.Delete(e.Key);
                                expiration.Delete(e.Key);
                                usage.Delete(e.Key);
                            });

                        //find out least used items
                        var leastUsed = usage.OrderByDescending(s => s.Value).Skip(maxCount - threshold);
                        leastUsed.ForEach(u =>
                        {
                            table.Delete(u.Key);
                            expiration.Delete(u.Key);
                            usage.Delete(u.Key);
                        });

                        table.Flush();
                        expiration.Flush();
                        usage.Flush();
                        engine.Commit();

                        if (!isMemory)
                            engine.Dispose();
                    }
                    break;
                default:
                    break;
            }
        }
    }
}

  

  

RawCache.cs

物理文件/Dictionary引擎

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using STSdb4.Database;
using fastJSON;
using System.IO;

namespace Com.SuperCache.Engine
{
    public class RawCache : BaseCache
    {
        private const string ExpirationFileExtension = "exp";
        private const string DataFileExtension = "dat";
        private const string statFile = "SuperCache.sta";
        private string dataPath;
        private static Dictionary<string, object> memoryData = new Dictionary<string, object>();
        private static Dictionary<string, DateTime?> memoryExpiration = new Dictionary<string, DateTime?>();
        private static object syncRoot = new object();
        private bool isMemory = false;
        private RecycleAlgorithms recycleAlgorithm;
        private int maxCount;
        private int threshold;
        private static Dictionary<string, KeyValue> usageStat = new Dictionary<string, KeyValue>();
        private Dictionary<string, KeyValuePair<DateTime, string>> expiredFiles = new Dictionary<string, KeyValuePair<DateTime, string>>();
        private RecycleModes recycleMode;

        public RawCache(string DataPath, RecycleAlgorithms RecycleAlgorithm, int MaxCount, int Threshold, RecycleModes RecycleMode)
        {
            dataPath = DataPath;
            if (!dataPath.EndsWith(Path.DirectorySeparatorChar.ToString()))
                dataPath += Path.DirectorySeparatorChar;

            isMemory = string.IsNullOrEmpty(DataPath);

            recycleAlgorithm = RecycleAlgorithm;
            maxCount = MaxCount;
            threshold = Threshold;
            recycleMode = RecycleMode;
        }

        public override void Add<K>(string Category, K Key, object Data)
        {
            Add(Category, Key, Data, null);
        }

        private string GetExpirationTable(string Category)
        {
            return KeyExpiration + "_" + Category;
        }

        public override void Add<K, V>(string Category, IEnumerable<KeyValuePair<K, V>> Items, DateTime? ExpirationDate)
        {
            long count = 0;

            lock (syncRoot)
            {
                Items.ForEach(i =>
                    {
                        var key = i.Key;
                        var data = i.Value;
                        var cacheKey = GetKey(Category, key.ToString());

                        if (isMemory)
                        {
                            memoryData[cacheKey] = data;
                            memoryExpiration[cacheKey] = ExpirationDate;

                            //recycle algo
                            switch (recycleAlgorithm)
                            {
                                case RecycleAlgorithms.MRU:
                                    usageStat[cacheKey] = new KeyValue(string.Empty, 0);
                                    if (recycleMode == RecycleModes.Active)
                                        Recycle<K>(Category, memoryData.Count);
                                    break;
                                default:
                                    break;
                            }
                        }
                        else
                        {
                            //will only serialize object other than string
                            var result = typeof(V) == typeof(string) ? data as string : JSON.Instance.ToJSON(data);
                            var fileKey = key.ToString();
                            var dataFile = GetFile(Category, fileKey, true);
                            bool exists = File.Exists(dataFile);
                            File.WriteAllText(dataFile, result);

                            //specify expiration
                            //default 30 mins to expire from now
                            var expirationDate = ExpirationDate == null || ExpirationDate <= DateTime.Now ? DateTime.Now.AddMinutes(30) : (DateTime)ExpirationDate;
                            var expirationFile = GetFile(Category, fileKey, false);
                            File.WriteAllText(expirationFile, expirationDate.ToString());

                            //recycle algo
                            if (recycleAlgorithm != RecycleAlgorithms.None)
                            {
                                var statFilePath = dataPath + statFile;
                                if (File.Exists(statFilePath))
                                {
                                    var buffer = File.ReadAllText(statFilePath);
                                    count = Convert.ToInt32(buffer);
                                }
                                if (!exists)
                                {
                                    count++;
                                    File.WriteAllText(statFilePath, count.ToString());
                                }
                                switch (recycleAlgorithm)
                                {
                                    case RecycleAlgorithms.MRU:
                                        usageStat[cacheKey] = new KeyValue(expirationFile, 0);
                                        expiredFiles[cacheKey] = new KeyValuePair<DateTime, string>(expirationDate, expirationFile);
                                        if (recycleMode == RecycleModes.Active)
                                            Recycle<K>(Category, count);
                                        break;
                                    default:
                                        break;
                                }
                            }
                        }
                    });

                if (recycleAlgorithm != RecycleAlgorithms.None && recycleMode == RecycleModes.Passive)
                {
                    if (isMemory)
                        count = memoryData.Count;
                    Recycle<K>(Category, count);
                }
            }
        }

        public override void Add<K>(string Category, K Key, object Data, DateTime? ExpirationDate)
        {
            Add<K, object>(Category, new List<KeyValuePair<K, object>> { new KeyValuePair<K, object>(Key, Data) }, ExpirationDate);
        }

        private string GetFile(string Category, string FileName, bool IsData)
        {
            var path = dataPath + Category.NormalizeFileName() + @"\";
            if (!Directory.Exists(path))
                Directory.CreateDirectory(path);
            return path + FileName.NormalizeFileName() + "." + (IsData ? "dat" : ExpirationFileExtension);
        }

        private string GetKey(string Category, string Key)
        {
            return Category + "_" + Key;
        }

        public override List<KeyValuePair<K, V>> Get<K, V>(string Category, IEnumerable<K> Keys)
        {
            var result = new List<KeyValuePair<K, V>>();
            lock (syncRoot)
            {
                Keys.ForEach(key =>
                    {
                        string buffer;
                        V value;
                        var cacheKey = GetKey(Category, key.ToString());
                        if (isMemory)
                        {
                            object memBuffer;
                            if (memoryData.TryGetValue(cacheKey, out memBuffer))
                            {
                                //track recycle
                                switch (recycleAlgorithm)
                                {
                                    case RecycleAlgorithms.MRU:
                                        usageStat[cacheKey].Value++;
                                        break;
                                    default:
                                        break;
                                }

                                value = (V)memBuffer;
                                DateTime? expirationDate;
                                if (memoryExpiration.TryGetValue(cacheKey, out expirationDate))
                                {
                                    //expired
                                    if (expirationDate != null && (DateTime)expirationDate < DateTime.Now)
                                    {
                                        value = default(V);
                                        memoryData.Remove(cacheKey);
                                        memoryExpiration.Remove(cacheKey);
                                    }
                                }
                            }
                            else
                                value = default(V);
                        }
                        else
                        {
                            var dataFilePath = GetFile(Category, key.ToString(), true);
                            if (File.Exists(dataFilePath))
                            {
                                buffer = File.ReadAllText(dataFilePath);

                                //track recycle
                                switch (recycleAlgorithm)
                                {
                                    case RecycleAlgorithms.MRU:
                                        usageStat[cacheKey].Value++;
                                        break;
                                    default:
                                        break;
                                }

                                //will only deserialize object other than string
                                value = typeof(V) == typeof(string) ? (V)(object)buffer : JSON.Instance.ToObject<V>(buffer);
                                DateTime expirationDate;
                                var expirationFilePath = GetFile(Category, key.ToString(), false);
                                if (File.Exists(expirationFilePath))
                                {
                                    buffer = File.ReadAllText(expirationFilePath);
                                    expirationDate = Convert.ToDateTime(buffer);
                                    //expired
                                    if (expirationDate < DateTime.Now)
                                    {
                                        value = default(V);
                                        File.Delete(dataFilePath);
                                        File.Delete(expirationFilePath);
                                    }
                                }
                            }
                            else
                                value = default(V);
                        }

                        result.Add(new KeyValuePair<K, V>(key, value));
                    });
            }
            return result;
        }

        public override V Get<K, V>(string Category, K Key)
        {
            var buffer = Get<K, V>(Category, new K[] { Key });
            var result = buffer.FirstOrDefault();
            return result.Value;
        }

        public override void Recycle<K>(string Category, long Count)
        {
            if (Count < maxCount)
                return;

            switch (recycleAlgorithm)
            {
                case RecycleAlgorithms.MRU:
                    lock (syncRoot)
                    {
                        var recycledFileCount = 0;

                        if (isMemory)
                        {
                            //find out expired items
                            var memExpired = memoryExpiration.Where(e => e.Value != null && (DateTime)e.Value < DateTime.Now);
                            memExpired.ForEach(u =>
                            {
                                memoryData.Remove(u.Key);
                                memoryExpiration.Remove(u.Key);
                                usageStat.Remove(u.Key);
                            });
                        }
                        else
                        {
                            if (expiredFiles.Count == 0)
                            {
                                Directory.GetFiles(dataPath, "*." + ExpirationFileExtension).ForEach(f =>
                                    {
                                        var buffer = File.ReadAllText(f);
                                        var expirationDate = Convert.ToDateTime(buffer);
                                        expiredFiles[Path.GetFileNameWithoutExtension(f)] = new KeyValuePair<DateTime, string>(expirationDate, f);
                                    });
                            }
                            //find out expired items
                            var fileExpired = expiredFiles.Where(e => e.Value.Key < DateTime.Now);
                            fileExpired.ForEach(u =>
                            {
                                var dataFile = Path.ChangeExtension(u.Value.Value, DataFileExtension);
                                File.Delete(dataFile);
                                File.Delete(u.Value.Value);
                                usageStat.Remove(u.Key);
                                recycledFileCount++;
                            });
                        }

                        //find out least used items
                        var leastUsed = usageStat.OrderByDescending(s => s.Value.Value).Skip(maxCount - threshold);
                        leastUsed.ForEach(u =>
                            {
                                if (isMemory)
                                {
                                    memoryData.Remove(u.Key);
                                    memoryExpiration.Remove(u.Key);
                                }
                                else
                                {
                                    var dataFile = Path.ChangeExtension(u.Value.Key, DataFileExtension);
                                    if (File.Exists(dataFile))
                                    {
                                        recycledFileCount++;
                                        File.Delete(dataFile);
                                    }
                                    if (File.Exists(u.Value.Key))
                                        File.Delete(u.Value.Key);
                                }
                                usageStat.Remove(u.Key);
                            });

                        if (!isMemory)
                        {
                            var statFilePath = dataPath + statFile;
                            var count = 0;
                            if (File.Exists(statFilePath))
                            {
                                var buffer = File.ReadAllText(statFilePath);
                                count = Convert.ToInt32(buffer);
                            }
                            count = count - recycledFileCount;
                            if (count < 0)
                                count = 0;
                            File.WriteAllText(statFilePath, count.ToString());
                        }
                    }
                    break;
                default:
                    break;
            }
        }
    }
}

  

Extensions.cs

扩展函数

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;

namespace Com.SuperCache.Engine
{
    public static class Extensions
    {
        public static void ForEach<T>(this IEnumerable<T> source, Action<T> action)
        {
            if (source != null)
            {
                foreach (var item in source)
                {
                    action(item);
                }
            }
        }

        public static string NormalizeFileName(this string FileName)
        {
            var result = FileName;
            Path.GetInvalidFileNameChars().ForEach(c =>
                {
                    result = result.Replace(c.ToString(), string.Empty);
                });
            return result;
        }
    }
}

  

新建

构造CacheEngine需要传递缓存保存到哪个文件夹。

基于内存

如果你不喜欢基于磁盘的缓存,可以使用基于内存,构造函数传递空字符串便可。

增加/更新

同一个方法:Add。用户可以指定类型(Category),譬如User,Employee等。键(Key)支持泛型,值(Data)是object。有一个overload是过期日期(ExpirationDate),默认当前时间30分钟后

获取

Get方法需要指定类型(Category)和键(Key)。

 

例子

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Diagnostics;
using Com.SuperCache.Engine;

namespace Com.SuperCache.Test
{
    public class Foo
    {
        public string Name { get; set; }
        public int Age { get; set; }
        public double? Some { get; set; }
        public DateTime? Birthday { get; set; }
    }

    class Program
    {
        static void Main(string[] args)
        {
            //TestAddGet();

            //Thread.Sleep(4000);
            //TestExpiration();

            TestDefaultDiskPerformance();
            TestDefaultMemoryPerformance();
            TestRawDiskPerformance();
            TestRawMemoryPerformance();

            //TestConcurrent();

            Console.Read();
        }

        private static void TestConcurrent()
        {
            var w = new Stopwatch();
            w.Start();
            Parallel.For(1, 3, (a) =>
                {
                    var employees = Enumerable.Range((a - 1) * 1000, a * 1000).Select(i => new KeyValuePair<int, string>(i, "Wilson " + i + " Chen"));
                    var engine = new CacheEngine(@"..\..\data");
                    engine.Add<int, string>("Employee", employees, DateTime.Now.AddMinutes(1));
                });
            w.Stop();
            Console.WriteLine("add:" + w.Elapsed);

            var engine2 = new CacheEngine(@"..\..\data");
            var o = engine2.Get<int, string>("Employee", 1005);
            Console.WriteLine(o);
        }

        private static void TestDefaultDiskPerformance()
        {
            TestPerformance(CacheProviders.Default, @"..\..\data");
        }

        private static void TestDefaultMemoryPerformance()
        {
            TestPerformance(CacheProviders.Default, string.Empty);
        }

        private static void TestRawDiskPerformance()
        {
            TestPerformance(CacheProviders.Raw, @"..\..\data");
        }

        private static void TestRawMemoryPerformance()
        {
            TestPerformance(CacheProviders.Raw, string.Empty);
        }

        private static void TestPerformance(CacheProviders Provider, string DataPath)
        {
            Console.WriteLine("Performance Test: " + Provider.ToString() + ", " + (string.IsNullOrEmpty(DataPath) ? "Memory" : DataPath));
            var engine = new CacheEngine(Provider, DataPath, RecycleAlgorithms.MRU, 900, 100, RecycleModes.Passive);
            var w = new Stopwatch();

            w.Start();
            var employees = Enumerable.Range(0, 1000).Select(i => new KeyValuePair<int, string>(i, "Wilson " + i + " Chen"));
            engine.Add<int, string>("Employee", employees, DateTime.Now.AddMinutes(1));
            w.Stop();
            Console.WriteLine("add:" + w.Elapsed);

            /*w.Restart();
            employees.ForEach(key =>
                {
                    var o1 = engine.Get<int, string>("Employee", key.Key);
                });
            w.Stop();
            Console.WriteLine("individual get:" + w.Elapsed);*/

            w.Restart();
            var keys = employees.Select(i => i.Key);
            var o = engine.Get<int, string>("Employee", keys);
            w.Stop();
            Console.WriteLine("get:" + w.Elapsed);
            Console.WriteLine();
        }

        private static void TestExpiration()
        {
            var engine = new CacheEngine(@"..\..\data");
            var o = engine.Get<string, Foo>("User", "wchen");
            Console.WriteLine(o != null ? o.Name : "wchen does not exist or expired");
        }

        private static void TestAddGet()
        {
            var engine = new CacheEngine(@"..\..\data");
            var f = new Foo { Name = "Wilson Chen", Age = 30, Birthday = DateTime.Now, Some = 123.456 };
            engine.Add("User", "wchen", f, DateTime.Now.AddSeconds(5));

            var o = engine.Get<string, Foo>("User", "wchen");
            Console.WriteLine(o.Name);

            var o4 = engine.Get<string, Foo>("User", "foo");
            Console.WriteLine(o4 != null ? o4.Name : "foo does not exist");

            var o3 = engine.Get<string, string>("PlainText", "A");
            Console.WriteLine(o3 ?? "A does not exist");
        }
    }
}

  

  

 

性能

通过上述性能测试例子,你会发现STSdb的磁盘存取速度要比一个记录对应一个物理文件快。想了解更多,请访问官方网站

测试条件:1000条记录,7200RPM磁盘,i7。

引擎 介质 写入 读取
STSdb 磁盘 0.4s 0.07s
  内存 0.06s 0.02s
Raw 磁盘 1.0s 0.56s
  内存  0.01s 0.002s

 

   

说明

项目中引用了System.Management是因为STSdb支持内存数据库,需要判断最大物理内存。如果不喜欢,大家可以移除引用,并且去掉STSdb4.Database.STSdb.FromMemory方法便可。

下载

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