C# B对动态表达式的响应或结果的内存缓存
我正在尝试为C# B对动态表达式的响应或结果的内存缓存,c#,mongodb,mongodb-.net-driver,C#,Mongodb,Mongodb .net Driver,我正在尝试为IMongoCollection编写一个代理类,这样我就可以在一些方法实现中使用内存缓存。然而,问题是几乎所有的过滤器都是FilterDefinition类型,这意味着我们可以调用Render来获取BsonDocument。我想知道是否有一种方法可以将过滤器BsonDocument转换为动态表达式,这样我就可以在内存列表中运行它了。或者,也许有一种更好的方法来进行内存缓存,但我并不知道。多谢各位 更新: 我很想按照@simon mourier的建议编写一个解决方案,但这个黑客解决方案
IMongoCollection
编写一个代理类,这样我就可以在一些方法实现中使用内存缓存。然而,问题是几乎所有的过滤器都是FilterDefinition
类型,这意味着我们可以调用Render
来获取BsonDocument
。我想知道是否有一种方法可以将过滤器BsonDocument
转换为动态表达式,这样我就可以在内存列表中运行它了。或者,也许有一种更好的方法来进行内存缓存,但我并不知道。多谢各位
更新:
我很想按照@simon mourier的建议编写一个解决方案,但这个黑客解决方案的问题是C#mongo驱动程序返回IAsyncCursor
进行查找操作,这基本上是一个BsonDocument
s流,每次读取后它都指向最后一个索引并自行处理。并且没有办法将流重置到其初始位置。这意味着下面的代码第一次工作,但在那之后,我们得到一个异常,游标位于流的末尾,并且已经被释放
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Threading;
using System.Threading.Tasks;
using DAL.Extensions;
using MongoDB.Bson;
using MongoDB.Bson.Serialization;
using MongoDB.Driver;
namespace DAL.Proxies
{
public static class MongoCollectionProxy
{
private static readonly Dictionary<Type, object> _instances = new Dictionary<Type, object>();
public static IMongoCollection<T> New<T>(IMongoCollection<T> proxy)
{
return ((IMongoCollection<T>)_instances.AddOrUpdate(typeof(T), () => new MongoCollectionBaseProxyImpl<T>(proxy)));
}
}
public class MongoCollectionBaseProxyImpl<T> : MongoCollectionBase<T>
{
private readonly IMongoCollection<T> _proxy;
private readonly ConcurrentDictionary<string, object> _cache = new ConcurrentDictionary<string, object>();
public MongoCollectionBaseProxyImpl(IMongoCollection<T> proxy)
{
_proxy = proxy;
}
public override Task<IAsyncCursor<TResult>> AggregateAsync<TResult>(PipelineDefinition<T, TResult> pipeline,
AggregateOptions options = null,
CancellationToken cancellationToken = new CancellationToken())
{
return _proxy.AggregateAsync(pipeline, options, cancellationToken);
}
public override Task<BulkWriteResult<T>> BulkWriteAsync(IEnumerable<WriteModel<T>> requests,
BulkWriteOptions options = null,
CancellationToken cancellationToken = new CancellationToken())
{
return _proxy.BulkWriteAsync(requests, options, cancellationToken);
}
[Obsolete("Use CountDocumentsAsync or EstimatedDocumentCountAsync instead.")]
public override Task<long> CountAsync(FilterDefinition<T> filter, CountOptions options = null,
CancellationToken cancellationToken = new CancellationToken())
{
return _proxy.CountAsync(filter, options, cancellationToken);
}
public override Task<IAsyncCursor<TField>> DistinctAsync<TField>(FieldDefinition<T, TField> field,
FilterDefinition<T> filter, DistinctOptions options = null,
CancellationToken cancellationToken = new CancellationToken())
{
return _proxy.DistinctAsync(field, filter, options, cancellationToken);
}
public override async Task<IAsyncCursor<TProjection>> FindAsync<TProjection>(FilterDefinition<T> filter,
FindOptions<T, TProjection> options = null,
CancellationToken cancellationToken = new CancellationToken())
{
// ReSharper disable once SpecifyACultureInStringConversionExplicitly
return await CacheResult(filter.Render().ToString(), () => _proxy.FindAsync(filter, options, cancellationToken));
}
public override async Task<TProjection> FindOneAndDeleteAsync<TProjection>(FilterDefinition<T> filter,
FindOneAndDeleteOptions<T, TProjection> options = null,
CancellationToken cancellationToken = new CancellationToken())
{
return await InvalidateCache(_proxy.FindOneAndDeleteAsync(filter, options, cancellationToken));
}
public override async Task<TProjection> FindOneAndReplaceAsync<TProjection>(FilterDefinition<T> filter,
T replacement,
FindOneAndReplaceOptions<T, TProjection> options = null,
CancellationToken cancellationToken = new CancellationToken())
{
return await InvalidateCache(_proxy.FindOneAndReplaceAsync(filter, replacement, options,
cancellationToken));
}
public override async Task<TProjection> FindOneAndUpdateAsync<TProjection>(FilterDefinition<T> filter,
UpdateDefinition<T> update,
FindOneAndUpdateOptions<T, TProjection> options = null,
CancellationToken cancellationToken = new CancellationToken())
{
return await InvalidateCache(_proxy.FindOneAndUpdateAsync(filter, update, options, cancellationToken));
}
public override Task<IAsyncCursor<TResult>> MapReduceAsync<TResult>(BsonJavaScript map, BsonJavaScript reduce,
MapReduceOptions<T, TResult> options = null,
CancellationToken cancellationToken = new CancellationToken())
{
return _proxy.MapReduceAsync(map, reduce, options, cancellationToken);
}
public override IFilteredMongoCollection<TDerivedDocument> OfType<TDerivedDocument>()
{
return _proxy.OfType<TDerivedDocument>();
}
public override IMongoCollection<T> WithReadPreference(ReadPreference readPreference)
{
return _proxy.WithReadPreference(readPreference);
}
public override IMongoCollection<T> WithWriteConcern(WriteConcern writeConcern)
{
return _proxy.WithWriteConcern(writeConcern);
}
public override CollectionNamespace CollectionNamespace => _proxy.CollectionNamespace;
public override IMongoDatabase Database => _proxy.Database;
public override IBsonSerializer<T> DocumentSerializer => _proxy.DocumentSerializer;
public override IMongoIndexManager<T> Indexes => _proxy.Indexes;
public override MongoCollectionSettings Settings => _proxy.Settings;
private async Task<TResult> CacheResult<TResult>(string key, Func<Task<TResult>> result)
{
return _cache.ContainsKey(key) ? (TResult) _cache[key] : (TResult) _cache.AddOrUpdate(key, await result());
}
private TResult InvalidateCache<TResult>(TResult result)
{
_cache.Clear();
return result;
}
}
}
使用系统;
使用System.Collections.Concurrent;
使用System.Collections.Generic;
使用系统线程;
使用System.Threading.Tasks;
使用DAL扩展;
使用MongoDB.Bson;
使用MongoDB.Bson.Serialization;
使用MongoDB.Driver;
名称空间DAL.Proxies
{
公共静态类MongoCollectionProxy
{
私有静态只读字典_实例=新字典();
公共静态IMongoCollection新建(IMongoCollection代理)
{
return((IMongoCollection)_instances.AddOrUpdate(typeof(T),()=>newmongocollectionbaseproxyimpl(proxy));
}
}
公共类MongoCollectionBaseProxyImpl:MongoCollectionBase
{
私有只读IMongoCollection\u代理;
私有只读ConcurrentDictionary _cache=新ConcurrentDictionary();
公共MongoCollectionBaseProxyImpl(IMongoCollection代理)
{
_代理=代理;
}
公共覆盖任务聚合同步(PipelineDefinition管道,
AggregateOptions=null,
CancellationToken CancellationToken=新的CancellationToken()
{
return _proxy.AggregateAsync(管道、选项、取消令牌);
}
公共覆盖任务BulkWriteAsync(IEnumerable请求,
BulkWriteOptions=null,
CancellationToken CancellationToken=新的CancellationToken()
{
return _proxy.BulkWriteAsync(请求、选项、取消令牌);
}
[过时(“改用CountDocumentsSync或EstimatedDocumentCountAsync。”)]
公共重写任务CountAsync(FilterDefinition筛选器,CountOptions=null,
CancellationToken CancellationToken=新的CancellationToken()
{
返回_proxy.CountAsync(过滤器、选项、取消令牌);
}
公共覆盖任务DistinctAsync(字段定义字段,
FilterDefinition筛选器,DistinctOptions选项=null,
CancellationToken CancellationToken=新的CancellationToken()
{
返回_proxy.DistinctAsync(字段、筛选器、选项、取消令牌);
}
公共重写异步任务FindAsync(FilterDefinition筛选器,
FindOptions=null,
CancellationToken CancellationToken=新的CancellationToken()
{
//ReSharper禁用一次指定CultureInstallingConversionExplicitly
返回等待缓存结果(filter.Render().ToString(),()=>_proxy.FindAsync(filter,options,cancellationToken));
}
公共重写异步任务FindOnAndDeleteAsync(FilterDefinition筛选器,
FindDoneAndDeleteOptions=null,
CancellationToken CancellationToken=新的CancellationToken()
{
return await InvalidateCache(_proxy.FindOneAndDeleteAsync(filter,options,cancellationToken));
}
公共重写异步任务FindOnAndReplaceAncy(FilterDefinition筛选器,
T替换,
FindOneAndReplaceOptions=null,
CancellationToken CancellationToken=新的CancellationToken()
{
return wait InvalidateCache(_proxy.findoneandresplaceasync(过滤器、替换、选项、,
取消令牌);
}
公共重写异步任务FindOneAndUpdateAsync(FilterDefinition筛选器,
更新定义更新,
FindOneAndUpdateOptions=null,
CancellationToken CancellationToken=新的CancellationToken()
{
return wait wait InvalidateCache(_proxy.FindOneAndUpdateAsync(过滤器、更新、选项、取消令牌));
}
公共覆盖任务MapReduceAsync(BsonJavaScript映射、BsonJavaScript还原、,
MapReduceOptions选项=null,
CancellationToken CancellationToken=新的CancellationToken()
{
return _proxy.MapReduceAsync(map、reduce、options、cancellationToken);
}
公共重写类型()的IFilteredMongoCollection
{
返回_proxy.of type();
}
使用ReadPreference(ReadPreference ReadPreference)公共重写IMongoCollection
{
返回_proxy.WithReadPreference(readPreference);
}
使用WriteConcern(WriteConcern WriteConcern)公共重写IMongoCollection
{
返回_proxy.with writeConcern(writeConcern);
}
公共覆盖CollectionNamespace CollectionNamespace=>\u proxy.CollectionNamespace;
公共覆盖IMongoDatabase Database=>\u proxy.Database;
public override IBsonSerializer DocumentSerializer=>\u proxy.DocumentSerializer;
公共覆盖IMongoIndexManager索引=>\u proxy.index;
聚氨基甲酸酯
public interface IUserRepository
{
User GetById(Guid userId);
ReadOnlyCollection<User> GetAll();
}
public class MongoUserRepository: IUserRepository
{
private readonly IMongoCollection<User> userCollection;
public MongoUserRepository(IMongoCollection<User> userCollection)
{
this.userCollection = userCollection ?? throw new ArgumentNullException(nameof(userCollection));
}
// interface members implementation omitted for simplicity
}
public class UserRepositoryCachingDecorator: IUserRepository
{
private readonly IUserRepository decoratee;
private readonly IMemoryCache cache;
public UserRepositoryCachingDecorator(IUserRepository decoratee, IMemoryCache cache)
{
this.decoratee = decoratee ?? throw new ArgumentNullException(nameof(decoratee));
this.cache = cache ?? throw new ArgumentNullException(nameof(cache));
}
// interface members implementation omitted for simplicity
}