.NET分布式Orleans – 6 – 事件溯源

<PackageReference Include="Microsoft.Orleans.EventSourcing" Version="8.0.0" /> <PackageReference Include="Microsoft.Orleans.Clustering.AdoNet" Version="8.0.0" /> <PackageReference Include="Microsoft.Orleans.Persistence.AdoNet" Version="8.0.0" /> <PackageReference Include="Microsoft.Orleans.Server" Version="8.0.0" />

builder.Host.UseOrleans(static siloHostBuilder => {     var invariant = "System.Data.SqlClient";      var connectionString = "Data Source=localhost\SQLEXPRESS;Initial Catalog=orleanstest;User Id=sa;Password=12334;";      siloHostBuilder.AddLogStorageBasedLogConsistencyProvider("LogStorage");      // Use ADO.NET for clustering     siloHostBuilder.UseAdoNetClustering(options =>     {         options.Invariant = invariant;         options.ConnectionString = connectionString;     }).ConfigureLogging(logging => logging.AddConsole());      siloHostBuilder.Configure<ClusterOptions>(options =>     {         options.ClusterId = "my-first-cluster";         options.ServiceId = "SampleApp";     });      // Use ADO.NET for persistence     siloHostBuilder.AddAdoNetGrainStorage("GrainStorageForTest", options =>     {         options.Invariant = invariant;         options.ConnectionString = connectionString;         //options.GrainStorageSerializer = new JsonGrainStorageSerializer()           }); });

// the classes below represent events/transactions on the account // all fields are user-defined (none have a special meaning), // so these can be any type of object you like, as long as they are serializable // (so they can be sent over the wire and persisted in a log).  [Serializable] [GenerateSerializer] public abstract class Transaction {     /// <summary> A unique identifier for this transaction  </summary>     [Id(0)]     public Guid Guid { get; set; }      /// <summary> A description for this transaction  </summary>     [Id(1)]     public string Description { get; set; }      /// <summary> time on which the request entered the system  </summary>     [Id(2)]     public DateTime IssueTime { get; set; } }  [Serializable] [GenerateSerializer] public class DepositTransaction : Transaction {     [Id(0)]     public uint DepositAmount { get; set; } }  [Serializable] [GenerateSerializer] public class WithdrawalTransaction : Transaction {     [Id(0)]     public uint WithdrawalAmount { get; set; } }

/// <summary> /// An example of a journaled grain that models a bank account. ///  /// Configured to use the default storage provider. /// Configured to use the LogStorage consistency provider. ///  /// This provider persists all events, and allows us to retrieve them all. /// </summary>  /// <summary> /// A grain that models a bank account /// </summary> public interface IAccountGrain : IGrainWithStringKey {     Task<uint> Balance();      Task Deposit(uint amount, Guid guid, string desc);      Task<bool> Withdraw(uint amount, Guid guid, string desc);      Task<IReadOnlyList<Transaction>> GetTransactionLog(); }  [StorageProvider(ProviderName = "GrainStorageForTest")] [LogConsistencyProvider(ProviderName = "LogStorage")]  public class AccountGrain : JournaledGrain<AccountGrain.GrainState, Transaction>, IAccountGrain {     /// <summary>     /// The state of this grain is just the current balance.     /// </summary>     [Serializable]     [Orleans.GenerateSerializer]     public class GrainState     {         [Orleans.Id(0)]         public uint Balance { get; set; }          public void Apply(DepositTransaction d)         {             Balance = Balance + d.DepositAmount;         }          public void Apply(WithdrawalTransaction d)         {             if (d.WithdrawalAmount > Balance)                 throw new InvalidOperationException("we make sure this never happens");              Balance = Balance - d.WithdrawalAmount;         }     }      public Task<uint> Balance()     {         return Task.FromResult(State.Balance);     }      public Task Deposit(uint amount, Guid guid, string description)     {         RaiseEvent(new DepositTransaction()         {             Guid = guid,             IssueTime = DateTime.UtcNow,             DepositAmount = amount,             Description = description         });          // we wait for storage ack         return ConfirmEvents();     }      public Task<bool> Withdraw(uint amount, Guid guid, string description)     {         // if the balance is too low, can't withdraw         // reject it immediately         if (State.Balance < amount)             return Task.FromResult(false);          // use a conditional event for withdrawal         // (conditional events commit only if the version hasn't already changed in the meantime)         // this is important so we can guarantee that we never overdraw         // even if racing with other clusters, of in transient duplicate grain situations         return RaiseConditionalEvent(new WithdrawalTransaction()         {             Guid = guid,             IssueTime = DateTime.UtcNow,             WithdrawalAmount = amount,             Description = description         });     }      public Task<IReadOnlyList<Transaction>> GetTransactionLog()     {         return RetrieveConfirmedEvents(0, Version);     } }

var palyer = client.GetGrain<IAccountGrain>("zhangsan"); await palyer.Deposit(1000, Guid.NewGuid(), "aaa"); var logs = await palyer.GetTransactionLog(); return Results.Ok(logs);