Add Garnet lock feature

Author: hishamco

src/OrchardCoreContrib.Garnet/Manifest.cs

@@ -38,3 +38,11 @@
     Dependencies = ["OrchardCoreContrib.Garnet"],
     Category = "Distributed Caching"
 )]
+
+[assembly: Feature(
+    Id = "OrchardCoreContrib.Garnet.Lock",
+    Name = "Garnet Lock",
+    Description = "Distributed Lock using Garnet.",
+    Dependencies = ["OrchardCoreContrib.Garnet"],
+    Category = "Distributed Caching"
+)]

src/OrchardCoreContrib.Garnet/Services/GarnetLock.cs

@@ -0,0 +1,239 @@
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+using OrchardCore.Environment.Shell;
+using OrchardCore.Locking;
+using OrchardCore.Locking.Distributed;
+using StackExchange.Redis;
+using System.Diagnostics;
+using System.Net;
+
+namespace OrchardCoreContrib.Garnet.Services;
+
+/// <summary>
+/// Represents a distributed lock implementation based on Garnet service.
+/// </summary>
+/// <param name="garnetService">The <see cref="IGarnetService"/>.</param>
+/// <param name="garnetOptions">The <see cref="IOptions{GarnetOptions}"/>.</param>
+/// <param name="shellSettings">The <see cref="ShellSettings"/>.</param>
+/// <param name="logger">The <see cref="ILogger{GarnetLock}"/>.</param>
+public class GarnetLock(
+    IGarnetService garnetService,
+    IOptions<GarnetOptions> garnetOptions,
+    ShellSettings shellSettings,
+    ILogger<GarnetLock> logger) : IDistributedLock
+{
+    private static readonly double _baseDelay = 100;
+    private static readonly double _maxDelay = 10000;
+
+    private readonly GarnetOptions _garnetOptions = garnetOptions.Value;
+    private readonly string _hostName = Dns.GetHostName() + ':' + Environment.ProcessId;
+    private readonly string _prefix = garnetService.InstancePrefix + shellSettings.Name + ':';
+
+    /// <summary>
+    /// Waits indefinitely until acquiring a named lock with a given expiration for the current tenant
+    /// </summary>
+    /// <param name="key">The key.</param>
+    /// <param name="expiration">The expiration time for the lock.</param>
+    public async Task<ILocker> AcquireLockAsync(string key, TimeSpan? expiration = null)
+        => (await TryAcquireLockAsync(key, TimeSpan.MaxValue, expiration)).locker;
+
+    /// <summary>
+    /// Tries to acquire a named lock in a given timeout with a given expiration for the current tenant.
+    /// </summary>
+    /// <param name="key">The key.</param>
+    /// <param name="timeout">The timeout for acquiring the lock.</param>
+    /// <param name="expiration">The expiration time for the lock.</param>
+    /// <returns></returns>
+    public async Task<(ILocker locker, bool locked)> TryAcquireLockAsync(string key, TimeSpan timeout, TimeSpan? expiration = null)
+    {
+        using (var cts = new CancellationTokenSource(timeout != TimeSpan.MaxValue ? timeout : Timeout.InfiniteTimeSpan))
+        {
+            var retries = 0.0;
+
+            while (!cts.IsCancellationRequested)
+            {
+                var locked = await LockAsync(key, expiration ?? TimeSpan.MaxValue);
+
+                if (locked)
+                {
+                    return (new Locker(this, key), locked);
+                }
+
+                try
+                {
+                    await Task.Delay(GetDelay(++retries), cts.Token);
+                }
+                catch (TaskCanceledException)
+                {
+                    if (logger.IsEnabled(LogLevel.Debug))
+                    {
+                        logger.LogDebug("Timeout elapsed before acquiring the named lock '{LockName}' after the given timeout of '{Timeout}'.",
+                            _prefix + key, timeout.ToString());
+                    }
+                }
+            }
+        }
+
+        return (null, false);
+    }
+
+    public async Task<bool> IsLockAcquiredAsync(string key)
+    {
+        if (garnetService.Client == null)
+        {
+            await garnetService.ConnectAsync();
+
+            if (garnetService.Client == null)
+            {
+                logger.LogError("Fails to check whether the named lock '{LockName}' is already acquired.", _prefix + key);
+
+                return false;
+            }
+        }
+
+        try
+        {
+            var database = (await ConnectionMultiplexer
+                .ConnectAsync(GetConfigurationOptions(_garnetOptions)))
+                .GetDatabase();
+            
+            return (await database.LockQueryAsync(_prefix + key)).HasValue;
+        }
+        catch (Exception e)
+        {
+            logger.LogError(e, "Fails to check whether the named lock '{LockName}' is already acquired.", _prefix + key);
+        }
+
+        return false;
+    }
+
+    private async Task<bool> LockAsync(string key, TimeSpan expiry)
+    {
+        if (garnetService.Client == null)
+        {
+            await garnetService.ConnectAsync();
+
+            if (garnetService.Client == null)
+            {
+                logger.LogError("Fails to acquire the named lock '{LockName}'.", _prefix + key);
+                
+                return false;
+            }
+        }
+
+        try
+        {
+            var database = (await ConnectionMultiplexer
+                .ConnectAsync(GetConfigurationOptions(_garnetOptions)))
+                .GetDatabase();
+
+            return await database.LockTakeAsync(_prefix + key, _hostName, expiry);
+        }
+        catch (Exception e)
+        {
+            logger.LogError(e, "Fails to acquire the named lock '{LockName}'.", _prefix + key);
+        }
+
+        return false;
+    }
+
+    private async ValueTask ReleaseAsync(string key)
+    {
+        try
+        {
+            var database = (await ConnectionMultiplexer
+               .ConnectAsync(GetConfigurationOptions(_garnetOptions)))
+               .GetDatabase();
+
+            await database.LockReleaseAsync(_prefix + key, _hostName);
+        }
+        catch (Exception e)
+        {
+            logger.LogError(e, "Fails to release the named lock '{LockName}'.", _prefix + key);
+        }
+    }
+
+    private void Release(string key)
+    {
+        try
+        {
+            var database = ConnectionMultiplexer
+               .ConnectAsync(GetConfigurationOptions(_garnetOptions))
+               .GetAwaiter()
+               .GetResult()
+               .GetDatabase();
+
+            database.LockRelease(_prefix + key, _hostName);
+        }
+        catch (Exception e)
+        {
+            logger.LogError(e, "Fails to release the named lock '{LockName}'.", _prefix + key);
+        }
+    }
+
+    private sealed class Locker(GarnetLock garnetLock, string key) : ILocker
+    {
+        private bool _disposed;
+
+        public ValueTask DisposeAsync()
+        {
+            if (_disposed)
+            {
+                return default;
+            }
+
+            _disposed = true;
+
+            return garnetLock.ReleaseAsync(key);
+        }
+
+        public void Dispose()
+        {
+            if (_disposed)
+            {
+                return;
+            }
+
+            _disposed = true;
+
+            garnetLock.Release(key);
+        }
+    }
+
+    private static TimeSpan GetDelay(double retries)
+    {
+        var delay = _baseDelay * (1.0 + ((Math.Pow(1.8, retries - 1.0) - 1.0) * (0.6 + new Random().NextDouble() * 0.4)));
+
+        return TimeSpan.FromMilliseconds(Math.Min(delay, _maxDelay));
+    }
+
+    // TODO: Use explicit conversion operators to convert between GarnetOptions and ConfigurationOptions
+    private static ConfigurationOptions GetConfigurationOptions(GarnetOptions garnetOptions)
+    {
+        var endPoints = new EndPointCollection
+        {
+            new DnsEndPoint(garnetOptions.Host, garnetOptions.Port)
+        };
+        var configOptions = new ConfigurationOptions
+        {
+            EndPoints = endPoints,
+            ConnectTimeout = (int)TimeSpan.FromSeconds(2).TotalMilliseconds,
+            SyncTimeout = (int)TimeSpan.FromSeconds(30).TotalMilliseconds,
+            AsyncTimeout = (int)TimeSpan.FromSeconds(30).TotalMilliseconds,
+            ReconnectRetryPolicy = new LinearRetry((int)TimeSpan.FromSeconds(10).TotalMilliseconds),
+            ConnectRetry = 5,
+            IncludeDetailInExceptions = true,
+            AbortOnConnectFail = true,
+            User = garnetOptions.UserName,
+            Password = garnetOptions.Password
+        };
+
+        if (Debugger.IsAttached)
+        {
+            configOptions.SyncTimeout = (int)TimeSpan.FromHours(2).TotalMilliseconds;
+            configOptions.AsyncTimeout = (int)TimeSpan.FromHours(2).TotalMilliseconds;
+        }
+
+        return configOptions;
+    }
+}

src/OrchardCoreContrib.Garnet/Startups/GarnetLockStartup.cs

@@ -0,0 +1,22 @@
+using Microsoft.Extensions.DependencyInjection;
+using OrchardCore.Locking.Distributed;
+using OrchardCore.Modules;
+using OrchardCoreContrib.Garnet.Services;
+
+namespace OrchardCoreContrib.Garnet;
+
+/// <summary>
+/// Represensts a startup point to register the required services by Garnet lock feature.
+/// </summary>
+[Feature("OrchardCoreContrib.Garnet.Lock")]
+public class GarnetLockStartup : StartupBase
+{
+    /// <inheritdoc/>
+    public override void ConfigureServices(IServiceCollection services)
+    {
+        if (services.Any(d => d.ServiceType == typeof(IGarnetService)))
+        {
+            services.AddSingleton<IDistributedLock, GarnetLock>();
+        }
+    }
+}