diff options
Diffstat (limited to 'libs/VNLib.Plugins.Sessions.VNCache/src/WebSessionProvider.cs')
| -rw-r--r-- | libs/VNLib.Plugins.Sessions.VNCache/src/WebSessionProvider.cs | 158 |
1 files changed, 73 insertions, 85 deletions
diff --git a/libs/VNLib.Plugins.Sessions.VNCache/src/WebSessionProvider.cs b/libs/VNLib.Plugins.Sessions.VNCache/src/WebSessionProvider.cs index 0fd981b..d2b1e7e 100644 --- a/libs/VNLib.Plugins.Sessions.VNCache/src/WebSessionProvider.cs +++ b/libs/VNLib.Plugins.Sessions.VNCache/src/WebSessionProvider.cs @@ -1,5 +1,5 @@ /* -* Copyright (c) 2022 Vaughn Nugent +* Copyright (c) 2023 Vaughn Nugent * * Library: VNLib * Package: VNLib.Plugins.Essentials.Sessions.VNCache @@ -25,117 +25,105 @@ using System; using System.Threading; using System.Threading.Tasks; -using System.Collections.Generic; using VNLib.Net.Http; +using VNLib.Utils.Extensions; using VNLib.Plugins.Essentials; using VNLib.Plugins.Essentials.Sessions; using VNLib.Plugins.Extensions.Loading; -using VNLib.Plugins.Sessions.Cache.Client; namespace VNLib.Plugins.Sessions.VNCache { - /// <summary> - /// The implementation of a VNCache web based session - /// </summary> - [ConfigurationName("web")] - internal sealed class WebSessionProvider : SessionCacheClient, ISessionProvider + + [ConfigurationName(WebSessionProviderEntry.WEB_SESSION_CONFIG)] + internal sealed class WebSessionProvider : ISessionProvider { - static readonly TimeSpan BackgroundUpdateTimeout = TimeSpan.FromSeconds(10); - - private readonly IWebSessionIdFactory factory; - private readonly uint MaxConnections; - - /// <summary> - /// Initializes a new <see cref="WebSessionProvider"/> - /// </summary> - /// <param name="client">The cache client to make cache operations against</param> - /// <param name="maxCacheItems">The max number of items to store in cache</param> - /// <param name="maxWaiting">The maxium number of waiting session events before 503s are sent</param> - /// <param name="factory">The session-id factory</param> - public WebSessionProvider(IRemoteCacheStore client, int maxCacheItems, uint maxWaiting, IWebSessionIdFactory factory) : base(client, maxCacheItems) + private static readonly SessionHandle _vf = new (null, FileProcessArgs.VirtualSkip, null); + + private readonly TimeSpan _validFor; + private readonly WebSessionStore _sessions; + private readonly uint _maxConnections; + + private uint _waitingConnections; + + public bool IsConnected => _sessions.IsConnected; + + public WebSessionProvider(PluginBase plugin, IConfigScope config) { - this.factory = factory; - MaxConnections = maxWaiting; + _validFor = config["valid_for_sec"].GetTimeSpan(TimeParseType.Seconds); + _maxConnections = config["max_waiting_connections"].GetUInt32(); + + //Init session provider + _sessions = plugin.GetOrCreateSingleton<WebSessionStore>(); } - private string UpdateSessionId(IHttpEvent entity, string oldId) + private SessionHandle PostProcess(WebSession? session) { - //Generate and set a new sessionid - string newid = factory.GenerateSessionId(entity); - //Aquire lock on cache - lock (CacheLock) + if (session == null) { - //Change the cache lookup id - if (CacheTable.Remove(oldId, out RemoteSession? session)) - { - CacheTable.Add(newid, session); - } + return SessionHandle.Empty; } - return newid; + + //Make sure the session has not expired yet + if (session.Created.Add(_validFor) < DateTimeOffset.UtcNow) + { + //Invalidate the session, so its technically valid for this request, but will be cleared on this handle close cycle + session.Invalidate(); + + //Clear basic login status + session.Token = null; + session.UserID = null; + session.Privilages = 0; + session.SetLoginToken(null); + } + + return new SessionHandle(session, OnSessionReleases); } - - protected override RemoteSession SessionCtor(string sessionId) => new WebSession(sessionId, Store, BackgroundUpdateTimeout, UpdateSessionId); - public async ValueTask<SessionHandle> GetSessionAsync(IHttpEvent entity, CancellationToken cancellationToken) + private ValueTask OnSessionReleases(ISession session, IHttpEvent entity) => _sessions.ReleaseSessionAsync((WebSession)session, entity); + + public ValueTask<SessionHandle> GetSessionAsync(IHttpEvent entity, CancellationToken cancellationToken) { - //Callback to close the session when the handle is closeed - static ValueTask HandleClosedAsync(ISession session, IHttpEvent entity) + //Limit max number of waiting clients and make sure were connected + if (!_sessions.IsConnected || _waitingConnections > _maxConnections) { - return (session as SessionBase)!.UpdateAndRelease(true, entity); + //Set 503 for temporary unavail + entity.CloseResponse(System.Net.HttpStatusCode.ServiceUnavailable); + return ValueTask.FromResult(_vf); } - - try + + ValueTask<WebSession?> result = _sessions.GetSessionAsync(entity, cancellationToken); + + if (result.IsCompleted) { - //Get session id - if (!factory.TryGetSessionId(entity, out string? sessionId)) - { - //Id not allowed/found, so do not attach a session - return SessionHandle.Empty; - } - - //Limit max number of waiting clients and make sure were connected - if (!IsConnected || WaitingConnections > MaxConnections) - { - //Set 503 for temporary unavail - entity.CloseResponse(System.Net.HttpStatusCode.ServiceUnavailable); - return new SessionHandle(null, FileProcessArgs.VirtualSkip, null); - } - - //Get session - RemoteSession session = await GetSessionAsync(entity, sessionId, cancellationToken); - - //If the session is new (not in cache), then overwrite the session id with a new one as user may have specified their own - if (session.IsNew) - { - session.RegenID(); - } - - //Make sure the session has not expired yet - if (session.Created.Add(factory.ValidFor) < DateTimeOffset.UtcNow) - { - //Invalidate the session, so its technically valid for this request, but will be cleared on this handle close cycle - session.Invalidate(); - //Clear basic login status - session.Token = null; - session.UserID = null; - session.Privilages = 0; - session.SetLoginToken(null); - } - - return new SessionHandle(session, HandleClosedAsync); + WebSession? session = result.GetAwaiter().GetResult(); + + //Post process and get handle for session + SessionHandle handle = PostProcess(session); + + return ValueTask.FromResult(handle); } - catch (OperationCanceledException) + else { - throw; + return new(AwaitAsyncGet(result)); } - catch (SessionException) + } + + private async Task<SessionHandle> AwaitAsyncGet(ValueTask<WebSession?> async) + { + //Inct wait count while async waiting + _waitingConnections++; + try { - throw; + //await the session + WebSession? session = await async.ConfigureAwait(false); + + //return empty session handle if the session could not be found + return PostProcess(session); } - catch (Exception ex) + finally { - throw new SessionException("Exception raised while retreiving or loading Web session", ex); + _waitingConnections--; } } } |