switch to flat file storage

MediaBrowser.Server.Implementations/Persistence/JsonUserDataRepository.cs

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+using MediaBrowser.Common.Configuration;
+using MediaBrowser.Common.Extensions;
+using MediaBrowser.Controller.Entities;
+using MediaBrowser.Controller.Persistence;
+using MediaBrowser.Model.Logging;
+using MediaBrowser.Model.Serialization;
+using System;
+using System.Collections.Concurrent;
+using System.IO;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace MediaBrowser.Server.Implementations.Persistence
+{
+    public class JsonUserDataRepository : IUserDataRepository
+    {
+        private readonly ConcurrentDictionary<string, SemaphoreSlim> _fileLocks = new ConcurrentDictionary<string, SemaphoreSlim>();
+
+        private SemaphoreSlim GetLock(string filename)
+        {
+            return _fileLocks.GetOrAdd(filename, key => new SemaphoreSlim(1, 1));
+        }
+        
+        private readonly ConcurrentDictionary<string, UserItemData> _userData = new ConcurrentDictionary<string, UserItemData>();
+
+        /// <summary>
+        /// Gets the name of the repository
+        /// </summary>
+        /// <value>The name.</value>
+        public string Name
+        {
+            get
+            {
+                return "Json";
+            }
+        }
+
+        private readonly IJsonSerializer _jsonSerializer;
+
+        private readonly string _dataPath;
+
+        private readonly ILogger _logger;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="JsonUserDataRepository" /> class.
+        /// </summary>
+        /// <param name="appPaths">The app paths.</param>
+        /// <param name="jsonSerializer">The json serializer.</param>
+        /// <param name="logManager">The log manager.</param>
+        /// <exception cref="System.ArgumentNullException">
+        /// jsonSerializer
+        /// or
+        /// appPaths
+        /// </exception>
+        public JsonUserDataRepository(IApplicationPaths appPaths, IJsonSerializer jsonSerializer, ILogManager logManager)
+        {
+            if (jsonSerializer == null)
+            {
+                throw new ArgumentNullException("jsonSerializer");
+            }
+            if (appPaths == null)
+            {
+                throw new ArgumentNullException("appPaths");
+            }
+
+            _logger = logManager.GetLogger(GetType().Name);
+            _jsonSerializer = jsonSerializer;
+            _dataPath = Path.Combine(appPaths.DataPath, "userdata");
+        }
+
+        /// <summary>
+        /// Opens the connection to the database
+        /// </summary>
+        /// <returns>Task.</returns>
+        public Task Initialize()
+        {
+            return Task.FromResult(true);
+        }
+
+        /// <summary>
+        /// Saves the user data.
+        /// </summary>
+        /// <param name="userId">The user id.</param>
+        /// <param name="key">The key.</param>
+        /// <param name="userData">The user data.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        /// <returns>Task.</returns>
+        /// <exception cref="System.ArgumentNullException">userData
+        /// or
+        /// cancellationToken
+        /// or
+        /// userId
+        /// or
+        /// userDataId</exception>
+        public async Task SaveUserData(Guid userId, string key, UserItemData userData, CancellationToken cancellationToken)
+        {
+            if (userData == null)
+            {
+                throw new ArgumentNullException("userData");
+            }
+            if (cancellationToken == null)
+            {
+                throw new ArgumentNullException("cancellationToken");
+            }
+            if (userId == Guid.Empty)
+            {
+                throw new ArgumentNullException("userId");
+            }
+            if (string.IsNullOrEmpty(key))
+            {
+                throw new ArgumentNullException("key");
+            }
+
+            cancellationToken.ThrowIfCancellationRequested();
+
+            try
+            {
+                await PersistUserData(userId, key, userData, cancellationToken).ConfigureAwait(false);
+
+                // Once it succeeds, put it into the dictionary to make it available to everyone else
+                _userData.AddOrUpdate(GetInternalKey(userId, key), userData, delegate { return userData; });
+            }
+            catch (Exception ex)
+            {
+                _logger.ErrorException("Error saving user data", ex);
+
+                throw;
+            }
+        }
+
+        /// <summary>
+        /// Gets the internal key.
+        /// </summary>
+        /// <param name="userId">The user id.</param>
+        /// <param name="key">The key.</param>
+        /// <returns>System.String.</returns>
+        private string GetInternalKey(Guid userId, string key)
+        {
+            return userId + key;
+        }
+
+        /// <summary>
+        /// Persists the user data.
+        /// </summary>
+        /// <param name="userId">The user id.</param>
+        /// <param name="key">The key.</param>
+        /// <param name="userData">The user data.</param>
+        /// <param name="cancellationToken">The cancellation token.</param>
+        /// <returns>Task.</returns>
+        public async Task PersistUserData(Guid userId, string key, UserItemData userData, CancellationToken cancellationToken)
+        {
+            cancellationToken.ThrowIfCancellationRequested();
+
+            var path = GetUserDataPath(userId, key);
+
+            var parentPath = Path.GetDirectoryName(path);
+            if (!Directory.Exists(parentPath))
+            {
+                Directory.CreateDirectory(parentPath);
+            }
+
+            var semaphore = GetLock(path);
+
+            await semaphore.WaitAsync(cancellationToken).ConfigureAwait(false);
+
+            try
+            {
+                _jsonSerializer.SerializeToFile(userData, path);
+            }
+            finally
+            {
+                semaphore.Release();
+            }
+        }
+
+        /// <summary>
+        /// Gets the user data.
+        /// </summary>
+        /// <param name="userId">The user id.</param>
+        /// <param name="key">The key.</param>
+        /// <returns>Task{UserItemData}.</returns>
+        /// <exception cref="System.ArgumentNullException">
+        /// userId
+        /// or
+        /// key
+        /// </exception>
+        public UserItemData GetUserData(Guid userId, string key)
+        {
+            if (userId == Guid.Empty)
+            {
+                throw new ArgumentNullException("userId");
+            }
+            if (string.IsNullOrEmpty(key))
+            {
+                throw new ArgumentNullException("key");
+            }
+
+            return _userData.GetOrAdd(GetInternalKey(userId, key), keyName => RetrieveUserData(userId, key));
+        }
+
+        /// <summary>
+        /// Retrieves the user data.
+        /// </summary>
+        /// <param name="userId">The user id.</param>
+        /// <param name="key">The key.</param>
+        /// <returns>Task{UserItemData}.</returns>
+        private UserItemData RetrieveUserData(Guid userId, string key)
+        {
+            var path = GetUserDataPath(userId, key);
+
+            try
+            {
+                return _jsonSerializer.DeserializeFromFile<UserItemData>(path);
+            }
+            catch (IOException)
+            {
+                // File doesn't exist or is currently bring written to
+                return new UserItemData { UserId = userId };
+            }
+        }
+
+        private string GetUserDataPath(Guid userId, string key)
+        {
+            var userFolder = Path.Combine(_dataPath, userId.ToString());
+
+            var keyHash = key.GetMD5().ToString();
+
+            var prefix = keyHash.Substring(0, 1);
+
+            return Path.Combine(userFolder, prefix, keyHash + ".json");
+        }
+
+        public void Dispose()
+        {
+            // Wait up to two seconds for any existing writes to finish
+            var locks = _fileLocks.Values.ToList()
+                                  .Where(i => i.CurrentCount == 1)
+                                  .Select(i => i.WaitAsync(2000));
+
+            var task = Task.WhenAll(locks);
+
+            Task.WaitAll(task);
+        }
+    }
+}