jellyfin/MediaBrowser.Server.Sqlite/SQLiteRepository.cs

318 lines
9.6 KiB
C#

using MediaBrowser.Model.Logging;
using System;
using System.Collections.Concurrent;
using System.Data;
using System.Data.Common;
using System.Data.SQLite;
using System.IO;
using System.Threading;
using System.Threading.Tasks;
namespace MediaBrowser.Server.Sqlite
{
/// <summary>
/// Class SqliteRepository
/// </summary>
public abstract class SqliteRepository : IDisposable
{
/// <summary>
/// The db file name
/// </summary>
protected string dbFileName;
/// <summary>
/// The connection
/// </summary>
protected SQLiteConnection connection;
/// <summary>
/// The delayed commands
/// </summary>
protected ConcurrentQueue<SQLiteCommand> delayedCommands = new ConcurrentQueue<SQLiteCommand>();
/// <summary>
/// The flush interval
/// </summary>
private const int FlushInterval = 5000;
/// <summary>
/// The flush timer
/// </summary>
private Timer FlushTimer;
/// <summary>
/// Gets the logger.
/// </summary>
/// <value>The logger.</value>
protected ILogger Logger { get; private set; }
/// <summary>
/// Initializes a new instance of the <see cref="SqliteRepository" /> class.
/// </summary>
/// <param name="logger">The logger.</param>
/// <exception cref="System.ArgumentNullException">logger</exception>
protected SqliteRepository(ILogger logger)
{
if (logger == null)
{
throw new ArgumentNullException("logger");
}
Logger = logger;
}
/// <summary>
/// Connects to DB.
/// </summary>
/// <param name="dbPath">The db path.</param>
/// <returns>Task{System.Boolean}.</returns>
/// <exception cref="System.ArgumentNullException">dbPath</exception>
protected async Task ConnectToDB(string dbPath)
{
if (string.IsNullOrEmpty(dbPath))
{
throw new ArgumentNullException("dbPath");
}
dbFileName = dbPath;
var connectionstr = new SQLiteConnectionStringBuilder
{
PageSize = 4096,
CacheSize = 40960,
SyncMode = SynchronizationModes.Off,
DataSource = dbPath,
JournalMode = SQLiteJournalModeEnum.Memory
};
connection = new SQLiteConnection(connectionstr.ConnectionString);
await connection.OpenAsync().ConfigureAwait(false);
// Run once
FlushTimer = new Timer(Flush, null, TimeSpan.FromMilliseconds(FlushInterval), TimeSpan.FromMilliseconds(-1));
}
/// <summary>
/// Runs the queries.
/// </summary>
/// <param name="queries">The queries.</param>
/// <returns><c>true</c> if XXXX, <c>false</c> otherwise</returns>
/// <exception cref="System.ArgumentNullException">queries</exception>
protected void RunQueries(string[] queries)
{
if (queries == null)
{
throw new ArgumentNullException("queries");
}
using (var tran = connection.BeginTransaction())
{
try
{
var cmd = connection.CreateCommand();
foreach (var query in queries)
{
cmd.Transaction = tran;
cmd.CommandText = query;
cmd.ExecuteNonQuery();
}
tran.Commit();
}
catch (Exception e)
{
Logger.ErrorException("Error running queries", e);
tran.Rollback();
throw;
}
}
}
/// <summary>
/// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
/// </summary>
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
/// <summary>
/// Releases unmanaged and - optionally - managed resources.
/// </summary>
/// <param name="dispose"><c>true</c> to release both managed and unmanaged resources; <c>false</c> to release only unmanaged resources.</param>
protected virtual void Dispose(bool dispose)
{
if (dispose)
{
Logger.Info("Disposing " + GetType().Name);
try
{
// If we're not already flushing, do it now
if (!IsFlushing)
{
Flush(null);
}
// Don't dispose in the middle of a flush
while (IsFlushing)
{
Thread.Sleep(50);
}
if (FlushTimer != null)
{
FlushTimer.Dispose();
FlushTimer = null;
}
if (connection.IsOpen())
{
connection.Close();
}
connection.Dispose();
}
catch (Exception ex)
{
Logger.ErrorException("Error disposing database", ex);
}
}
}
/// <summary>
/// Queues the command.
/// </summary>
/// <param name="cmd">The CMD.</param>
/// <exception cref="System.ArgumentNullException">cmd</exception>
protected void QueueCommand(SQLiteCommand cmd)
{
if (cmd == null)
{
throw new ArgumentNullException("cmd");
}
delayedCommands.Enqueue(cmd);
}
/// <summary>
/// The is flushing
/// </summary>
private bool IsFlushing;
/// <summary>
/// Flushes the specified sender.
/// </summary>
/// <param name="sender">The sender.</param>
private void Flush(object sender)
{
// Cannot call Count on a ConcurrentQueue since it's an O(n) operation
// Use IsEmpty instead
if (delayedCommands.IsEmpty)
{
FlushTimer.Change(TimeSpan.FromMilliseconds(FlushInterval), TimeSpan.FromMilliseconds(-1));
return;
}
if (IsFlushing)
{
return;
}
IsFlushing = true;
var numCommands = 0;
using (var tran = connection.BeginTransaction())
{
try
{
while (!delayedCommands.IsEmpty)
{
SQLiteCommand command;
delayedCommands.TryDequeue(out command);
command.Connection = connection;
command.Transaction = tran;
command.ExecuteNonQuery();
numCommands++;
}
tran.Commit();
}
catch (Exception e)
{
Logger.ErrorException("Failed to commit transaction.", e);
tran.Rollback();
}
}
Logger.Info("SQL Delayed writer executed " + numCommands + " commands");
FlushTimer.Change(TimeSpan.FromMilliseconds(FlushInterval), TimeSpan.FromMilliseconds(-1));
IsFlushing = false;
}
/// <summary>
/// Executes the command.
/// </summary>
/// <param name="cmd">The CMD.</param>
/// <returns>Task.</returns>
/// <exception cref="System.ArgumentNullException">cmd</exception>
public async Task ExecuteCommand(DbCommand cmd)
{
if (cmd == null)
{
throw new ArgumentNullException("cmd");
}
using (var tran = connection.BeginTransaction())
{
try
{
cmd.Connection = connection;
cmd.Transaction = tran;
await cmd.ExecuteNonQueryAsync().ConfigureAwait(false);
tran.Commit();
}
catch (Exception e)
{
Logger.ErrorException("Failed to commit transaction.", e);
tran.Rollback();
}
}
}
/// <summary>
/// Gets a stream from a DataReader at a given ordinal
/// </summary>
/// <param name="reader">The reader.</param>
/// <param name="ordinal">The ordinal.</param>
/// <returns>Stream.</returns>
/// <exception cref="System.ArgumentNullException">reader</exception>
protected static Stream GetStream(IDataReader reader, int ordinal)
{
if (reader == null)
{
throw new ArgumentNullException("reader");
}
var memoryStream = new MemoryStream();
var num = 0L;
var array = new byte[4096];
long bytes;
do
{
bytes = reader.GetBytes(ordinal, num, array, 0, array.Length);
memoryStream.Write(array, 0, (int)bytes);
num += bytes;
}
while (bytes > 0L);
memoryStream.Position = 0;
return memoryStream;
}
}
}