jellyfin-server/Emby.Server.Implementations/Data/BaseSqliteRepository.cs
2019-08-15 00:00:21 +02:00

289 lines
9.0 KiB
C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using Microsoft.Extensions.Logging;
using SQLitePCL.pretty;
namespace Emby.Server.Implementations.Data
{
public abstract class BaseSqliteRepository : IDisposable
{
private bool _disposed = false;
protected BaseSqliteRepository(ILogger logger)
{
Logger = logger;
}
/// <summary>
/// Gets or sets the path to the DB file.
/// </summary>
/// <value>Path to the DB file.</value>
protected string DbFilePath { get; set; }
/// <summary>
/// Gets the logger.
/// </summary>
/// <value>The logger.</value>
protected ILogger Logger { get; }
/// <summary>
/// Gets the default connection flags.
/// </summary>
/// <value>The default connection flags.</value>
protected virtual ConnectionFlags DefaultConnectionFlags => ConnectionFlags.NoMutex;
/// <summary>
/// Gets the transaction mode.
/// </summary>
/// <value>The transaction mode.</value>>
protected TransactionMode TransactionMode => TransactionMode.Deferred;
/// <summary>
/// Gets the transaction mode for read-only operations.
/// </summary>
/// <value>The transaction mode.</value>
protected TransactionMode ReadTransactionMode => TransactionMode.Deferred;
/// <summary>
/// Gets the cache size.
/// </summary>
/// <value>The cache size or null.</value>
protected virtual int? CacheSize => null;
/// <summary>
/// Gets the journal mode.
/// </summary>
/// <value>The journal mode.</value>
protected virtual string JournalMode => "WAL";
/// <summary>
/// Gets the page size.
/// </summary>
/// <value>The page size or null.</value>
protected virtual int? PageSize => null;
/// <summary>
/// Gets the temp store mode.
/// </summary>
/// <value>The temp store mode.</value>
/// <see cref="TempStoreMode"/>
protected virtual TempStoreMode TempStore => TempStoreMode.Default;
/// <summary>
/// Gets the synchronous mode.
/// </summary>
/// <value>The synchronous mode or null.</value>
/// <see cref="SynchronousMode"/>
protected virtual SynchronousMode? Synchronous => null;
/// <summary>
/// Gets or sets the write lock.
/// </summary>
/// <value>The write lock.</value>
protected SemaphoreSlim WriteLock { get; set; } = new SemaphoreSlim(1, 1);
/// <summary>
/// Gets or sets the write connection.
/// </summary>
/// <value>The write connection.</value>
protected SQLiteDatabaseConnection WriteConnection { get; set; }
protected ManagedConnection GetConnection(bool _ = false)
{
WriteLock.Wait();
if (WriteConnection != null)
{
return new ManagedConnection(WriteConnection, WriteLock);
}
WriteConnection = SQLite3.Open(
DbFilePath,
DefaultConnectionFlags | ConnectionFlags.Create | ConnectionFlags.ReadWrite,
null);
if (CacheSize.HasValue)
{
WriteConnection.Execute("PRAGMA cache_size=" + CacheSize.Value);
}
if (!string.IsNullOrWhiteSpace(JournalMode))
{
WriteConnection.Execute("PRAGMA journal_mode=" + JournalMode);
}
if (Synchronous.HasValue)
{
WriteConnection.Execute("PRAGMA synchronous=" + (int)Synchronous.Value);
}
if (PageSize.HasValue)
{
WriteConnection.Execute("PRAGMA page_size=" + PageSize.Value);
}
WriteConnection.Execute("PRAGMA temp_store=" + (int)TempStore);
// Configuration and pragmas can affect VACUUM so it needs to be last.
WriteConnection.Execute("VACUUM");
return new ManagedConnection(WriteConnection, WriteLock);
}
public IStatement PrepareStatement(ManagedConnection connection, string sql)
=> connection.PrepareStatement(sql);
public IStatement PrepareStatement(IDatabaseConnection connection, string sql)
=> connection.PrepareStatement(sql);
public IEnumerable<IStatement> PrepareAll(IDatabaseConnection connection, IEnumerable<string> sql)
=> sql.Select(connection.PrepareStatement);
protected bool TableExists(ManagedConnection connection, string name)
{
return connection.RunInTransaction(db =>
{
using (var statement = PrepareStatement(db, "select DISTINCT tbl_name from sqlite_master"))
{
foreach (var row in statement.ExecuteQuery())
{
if (string.Equals(name, row.GetString(0), StringComparison.OrdinalIgnoreCase))
{
return true;
}
}
}
return false;
}, ReadTransactionMode);
}
protected List<string> GetColumnNames(IDatabaseConnection connection, string table)
{
var columnNames = new List<string>();
foreach (var row in connection.Query("PRAGMA table_info(" + table + ")"))
{
if (row[1].SQLiteType != SQLiteType.Null)
{
var name = row[1].ToString();
columnNames.Add(name);
}
}
return columnNames;
}
protected void AddColumn(IDatabaseConnection connection, string table, string columnName, string type, List<string> existingColumnNames)
{
if (existingColumnNames.Contains(columnName, StringComparer.OrdinalIgnoreCase))
{
return;
}
connection.Execute("alter table " + table + " add column " + columnName + " " + type + " NULL");
}
protected void CheckDisposed()
{
if (_disposed)
{
throw new ObjectDisposedException(GetType().Name, "Object has been disposed and cannot be accessed.");
}
}
/// <inheritdoc />
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 (_disposed)
{
return;
}
if (dispose)
{
WriteLock.Wait();
try
{
WriteConnection?.Dispose();
}
finally
{
WriteLock.Release();
}
WriteLock.Dispose();
}
WriteConnection = null;
WriteLock = null;
_disposed = true;
}
}
/// <summary>
/// The disk synchronization mode, controls how aggressively SQLite will write data
/// all the way out to physical storage.
/// </summary>
public enum SynchronousMode
{
/// <summary>
/// SQLite continues without syncing as soon as it has handed data off to the operating system
/// </summary>
Off = 0,
/// <summary>
/// SQLite database engine will still sync at the most critical moments
/// </summary>
Normal = 1,
/// <summary>
/// SQLite database engine will use the xSync method of the VFS
/// to ensure that all content is safely written to the disk surface prior to continuing.
/// </summary>
Full = 2,
/// <summary>
/// EXTRA synchronous is like FULL with the addition that the directory containing a rollback journal
/// is synced after that journal is unlinked to commit a transaction in DELETE mode.
/// </summary>
Extra = 3
}
/// <summary>
/// Storage mode used by temporary database files.
/// </summary>
public enum TempStoreMode
{
/// <summary>
/// The compile-time C preprocessor macro SQLITE_TEMP_STORE
/// is used to determine where temporary tables and indices are stored.
/// </summary>
Default = 0,
/// <summary>
/// Temporary tables and indices are stored in a file.
/// </summary>
File = 1,
/// <summary>
/// Temporary tables and indices are kept in as if they were pure in-memory databases memory.
/// </summary>
Memory = 2
}
}