public SqliteCache(SqliteCacheOptions options, ILogger <SqliteCache>?logger = null)
{
_config = options;
_logger = logger ?? new NullLogger <SqliteCache>();
// Silence warnings about variables not initialized in constructor because they ARE
// initialized in the call to `Connect()`.
_db = null !;
Commands = null !;
Connect();
// Directly checking _db/Commands will cause Roslyn to think they may be null
var x = _db;
Debug.Assert(x != null);
var y = Commands;
Debug.Assert(y != null);
// This has to be after the call to Connect()
if (_config.CleanupInterval.HasValue)
{
_cleanupTimer = new Timer(_ =>
{
_logger.LogTrace("Beginning background cache cleanup");
RemoveExpired();
_logger.LogTrace("Completed background cache cleanup");
}, null, TimeSpan.Zero, _config.CleanupInterval.Value);
}
}
private void Connect()
{
if (_db == null)
{
var connectionString = _config.ConnectionString;
_logger.LogTrace("Opening connection to SQLite database: " +
"{ConnectionString}", connectionString);
// First try to open an existing database
if (!_config.MemoryOnly && System.IO.File.Exists(_config.CachePath))
{
_logger.LogTrace("Found existing database at {CachePath}", _config.CachePath);
var db = new DbConnection(_config.ConnectionString);
db.Open();
if (CheckExistingDb(db))
{
// Everything checks out, we can use this as our cache db
_db = db;
}
else
{
if (db is not null)
{
_logger.LogTrace("Closing connection to SQLite database at {SqliteCacheDbPath}", _config.CachePath);
db.Close();
db.Dispose();
}
_logger.LogInformation("Deleting existing incompatible cache db file {CachePath}", _config.CachePath);
System.IO.File.Delete(_config.CachePath);
}
}
if (_db == null)
{
_db = new DbConnection(_config.ConnectionString);
_db.Open();
Initialize();
}
Commands = new DbCommandPool(_db, _logger);
// Explicitly set default journal mode and fsync behavior
using (var cmd = new DbCommand("PRAGMA journal_mode = WAL;", _db))
{
cmd.ExecuteNonQuery();
}
using (var cmd = new DbCommand("PRAGMA synchronous = NORMAL;", _db))
{
cmd.ExecuteNonQuery();
}
}
}
public async ValueTask ConnectAsync(CancellationToken cancel)
{
if (_db == null)
{
var connectionString = _config.ConnectionString;
_logger.LogTrace("Opening connection to SQLite database: " +
"{ConnectionString}", connectionString);
// First try to open an existing database
if (!_config.MemoryOnly && System.IO.File.Exists(_config.CachePath))
{
_logger.LogTrace("Found existing database at {CachePath}", _config.CachePath);
var db = new SqliteConnection(_config.ConnectionString);
await db.OpenAsync();
if (await CheckExistingDbAsync(db, cancel))
{
// Everything checks out, we can use this as our cache db
_db = db;
}
else
{
db?.Dispose();
db?.Close();
_logger.LogInformation("Deleting existing incompatible cache db file {CachePath}", _config.CachePath);
System.IO.File.Delete(_config.CachePath);
}
}
if (_db == null)
{
_db = new DbConnection(_config.ConnectionString);
await _db.OpenAsync();
await InitializeAsync(cancel);
}
Commands = new DbCommandPool(_db, _logger);
}
}
private void Connect()
{
if (_db == null)
{
var connectionString = _config.ConnectionString;
_logger.LogTrace("Opening connection to SQLite database: " +
"{ConnectionString}", connectionString);
// First try to open an existing database
if (!_config.MemoryOnly && System.IO.File.Exists(_config.CachePath))
{
_logger.LogTrace("Found existing database at {CachePath}", _config.CachePath);
var db = new DbConnection(_config.ConnectionString);
db.Open();
if (CheckExistingDb(db))
{
// Everything checks out, we can use this as our cache db
_db = db;
}
else
{
db?.Dispose();
db?.Close();
_logger.LogInformation("Deleting existing incompatible cache db file {CachePath}", _config.CachePath);
System.IO.File.Delete(_config.CachePath);
}
}
if (_db == null)
{
_db = new DbConnection(_config.ConnectionString);
_db.Open();
Initialize();
}
Commands = new DbCommandPool(_db, _logger);
}
}