/// <summary>
/// Initializes the SQLite logging facilities.
/// </summary>
public static void Initialize()
{
//
// BUFXIX: We cannot initialize the logging interface if the SQLite
// core library has already been initialized anywhere in
// the process (see ticket [2ce0870fad]).
//
if (SQLite3.StaticIsInitialized())
{
return;
}
//
// BUGFIX: To avoid nasty situations where multiple AppDomains are
// attempting to initialize and/or shutdown what is really
// a shared native resource (i.e. the SQLite core library
// is loaded per-process and has only one logging callback,
// not one per-AppDomain, which it knows nothing about),
// prevent all non-default AppDomains from registering a
// log handler unless the "Force_SQLiteLog" environment
// variable is used to manually override this safety check.
//
if (!AppDomain.CurrentDomain.IsDefaultAppDomain() &&
Environment.GetEnvironmentVariable("Force_SQLiteLog") == null)
{
return;
}
lock (syncRoot)
{
//
// NOTE: Add an event handler for the DomainUnload event so
// that we can unhook our logging managed function
// pointer from the native SQLite code prior to it
// being invalidated.
//
// BUGFIX: Make sure this event handler is only added one
// time (per-AppDomain).
//
if (_domainUnload == null)
{
_domainUnload = new EventHandler(DomainUnload);
AppDomain.CurrentDomain.DomainUnload += _domainUnload;
}
//
// NOTE: Create an instance of the SQLite wrapper class.
//
if (_sql == null)
{
_sql = new SQLite3(SQLiteDateFormats.Default,
DateTimeKind.Unspecified);
}
//
// NOTE: Create a single "global" (i.e. per-process) callback
// to register with SQLite. This callback will pass the
// event on to any registered handler. We only want to
// do this once.
//
if (_callback == null)
{
_callback = new SQLiteLogCallback(LogCallback);
int rc = _sql.SetLogCallback(_callback);
if (rc != 0)
{
throw new SQLiteException(rc,
"Failed to initialize logging.");
}
}
//
// NOTE: Logging is enabled by default.
//
_enabled = true;
//
// NOTE: For now, always setup the default log event handler.
//
AddDefaultHandler();
}
}
///////////////////////////////////////////////////////////////////////////////////////////////
#region Static "Factory" Methods
/// <summary>
/// Creates a <see cref="SQLiteBlob" /> object. This will not work
/// for tables that were created WITHOUT ROWID -OR- if the query
/// does not include the "rowid" column or one of its aliases -OR-
/// if the <see cref="SQLiteDataReader" /> was not created with the
/// <see cref="CommandBehavior.KeyInfo" /> flag.
/// </summary>
/// <param name="dataReader">
/// The <see cref="SQLiteDataReader" /> instance with a result set
/// containing the desired blob column.
/// </param>
/// <param name="i">
/// The index of the blob column.
/// </param>
/// <param name="readOnly">
/// Non-zero to open the blob object for read-only access.
/// </param>
/// <returns>
/// The newly created <see cref="SQLiteBlob" /> instance -OR- null
/// if an error occurs.
/// </returns>
public static SQLiteBlob Create(
SQLiteDataReader dataReader,
int i,
bool readOnly
)
{
SQLiteConnection connection = SQLiteDataReader.GetConnection(
dataReader);
if (connection == null)
{
throw new InvalidOperationException("Connection not available");
}
SQLite3 sqlite3 = connection._sql as SQLite3;
if (sqlite3 == null)
{
throw new InvalidOperationException("Connection has no wrapper");
}
SQLiteConnectionHandle handle = sqlite3._sql;
if (handle == null)
{
throw new InvalidOperationException("Connection has an invalid handle.");
}
long?rowId = dataReader.GetRowId(i);
if (rowId == null)
{
throw new InvalidOperationException("No RowId is available");
}
SQLiteBlobHandle blob = null;
try
{
// do nothing.
}
finally /* NOTE: Thread.Abort() protection. */
{
IntPtr ptrBlob = IntPtr.Zero;
SQLiteErrorCode rc = UnsafeNativeMethods.sqlite3_blob_open(
sqlite3._sql, SQLiteConvert.ToUTF8(
dataReader.GetDatabaseName(i)), SQLiteConvert.ToUTF8(
dataReader.GetTableName(i)), SQLiteConvert.ToUTF8(
dataReader.GetName(i)), (long)rowId, readOnly ? 0 : 1,
ref ptrBlob);
if (rc != SQLiteErrorCode.Ok)
{
throw new SQLiteException(rc, null);
}
blob = new SQLiteBlobHandle(handle, ptrBlob);
}
SQLiteConnection.OnChanged(null, new ConnectionEventArgs(
SQLiteConnectionEventType.NewCriticalHandle, null,
null, null, dataReader, blob, null, new object[] {
typeof(SQLiteBlob), dataReader, i, readOnly
}));
return(new SQLiteBlob(sqlite3, blob));
}
