/// <summary>
/// Disposes ambient database context.
/// </summary>
public void Dispose()
{
var immutableStack = _storageHelper.GetStack();
// This can only happen if the consumer of the library is messing with the storage.
if (immutableStack.IsEmpty)
{
throw new AmbientDbContextException("Could not dispose ambient database context because it does not exist in storage.");
}
var topItem = immutableStack.Peek();
if (this != topItem)
{
throw new InvalidOperationException("Could not dispose ambient database context because it is not the active ambient database context. This could occur because ambient database context is being disposed out of order.");
}
immutableStack = immutableStack.Pop();
_storageHelper.SaveStack(immutableStack);
if (Parent == null)
{
if (Connection?.State == ConnectionState.Open)
{
Connection.Close();
Connection.Dispose();
Connection = null;
}
}
}
/// <summary>
/// Initializes the underlying contextual storage.
/// </summary>
/// <returns>
/// The immutable stack containing active ambient database contexts.
/// </returns>
private IImmutableStack <IAmbientDbContext> PrepareStorageAndStack()
{
var storage = AmbientDbContextStorageProvider.Storage;
_storageHelper = new ContextualStorageHelper(storage);
return(_storageHelper.GetStack());
}
/// <summary>
/// Retrieves active ambient database context from the storage.
/// </summary>
/// <returns>
/// The active <see cref="IAmbientDbContextQueryProxy"/> instance.
/// </returns>
/// <exception cref="AmbientDbContextException">
/// when the contextual storage does not contain an active ambient database context.
/// </exception>
public IAmbientDbContextQueryProxy Get()
{
var immutableStack = _storageHelper.GetStack();
if (immutableStack.IsEmpty)
{
throw new InvalidOperationException("Could not find active ambient database context instance. Use AmbientDbContextFactory to create ambient database context before attempting to execute queries.");
}
return((IAmbientDbContextQueryProxy)immutableStack.Peek());
}