/// <summary>
/// Save all db context changes and commit all the transactions
/// </summary>
public async Task SaveAndCommitChangesAsync(CancellationToken cancellationToken)
{
if (_savedContextData.Disposed)
{
//this can only happen when a parallel threads are executing with the main thread and the parallel/main
//thread has disposed before the main and/or other parallel has finished execution
//This should never happen.Only programming error coul cause this issue.
throw new ObjectDisposedException("Object already disposed exception");
}
var contextData = CallContextContextData.GetContextData();
if (contextData != _savedContextData)
{
//Duplicate contextdata has been created by someother thread. Could be result of two thread trying to create contextData at same time.
throw new Exception(
"Duplicate context seen. Something went terribly wrong in the programming. Please check your code to correct.");
}
if (!_isParentScope)
{
_isCompleted = true;
return;
}
await _savedContextData.SaveAndCommitAsync(cancellationToken);
_isCompleted = true;
}
public new void Dispose()
{
base.Dispose();
var memento = _ambientDbContextHouseKeeper.Memento;
CallContextContextData.AddContextData(ContextKey, memento.ContextData);
}
/// <summary>
/// Commit all dbContext transactions.
/// </summary>
public void Commit()
{
if (_savedContextData.Disposed)
{
//this can only happen when a parallel threads are executing with the main thread and the parallel/main
//thread has disposed before the main and/or other parallel has finished execution
//This should never happen.Only programming error could cause this issue.
throw new ObjectDisposedException("Object already disposed exception");
}
var contextData = CallContextContextData.GetContextData();
if (contextData != _savedContextData)
{
//Duplicate contextdata has been created by someother thread. Could be result of two thread trying to create contextData at same time.
throw new Exception(
"Duplicate context seen. Something went terribly wrong in the programming. Please check your code to correct.");
}
if (!_isParentScope)
{
_isCompleted = true;
Debug.WriteLine("Cannot commit the transaction as Commit method is called from a child dbContextScope");
return;
}
_savedContextData.Commit();
_isCompleted = true;
}
internal override void Initialize()
{
//copy the ambient dbcontext to the memento object
var contextData = CallContextContextData.GetContextData();
_ambientDbContextHouseKeeper.Memento = new Memento
{
ContextData = contextData
};
CallContextContextData.RemoveContextData();
base.Initialize();
}
internal virtual void Initialize()
{
_savedContextData = null;
var contextData = CallContextContextData.GetContextData();
if (contextData == null)
{
Debug.WriteLine("Creating a new DbContext");
contextData = ContextData.CreateContextData <T>(_mode, _isolationLevel, _dbTransaction,
_sqlConnection);
_isParentScope = true;
}
else
{
_isParentScope = false;
var dbcontext = contextData.GetDbContextByType <T>();
if (dbcontext == null)
{
Debug.WriteLine("Creating a new DbContext");
contextData.CreateNewDbContextIfNotExists <T>(_mode, _isolationLevel, _dbTransaction,
_sqlConnection);
}
else
{
Debug.WriteLine("DbContext exists in CallContext, just re-using it");
if (_isolationLevel != null && _isolationLevel != IsolationLevel.ReadCommitted && contextData.IsolationLevel != _isolationLevel)
{
throw new InvalidOperationException("Cannot change the isolation level on an Ambient transaction");
}
if (dbcontext.Mode == DbContextOption.Mode.Read && _mode == DbContextOption.Mode.Write)
{
throw new InvalidOperationException("Cannot nested read/write when parent is in read mode");
}
}
}
_savedContextData = contextData;
//Check the callcontext to see if there is an existing context data.
contextData = CallContextContextData.GetContextData();
//Add the context data back to the CallContext with new context key
if (contextData == null)
{
CallContextContextData.AddContextData(ContextKey, _savedContextData);
}
}
/// <summary>
/// This method is used when a non Ambient transaction is nested inside a Ambient transaction, so that any updated objects inside of the non ambient context
/// should be loaded back into the parent context to avoid stale objects in the parent cache.
/// </summary>
/// <param name="entities">list of entities to be refreshed in parent scope</param>
/// <param name="cancellationToken"><see cref="CancellationToken"/></param>
public void RefreshParentCacheWithUpdatedEntitiesAsync(IEnumerable entities, CancellationToken cancellationToken)
{
foreach (var dbContext in _savedContextData.DbContextCollection.GetAllDbContext())
{
var ambientContextData = CallContextContextData.GetContextData();
if (ambientContextData == null)
{
return;
}
foreach (var ambientDbContext in ambientContextData.DbContextCollection.GetAllDbContext())
{
if (ambientContextData.GetType() == dbContext.GetType())
{
foreach (var entity in entities)
{
ObjectStateEntry objectStateEntry;
//Get the entity state entry of the entity from the dbcontext under which it was modified
//and get the EntityKey of it so that this key could be used to load the entity from parent
//Ambient dbContext if any exists.
if (
((IObjectContextAdapter)dbContext).ObjectContext.ObjectStateManager
.TryGetObjectStateEntry(entity, out objectStateEntry))
{
var key = objectStateEntry.EntityKey;
ObjectStateEntry parentObjectStateEntry;
if (
((IObjectContextAdapter)ambientDbContext).ObjectContext.ObjectStateManager
.TryGetObjectStateEntry(key, out parentObjectStateEntry))
{
//Modify it only when the parent context entity state entry is unmodified. Else
//just leave it to the database to resolve the issue.
if (parentObjectStateEntry.State == EntityState.Unchanged)
{
((IObjectContextAdapter)ambientDbContext).ObjectContext.RefreshAsync(
RefreshMode.StoreWins, entity, cancellationToken);
}
}
}
}
}
}
}
}
/// <summary>
/// Save the db context changes. Note the transaction is not committed yet.
/// </summary>
public void SaveChanges()
{
if (_savedContextData.Disposed)
{
//this can only happen when a parallel threads are executing with the main thread and the parallel/main
//thread has disposed before the main and/or other parallel has finished execution
//This should never happen.Only programming error could cause this issue.
throw new ObjectDisposedException("Object already disposed exception");
}
var contextData = CallContextContextData.GetContextData();
if (contextData != _savedContextData)
{
//Duplicate contextdata has been created by someother thread. Could be result of two thread trying to create contextData at same time.
throw new Exception(
"Duplicate context seen. Something went terribly wrong in the programming. Please check your code to correct.");
}
_savedContextData.Save();
}
public void Dispose()
{
if (_savedContextData.Disposed)
{
//too late to throw error.
return;
}
if (!_isParentScope)
{
_savedContextData = null;
return;
}
var contextData = CallContextContextData.GetContextData();
if (contextData != _savedContextData)
{
//Duplicate contextdata has been created by someother thread. Could be result of two thread trying to create contextData at same time.
throw new Exception(
"Context disposed or duplicate context seen. Something went terribly wrong in the programming. Please check your code to correct.");
}
if (_isParentScope)
{
if (!_isCompleted && _mode == DbContextOption.Mode.Write)
{
//Cleaning as much as possible. If DbContext is getting disposed before transaction is completed
// atleast rollback all uncommitted transaction.
_savedContextData.Rollback();
}
contextData.Dispose();
//Remove the contextData from the CallContext.
CallContextContextData.RemoveContextData();
contextData.Disposed = true;
Debug.WriteLine("DbContext disposed successfully");
}
}
internal static T GetDbContext()
{
var contextData = CallContextContextData.GetContextData();
return(contextData.GetDbContextByType <T>());
}
