private void InternalUpdate <T>(T entity, string name, ConcurrentSaveOptions saveOptions) // where T : IMongoEntity
{
var mongoEntity = (IMongoEntity)entity;
MongoCollection <T> coll = Db.GetCollection <T>(name);
IMongoQuery find;
if (saveOptions == ConcurrentSaveOptions.ProtectServerChanges)
{
find = Query.And(Query.EQ("_id", mongoEntity._id), Query.EQ("_accessId", mongoEntity._accessId));
}
else
{
find = Query.EQ("_id", mongoEntity._id);
}
string originalAccessId = mongoEntity._accessId;
mongoEntity._accessId = BuildAccessId();
try
{
var wrap = new BsonDocumentWrapper(entity);
var update = new UpdateDocument(wrap.ToBsonDocument());
WriteConcernResult res = coll.Update(find, update);
if (res.DocumentsAffected == 1 && res.Ok)
{
// success
return;
}
if (!res.Ok)
{
throw new MongoConcurrencyException(res.ErrorMessage);
}
// problem. is there just no document or is there a concurrency problem.
// let's do a little work to no be overly agressive on the errors.
bool isConcurrencyError = coll.Find(Query.EQ("_id", mongoEntity._id)).Any();
//coll.AsQueryable().Any(e => e._id == mongoEntity._id);
if (isConcurrencyError)
{
throw new MongoConcurrencyException("Entity modified by other writer since being retreived from db: id = " +
mongoEntity._id);
}
throw new MongoException("Cannot update entity (no entity with ID " + mongoEntity._id + " exists in the db.");
}
catch
{
mongoEntity._accessId = originalAccessId;
throw;
}
}
public void Save <T>(T entity, string connectionName, ConcurrentSaveOptions saveOptions) where T : class
{
if (entity == null)
{
throw new ArgumentNullException("entity");
}
var mongoEntity = entity as IMongoEntity;
if (mongoEntity == null)
{
throw new InvalidOperationException("Cannot save entity in ConcurrentDataContext. " + typeof(T).Name +
" does not implemented IMongoEntity.");
}
if (mongoEntity._id == ObjectId.Empty)
{
InternalInsert(entity, connectionName);
}
else
{
InternalUpdate(entity, connectionName, saveOptions);
}
}
/// <summary>
/// Save changes to entity back to MongoDB with concurrency protection
/// specified by saveOptions. If you want to *overwrite* changes made
/// on the server use ConcurrentSaveOptions.OverwriteServerChanges.
/// </summary>
/// <typeparam name="T">Type of entity</typeparam>
/// <param name="entity">The entity to be saved</param>
/// <param name="saveOptions">
/// Enables or disables concurrency projected,
/// ConcurrentSaveOptions.ProtectServerChanges is recommended.
/// </param>
public void Save <T>(T entity, ConcurrentSaveOptions saveOptions) where T : class
{
Save(entity, GetCollectionName <T>(), saveOptions);
}
