- `PortfolioTargetCollection` avoid calling `Count` on
ConcurrentDictionary directly -> has to take all locks
- `SecurityChanges` change Union for Concat since constructor will call
HashSet
- Make `DynamicSecurityData` hold lazy data objects
- `RegisteredSecurityDataTypesProvider` avoid looping over all
registered types, adding `TryGetType`
- `Security.Update()` will no call group by on data since this data is
already grouped by type. Adding `ContainsFillForwardData` will allows to
be lazy and not re loop through the data unless necessary
- `DefaultAlphaHandler` will use the `static`
`Enumerable.Empty<Insight>` instance when possible
- `SubscriptionSynchronizer` will be lazy to construct the
`universeData` dictionary which is not used in most of the times. Will
use `Count` vs `Any` -> `Count` is known by the dictionary
- For python algorithms `JobQueue` will respect `AlgorithmLocation`, was
using unexisting `"algorithm-path-python"`
- `TimeSliceFactory` will avoid creating empty collections
- `ExecutionModels` will check target collection count before trying to
enumerate
- Reduce calls to .`TotalPortfolioValue`
- `SecurityValues` will only be created when required
- `TimeKeeper` will use TimeZone unique Id as dictionary key. The
TimeZone hash is expensive.
- `AlgorithmManager` will avoid calling `DateTime.UtcNow`,
`ConvertFromUtc()` and `RoundDownInTimeZone()`
- Using `Aggregate(lambda)` vs `Sum(lambda)` since the later is slower
due to performing an extra `Select`
- For `QCAlgorithm.Framework.OnFrameworkData()` will avoid calling
`ToArray()` on empty `Enumerables` due to its cost * the number of
calls. If the `Enumerable` is the empty instance, which is static,
will create a new empty array and return it instead.
- Replacing `SecurityIdentifier` `SecurityType` and `GetHashCode`
implementations for `Lazy` versions, that are performed just once, since
these values do not change and are used multiple times.
- For the different `DataDictionary<T>` implementations adding `this[
Symbol] get; set` since existing overload `this [string]` produces an
extra round operations `Symbol->string->Symbol` with a significant
impact.
- Adding `PortfolioTargetCollection.AddRange()` overload using an array
to avoid unnecessary convertions.
VWAP will submit market orders while the current price is more favorable than VWAP.
STD will submit market orders while the current price is a configured number of
standard deviations away from the mean in the favorable direction.