When handling the Nodes collection in MiniYaml, individual nodes are located via one of two methods:
// Lookup a single key with linear search.
var node = yaml.Nodes.FirstOrDefault(n => n.Key == "SomeKey");
// Convert to dictionary, expecting many key lookups.
var dict = nodes.ToDictionary();
// Lookup a single key in the dictionary.
var node = dict["SomeKey"];
To simplify lookup of individual keys via linear search, provide helper methods NodeWithKeyOrDefault and NodeWithKey. These helpers do the equivalent of Single{OrDefault} searches. Whilst this requires checking the whole list, it provides a useful correctness check. Two duplicated keys in TS yaml are fixed as a result. We can also optimize the helpers to not use LINQ, avoiding allocation of the delegate to search for a key.
Adjust existing code to use either lnear searches or dictionary lookups based on whether it will be resolving many keys. Resolving few keys can be done with linear searches to avoid building a dictionary. Resolving many keys should be done with a dictionary to avoid quaradtic runtime from repeated linear searches.
Previously, the ClosestTo and PositionClosestTo existed to perform a simple distance based check to choose the closest location from a choice of locations to a single other location. For some functions this is sufficient, but for many functions we want to then move between the locations. If the location selected is in fact unreachable (e.g. on another island) then we would not want to consider it.
We now introduce ClosestToIgnoringPath for checks where we don't care about a path existing, e.g. weapons hitting nearby targets. When we do care about paths, we introduce ClosestToWithPathFrom and ClosestToWithPathTo which will check that a path exists. The PathFrom check will make sure one of the actors from the list can make it to the single target location. The PathTo check will make sure the single actor can make it to one of the target locations. This difference allows us to specify which actor will be doing the moving. This is important as a path might exists for one actor, but not another. Consider two islands with a hovercraft on one and a tank on the other. The hovercraft can path to the tank, but the tank cannot path to the hovercraft.
We also introduce WithPathFrom and WithPathTo. These will perform filtering by checking for valid paths, but won't select the closest location.
By employing the new methods that filter for paths, we fix various behaviour that would cause actors to get confused. Imagine an islands map, by checking for paths we ensure logic will locate reachable locations on the island, rather than considering a location on a nearby island that is physically closer but unreachable. This fixes AI squad automation, and other automated behaviours such as rearming.
This changeset is motivated by a simple concept - get rid of the MiniYaml.Clone and MiniYamlNode.Clone methods to avoid deep copying yaml trees during merging. MiniYaml becoming immutable allows the merge function to reuse existing yaml trees rather than cloning them, saving on memory and improving merge performance. On initial loading the YAML for all maps is processed, so this provides a small reduction in initial loading time.
The rest of the changeset is dealing with the change in the exposed API surface. Some With* helper methods are introduced to allow creating new YAML from existing YAML. Areas of code that generated small amounts of YAML are able to transition directly to the immutable model without too much ceremony. Some use cases are far less ergonomic even with these helper methods and so a MiniYamlBuilder is introduced to retain mutable creation functionality. This allows those areas to continue to use the old mutable structures. The main users are the update rules and linting capabilities.
- In FieldLoader, cache boxed bools and some boxed ints.
- In FieldLoader, presize collections when parsing a List, HashSet or Dictionary.
- In FieldLoader, don't allocate a list of missing items until required.
- In FieldLoader, when a string value is passed, avoid wrapping this in a MiniYaml object by allowing both strings and yaml to be passed in the GetValue overload that does the real work.
- In Animation, avoid allocating no-op actions.
- In VxlReader, use EnsureCapcity to better size the Dictionary.
- In VxlReader change VxlElement to a struct.
- In Locomotor, presize TerrainSpeeds dictionary.
- In MixFile, the Distinct call doesn't presize the HashSet it uses internally. As we know we will enumerate all results, create the HashSet ourselves so that is it presized correctly.
- In ObjectCreator, stream the assembly when hashing rather than reading all bytes into memory.
These changes avoid some allocations on the large object heap, in turn this means the GC can avoid performing unnecessary Gen 2 collections just to clear down the LOH.
- In RLEZerosCompression use dedicated Array.Clear method instead of open-coded loop.
- In VoxelLoader.GenerateSlicePlanes.Get use TryGetValue to avoid repeated array and dictionary lookups.
- In TmpTSLoader.UnpackTileData use ReadBytes to populate array with less overhead compared to repeated one byte reads.
- Resolve TODO in VqaVideo.
- Consuming methods cared only about the count and not the actual actors, so only counts the actors rather that creating lists.
- ProvidesPrerequisites implementations return cached objects rather then allocating new enumerables on each call.
Split out ImportGen2MapCommand from ImportTSMapCommand, to also serve as a base for a RA2 map importer.
Also renamed TS importer to ImportTiberianSunMapCommand.
- Enforce SA1604 ElementDocumentationShouldHaveSummary.
- Enforce SA1629 DocumentationTextShouldEndWithAPeriod.
- Turn off some rules covered by IDExxxx rules.
- Remaining rules are treated as part of OpenRA style.
Multiple layers of Lazy<T>ness are replaced with
an explicit two-part loading scheme.
Sequences are parsed immediately, without the need
for the sprite assets, and tell the SpriteCache
which frames they need. Use-cases that want the
actual sprites can then tell the SpriteCache to
load the frames and the sequences to resolve the
sprites.
