Generated maps are created at runtime using a
mod-defined trait. They are embedded directly
into replays and save games as they exist in
memory only, and disappear after the game exits.
Previously, the MiniYaml.From* helpers such as FromStream would consume the entire input and then return a list of top-level nodes. Now, the input is processed using deferred execution and top-level nodes are yielded as they are resolved from the input.
The motivating use-case is MapCache, which currently manually buffers nodes before passing to MiniYaml.FromString in order to improve responsiveness when large payloads are processed. Now that MiniYaml.FromStream yields results back as they come in, we can switch to that without disadvantage.
The maintains the performance where map cache can update search results as each node comes in over the network rather than having to wait for the entire batch to be transferred. Now we can also remove the string buffer that captures each node, reducing memory pressure and simplifying the code.
- Rename the filename parameter to name and make it mandatory. Review all callers and ensure a useful string is provided as input, to ensure sufficient context is included for logging and debugging. This can be a filename, url, or any arbitrary text so include whatever context seems reasonable.
- When several MiniYamls are created that have similar content, provide a shared string pool. This allows strings that are common between all the yaml to be shared, reducing long term memory usage. We also change the pool from a dictionary to a set. Originally a Dictionary had to be used so we could call TryGetValue to get a reference to the pooled string. Now that more recent versions of dotnet provide a TryGetValue on HashSet, we can use a set directly without the memory wasted by having to store both keys and values in a dictionary.
This avoids loading, parsing and merging YAML rules for the mod during loading of each individual map. This saves significant time resolving custom rules on each map loaded.
- Enforce SA1604 ElementDocumentationShouldHaveSummary.
- Enforce SA1629 DocumentationTextShouldEndWithAPeriod.
- Turn off some rules covered by IDExxxx rules.
- Remaining rules are treated as part of OpenRA style.
- Stream lines in as memory rather than needing to realise a string for each line, via a new method in StreamExts.
- Use span to avoid string allocations during parsing until we want to realise the node itself, in MiniYaml.FromLines.
- Change several callsites to use the streaming extension method rather than string method where possible.
These config files often contain many repeated strings which result in different string references in memory. By using a pool, we can detect when the strings are equal and reuse an existing reference as strings are immutable.
The FromLines will now use a pool to de-duplicate strings for a single call. By allowing a pool to be provided as a parameter, we can reuse even more strings. The MapCache defines such a pool so that strings are reused across all maps in the cache for even more savings.
