dsmiley commented on code in PR #13570: URL: https://github.com/apache/lucene/pull/13570#discussion_r1690256783
########## lucene/core/src/java/org/apache/lucene/store/MMapDirectory.java: ########## @@ -83,6 +94,41 @@ public class MMapDirectory extends FSDirectory { */ public static final BiPredicate<String, IOContext> NO_FILES = (filename, context) -> false; + /** + * This sysprop allows to control the total maximum number of mmapped files that can be associated + * with a single shared {@link java.lang.foreign.Arena foreign Arena}. For example, to set the max + * number of permits to 256, pass the following on the command line pass {@code + * -Dorg.apache.lucene.store.MMapDirectory.sharedArenaMaxPermits=256}. Setting a value of 1 + * associates one file to one shared arena. + * + * @lucene.internal + */ + public static final String SHARED_ARENA_MAX_PERMITS_SYSPROP = + "org.apache.lucene.store.MMapDirectory.sharedArenaMaxPermits"; + + /** Argument for {@link #setGroupingFunction(Function)} that configures no grouping. */ + public static final Function<String, Optional<String>> NO_GROUPING = filename -> Optional.empty(); + + /** Argument for {@link #setGroupingFunction(Function)} that configures grouping by segment. */ + public static final Function<String, Optional<String>> GROUP_BY_SEGMENT = + filename -> { + if (!CODEC_FILE_PATTERN.matcher(filename).matches()) { + return Optional.empty(); + } + String groupKey = IndexFileNames.parseSegmentName(filename).substring(1); + try { + // keep the original generation (=0) in base group, later generations in extra group + if (IndexFileNames.parseGeneration(filename) > 0) { + groupKey += "-g"; + } + } catch ( + @SuppressWarnings("unused") + NumberFormatException unused) { + // does not confirm to the generation syntax, or trash Review Comment: I would use an assert here -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: issues-unsubscr...@lucene.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@lucene.apache.org For additional commands, e-mail: issues-h...@lucene.apache.org