ChrisHegarty commented on code in PR #14482: URL: https://github.com/apache/lucene/pull/14482#discussion_r2057896977
########## lucene/core/src/java/org/apache/lucene/store/Directory.java: ########## @@ -79,6 +83,31 @@ public abstract class Directory implements Closeable { */ public abstract long fileLength(String name) throws IOException; + protected void validateIOContext(IOContext context) { + Map<Class<? extends IOContext.FileOpenHint>, List<IOContext.FileOpenHint>> hintClasses = + context.hints().stream().collect(Collectors.groupingBy(IOContext.FileOpenHint::getClass)); + + // there should only be one of FileType, FileData, DataAccess + List<IOContext.FileOpenHint> fileTypes = + hintClasses.getOrDefault(FileTypeHint.class, List.of()); + if (fileTypes.size() > 1) { + throw new IllegalArgumentException("Multiple file type hints specified: " + fileTypes); + } + List<IOContext.FileOpenHint> fileData = hintClasses.getOrDefault(FileDataHint.class, List.of()); + if (fileData.size() > 1) { + throw new IllegalArgumentException("Multiple file data hints specified: " + fileData); + } + List<IOContext.FileOpenHint> dataAccess = + hintClasses.getOrDefault(DataAccessHint.class, List.of()); + if (dataAccess.size() > 1) { + throw new IllegalArgumentException("Multiple data access hints specified: " + dataAccess); + } + } + + protected ReadAdvice toReadAdvice(IOContext context) { Review Comment: The final api position as I understand it, `IOContext` has no knowledge of `ReadAdvice` ( `IOConext::withReadAdvice` and `IOContext::readAdvice` will be removed ). EDIT: this is incorrect. D'oh!! ~`ReadAdvice` is rather determined by the directory when given the higher-level hints from the IOContext. For example, the `MMapDirectory` implementation of openInput would do something like.~ ```java public IndexInput openInput(String name, IOContext context) throws IOException { ... return PROVIDER.openInput(..., toReadAdvice(context), preload.test(name, context),...); } ``` ~... so it's somewhat akin to the the current preLoad model.~ ~For a custom filter wrapper one would do:~ ```java Directory dir = new FilterDirectory(mmapDirectory) { @Override public ReadAdvice toReadAdvice(IOContext context) { if (someCondition) { // enforce specific read advice instead of relying on hints return ReadAdvice.NORMAL; } // hints to readAdvice } } ``` -- 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