mikemccand commented on a change in pull request #179: URL: https://github.com/apache/lucene/pull/179#discussion_r697508778
########## File path: lucene/facet/src/java/org/apache/lucene/facet/taxonomy/directory/DirectoryTaxonomyReader.java ########## @@ -351,12 +348,140 @@ public FacetLabel getPath(int ordinal) throws IOException { } synchronized (categoryCache) { - categoryCache.put(catIDInteger, ret); + categoryCache.put(ordinal, ret); } return ret; } + private FacetLabel getPathFromCache(int ordinal) { + // TODO: can we use an int-based hash impl, such as IntToObjectMap, + // wrapped as LRU? + synchronized (categoryCache) { + return categoryCache.get(ordinal); + } + } + + private void checkOrdinalBounds(int ordinal) throws IllegalArgumentException { + if (ordinal < 0 || ordinal >= indexReader.maxDoc()) { + throw new IllegalArgumentException( + "ordinal " + + ordinal + + " is out of the range of the indexReader " + + indexReader.toString() + + ". The maximum possible ordinal number is " + + (indexReader.maxDoc() - 1)); + } + } + + /** + * Returns an array of FacetLabels for a given array of ordinals. + * + * <p>This API is generally faster than iteratively calling {@link #getPath(int)} over an array of + * ordinals. It uses the {@link #getPath(int)} method iteratively when it detects that the index + * was created using StoredFields (with no performance gains) and uses DocValues based iteration + * when the index is based on BinaryDocValues. Lucene switched to BinaryDocValues in version 9.0 + * + * @param ordinals Array of ordinals that are assigned to categories inserted into the taxonomy + * index + */ + public FacetLabel[] getBulkPath(int... ordinals) throws IOException { + ensureOpen(); + + int ordinalsLength = ordinals.length; + FacetLabel[] bulkPath = new FacetLabel[ordinalsLength]; + // remember the original positions of ordinals before they are sorted + int[] originalPosition = new int[ordinalsLength]; + Arrays.setAll(originalPosition, IntUnaryOperator.identity()); + + for (int i = 0; i < ordinalsLength; i++) { + // check whether the ordinal is valid before accessing the cache + checkOrdinalBounds(ordinals[i]); + // check the cache before trying to find it in the index + FacetLabel ordinalPath = getPathFromCache(ordinals[i]); + if (ordinalPath != null) { + bulkPath[i] = ordinalPath; + } + } + + /* parallel sort the ordinals and originalPosition array based on the values in the ordinals array */ + new InPlaceMergeSorter() { + @Override + protected void swap(int i, int j) { + int x = ordinals[i]; + ordinals[i] = ordinals[j]; + ordinals[j] = x; + + x = originalPosition[i]; + originalPosition[i] = originalPosition[j]; + originalPosition[j] = x; + } + + @Override + public int compare(int i, int j) { + return Integer.compare(ordinals[i], ordinals[j]); + } + }.sort(0, ordinalsLength); + + int readerIndex; + int leafReaderMaxDoc = 0; + int leafReaderDocBase = 0; + LeafReader leafReader; + LeafReaderContext leafReaderContext; + BinaryDocValues values = null; + + for (int i = 0; i < ordinalsLength; i++) { + if (bulkPath[originalPosition[i]] == null) { + /* + If ordinals[i] >= leafReaderDocBase + leafReaderMaxDoc then we find the next leaf that contains our ordinal. + Remember: ordinals[i] operates in the global ordinal space and hence we add leafReaderDocBase to the leafReaderMaxDoc + (which is the maxDoc of the specific leaf) + */ + if (values == null || ordinals[i] >= leafReaderDocBase + leafReaderMaxDoc) { Review comment: Oh sorry I thought it was a correctness issue! Since it was just performance, and very tricky to test, let's skip the test. -- 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