madrob commented on a change in pull request #592: URL: https://github.com/apache/solr/pull/592#discussion_r838897149
########## File path: solr/core/src/java/org/apache/solr/search/SolrIndexSearcher.java ########## @@ -935,22 +956,96 @@ private DocSet getAndCacheDocSet(Query query) throws IOException { return filterCache.computeIfAbsent(query, q -> getDocSetNC(q, null)); } - private static Query matchAllDocsQuery = new MatchAllDocsQuery(); - private volatile BitDocSet liveDocs; + private static final MatchAllDocsQuery MATCH_ALL_DOCS_QUERY = new MatchAllDocsQuery(); + + /** + * A naively cached canonical `liveDocs` DocSet. This does not need to be volatile. It may be set + * multiple times, but should always be set to the same value, as all set values should pass + * through `liveDocsCache.computeIfAbsent` + */ + private BitDocSet liveDocs; + + private static final BitDocSet EMPTY = new BitDocSet(new FixedBitSet(0), 0); + + private BitDocSet computeLiveDocs() { + switch (leafContexts.size()) { + case 0: + assert numDocs() == 0; + return EMPTY; + case 1: + final Bits onlySegLiveDocs = leafContexts.get(0).reader().getLiveDocs(); + final FixedBitSet fbs; + if (onlySegLiveDocs == null) { + // `LeafReader.getLiveDocs()` returns null if no deleted docs -- accordingly, set all bits + final int onlySegMaxDoc = maxDoc(); + fbs = new FixedBitSet(onlySegMaxDoc); + fbs.set(0, onlySegMaxDoc); + } else { + fbs = FixedBitSet.copyOf(onlySegLiveDocs); + } + assert fbs.cardinality() == numDocs(); + return new BitDocSet(fbs, numDocs()); + default: + final FixedBitSet bs = new FixedBitSet(maxDoc()); + for (LeafReaderContext ctx : leafContexts) { + final LeafReader r = ctx.reader(); + final Bits segLiveDocs = r.getLiveDocs(); + final int segDocBase = ctx.docBase; + if (segLiveDocs == null) { + // `LeafReader.getLiveDocs()` returns null if no deleted docs -- accordingly, set all + // bits in seg range + bs.set(segDocBase, segDocBase + r.maxDoc()); + } else { + DocSetUtil.copyTo(segLiveDocs, 0, r.maxDoc(), bs, segDocBase); + } + } + assert bs.cardinality() == numDocs(); + return new BitDocSet(bs, numDocs()); + } + } + + private BitDocSet populateLiveDocs(Supplier<BitDocSet> liveDocsSupplier) { + final boolean computeInline; + final CompletableFuture<BitDocSet> liveDocsCacheInstance; + synchronized (liveDocsCache) { + if (liveDocsCache[0] != null) { + computeInline = false; + liveDocsCacheInstance = liveDocsCache[0]; + } else { + computeInline = true; + liveDocsCacheInstance = new CompletableFuture<>(); + liveDocsCache[0] = liveDocsCacheInstance; + } + } + final BitDocSet docs; + if (computeInline) { + docs = liveDocsSupplier.get(); + liveDocsCacheInstance.complete(docs); + liveDocs = docs; + liveDocsInsertsCount.increment(); + } else { Review comment: If we do everything in the synchronized block, then there's no reason for the CompletableFuture at all anymore, right? I feel like at that point we're losing concurrency gains, but would have to think about it more to be sure. -- 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...@solr.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@solr.apache.org For additional commands, e-mail: issues-h...@solr.apache.org