Handle fetchPostings being called multiple times.

8 files changed, 62 insertions, 66 deletions

diff --git a/searchlib/src/vespa/searchlib/attribute/imported_search_context.cpp b/searchlib/src/vespa/searchlib/attribute/imported_search_context.cpp
index 5f49111f77b..bc0d965bcc1 100644
--- a/searchlib/src/vespa/searchlib/attribute/imported_search_context.cpp
+++ b/searchlib/src/vespa/searchlib/attribute/imported_search_context.cpp
@@ -44,7 +44,6 @@ ImportedSearchContext::ImportedSearchContext(
       _target_search_context(_target_attribute.createSearchContext(std::move(term), params)),
       _targetLids(_reference_attribute.getTargetLids()),
       _merger(_reference_attribute.getCommittedDocIdLimit()),
-      _fetchPostingsDone(false),
       _params(params)
 {
 }
@@ -239,15 +238,11 @@ ImportedSearchContext::considerAddSearchCacheEntry()
 }
 
 void ImportedSearchContext::fetchPostings(const queryeval::ExecuteInfo &execInfo) {
-    assert(!_fetchPostingsDone);
-    _fetchPostingsDone = true;
     if (!_searchCacheLookup) {
         _target_search_context->fetchPostings(execInfo);
-        if (execInfo.isStrict()
-            || (_target_attribute.getIsFastSearch() && execInfo.hitRate() > 0.01))
-        {
-            makeMergedPostings(_target_attribute.getIsFilter());
-            considerAddSearchCacheEntry();
+        if (!_merger.merge_done() && (execInfo.isStrict() || (_target_attribute.getIsFastSearch() && execInfo.hitRate() > 0.01))) {
+                makeMergedPostings(_target_attribute.getIsFilter());
+                considerAddSearchCacheEntry();
         }
     }
 }
diff --git a/searchlib/src/vespa/searchlib/attribute/imported_search_context.h b/searchlib/src/vespa/searchlib/attribute/imported_search_context.h
index 1c73ac6c8c2..4c3b6a89a14 100644
--- a/searchlib/src/vespa/searchlib/attribute/imported_search_context.h
+++ b/searchlib/src/vespa/searchlib/attribute/imported_search_context.h
@@ -37,7 +37,6 @@ class ImportedSearchContext : public ISearchContext {
     std::unique_ptr<ISearchContext>                 _target_search_context;
     TargetLids                                      _targetLids;
     PostingListMerger<int32_t>                      _merger;
-    bool                                            _fetchPostingsDone;
     SearchContextParams                             _params;
 
     uint32_t getTargetLid(uint32_t lid) const {
diff --git a/searchlib/src/vespa/searchlib/attribute/posting_list_merger.h b/searchlib/src/vespa/searchlib/attribute/posting_list_merger.h
index 6a10ba73951..1c2e6583ad9 100644
--- a/searchlib/src/vespa/searchlib/attribute/posting_list_merger.h
+++ b/searchlib/src/vespa/searchlib/attribute/posting_list_merger.h
@@ -62,6 +62,8 @@ public:
                                 { if (__builtin_expect(key < limit, true)) { bv.setBit(key); } });
     }
 
+    bool merge_done() const { return hasArray() || hasBitVector(); }
+
     // Until diversity handling has been rewritten
     PostingVector &getWritableArray() { return _array; }
     StartVector   &getWritableStartPos() { return _startPos; }
diff --git a/searchlib/src/vespa/searchlib/attribute/postinglistsearchcontext.h b/searchlib/src/vespa/searchlib/attribute/postinglistsearchcontext.h
index 69450acd98d..8cd7a7064f6 100644
--- a/searchlib/src/vespa/searchlib/attribute/postinglistsearchcontext.h
+++ b/searchlib/src/vespa/searchlib/attribute/postinglistsearchcontext.h
@@ -107,7 +107,6 @@ protected:
      * Synthetic posting lists for range search, in array or bitvector form
      */
     PostingListMerger<DataT> _merger;
-    bool           _fetchPostingsDone;
 
     static const long MIN_UNIQUE_VALUES_BEFORE_APPROXIMATION = 100;
     static const long MIN_UNIQUE_VALUES_TO_NUMDOCS_RATIO_BEFORE_APPROXIMATION = 20;
diff --git a/searchlib/src/vespa/searchlib/attribute/postinglistsearchcontext.hpp b/searchlib/src/vespa/searchlib/attribute/postinglistsearchcontext.hpp
index 4cd8db9010a..09e5a9da5bc 100644
--- a/searchlib/src/vespa/searchlib/attribute/postinglistsearchcontext.hpp
+++ b/searchlib/src/vespa/searchlib/attribute/postinglistsearchcontext.hpp
@@ -25,8 +25,7 @@ PostingListSearchContextT(const Dictionary &dictionary, uint32_t docIdLimit, uin
                           uint32_t minBvDocFreq, bool useBitVector, const ISearchContext &searchContext)
     : PostingListSearchContext(dictionary, docIdLimit, numValues, hasWeight, esb, minBvDocFreq, useBitVector, searchContext),
       _postingList(postingList),
-      _merger(docIdLimit),
-      _fetchPostingsDone(false)
+      _merger(docIdLimit)
 {
 }
 
@@ -116,22 +115,18 @@ template <typename DataT>
 void
 PostingListSearchContextT<DataT>::fetchPostings(const queryeval::ExecuteInfo & execInfo)
 {
-    if (_fetchPostingsDone) return;
-
-    _fetchPostingsDone = true;
-
-    if (_uniqueValues < 2u) return;
-
-    if (execInfo.isStrict() && !fallbackToFiltering()) {
-        size_t sum(countHits());
-        if (sum < _docIdLimit / 64) {
-            _merger.reserveArray(_uniqueValues, sum);
-            fillArray();
-        } else {
-            _merger.allocBitVector();
-            fillBitVector();
+    if (!_merger.merge_done() && _uniqueValues >= 2u) {
+        if (execInfo.isStrict() && !fallbackToFiltering()) {
+            size_t sum(countHits());
+            if (sum < _docIdLimit / 64) {
+                _merger.reserveArray(_uniqueValues, sum);
+                fillArray();
+            } else {
+                _merger.allocBitVector();
+                fillBitVector();
+            }
+            _merger.merge();
         }
-        _merger.merge();
     }
 }
 
@@ -141,12 +136,12 @@ void
 PostingListSearchContextT<DataT>::diversify(bool forward, size_t wanted_hits, const IAttributeVector &diversity_attr,
                                             size_t max_per_group, size_t cutoff_groups, bool cutoff_strict)
 {
-    assert(!_fetchPostingsDone);
-    _fetchPostingsDone = true;
-    _merger.reserveArray(128, wanted_hits);
-    diversity::diversify(forward, _lowerDictItr, _upperDictItr, _postingList, wanted_hits, diversity_attr,
-                         max_per_group, cutoff_groups, cutoff_strict, _merger.getWritableArray(), _merger.getWritableStartPos());
-    _merger.merge();
+    if (!_merger.merge_done()) {
+        _merger.reserveArray(128, wanted_hits);
+        diversity::diversify(forward, _lowerDictItr, _upperDictItr, _postingList, wanted_hits, diversity_attr,
+                             max_per_group, cutoff_groups, cutoff_strict, _merger.getWritableArray(), _merger.getWritableStartPos());
+        _merger.merge();
+    }
 }
 
 
@@ -155,7 +150,6 @@ SearchIterator::UP
 PostingListSearchContextT<DataT>::
 createPostingIterator(fef::TermFieldMatchData *matchData, bool strict)
 {
-    assert(_fetchPostingsDone);
     if (_uniqueValues == 0u) {
         return std::make_unique<EmptySearch>();
     }
diff --git a/searchlib/src/vespa/searchlib/diskindex/disktermblueprint.cpp b/searchlib/src/vespa/searchlib/diskindex/disktermblueprint.cpp
index 09024505450..8231d0b4cd7 100644
--- a/searchlib/src/vespa/searchlib/diskindex/disktermblueprint.cpp
+++ b/searchlib/src/vespa/searchlib/diskindex/disktermblueprint.cpp
@@ -70,10 +70,12 @@ void
 DiskTermBlueprint::fetchPostings(const queryeval::ExecuteInfo &execInfo)
 {
     (void) execInfo;
-    _hasEquivParent = areAnyParentsEquiv(getParent());
-    _bitVector = _diskIndex.readBitVector(*_lookupRes);
-    if (!_useBitVector || !_bitVector) {
-        _postingHandle = _diskIndex.readPostingList(*_lookupRes);
+    if (!_fetchPostingsDone) {
+        _hasEquivParent = areAnyParentsEquiv(getParent());
+        _bitVector = _diskIndex.readBitVector(*_lookupRes);
+        if (!_useBitVector || !_bitVector) {
+            _postingHandle = _diskIndex.readPostingList(*_lookupRes);
+        }
     }
     _fetchPostingsDone = true;
 }
diff --git a/searchlib/src/vespa/searchlib/queryeval/predicate_blueprint.cpp b/searchlib/src/vespa/searchlib/queryeval/predicate_blueprint.cpp
index 034f57bbb36..97e7044ec0f 100644
--- a/searchlib/src/vespa/searchlib/queryeval/predicate_blueprint.cpp
+++ b/searchlib/src/vespa/searchlib/queryeval/predicate_blueprint.cpp
@@ -163,7 +163,8 @@ PredicateBlueprint::PredicateBlueprint(const FieldSpecBase &field,
       _bounds_btree_iterators(),
       _bounds_vector_iterators(),
       _zstar_btree_iterator(),
-      _zstar_vector_iterator()
+      _zstar_vector_iterator(),
+      _fetch_postings_done(false)
 {
     const auto &interval_index = _index.getIntervalIndex();
     const auto zero_constraints_docs = _index.getZeroConstraintDocs();
@@ -234,36 +235,39 @@ namespace {
 }
 
 void PredicateBlueprint::fetchPostings(const ExecuteInfo &) {
-    const auto &interval_index = _index.getIntervalIndex();
-    const auto &bounds_index = _index.getBoundsIndex();
-    lookupPostingLists(_interval_dict_entries, _interval_vector_iterators,
-                       _interval_btree_iterators, interval_index);
-    lookupPostingLists(_bounds_dict_entries, _bounds_vector_iterators,
-                       _bounds_btree_iterators, bounds_index);
-
-    // Lookup zstar interval iterator
-    if (_zstar_dict_entry.valid()) {
-        auto vector_iterator = interval_index.getVectorPostingList(Constants::z_star_compressed_hash);
-        if (vector_iterator) {
-            _zstar_vector_iterator.emplace(std::move(*vector_iterator));
-        } else {
-            _zstar_btree_iterator.emplace(interval_index.getBTreePostingList(_zstar_dict_entry));
+    if (!_fetch_postings_done) {
+        const auto &interval_index = _index.getIntervalIndex();
+        const auto &bounds_index = _index.getBoundsIndex();
+        lookupPostingLists(_interval_dict_entries, _interval_vector_iterators,
+                           _interval_btree_iterators, interval_index);
+        lookupPostingLists(_bounds_dict_entries, _bounds_vector_iterators,
+                           _bounds_btree_iterators, bounds_index);
+
+        // Lookup zstar interval iterator
+        if (_zstar_dict_entry.valid()) {
+            auto vector_iterator = interval_index.getVectorPostingList(Constants::z_star_compressed_hash);
+            if (vector_iterator) {
+                _zstar_vector_iterator.emplace(std::move(*vector_iterator));
+            } else {
+                _zstar_btree_iterator.emplace(interval_index.getBTreePostingList(_zstar_dict_entry));
+            }
         }
-    }
 
-    PredicateAttribute::MinFeatureHandle mfh = predicate_attribute().getMinFeatureVector();
-    Alloc kv(Alloc::alloc(mfh.second, vespalib::alloc::MemoryAllocator::HUGEPAGE_SIZE*4));
-    _kVBacking.swap(kv);
-    _kV = BitVectorCache::CountVector(static_cast<uint8_t *>(_kVBacking.get()), mfh.second);
-    _index.computeCountVector(_cachedFeatures, _kV);
-    for (const auto & entry : _bounds_dict_entries) {
-        addBoundsPostingToK(entry.feature);
-    }
-    for (const auto & entry : _interval_dict_entries) {
-        addPostingToK(entry.feature);
+        PredicateAttribute::MinFeatureHandle mfh = predicate_attribute().getMinFeatureVector();
+        Alloc kv(Alloc::alloc(mfh.second, vespalib::alloc::MemoryAllocator::HUGEPAGE_SIZE*4));
+        _kVBacking.swap(kv);
+        _kV = BitVectorCache::CountVector(static_cast<uint8_t *>(_kVBacking.get()), mfh.second);
+        _index.computeCountVector(_cachedFeatures, _kV);
+        for (const auto & entry : _bounds_dict_entries) {
+            addBoundsPostingToK(entry.feature);
+        }
+        for (const auto & entry : _interval_dict_entries) {
+            addPostingToK(entry.feature);
+        }
+        addPostingToK(Constants::z_star_compressed_hash);
+        addZeroConstraintToK();
+        _fetch_postings_done = true;
     }
-    addPostingToK(Constants::z_star_compressed_hash);
-    addZeroConstraintToK();
 }
 
 SearchIterator::UP
diff --git a/searchlib/src/vespa/searchlib/queryeval/predicate_blueprint.h b/searchlib/src/vespa/searchlib/queryeval/predicate_blueprint.h
index c9a19a0f5bb..9609cd4f6c9 100644
--- a/searchlib/src/vespa/searchlib/queryeval/predicate_blueprint.h
+++ b/searchlib/src/vespa/searchlib/queryeval/predicate_blueprint.h
@@ -87,6 +87,7 @@ private:
     // The zstar iterator is either a vector or a btree iterator.
     optional<BTreeIterator> _zstar_btree_iterator;
     optional<VectorIterator> _zstar_vector_iterator;
+    bool _fetch_postings_done;
 };
 
 }