Prepare for direct btree posting list iterators with only docids.

12 files changed, 58 insertions, 33 deletions

diff --git a/searchlib/src/tests/attribute/searchable/attribute_searchable_adapter_test.cpp b/searchlib/src/tests/attribute/searchable/attribute_searchable_adapter_test.cpp
index 029c3130609..9ed28a7714c 100644
--- a/searchlib/src/tests/attribute/searchable/attribute_searchable_adapter_test.cpp
+++ b/searchlib/src/tests/attribute/searchable/attribute_searchable_adapter_test.cpp
@@ -572,7 +572,7 @@ TEST("require that attribute weighted set term works") {
         ASSERT_EQUAL(5u, result.hits.size());
         if (fast_search && result.iterator_dump.find("MonitoringDumpIterator") == vespalib::string::npos) {
             fprintf(stderr, "DUMP: %s\n", result.iterator_dump.c_str());
-            EXPECT_TRUE(result.iterator_dump.find("AttributeIteratorPack") != vespalib::string::npos);
+            EXPECT_TRUE(result.iterator_dump.find("PostingIteratorPack") != vespalib::string::npos);
         }
         EXPECT_EQUAL(10u, result.hits[0].docid);
         EXPECT_EQUAL(20, result.hits[0].match_weight);
diff --git a/searchlib/src/vespa/searchlib/attribute/CMakeLists.txt b/searchlib/src/vespa/searchlib/attribute/CMakeLists.txt
index 76389311eaa..f80e8dbe7be 100644
--- a/searchlib/src/vespa/searchlib/attribute/CMakeLists.txt
+++ b/searchlib/src/vespa/searchlib/attribute/CMakeLists.txt
@@ -74,7 +74,6 @@ vespa_add_library(searchlib_attribute OBJECT
     imported_search_context.cpp
     integerbase.cpp
     ipostinglistsearchcontext.cpp
-    iterator_pack.cpp
     load_utils.cpp
     loadedenumvalue.cpp
     loadednumericvalue.cpp
@@ -104,6 +103,7 @@ vespa_add_library(searchlib_attribute OBJECT
     numeric_search_context.cpp
     numeric_sort_blob_writer.cpp
     numericbase.cpp
+    posting_iterator_pack.cpp
     posting_list_merger.cpp
     postingchange.cpp
     postinglistattribute.cpp
diff --git a/searchlib/src/vespa/searchlib/attribute/attribute_blueprint_factory.cpp b/searchlib/src/vespa/searchlib/attribute/attribute_blueprint_factory.cpp
index 8c56fc081fc..6ccfa472b42 100644
--- a/searchlib/src/vespa/searchlib/attribute/attribute_blueprint_factory.cpp
+++ b/searchlib/src/vespa/searchlib/attribute/attribute_blueprint_factory.cpp
@@ -7,7 +7,7 @@
 #include "direct_multi_term_blueprint.h"
 #include "document_weight_or_filter_search.h"
 #include "i_direct_posting_store.h"
-#include "iterator_pack.h"
+#include "posting_iterator_pack.h"
 #include "predicate_attribute.h"
 #include <vespa/eval/eval/value.h>
 #include <vespa/searchlib/common/location.h>
diff --git a/searchlib/src/vespa/searchlib/attribute/document_weight_or_filter_search.cpp b/searchlib/src/vespa/searchlib/attribute/document_weight_or_filter_search.cpp
index 7ae7a24b80f..5159c2be06c 100644
--- a/searchlib/src/vespa/searchlib/attribute/document_weight_or_filter_search.cpp
+++ b/searchlib/src/vespa/searchlib/attribute/document_weight_or_filter_search.cpp
@@ -1,7 +1,7 @@
 // Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 
 #include "document_weight_or_filter_search.h"
-#include "iterator_pack.h"
+#include "posting_iterator_pack.h"
 #include <vespa/searchlib/fef/matchdata.h>
 #include <vespa/searchlib/queryeval/iterator_pack.h>
 #include <vespa/searchlib/common/bitvector.h>
@@ -93,8 +93,8 @@ DocumentWeightOrFilterSearch::create(std::vector<DocidWithWeightIterator>&& chil
     } else {
         std::sort(children.begin(), children.end(),
                   [](const auto & a, const auto & b) { return a.size() > b.size(); });
-        using OrFilter = DocumentWeightOrFilterSearchImpl<AttributeIteratorPack>;
-        return std::make_unique<OrFilter>(AttributeIteratorPack(std::move(children)));
+        using OrFilter = DocumentWeightOrFilterSearchImpl<DocidWithWeightIteratorPack>;
+        return std::make_unique<OrFilter>(DocidWithWeightIteratorPack(std::move(children)));
     }
 }
 
diff --git a/searchlib/src/vespa/searchlib/attribute/i_direct_posting_store.h b/searchlib/src/vespa/searchlib/attribute/i_direct_posting_store.h
index 1d26f3ef202..559a365923a 100644
--- a/searchlib/src/vespa/searchlib/attribute/i_direct_posting_store.h
+++ b/searchlib/src/vespa/searchlib/attribute/i_direct_posting_store.h
@@ -10,6 +10,14 @@ namespace search::queryeval { class SearchIterator; }
 
 namespace search {
 
+/**
+ * Direct (low-level) iterator over a btree posting list that contains only docids.
+ */
+using DocidIterator = attribute::PostingListTraits<vespalib::btree::BTreeNoLeafData>::const_iterator;
+
+/**
+ * Direct (low-level) iterator over a btree posting list that contains {docid, weight} tuples.
+ */
 using DocidWithWeightIterator = attribute::PostingListTraits<int32_t>::const_iterator;
 
 /**
diff --git a/searchlib/src/vespa/searchlib/attribute/iterator_pack.cpp b/searchlib/src/vespa/searchlib/attribute/posting_iterator_pack.cpp
index 7f40a38fc7f..662d77dd5d7 100644
--- a/searchlib/src/vespa/searchlib/attribute/iterator_pack.cpp
+++ b/searchlib/src/vespa/searchlib/attribute/posting_iterator_pack.cpp
@@ -1,28 +1,32 @@
 // Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 
-#include "iterator_pack.h"
+#include "posting_iterator_pack.h"
 #include <vespa/searchlib/common/bitvector.h>
 #include <limits>
 
 namespace search {
 
-AttributeIteratorPack::~AttributeIteratorPack() = default;
+template <typename IteratorType>
+PostingIteratorPack<IteratorType>::~PostingIteratorPack() = default;
 
-AttributeIteratorPack::AttributeIteratorPack(std::vector<DocidWithWeightIterator> &&children)
+template <typename IteratorType>
+PostingIteratorPack<IteratorType>::PostingIteratorPack(std::vector<IteratorType> &&children)
     : _children(std::move(children))
 {
     assert(_children.size() <= std::numeric_limits<ref_t>::max());
 }
 
+template <typename IteratorType>
 std::unique_ptr<BitVector>
-AttributeIteratorPack::get_hits(uint32_t begin_id, uint32_t end_id) {
+PostingIteratorPack<IteratorType>::get_hits(uint32_t begin_id, uint32_t end_id) {
     BitVector::UP result(BitVector::create(begin_id, end_id));
     or_hits_into(*result, begin_id);
     return result;
 }
 
+template <typename IteratorType>
 void
-AttributeIteratorPack::or_hits_into(BitVector &result, uint32_t begin_id) {
+PostingIteratorPack<IteratorType>::or_hits_into(BitVector &result, uint32_t begin_id) {
     for (size_t i = 0; i < size(); ++i) {
         uint32_t docId = get_docid(i);
         if (begin_id > docId) {
@@ -35,6 +39,14 @@ AttributeIteratorPack::or_hits_into(BitVector &result, uint32_t begin_id) {
     result.invalidateCachedCount();
 }
 
+template <>
+int32_t
+PostingIteratorPack<DocidIterator>::get_weight(ref_t, uint32_t)
+{
+    return 1;
+}
 
+template class PostingIteratorPack<DocidIterator>;
+template class PostingIteratorPack<DocidWithWeightIterator>;
 
 }
diff --git a/searchlib/src/vespa/searchlib/attribute/iterator_pack.h b/searchlib/src/vespa/searchlib/attribute/posting_iterator_pack.h
index 3d2bedc7b3a..28150730bad 100644
--- a/searchlib/src/vespa/searchlib/attribute/iterator_pack.h
+++ b/searchlib/src/vespa/searchlib/attribute/posting_iterator_pack.h
@@ -9,19 +9,22 @@ namespace search {
 
 class BitVector;
 
-class AttributeIteratorPack
-{
+/**
+ * Class that wraps a set of underlying low-level posting lists and provides an API to search in them.
+ */
+template <typename IteratorType>
+class PostingIteratorPack {
 private:
-    std::vector<DocidWithWeightIterator> _children;
+    std::vector<IteratorType> _children;
 
 public:
     using ref_t = uint16_t;
-    AttributeIteratorPack() noexcept : _children() {}
-    AttributeIteratorPack(AttributeIteratorPack &&rhs) noexcept = default;
-    AttributeIteratorPack &operator=(AttributeIteratorPack &&rhs) noexcept = default;
+    PostingIteratorPack() noexcept : _children() {}
+    PostingIteratorPack(PostingIteratorPack &&rhs) noexcept = default;
+    PostingIteratorPack &operator=(PostingIteratorPack &&rhs) noexcept = default;
 
-    explicit AttributeIteratorPack(std::vector<DocidWithWeightIterator> &&children);
-    ~AttributeIteratorPack();
+    explicit PostingIteratorPack(std::vector<IteratorType> &&children);
+    ~PostingIteratorPack();
 
     uint32_t get_docid(ref_t ref) const {
         return _children[ref].valid() ? _children[ref].getKey() : endDocId;
@@ -56,6 +59,8 @@ private:
     }
 };
 
+using DocidIteratorPack = PostingIteratorPack<DocidIterator>;
+using DocidWithWeightIteratorPack = PostingIteratorPack<DocidWithWeightIterator>;
 
-} // namespace search
+}
 
diff --git a/searchlib/src/vespa/searchlib/queryeval/dot_product_search.cpp b/searchlib/src/vespa/searchlib/queryeval/dot_product_search.cpp
index 8f4df612023..3f8069a2a26 100644
--- a/searchlib/src/vespa/searchlib/queryeval/dot_product_search.cpp
+++ b/searchlib/src/vespa/searchlib/queryeval/dot_product_search.cpp
@@ -181,13 +181,13 @@ DotProductSearch::create(TermFieldMatchData &tmd,
                          const std::vector<int32_t> &weights,
                          std::vector<DocidWithWeightIterator> &&iterators)
 {
-    using ArrayHeapImpl = DotProductSearchImpl<vespalib::LeftArrayHeap, AttributeIteratorPack>;
-    using HeapImpl = DotProductSearchImpl<vespalib::LeftHeap, AttributeIteratorPack>;
+    using ArrayHeapImpl = DotProductSearchImpl<vespalib::LeftArrayHeap, DocidWithWeightIteratorPack>;
+    using HeapImpl = DotProductSearchImpl<vespalib::LeftHeap, DocidWithWeightIteratorPack>;
 
     if (iterators.size() < 128) {
-        return std::make_unique<ArrayHeapImpl>(tmd, field_is_filter, weights, AttributeIteratorPack(std::move(iterators)));
+        return std::make_unique<ArrayHeapImpl>(tmd, field_is_filter, weights, DocidWithWeightIteratorPack(std::move(iterators)));
     }
-    return std::make_unique<HeapImpl>(tmd, field_is_filter, weights, AttributeIteratorPack(std::move(iterators)));
+    return std::make_unique<HeapImpl>(tmd, field_is_filter, weights, DocidWithWeightIteratorPack(std::move(iterators)));
 }
 
 //-----------------------------------------------------------------------------
diff --git a/searchlib/src/vespa/searchlib/queryeval/dot_product_search.h b/searchlib/src/vespa/searchlib/queryeval/dot_product_search.h
index d06ea9439d2..2f1a4386a95 100644
--- a/searchlib/src/vespa/searchlib/queryeval/dot_product_search.h
+++ b/searchlib/src/vespa/searchlib/queryeval/dot_product_search.h
@@ -6,7 +6,7 @@
 #include <vespa/vespalib/util/priority_queue.h>
 #include <vespa/searchlib/fef/matchdata.h>
 #include <vespa/searchlib/fef/termfieldmatchdataarray.h>
-#include <vespa/searchlib/attribute/iterator_pack.h>
+#include <vespa/searchlib/attribute/posting_iterator_pack.h>
 
 namespace search::fef { class TermFieldMatchData; }
 
diff --git a/searchlib/src/vespa/searchlib/queryeval/wand/wand_parts.h b/searchlib/src/vespa/searchlib/queryeval/wand/wand_parts.h
index 84fd2eb0d9e..9431b527510 100644
--- a/searchlib/src/vespa/searchlib/queryeval/wand/wand_parts.h
+++ b/searchlib/src/vespa/searchlib/queryeval/wand/wand_parts.h
@@ -8,7 +8,7 @@
 #include <vespa/searchlib/fef/termfieldmatchdata.h>
 #include <vespa/searchlib/queryeval/searchiterator.h>
 #include <vespa/searchlib/queryeval/iterator_pack.h>
-#include <vespa/searchlib/attribute/iterator_pack.h>
+#include <vespa/searchlib/attribute/posting_iterator_pack.h>
 #include <vespa/vespalib/objects/objectvisitor.h>
 #include <vespa/vespalib/util/priority_queue.h>
 #include <vespa/searchlib/attribute/i_docid_with_weight_posting_store.h>
@@ -264,7 +264,7 @@ VectorizedIteratorTerms::VectorizedIteratorTerms(const Terms &t, const Scorer &,
 
 //-----------------------------------------------------------------------------
 
-struct VectorizedAttributeTerms : VectorizedState<AttributeIteratorPack> {
+struct VectorizedAttributeTerms : VectorizedState<DocidWithWeightIteratorPack> {
     template <typename Scorer>
     VectorizedAttributeTerms(const std::vector<int32_t> &weights,
                              const std::vector<IDirectPostingStore::LookupResult> &dict_entries,
@@ -279,7 +279,7 @@ struct VectorizedAttributeTerms : VectorizedState<AttributeIteratorPack> {
             attr.create(dict_entries[order[i]].posting_idx, iterators);
             docId(i) = (iterators.back().valid()) ? iterators.back().getKey() : search::endDocId;
         }
-        iteratorPack() = AttributeIteratorPack(std::move(iterators));
+        iteratorPack() = DocidWithWeightIteratorPack(std::move(iterators));
     }
     void visit_members(vespalib::ObjectVisitor &) const {}
 };
diff --git a/searchlib/src/vespa/searchlib/queryeval/weighted_set_term_search.cpp b/searchlib/src/vespa/searchlib/queryeval/weighted_set_term_search.cpp
index 9e58cd489ac..0ffff30cee2 100644
--- a/searchlib/src/vespa/searchlib/queryeval/weighted_set_term_search.cpp
+++ b/searchlib/src/vespa/searchlib/queryeval/weighted_set_term_search.cpp
@@ -190,13 +190,13 @@ WeightedSetTermSearch::create(fef::TermFieldMatchData &tmd,
                               const std::vector<int32_t> &weights,
                               std::vector<DocidWithWeightIterator> &&iterators)
 {
-    using ArrayHeapImpl = WeightedSetTermSearchImpl<vespalib::LeftArrayHeap, AttributeIteratorPack>;
-    using HeapImpl = WeightedSetTermSearchImpl<vespalib::LeftHeap, AttributeIteratorPack>;
+    using ArrayHeapImpl = WeightedSetTermSearchImpl<vespalib::LeftArrayHeap, DocidWithWeightIteratorPack>;
+    using HeapImpl = WeightedSetTermSearchImpl<vespalib::LeftHeap, DocidWithWeightIteratorPack>;
 
     if (iterators.size() < 128) {
-        return SearchIterator::UP(new ArrayHeapImpl(tmd, field_is_filter, weights, AttributeIteratorPack(std::move(iterators))));
+        return SearchIterator::UP(new ArrayHeapImpl(tmd, field_is_filter, weights, DocidWithWeightIteratorPack(std::move(iterators))));
     }
-    return SearchIterator::UP(new HeapImpl(tmd, field_is_filter, weights, AttributeIteratorPack(std::move(iterators))));
+    return SearchIterator::UP(new HeapImpl(tmd, field_is_filter, weights, DocidWithWeightIteratorPack(std::move(iterators))));
 }
 
 //-----------------------------------------------------------------------------
diff --git a/searchlib/src/vespa/searchlib/queryeval/weighted_set_term_search.h b/searchlib/src/vespa/searchlib/queryeval/weighted_set_term_search.h
index 17239391df8..e6391124da0 100644
--- a/searchlib/src/vespa/searchlib/queryeval/weighted_set_term_search.h
+++ b/searchlib/src/vespa/searchlib/queryeval/weighted_set_term_search.h
@@ -6,7 +6,7 @@
 #include <vespa/vespalib/util/priority_queue.h>
 #include <vespa/searchlib/fef/matchdata.h>
 #include <vespa/searchlib/fef/termfieldmatchdataarray.h>
-#include <vespa/searchlib/attribute/iterator_pack.h>
+#include <vespa/searchlib/attribute/posting_iterator_pack.h>
 #include <memory>
 #include <vector>