Use acquire_elem_ref() method when accessing meta data store from readers.

Use ConstArrayRef to pass view of meta data to saver.

6 files changed, 24 insertions, 25 deletions

diff --git a/searchcore/src/vespa/searchcore/proton/documentmetastore/documentmetastore.cpp b/searchcore/src/vespa/searchcore/proton/documentmetastore/documentmetastore.cpp
index 5d2f358e4c8..d4b0f173087 100644
--- a/searchcore/src/vespa/searchcore/proton/documentmetastore/documentmetastore.cpp
+++ b/searchcore/src/vespa/searchcore/proton/documentmetastore/documentmetastore.cpp
@@ -261,7 +261,8 @@ DocumentMetaStore::onInitSave(vespalib::stringref fileName)
     GenerationHandler::Guard guard(getGuard());
     return std::make_unique<DocumentMetaStoreSaver>
         (std::move(guard), createAttributeHeader(fileName),
-         _gidToLidMap.getFrozenView().begin(), _metaDataStore);
+         _gidToLidMap.getFrozenView().begin(),
+         vespalib::ConstArrayRef(&_metaDataStore[0], getCommittedDocIdLimit()));
 }
 
 DocumentMetaStore::DocId
diff --git a/searchcore/src/vespa/searchcore/proton/documentmetastore/documentmetastore.h b/searchcore/src/vespa/searchcore/proton/documentmetastore/documentmetastore.h
index e393ad16178..305b81d58a6 100644
--- a/searchcore/src/vespa/searchcore/proton/documentmetastore/documentmetastore.h
+++ b/searchcore/src/vespa/searchcore/proton/documentmetastore/documentmetastore.h
@@ -178,7 +178,7 @@ public:
     bool validLidFast(DocId lid) const { return _lidAlloc.validLid(lid); }
     bool validLid(DocId lid) const override { return validLidFast(lid); }
     void removeBatch(const std::vector<DocId> &lidsToRemove, const DocId docIdLimit) override;
-    const RawDocumentMetaData & getRawMetaData(DocId lid) const override { return _metaDataStore[lid]; }
+    const RawDocumentMetaData & getRawMetaData(DocId lid) const override { return _metaDataStore.acquire_elem_ref(lid); }
 
     /**
      * Implements search::IDocumentMetaStore
diff --git a/searchcore/src/vespa/searchcore/proton/documentmetastore/documentmetastoresaver.cpp b/searchcore/src/vespa/searchcore/proton/documentmetastore/documentmetastoresaver.cpp
index 0abe88da719..e4ad9cf8ac2 100644
--- a/searchcore/src/vespa/searchcore/proton/documentmetastore/documentmetastoresaver.cpp
+++ b/searchcore/src/vespa/searchcore/proton/documentmetastore/documentmetastoresaver.cpp
@@ -14,33 +14,31 @@ namespace {
 
 /*
  * Functor class to write meta data for a single lid. Note that during
- * a background save with active feeding, timestamp, bucketused bits
+ * a background save with active feeding, timestamp, bucket used bits
  * and size might reflect future values due to missing snapshot
- * properties in MetaDataStore.  size might also reflect a mix between
- * current ant future value due to non-atomic access.
+ * properties in RcuVector. Size might also reflect a mix between
+ * current and future value due to non-atomic access.
  */
 class WriteMetaData
 {
-    search::BufferWriter &_datWriter;
-    const RawDocumentMetaData *_metaDataStore;
-    uint32_t _metaDataStoreSize;
-    bool _writeDocSize;
-    using MetaDataStore = DocumentMetaStoreSaver::MetaDataStore;
+    using MetaDataView = DocumentMetaStoreSaver::MetaDataView;
     using GlobalId = documentmetastore::IStore::GlobalId;
     using BucketId = documentmetastore::IStore::BucketId;
     using Timestamp = documentmetastore::IStore::Timestamp;
+    search::BufferWriter &_datWriter;
+    MetaDataView _metaDataView;
+    bool _writeDocSize;
 public:
-    WriteMetaData(search::BufferWriter &datWriter, const MetaDataStore &metaDataStore, bool writeDocSize)
+    WriteMetaData(search::BufferWriter &datWriter, MetaDataView metaDataView, bool writeDocSize)
         : _datWriter(datWriter),
-          _metaDataStore(&metaDataStore[0]),
-          _metaDataStoreSize(metaDataStore.size()),
+          _metaDataView(metaDataView),
           _writeDocSize(writeDocSize)
     { }
 
     void operator()(documentmetastore::GidToLidMapKey key) {
         auto lid = key.get_lid();
-        assert(lid < _metaDataStoreSize);
-        const RawDocumentMetaData &metaData = _metaDataStore[lid];
+        assert(lid < _metaDataView.size());
+        const RawDocumentMetaData &metaData = _metaDataView[lid];
         const GlobalId &gid = metaData.getGid();
         // 6 bits used for bucket bits
         uint8_t bucketUsedBits = metaData.getBucketUsedBits();
@@ -71,10 +69,10 @@ DocumentMetaStoreSaver::
 DocumentMetaStoreSaver(vespalib::GenerationHandler::Guard &&guard,
                        const search::attribute::AttributeHeader &header,
                        const GidIterator &gidIterator,
-                       const MetaDataStore &metaDataStore)
+                       MetaDataView metaDataView)
     : AttributeSaver(std::move(guard), header),
       _gidIterator(gidIterator),
-      _metaDataStore(metaDataStore),
+      _metaDataView(metaDataView),
       _writeDocSize(true)
 {
     if (header.getVersion() == documentmetastore::NO_DOCUMENT_SIZE_TRACKING_VERSION) {
@@ -92,7 +90,7 @@ DocumentMetaStoreSaver::onSave(IAttributeSaveTarget &saveTarget)
     // write <lid,gid> pairs, sorted on gid
     std::unique_ptr<search::BufferWriter>
         datWriter(saveTarget.datWriter().allocBufferWriter());
-    _gidIterator.foreach_key(WriteMetaData(*datWriter, _metaDataStore, _writeDocSize));
+    _gidIterator.foreach_key(WriteMetaData(*datWriter, _metaDataView, _writeDocSize));
     datWriter->flush();
     return true;
 }
diff --git a/searchcore/src/vespa/searchcore/proton/documentmetastore/documentmetastoresaver.h b/searchcore/src/vespa/searchcore/proton/documentmetastore/documentmetastoresaver.h
index f0be17540a2..5f97ba1e0b0 100644
--- a/searchcore/src/vespa/searchcore/proton/documentmetastore/documentmetastoresaver.h
+++ b/searchcore/src/vespa/searchcore/proton/documentmetastore/documentmetastoresaver.h
@@ -25,11 +25,11 @@ public:
         vespalib::btree::BTreeNoLeafData,
         vespalib::btree::NoAggregated,
         const KeyComp &>;
-    using MetaDataStore = vespalib::RcuVectorBase<RawDocumentMetaData>;
+    using MetaDataView = vespalib::ConstArrayRef<RawDocumentMetaData>;
 
 private:
     GidIterator _gidIterator; // iterator over frozen tree
-    const MetaDataStore &_metaDataStore;
+    MetaDataView _metaDataView;
     bool _writeDocSize;
 
     bool onSave(search::IAttributeSaveTarget &saveTarget) override;
@@ -37,7 +37,7 @@ public:
     DocumentMetaStoreSaver(vespalib::GenerationHandler::Guard &&guard,
                            const search::attribute::AttributeHeader &header,
                            const GidIterator &gidIterator,
-                           const MetaDataStore &metaDataStore);
+                           MetaDataView metaDataView);
 
     ~DocumentMetaStoreSaver() override;
 };
diff --git a/searchcore/src/vespa/searchcore/proton/documentmetastore/lid_gid_key_comparator.cpp b/searchcore/src/vespa/searchcore/proton/documentmetastore/lid_gid_key_comparator.cpp
index d52e87a0871..40cd3c89a6d 100644
--- a/searchcore/src/vespa/searchcore/proton/documentmetastore/lid_gid_key_comparator.cpp
+++ b/searchcore/src/vespa/searchcore/proton/documentmetastore/lid_gid_key_comparator.cpp
@@ -7,7 +7,7 @@ namespace proton::documentmetastore {
 LidGidKeyComparator::LidGidKeyComparator(const document::GlobalId &gid,
                                          const MetaDataStore &metaDataStore)
     : _gid(gid),
-      _metaDataStore(metaDataStore),
+      _metaDataView(&metaDataStore.acquire_elem_ref(0)),
       _gidCompare()
 {
 }
@@ -15,7 +15,7 @@ LidGidKeyComparator::LidGidKeyComparator(const document::GlobalId &gid,
 LidGidKeyComparator::LidGidKeyComparator(const RawDocumentMetaData &metaData,
                                          const MetaDataStore &metaDataStore)
     : _gid(metaData.getGid()),
-      _metaDataStore(metaDataStore),
+      _metaDataView(&metaDataStore.acquire_elem_ref(0)),
       _gidCompare()
 {
 }
diff --git a/searchcore/src/vespa/searchcore/proton/documentmetastore/lid_gid_key_comparator.h b/searchcore/src/vespa/searchcore/proton/documentmetastore/lid_gid_key_comparator.h
index c18224370e1..5970342c750 100644
--- a/searchcore/src/vespa/searchcore/proton/documentmetastore/lid_gid_key_comparator.h
+++ b/searchcore/src/vespa/searchcore/proton/documentmetastore/lid_gid_key_comparator.h
@@ -21,12 +21,12 @@ private:
     typedef vespalib::RcuVectorBase<RawDocumentMetaData> MetaDataStore;
 
     const document::GlobalId &_gid;
-    const MetaDataStore      &_metaDataStore;
+    const RawDocumentMetaData* _metaDataView;
     const document::GlobalId::BucketOrderCmp _gidCompare;
 
     const document::GlobalId &getGid(const GidToLidMapKey &key) const {
         if (!key.is_find_key()) {
-            return _metaDataStore[key.get_lid()].getGid();
+            return _metaDataView[key.get_lid()].getGid();
         }
         return _gid;
     }