- Move when possible.

- Add noexcept to enable more movement
- Minor code cleanup.

5 files changed, 55 insertions, 49 deletions

diff --git a/searchlib/src/tests/docstore/document_store/visitcache_test.cpp b/searchlib/src/tests/docstore/document_store/visitcache_test.cpp
index 14e3c19fe33..3f80bb6004f 100644
--- a/searchlib/src/tests/docstore/document_store/visitcache_test.cpp
+++ b/searchlib/src/tests/docstore/document_store/visitcache_test.cpp
@@ -62,7 +62,7 @@ TEST("require that BlobSet can be built") {
     a.append(9, B("bbbbb",5));
     verifyAB(a);
     CompressionConfig cfg(CompressionConfig::LZ4);
-    CompressedBlobSet ca(cfg, a);
+    CompressedBlobSet ca(cfg, std::move(a));
     BlobSet b = ca.getBlobSet();
     verifyAB(b);
 }
diff --git a/searchlib/src/tests/docstore/logdatastore/logdatastore_test.cpp b/searchlib/src/tests/docstore/logdatastore/logdatastore_test.cpp
index 1080d44f2fb..1ca020bca86 100644
--- a/searchlib/src/tests/docstore/logdatastore/logdatastore_test.cpp
+++ b/searchlib/src/tests/docstore/logdatastore/logdatastore_test.cpp
@@ -368,13 +368,13 @@ TEST("test visit cache does not cache empty ones and is able to access some back
     IDataStore & datastore = store.getStore();
 
     VisitCache visitCache(datastore, 100000, CompressionConfig::Type::LZ4);
-    EXPECT_EQUAL(0u, visitCache.read({1}).size());
+    EXPECT_EQUAL(12u, visitCache.read({1}).byteSize());
     EXPECT_TRUE(visitCache.read({1}).empty());
     datastore.write(1,1, A7, 7);
-    EXPECT_EQUAL(0u, visitCache.read({2}).size());
+    EXPECT_EQUAL(12u, visitCache.read({2}).byteSize());
     CompressedBlobSet cbs = visitCache.read({1});
     EXPECT_FALSE(cbs.empty());
-    EXPECT_EQUAL(19u, cbs.size());
+    EXPECT_EQUAL(19u, cbs.byteSize());
     BlobSet bs(cbs.getBlobSet());
     EXPECT_EQUAL(7u, bs.get(1).size());
     EXPECT_EQUAL(0, strncmp(A7, bs.get(1).c_str(), 7));
@@ -664,14 +664,14 @@ TEST("test that the integrated visit cache works.") {
     vcs.remove(17);
     TEST_DO(verifyCacheStats(ds.getCacheStats(), 101, 104, 97, BASE_SZ-671));
     vcs.verifyVisit({7,9,17,19,67,88,89}, {7,9,19,67,88,89}, true);
-    TEST_DO(verifyCacheStats(ds.getCacheStats(), 101, 105, 98, BASE_SZ-89));
+    TEST_DO(verifyCacheStats(ds.getCacheStats(), 101, 105, 98, BASE_SZ-70));
 
     vcs.verifyVisit({41, 42}, true);
-    TEST_DO(verifyCacheStats(ds.getCacheStats(), 101, 106, 99, BASE_SZ+215));
+    TEST_DO(verifyCacheStats(ds.getCacheStats(), 101, 106, 99, BASE_SZ+230));
     vcs.verifyVisit({43, 44}, true);
-    TEST_DO(verifyCacheStats(ds.getCacheStats(), 101, 107, 100, BASE_SZ+520));
+    TEST_DO(verifyCacheStats(ds.getCacheStats(), 101, 107, 100, BASE_SZ+540));
     vcs.verifyVisit({41, 42, 43, 44}, true);
-    TEST_DO(verifyCacheStats(ds.getCacheStats(), 101, 108, 99, BASE_SZ+340));
+    TEST_DO(verifyCacheStats(ds.getCacheStats(), 101, 108, 99, BASE_SZ+360));
 }
 
 TEST("testWriteRead") {
diff --git a/searchlib/src/vespa/searchlib/docstore/documentstore.cpp b/searchlib/src/vespa/searchlib/docstore/documentstore.cpp
index 49beed34f08..7d585007d76 100644
--- a/searchlib/src/vespa/searchlib/docstore/documentstore.cpp
+++ b/searchlib/src/vespa/searchlib/docstore/documentstore.cpp
@@ -437,7 +437,8 @@ DocumentStore::getFileChunkStats() const
     return _backingStore.getFileChunkStats();
 }
 
-CacheStats DocumentStore::getCacheStats() const {
+CacheStats
+DocumentStore::getCacheStats() const {
     CacheStats visitStats = _visitCache->getCacheStats();
     CacheStats singleStats = _cache->get_stats();
     singleStats.add_extra_misses(_uncached_lookups.load(std::memory_order_relaxed));
diff --git a/searchlib/src/vespa/searchlib/docstore/visitcache.cpp b/searchlib/src/vespa/searchlib/docstore/visitcache.cpp
index c99bb50d4f8..e9023c48ee5 100644
--- a/searchlib/src/vespa/searchlib/docstore/visitcache.cpp
+++ b/searchlib/src/vespa/searchlib/docstore/visitcache.cpp
@@ -17,14 +17,14 @@ using vespalib::DataBuffer;
 using vespalib::alloc::Alloc;
 using vespalib::alloc::MemoryAllocator;
 
-KeySet::KeySet(uint32_t key) :
-    _keys()
+KeySet::KeySet(uint32_t key)
+    : _keys()
 {
     _keys.push_back(key);
 }
 
-KeySet::KeySet(const IDocumentStore::LidVector &keys) :
-    _keys(keys)
+KeySet::KeySet(const IDocumentStore::LidVector &keys)
+    : _keys(keys)
 {
     std::sort(_keys.begin(), _keys.end());
 }
@@ -34,24 +34,25 @@ KeySet::contains(const KeySet &rhs) const {
     return std::includes(_keys.begin(), _keys.end(), rhs._keys.begin(), rhs._keys.end());
 }
 
-BlobSet::BlobSet() :
-    _positions(),
-    _buffer(Alloc::alloc(0, 16 * MemoryAllocator::HUGEPAGE_SIZE), 0)
+BlobSet::BlobSet()
+    : _positions(),
+      _buffer(Alloc::alloc(0, 16 * MemoryAllocator::HUGEPAGE_SIZE), 0)
 { }
 
 BlobSet::~BlobSet() = default;
 
 namespace {
 
-size_t getBufferSize(const BlobSet::Positions & p) {
+size_t
+getBufferSize(const BlobSet::Positions & p) {
     return p.empty() ? 0 : p.back().offset() + p.back().size();
 }
 
 }
 
-BlobSet::BlobSet(const Positions & positions, Alloc && buffer) :
-    _positions(positions),
-    _buffer(std::move(buffer), getBufferSize(_positions))
+BlobSet::BlobSet(Positions positions, Alloc && buffer) noexcept
+    : _positions(std::move(positions)),
+      _buffer(std::move(buffer), getBufferSize(_positions))
 {
 }
 
@@ -74,20 +75,19 @@ BlobSet::get(uint32_t lid) const
     return buf;
 }
 
-CompressedBlobSet::CompressedBlobSet() :
-    _compression(CompressionConfig::Type::LZ4),
-    _positions(),
-    _buffer()
+CompressedBlobSet::CompressedBlobSet() noexcept
+    : _compression(CompressionConfig::Type::LZ4),
+      _positions(),
+      _buffer()
 {
 }
 
 CompressedBlobSet::~CompressedBlobSet() = default;
 
-
-CompressedBlobSet::CompressedBlobSet(CompressionConfig compression, const BlobSet & uncompressed) :
-    _compression(compression.type),
-    _positions(uncompressed.getPositions()),
-    _buffer()
+CompressedBlobSet::CompressedBlobSet(CompressionConfig compression, BlobSet uncompressed)
+    : _compression(compression.type),
+      _positions(uncompressed.stealPositions()),
+      _buffer()
 {
     if ( ! _positions.empty() ) {
         DataBuffer compressed;
@@ -113,7 +113,8 @@ CompressedBlobSet::getBlobSet() const
     return BlobSet(_positions, std::move(uncompressed).stealBuffer());
 }
 
-size_t CompressedBlobSet::size() const {
+size_t
+CompressedBlobSet::byteSize() const {
     return _positions.capacity() * sizeof(BlobSet::Positions::value_type) + _buffer->size();
 }
 
@@ -122,13 +123,10 @@ namespace {
 class VisitCollector : public IBufferVisitor
 {
 public:
-    VisitCollector() :
-        _blobSet()
-    { }
+    VisitCollector(BlobSet & blobSet) : _blobSet(blobSet) { }
     void visit(uint32_t lid, ConstBufferRef buf) override;
-    const BlobSet & getBlobSet() const { return _blobSet; }
 private:
-    BlobSet _blobSet;
+    BlobSet & _blobSet;
 };
 
 void
@@ -142,9 +140,11 @@ VisitCollector::visit(uint32_t lid, ConstBufferRef buf) {
 
 bool
 VisitCache::BackingStore::read(const KeySet &key, CompressedBlobSet &blobs) const {
-    VisitCollector collector;
+    BlobSet blobSet;
+    blobSet.reserve(key.getKeys().size());
+    VisitCollector collector(blobSet);
     _backingStore.read(key.getKeys(), collector);
-    blobs = CompressedBlobSet(_compression.load(std::memory_order_relaxed), collector.getBlobSet());
+    blobs = CompressedBlobSet(_compression.load(std::memory_order_relaxed), std::move(blobSet));
     return ! blobs.empty();
 }
 
@@ -237,8 +237,7 @@ VisitCache::Cache::removeKey(uint32_t subKey) {
     auto cacheGuard = getGuard();
     const auto foundLid = _lid2Id.find(subKey);
     if (foundLid != _lid2Id.end()) {
-        K keySet = _id2KeySet[foundLid->second];
-        invalidate(cacheGuard, keySet);
+        invalidate(cacheGuard, _id2KeySet[foundLid->second]);
     }
 }
 
diff --git a/searchlib/src/vespa/searchlib/docstore/visitcache.h b/searchlib/src/vespa/searchlib/docstore/visitcache.h
index baa594b8d28..8b7ae5e6753 100644
--- a/searchlib/src/vespa/searchlib/docstore/visitcache.h
+++ b/searchlib/src/vespa/searchlib/docstore/visitcache.h
@@ -19,7 +19,7 @@ namespace search::docstore {
  **/
 class KeySet {
 public:
-    KeySet() : _keys() { }
+    KeySet() noexcept : _keys() { }
     KeySet(uint32_t key);
     explicit KeySet(const IDocumentStore::LidVector &keys);
     uint32_t hash() const noexcept { return _keys.empty() ? 0 : _keys[0]; }
@@ -51,12 +51,14 @@ public:
 
     using Positions = std::vector<LidPosition>;
     BlobSet();
-    BlobSet(const Positions & positions, vespalib::alloc::Alloc && buffer);
-    BlobSet(BlobSet &&) = default;
-    BlobSet &operator = (BlobSet &&) = default;
+    BlobSet(Positions positions, vespalib::alloc::Alloc && buffer) noexcept;
+    BlobSet(BlobSet &&) noexcept = default;
+    BlobSet &operator = (BlobSet &&) noexcept = default;
     ~BlobSet();
+    void reserve(size_t elems) { _positions.reserve(elems);}
     void append(uint32_t lid, vespalib::ConstBufferRef blob);
     const Positions & getPositions() const { return _positions; }
+    Positions && stealPositions() { return std::move(_positions); }
     vespalib::ConstBufferRef get(uint32_t lid) const;
     vespalib::ConstBufferRef getBuffer() const { return vespalib::ConstBufferRef(_buffer.data(), _buffer.size()); }
 private:
@@ -73,14 +75,14 @@ private:
 class CompressedBlobSet {
 public:
     using CompressionConfig = vespalib::compression::CompressionConfig;
-    CompressedBlobSet();
-    CompressedBlobSet(CompressionConfig compression, const BlobSet & uncompressed);
-    CompressedBlobSet(CompressedBlobSet && rhs) = default;
-    CompressedBlobSet & operator=(CompressedBlobSet && rhs) = default;
+    CompressedBlobSet() noexcept;
+    CompressedBlobSet(CompressionConfig compression, BlobSet uncompressed);
+    CompressedBlobSet(CompressedBlobSet && rhs) noexcept = default;
+    CompressedBlobSet & operator=(CompressedBlobSet && rhs) noexcept = default;
     CompressedBlobSet(const CompressedBlobSet & rhs) = default;
     CompressedBlobSet & operator=(const CompressedBlobSet & rhs) = default;
     ~CompressedBlobSet();
-    size_t size() const;
+    size_t byteSize() const;
     bool empty() const { return _positions.empty(); }
     BlobSet getBlobSet() const;
 private:
@@ -129,11 +131,15 @@ private:
         std::atomic<CompressionConfig>  _compression;
     };
 
+    struct ByteSize {
+        size_t operator() (const CompressedBlobSet & arg) const noexcept { return arg.byteSize(); }
+    };
+
     using CacheParams = vespalib::CacheParam<
                             vespalib::LruParam<KeySet, CompressedBlobSet>,
                             BackingStore,
                             vespalib::zero<KeySet>,
-                            vespalib::size<CompressedBlobSet>
+                            ByteSize
                         >;
 
     /**