Add more class comments + style changes.

8 files changed, 148 insertions, 288 deletions

diff --git a/searchlib/src/vespa/searchlib/diskindex/diskindex.cpp b/searchlib/src/vespa/searchlib/diskindex/diskindex.cpp
index d71ddc2c2d6..64a54187254 100644
--- a/searchlib/src/vespa/searchlib/diskindex/diskindex.cpp
+++ b/searchlib/src/vespa/searchlib/diskindex/diskindex.cpp
@@ -39,7 +39,9 @@ DiskIndex::Key::Key() = default;
 DiskIndex::Key::Key(const IndexList & indexes, vespalib::stringref word) :
     _word(word),
     _indexes(indexes)
-{ }
+{
+}
+
 DiskIndex::Key::~Key() = default;
 
 DiskIndex::DiskIndex(const vespalib::string &indexDir, size_t cacheSize)
@@ -73,7 +75,6 @@ DiskIndex::loadSchema()
     return true;
 }
 
-
 bool
 DiskIndex::openDictionaries(const TuneFileSearch &tuneFileSearch)
 {
@@ -91,7 +92,6 @@ DiskIndex::openDictionaries(const TuneFileSearch &tuneFileSearch)
     return true;
 }
 
-
 bool
 DiskIndex::openField(const vespalib::string &fieldDir,
                      const TuneFileSearch &tuneFileSearch)
@@ -147,7 +147,6 @@ DiskIndex::openField(const vespalib::string &fieldDir,
     return true;
 }
 
-
 bool
 DiskIndex::setup(const TuneFileSearch &tuneFileSearch)
 {
@@ -165,7 +164,6 @@ DiskIndex::setup(const TuneFileSearch &tuneFileSearch)
     return true;
 }
 
-
 bool
 DiskIndex::setup(const TuneFileSearch &tuneFileSearch,
                  const DiskIndex &old)
@@ -315,7 +313,6 @@ DiskIndex::readPostingList(const LookupResult &lookupRes) const
     return handle;
 }
 
-
 BitVector::UP
 DiskIndex::readBitVector(const LookupResult &lookupRes) const
 {
@@ -327,7 +324,6 @@ DiskIndex::readBitVector(const LookupResult &lookupRes) const
     return dict->lookup(lookupRes.wordNum);
 }
 
-
 void
 DiskIndex::calculateSize()
 {
@@ -335,19 +331,18 @@ DiskIndex::calculateSize()
     _size = dirt.GetTreeSize();
 }
 
-
 namespace {
 
 DiskIndex::LookupResult _G_nothing;
 
-class LookupCache
-{
+class LookupCache {
 public:
     LookupCache(DiskIndex & diskIndex, const std::vector<uint32_t> & fieldIds) :
         _diskIndex(diskIndex),
         _fieldIds(fieldIds),
         _cache()
-    { }
+    {
+    }
     const DiskIndex::LookupResult &
     lookup(const vespalib::string & word, uint32_t fieldId) {
         Cache::const_iterator it = _cache.find(word);
@@ -363,14 +358,14 @@ public:
         return _G_nothing;
     }
 private:
+
     typedef vespalib::hash_map<vespalib::string, DiskIndex::LookupResultVector> Cache;
     DiskIndex &                   _diskIndex;
     const std::vector<uint32_t> & _fieldIds;
     Cache                         _cache;
 };
 
-class CreateBlueprintVisitor : public CreateBlueprintVisitorHelper
-{
+class CreateBlueprintVisitor : public CreateBlueprintVisitorHelper {
 private:
     LookupCache      &_cache;
     DiskIndex        &_diskIndex;
@@ -391,8 +386,7 @@ public:
     }
 
     template <class TermNode>
-    void visitTerm(TermNode &n)
-    {
+    void visitTerm(TermNode &n) {
         const vespalib::string termStr = termAsString(n);
         const DiskIndex::LookupResult & lookupRes = _cache.lookup(termStr, _fieldId);
         if (lookupRes.valid()) {
@@ -418,7 +412,6 @@ public:
     void visit(PredicateQuery &) override { }
 };
 
-
 Blueprint::UP
 createBlueprintHelper(LookupCache & cache, DiskIndex & diskIndex, const IRequestContext & requestContext,
                       const FieldSpec &field, uint32_t fieldId, const Node &term)
@@ -442,7 +435,6 @@ DiskIndex::createBlueprint(const IRequestContext & requestContext, const FieldSp
     return createBlueprintHelper(cache, *this, requestContext, field, fieldIds[0], term);
 }
 
-
 Blueprint::UP
 DiskIndex::createBlueprint(const IRequestContext & requestContext, const FieldSpecList &fields, const Node &term)
 {
diff --git a/searchlib/src/vespa/searchlib/diskindex/diskindex.h b/searchlib/src/vespa/searchlib/diskindex/diskindex.h
index 4bef53a3030..d83b2f56d7c 100644
--- a/searchlib/src/vespa/searchlib/diskindex/diskindex.h
+++ b/searchlib/src/vespa/searchlib/diskindex/diskindex.h
@@ -12,14 +12,13 @@
 namespace search::diskindex {
 
 /**
- * This class represents a disk index with a common dictionary, and
- * posting list files and bit vector files for each field.
- * Parts of the disk dictionary and all bit vector
- * dictionaries are loaded into memory during setup.  All other files
- * are just opened, ready for later access.
- **/
-class DiskIndex : public queryeval::Searchable
-{
+ * This class represents a disk index that contains a set of field indexes that are independent of each other.
+ *
+ * Each field index has a dictionary, posting list files and bit vector files.
+ * Parts of the disk dictionary and all bit vector dictionaries are loaded into memory during setup.
+ * All other files are just opened, ready for later access.
+ */
+class DiskIndex : public queryeval::Searchable {
 public:
     /**
      * The result after performing a disk dictionary lookup.
@@ -60,11 +59,12 @@ public:
         vespalib::string _word;
         IndexList        _indexes;
     };
+
 private:
-    typedef index::PostingListFileRandRead DiskPostingFile;
-    typedef Zc4PosOccRandRead DiskPostingFileReal;
-    typedef ZcPosOccRandRead DiskPostingFileDynamicKReal;
-    typedef vespalib::cache<vespalib::CacheParam<vespalib::LruParam<Key, LookupResultVector>, DiskIndex>> Cache;
+    using DiskPostingFile = index::PostingListFileRandRead;
+    using DiskPostingFileReal = Zc4PosOccRandRead;
+    using DiskPostingFileDynamicKReal = ZcPosOccRandRead;
+    using Cache = vespalib::cache<vespalib::CacheParam<vespalib::LruParam<Key, LookupResultVector>, DiskIndex>>;
 
     vespalib::string                       _indexDir;
     size_t                                 _cacheSize;
@@ -83,11 +83,11 @@ private:
 
 public:
     /**
-     * Create a view of the disk index located in the given directory
-     * described by the given schema.
+     * Create a view of the disk index located in the given directory.
      *
      * @param indexDir the directory where the disk index is located.
-     **/
+     * @param cacheSize optional size (in bytes) of the disk dictionary lookup cache.
+     */
     DiskIndex(const vespalib::string &indexDir, size_t cacheSize=0);
     ~DiskIndex();
 
@@ -95,29 +95,27 @@ public:
      * Setup this instance by opening and loading relevant index files.
      *
      * @return true if this instance was successfully setup.
-     **/
+     */
     bool setup(const TuneFileSearch &tuneFileSearch);
     bool setup(const TuneFileSearch &tuneFileSearch, const DiskIndex &old);
 
     /**
-     * Perform a dictionary lookup for the given word in the given
-     * field.
+     * Perform a dictionary lookup for the given word in the given field.
      *
-     * @param indexId the id of the field to
-     *                perform lookup for.
+     * @param indexId the id of the field to perform lookup for.
      * @param word the word to lookup.
      * @return the lookup result or nullptr if the word is not found.
-     **/
+     */
     LookupResult::UP lookup(uint32_t indexId, vespalib::stringref word);
-    LookupResultVector lookup(const std::vector<uint32_t> & indexes, vespalib::stringref word);
 
+    LookupResultVector lookup(const std::vector<uint32_t> & indexes, vespalib::stringref word);
 
     /**
      * Read the posting list corresponding to the given lookup result.
      *
      * @param lookupRes the result of the previous dictionary lookup.
      * @return a handle for the posting list in memory.
-     **/
+     */
     index::PostingListHandle::UP readPostingList(const LookupResult &lookupRes) const;
 
     /**
@@ -126,22 +124,19 @@ public:
      * @param lookupRes the result of the previous dictionary lookup.
      * @return the bit vector or nullptr if no bit vector exists for the
      *         word in the lookup result.
-     **/
+     */
     BitVector::UP readBitVector(const LookupResult &lookupRes) const;
 
-    queryeval::Blueprint::UP
-    createBlueprint(const queryeval::IRequestContext & requestContext,
-                    const queryeval::FieldSpec &field,
-                    const query::Node &term) override;
+    queryeval::Blueprint::UP createBlueprint(const queryeval::IRequestContext & requestContext,
+                                             const queryeval::FieldSpec &field,
+                                             const query::Node &term) override;
 
-    queryeval::Blueprint::UP
-    createBlueprint(const queryeval::IRequestContext & requestContext,
-                    const queryeval::FieldSpecList &fields,
-                    const query::Node &term) override;
+    queryeval::Blueprint::UP createBlueprint(const queryeval::IRequestContext & requestContext,
+                                             const queryeval::FieldSpecList &fields,
+                                             const query::Node &term) override;
 
     /**
      * Get the size on disk of this index.
-     * @return the size of the index.
      */
     uint64_t getSize() const { return _size; }
 
diff --git a/searchlib/src/vespa/searchlib/diskindex/fieldwriter.cpp b/searchlib/src/vespa/searchlib/diskindex/fieldwriter.cpp
index 6454c0851a7..8c2b33a933e 100644
--- a/searchlib/src/vespa/searchlib/diskindex/fieldwriter.cpp
+++ b/searchlib/src/vespa/searchlib/diskindex/fieldwriter.cpp
@@ -98,7 +98,6 @@ FieldWriter::open(const vespalib::string &prefix,
     return true;
 }
 
-
 void
 FieldWriter::flush()
 {
@@ -120,7 +119,6 @@ FieldWriter::flush()
     }
 }
 
-
 void
 FieldWriter::newWord(uint64_t wordNum, vespalib::stringref word)
 {
@@ -134,14 +132,12 @@ FieldWriter::newWord(uint64_t wordNum, vespalib::stringref word)
     _prevDocId = 0;
 }
 
-
 void
 FieldWriter::newWord(vespalib::stringref word)
 {
     newWord(_wordNum + 1, word);
 }
 
-
 bool
 FieldWriter::close()
 {
@@ -183,7 +179,6 @@ FieldWriter::getFeatureParams(PostingListParams &params)
     _posoccfile->getFeatureParams(params);
 }
 
-
 static const char *termOccNames[] =
 {
     "boolocc.bdat",
@@ -199,7 +194,6 @@ static const char *termOccNames[] =
     nullptr,
 };
 
-
 void
 FieldWriter::remove(const vespalib::string &prefix)
 {
diff --git a/searchlib/src/vespa/searchlib/diskindex/fieldwriter.h b/searchlib/src/vespa/searchlib/diskindex/fieldwriter.h
index 9a6edf90243..1e9afb717e8 100644
--- a/searchlib/src/vespa/searchlib/diskindex/fieldwriter.h
+++ b/searchlib/src/vespa/searchlib/diskindex/fieldwriter.h
@@ -10,15 +10,13 @@
 
 namespace search::diskindex {
 
-/*
- * FieldWriter is used to write a dictionary and posting list file
- * together.
+/**
+ * FieldWriter is used to write a dictionary and posting list file together.
  *
  * It is used by the fusion code to write the merged output for a field,
  * and by the memory index dump code to write a field to disk.
  */
-class FieldWriter
-{
+class FieldWriter {
 private:
     uint64_t _wordNum;
     uint32_t _prevDocId;
@@ -28,14 +26,15 @@ public:
 
     using DictionaryFileSeqWrite = index::DictionaryFileSeqWrite;
 
-    typedef index::PostingListFileSeqWrite PostingListFileSeqWrite;
-    typedef index::DocIdAndFeatures DocIdAndFeatures;
-    typedef index::Schema Schema;
-    typedef index::PostingListCounts PostingListCounts;
-    typedef index::PostingListParams PostingListParams;
+    using PostingListFileSeqWrite = index::PostingListFileSeqWrite;
+    using DocIdAndFeatures = index::DocIdAndFeatures;
+    using Schema = index::Schema;
+    using PostingListCounts = index::PostingListCounts;
+    using PostingListParams = index::PostingListParams;
 
     std::unique_ptr<DictionaryFileSeqWrite> _dictFile;
     std::unique_ptr<PostingListFileSeqWrite> _posoccfile;
+
 private:
     BitVectorCandidate _bvc;
     BitVectorFileWrite _bmapfile;
diff --git a/searchlib/src/vespa/searchlib/diskindex/indexbuilder.cpp b/searchlib/src/vespa/searchlib/diskindex/indexbuilder.cpp
index a3c37cb91f6..964f37eb5cf 100644
--- a/searchlib/src/vespa/searchlib/diskindex/indexbuilder.cpp
+++ b/searchlib/src/vespa/searchlib/diskindex/indexbuilder.cpp
@@ -33,8 +33,7 @@ noWordPos()
 }
 
 
-class FileHandle
-{
+class FileHandle {
 public:
     FieldWriter *_fieldWriter;
     DocIdAndFeatures _docIdAndFeatures;
@@ -43,22 +42,18 @@ public:
 
     ~FileHandle();
 
-    void
-    open(vespalib::stringref dir,
-         const SchemaUtil::IndexIterator &index,
-         uint32_t docIdLimit, uint64_t numWordIds,
-         const TuneFileSeqWrite &tuneFileWrite,
-         const FileHeaderContext &fileHeaderContext);
+    void open(vespalib::stringref dir,
+              const SchemaUtil::IndexIterator &index,
+              uint32_t docIdLimit, uint64_t numWordIds,
+              const TuneFileSeqWrite &tuneFileWrite,
+              const FileHeaderContext &fileHeaderContext);
 
-    void
-    close();
+    void close();
 };
 
-
 }
 
-class IndexBuilder::FieldHandle
-{
+class IndexBuilder::FieldHandle {
 public:
     FieldHandle(const Schema &schema,
                 uint32_t fieldId,
@@ -66,20 +61,15 @@ public:
 
     ~FieldHandle();
 
-    static uint32_t
-    noDocRef()
-    {
+    static uint32_t noDocRef() {
         return std::numeric_limits<uint32_t>::max();
     }
 
-    static uint32_t
-    noElRef()
-    {
+    static uint32_t noElRef() {
         return std::numeric_limits<uint32_t>::max();
     }
 
-    class FHWordDocFieldFeatures
-    {
+    class FHWordDocFieldFeatures {
     public:
         uint32_t _docId;
         uint32_t _numElements;
@@ -90,28 +80,12 @@ public:
         {
         }
 
-        uint32_t
-        getDocId() const
-        {
-            return _docId;
-        }
-
-        uint32_t
-        getNumElements() const
-        {
-            return _numElements;
-        }
-
-        void
-        incNumElements()
-        {
-            ++_numElements;
-        }
+        uint32_t getDocId() const { return _docId; }
+        uint32_t getNumElements() const { return _numElements; }
+        void incNumElements() { ++_numElements; }
     };
 
-    class FHWordDocElementFeatures
-        : public WordDocElementFeatures
-    {
+    class FHWordDocElementFeatures : public WordDocElementFeatures {
     public:
         uint32_t _docRef;
 
@@ -127,24 +101,21 @@ public:
         }
     };
 
-    class FHWordDocElementWordPosFeatures
-        : public WordDocElementWordPosFeatures
-    {
+    class FHWordDocElementWordPosFeatures : public WordDocElementWordPosFeatures {
     public:
         uint32_t _elementRef;
 
-        FHWordDocElementWordPosFeatures(
-                const WordDocElementWordPosFeatures &features,
-                uint32_t elementRef)
+        FHWordDocElementWordPosFeatures(const WordDocElementWordPosFeatures &features,
+                                        uint32_t elementRef)
             : WordDocElementWordPosFeatures(features),
               _elementRef(elementRef)
         {
         }
     };
 
-    typedef vespalib::Array<FHWordDocFieldFeatures>          FHWordDocFieldFeaturesVector;
-    typedef vespalib::Array<FHWordDocElementFeatures>        FHWordDocElementFeaturesVector;
-    typedef vespalib::Array<FHWordDocElementWordPosFeatures> FHWordDocElementWordPosFeaturesVector;
+    using FHWordDocFieldFeaturesVector = vespalib::Array<FHWordDocFieldFeatures>;
+    using FHWordDocElementFeaturesVector = vespalib::Array<FHWordDocElementFeatures>;
+    using FHWordDocElementWordPosFeaturesVector = vespalib::Array<FHWordDocElementWordPosFeatures>;
 
     FHWordDocFieldFeaturesVector          _wdff;
     FHWordDocElementFeaturesVector        _wdfef;
@@ -162,72 +133,35 @@ public:
 
     FileHandle _files;
 
-    void
-    startWord(vespalib::stringref word);
-
-    void
-    endWord();
-
-    void
-    startDocument(uint32_t docId);
-
-    void
-    endDocument();
-
-    void
-    startElement(uint32_t elementId,
-                 int32_t weight,
-                 uint32_t elementLen);
-
-    void
-    endElement();
-
-    void
-    addOcc(const WordDocElementWordPosFeatures &features);
-
-    void
-    setValid()
-    {
-        _valid = true;
-    }
-
-    bool
-    getValid() const
-    {
-        return _valid;
-    }
-
-    const Schema::IndexField &
-    getSchemaField();
-
-    const vespalib::string &
-    getName();
-
-    vespalib::string
-    getDir();
-
-    void
-    open(uint32_t docIdLimit, uint64_t numWordIds,
-         const TuneFileSeqWrite &tuneFileWrite,
-         const FileHeaderContext &fileHeaderContext);
-
-    void
-    close();
-
-    uint32_t
-    getIndexId() const
-    {
-        return _fieldId;
-    }
+    void startWord(vespalib::stringref word);
+    void endWord();
+    void startDocument(uint32_t docId);
+    void endDocument();
+    void startElement(uint32_t elementId,
+                      int32_t weight,
+                      uint32_t elementLen);
+    void endElement();
+    void addOcc(const WordDocElementWordPosFeatures &features);
+
+    const Schema::IndexField &getSchemaField();
+    const vespalib::string &getName();
+    vespalib::string getDir();
+    void open(uint32_t docIdLimit, uint64_t numWordIds,
+              const TuneFileSeqWrite &tuneFileWrite,
+              const FileHeaderContext &fileHeaderContext);
+    void close();
+
+    void setValid() { _valid = true; }
+    bool getValid() const { return _valid; }
+    uint32_t getIndexId() const { return _fieldId; }
 };
 
 
 namespace {
 
-class SingleIterator
-{
+class SingleIterator {
 public:
-    typedef IndexBuilder::FieldHandle FH;
+    using FH = IndexBuilder::FieldHandle;
     FH::FHWordDocFieldFeaturesVector::const_iterator _dFeatures;
     FH::FHWordDocFieldFeaturesVector::const_iterator _dFeaturesE;
     FH::FHWordDocElementFeaturesVector::const_iterator _elFeatures;
@@ -237,18 +171,13 @@ public:
 
     SingleIterator(FH &fieldHandle, uint32_t localFieldId);
 
-    void
-    appendFeatures(DocIdAndFeatures &features);
+    void appendFeatures(DocIdAndFeatures &features);
 
-    bool
-    isValid() const
-    {
+    bool isValid() const {
         return _dFeatures != _dFeaturesE;
     }
 
-    bool
-    operator<(const SingleIterator &rhs) const
-    {
+    bool operator<(const SingleIterator &rhs) const {
         if (_docId != rhs._docId) {
             return _docId < rhs._docId;
         }
@@ -256,23 +185,19 @@ public:
     }
 };
 
-
 }
 
-
 FileHandle::FileHandle()
     : _fieldWriter(nullptr),
       _docIdAndFeatures()
 {
 }
 
-
 FileHandle::~FileHandle()
 {
     delete _fieldWriter;
 }
 
-
 void
 FileHandle::open(vespalib::stringref dir,
                  const SchemaUtil::IndexIterator &index,
@@ -293,7 +218,6 @@ FileHandle::open(vespalib::stringref dir,
     }
 }
 
-
 void
 FileHandle::close()
 {
@@ -312,7 +236,6 @@ FileHandle::close()
     (void) ret;
 }
 
-
 IndexBuilder::FieldHandle::FieldHandle(const Schema &schema,
                                        uint32_t fieldId,
                                        IndexBuilder *ib)
@@ -331,10 +254,8 @@ IndexBuilder::FieldHandle::FieldHandle(const Schema &schema,
 {
 }
 
-
 IndexBuilder::FieldHandle::~FieldHandle() = default;
 
-
 void
 IndexBuilder::FieldHandle::startWord(vespalib::stringref word)
 {
@@ -342,7 +263,6 @@ IndexBuilder::FieldHandle::startWord(vespalib::stringref word)
     _files._fieldWriter->newWord(word);
 }
 
-
 void
 IndexBuilder::FieldHandle::endWord()
 {
@@ -362,7 +282,6 @@ IndexBuilder::FieldHandle::endWord()
     _elRef = noElRef();
 }
 
-
 void
 IndexBuilder::FieldHandle::startDocument(uint32_t docId)
 {
@@ -373,7 +292,6 @@ IndexBuilder::FieldHandle::startDocument(uint32_t docId)
     _lowestOKElementId = 0u;
 }
 
-
 void
 IndexBuilder::FieldHandle::endDocument()
 {
@@ -385,12 +303,10 @@ IndexBuilder::FieldHandle::endDocument()
     _docRef = noDocRef();
 }
 
-
 void
-IndexBuilder::FieldHandle::
-startElement(uint32_t elementId,
-             int32_t weight,
-             uint32_t elementLen)
+IndexBuilder::FieldHandle::startElement(uint32_t elementId,
+                                        int32_t weight,
+                                        uint32_t elementLen)
 {
     assert(_docRef != noDocRef());
     assert(_elRef == noElRef());
@@ -407,7 +323,6 @@ startElement(uint32_t elementId,
     _lowestOKWordPos = 0u;
 }
 
-
 void
 IndexBuilder::FieldHandle::endElement()
 {
@@ -418,10 +333,8 @@ IndexBuilder::FieldHandle::endElement()
     _lowestOKElementId = ef.getElementId() + 1;
 }
 
-
 void
-IndexBuilder::FieldHandle::
-addOcc(const WordDocElementWordPosFeatures &features)
+IndexBuilder::FieldHandle::addOcc(const WordDocElementWordPosFeatures &features)
 {
     assert(_elRef != noElRef());
     FHWordDocElementFeatures &ef = _wdfef[_elRef];
@@ -435,29 +348,24 @@ addOcc(const WordDocElementWordPosFeatures &features)
     ef.incNumOccs();
 }
 
-
 const Schema::IndexField &
 IndexBuilder::FieldHandle::getSchemaField()
 {
     return _schema->getIndexField(_fieldId);
 }
 
-
 const vespalib::string &
 IndexBuilder::FieldHandle::getName()
 {
     return getSchemaField().getName();
-
 }
 
-
 vespalib::string
 IndexBuilder::FieldHandle::getDir()
 {
     return _ib->appendToPrefix(getName());
 }
 
-
 void
 IndexBuilder::FieldHandle::open(uint32_t docIdLimit, uint64_t numWordIds,
                                 const TuneFileSeqWrite &tuneFileWrite,
@@ -468,14 +376,12 @@ IndexBuilder::FieldHandle::open(uint32_t docIdLimit, uint64_t numWordIds,
                 docIdLimit, numWordIds, tuneFileWrite, fileHeaderContext);
 }
 
-
 void
 IndexBuilder::FieldHandle::close()
 {
     _files.close();
 }
 
-
 SingleIterator::SingleIterator(FH &fieldHandle, uint32_t localFieldId)
     : _dFeatures(fieldHandle._wdff.begin()),
       _dFeaturesE(fieldHandle._wdff.end()),
@@ -486,7 +392,6 @@ SingleIterator::SingleIterator(FH &fieldHandle, uint32_t localFieldId)
 {
 }
 
-
 void
 SingleIterator::appendFeatures(DocIdAndFeatures &features)
 {
@@ -511,7 +416,6 @@ SingleIterator::appendFeatures(DocIdAndFeatures &features)
     }
 }
 
-
 IndexBuilder::IndexBuilder(const Schema &schema)
     : index::IndexBuilder(schema),
       _currentField(nullptr),
@@ -541,6 +445,27 @@ IndexBuilder::IndexBuilder(const Schema &schema)
 IndexBuilder::~IndexBuilder() = default;
 
 void
+IndexBuilder::startField(uint32_t fieldId)
+{
+    assert(_curDocId == noDocId());
+    assert(_currentField == nullptr);
+    assert(fieldId < _fields.size());
+    assert(fieldId >= _lowestOKFieldId);
+    _currentField = &_fields[fieldId];
+    assert(_currentField != nullptr);
+}
+
+void
+IndexBuilder::endField()
+{
+    assert(_curDocId == noDocId());
+    assert(!_inWord);
+    assert(_currentField != nullptr);
+    _lowestOKFieldId = _currentField->_fieldId + 1;
+    _currentField = nullptr;
+}
+
+void
 IndexBuilder::startWord(vespalib::stringref word)
 {
     assert(_currentField != nullptr);
@@ -551,7 +476,6 @@ IndexBuilder::startWord(vespalib::stringref word)
     _currentField->startWord(word);
 }
 
-
 void
 IndexBuilder::endWord()
 {
@@ -562,7 +486,6 @@ IndexBuilder::endWord()
     _lowestOKDocId = 1u;
 }
 
-
 void
 IndexBuilder::startDocument(uint32_t docId)
 {
@@ -575,7 +498,6 @@ IndexBuilder::startDocument(uint32_t docId)
     _currentField->startDocument(docId);
 }
 
-
 void
 IndexBuilder::endDocument()
 {
@@ -586,30 +508,6 @@ IndexBuilder::endDocument()
     _curDocId = noDocId();
 }
 
-
-void
-IndexBuilder::startField(uint32_t fieldId)
-{
-    assert(_curDocId == noDocId());
-    assert(_currentField == nullptr);
-    assert(fieldId < _fields.size());
-    assert(fieldId >= _lowestOKFieldId);
-    _currentField = &_fields[fieldId];
-    assert(_currentField != nullptr);
-}
-
-
-void
-IndexBuilder::endField()
-{
-    assert(_curDocId == noDocId());
-    assert(!_inWord);
-    assert(_currentField != nullptr);
-    _lowestOKFieldId = _currentField->_fieldId + 1;
-    _currentField = nullptr;
-}
-
-
 void
 IndexBuilder::startElement(uint32_t elementId,
                            int32_t weight,
@@ -619,7 +517,6 @@ IndexBuilder::startElement(uint32_t elementId,
     _currentField->startElement(elementId, weight, elementLen);
 }
 
-
 void
 IndexBuilder::endElement()
 {
@@ -627,7 +524,6 @@ IndexBuilder::endElement()
     _currentField->endElement();
 }
 
-
 void
 IndexBuilder::addOcc(const WordDocElementWordPosFeatures &features)
 {
@@ -635,14 +531,12 @@ IndexBuilder::addOcc(const WordDocElementWordPosFeatures &features)
     _currentField->addOcc(features);
 }
 
-
 void
 IndexBuilder::setPrefix(vespalib::stringref prefix)
 {
     _prefix = prefix;
 }
 
-
 vespalib::string
 IndexBuilder::appendToPrefix(vespalib::stringref name)
 {
@@ -652,7 +546,6 @@ IndexBuilder::appendToPrefix(vespalib::stringref name)
     return _prefix + "/" + name;
 }
 
-
 void
 IndexBuilder::open(uint32_t docIdLimit, uint64_t numWordIds,
                    const TuneFileIndexing &tuneFileIndexing,
@@ -682,7 +575,6 @@ IndexBuilder::open(uint32_t docIdLimit, uint64_t numWordIds,
     }
 }
 
-
 void
 IndexBuilder::close()
 {
diff --git a/searchlib/src/vespa/searchlib/diskindex/indexbuilder.h b/searchlib/src/vespa/searchlib/diskindex/indexbuilder.h
index fa818bf08e6..43ac49a0a72 100644
--- a/searchlib/src/vespa/searchlib/diskindex/indexbuilder.h
+++ b/searchlib/src/vespa/searchlib/diskindex/indexbuilder.h
@@ -13,12 +13,16 @@ namespace search::diskindex {
 
 class BitVectorCandidate;
 
-class IndexBuilder : public index::IndexBuilder
-{
+/**
+ * Class used to build a disk index for the set of index fields specified in a schema.
+ *
+ * The resulting disk index consists of field indexes that are independent of each other.
+ */
+class IndexBuilder : public index::IndexBuilder {
 public:
     class FieldHandle;
 
-    typedef index::Schema Schema;
+    using Schema = index::Schema;
 private:
     // Text fields
     FieldHandle             *_currentField;
@@ -49,19 +53,16 @@ public:
     IndexBuilder(const Schema &schema); 
     ~IndexBuilder() override;
 
+    void startField(uint32_t fieldId) override;
+    void endField() override;
     void startWord(vespalib::stringref word) override;
     void endWord() override;
     void startDocument(uint32_t docId) override;
     void endDocument() override;
-    void startField(uint32_t fieldId) override;
-    void endField() override;
     void startElement(uint32_t elementId, int32_t weight, uint32_t elementLen) override;
     void endElement() override;
     void addOcc(const WordDocElementWordPosFeatures &features) override;
 
-    // TODO: methods for attribute vectors.
-
-    // TODO: methods for document summary.
     void setPrefix(vespalib::stringref prefix);
 
     vespalib::string appendToPrefix(vespalib::stringref name);
diff --git a/searchlib/src/vespa/searchlib/index/indexbuilder.cpp b/searchlib/src/vespa/searchlib/index/indexbuilder.cpp
index 6b88c51e6cc..d585238107a 100644
--- a/searchlib/src/vespa/searchlib/index/indexbuilder.cpp
+++ b/searchlib/src/vespa/searchlib/index/indexbuilder.cpp
@@ -6,7 +6,8 @@ namespace search::index {
 
 IndexBuilder::IndexBuilder(const Schema &schema)
     : _schema(schema)
-{ }
+{
+}
 
 IndexBuilder::~IndexBuilder() = default;
 
diff --git a/searchlib/src/vespa/searchlib/index/indexbuilder.h b/searchlib/src/vespa/searchlib/index/indexbuilder.h
index 66ca740a20c..0496809336b 100644
--- a/searchlib/src/vespa/searchlib/index/indexbuilder.h
+++ b/searchlib/src/vespa/searchlib/index/indexbuilder.h
@@ -8,6 +8,15 @@ namespace search::index {
 class Schema;
 class WordDocElementWordPosFeatures;
 
+/**
+ * Interface used to build an index for the set of index fields specified in a schema.
+ *
+ *
+ * The index should be built as follows:
+ *   For each field add the set of unique words in sorted order.
+ *   For each word add the set of document ids in sorted order.
+ *   For each document id add the position information for that document.
+ */
 class IndexBuilder {
 protected:
     const Schema &_schema;
@@ -15,39 +24,16 @@ protected:
 public:
     IndexBuilder(const Schema &schema);
 
-    virtual
-    ~IndexBuilder();
-
-    virtual void
-    startWord(vespalib::stringref word) = 0;
-
-    virtual void
-    endWord() = 0;
-
-    virtual void
-    startDocument(uint32_t docId) = 0;
-
-    virtual void
-    endDocument() = 0;
-
-    virtual void
-    startField(uint32_t fieldId) = 0;
-
-    virtual void
-    endField() = 0;
-
-    virtual void
-    startElement(uint32_t elementId, int32_t weight, uint32_t elementLen) = 0;
-
-    virtual void
-    endElement() = 0;
-
-    virtual void
-    addOcc(const WordDocElementWordPosFeatures &features) = 0;
-
-    // TODO: methods for attribute vectors.
-
-    // TODO: methods for document summary.
+    virtual ~IndexBuilder();
+    virtual void startField(uint32_t fieldId) = 0;
+    virtual void endField() = 0;
+    virtual void startWord(vespalib::stringref word) = 0;
+    virtual void endWord() = 0;
+    virtual void startDocument(uint32_t docId) = 0;
+    virtual void endDocument() = 0;
+    virtual void startElement(uint32_t elementId, int32_t weight, uint32_t elementLen) = 0;
+    virtual void endElement() = 0;
+    virtual void addOcc(const WordDocElementWordPosFeatures &features) = 0;
 };
 
 }