Merge pull request #30227 from vespa-engine/balder/reduce-buffer-size-and-gc-some-unused-code

Use smaller buffer for reading file headers. And GC some unused code.

17 files changed, 80 insertions, 127 deletions

diff --git a/searchcore/src/apps/vespa-gen-testdocs/vespa-gen-testdocs.cpp b/searchcore/src/apps/vespa-gen-testdocs/vespa-gen-testdocs.cpp
index f7f5b2328c4..9ab8f4829a0 100644
--- a/searchcore/src/apps/vespa-gen-testdocs/vespa-gen-testdocs.cpp
+++ b/searchcore/src/apps/vespa-gen-testdocs/vespa-gen-testdocs.cpp
@@ -14,7 +14,6 @@
 #include <getopt.h>
 #include <vector>
 #include <limits>
-#include <unistd.h>
 #include <filesystem>
 
 #include <vespa/log/log.h>
@@ -552,7 +551,7 @@ DocumentGenerator::generate(uint32_t docMin, uint32_t docIdLimit,
 {
     string fullName(prependBaseDir(baseDir, feedFileName));
     std::filesystem::remove(std::filesystem::path(fullName));
-    Fast_BufferedFile f(new FastOS_File);
+    Fast_BufferedFile f;
     f.WriteOpen(fullName.c_str());
     if (json) {
         bool first = true;
diff --git a/searchcore/src/vespa/searchcorespi/index/indexreadutilities.cpp b/searchcore/src/vespa/searchcorespi/index/indexreadutilities.cpp
index d3f45ec081b..6683e9aa935 100644
--- a/searchcore/src/vespa/searchcorespi/index/indexreadutilities.cpp
+++ b/searchcore/src/vespa/searchcorespi/index/indexreadutilities.cpp
@@ -36,8 +36,7 @@ scanForIndexes(const vespalib::string &baseDir,
             if (name.find(IndexDiskLayout::FusionDirPrefix) == 0) {
                 if (!fusionDir.empty()) {
                     // Should never happen, since we run cleanup before load.
-                    LOG(warning, "Base directory '%s' contains multiple fusion indexes",
-                        baseDir.c_str());
+                    LOG(warning, "Base directory '%s' contains multiple fusion indexes", baseDir.c_str());
                 }
                 fusionDir = name;
             }
@@ -59,8 +58,8 @@ IndexReadUtilities::readFusionSpec(const vespalib::string &baseDir)
         fusionId = atoi(fusionDir.substr(IndexDiskLayout::FusionDirPrefix.size()).c_str());
     }
     std::set<uint32_t> flushIds;
-    for (size_t i = 0; i < flushDirs.size(); ++i) {
-        uint32_t id = atoi(flushDirs[i].substr(IndexDiskLayout::FlushDirPrefix.size()).c_str());
+    for (const auto & flushDir : flushDirs) {
+        uint32_t id = atoi(flushDir.substr(IndexDiskLayout::FlushDirPrefix.size()).c_str());
         flushIds.insert(id);
     }
 
@@ -74,7 +73,7 @@ SerialNum
 IndexReadUtilities::readSerialNum(const vespalib::string &dir)
 {
     const vespalib::string fileName = IndexDiskLayout::getSerialNumFileName(dir);
-    Fast_BufferedFile file;
+    Fast_BufferedFile file(16_Ki);
     file.ReadOpen(fileName.c_str());
 
     FileHeader fileHeader;
diff --git a/searchcore/src/vespa/searchcorespi/index/indexwriteutilities.cpp b/searchcore/src/vespa/searchcorespi/index/indexwriteutilities.cpp
index d2f77cfaf29..dfef52cc8e8 100644
--- a/searchcore/src/vespa/searchcorespi/index/indexwriteutilities.cpp
+++ b/searchcore/src/vespa/searchcorespi/index/indexwriteutilities.cpp
@@ -40,12 +40,11 @@ IndexWriteUtilities::writeSerialNum(SerialNum serialNum,
                                     const vespalib::string &dir,
                                     const FileHeaderContext &fileHeaderContext)
 {
-    const vespalib::string fileName =
-        IndexDiskLayout::getSerialNumFileName(dir);
+    const vespalib::string fileName = IndexDiskLayout::getSerialNumFileName(dir);
     const vespalib::string tmpFileName = fileName + ".tmp";
 
     SerialNumFileHeaderContext snFileHeaderContext(fileHeaderContext, serialNum);
-    Fast_BufferedFile file;
+    Fast_BufferedFile file(16_Ki);
     file.WriteOpen(tmpFileName.c_str());
     FileHeader fileHeader;
     snFileHeaderContext.addTags(fileHeader, fileName);
@@ -103,17 +102,13 @@ IndexWriteUtilities::copySerialNumFile(const vespalib::string &sourceDir,
 }
 
 void
-IndexWriteUtilities::writeSourceSelector(FixedSourceSelector::SaveInfo &
-                                         saveInfo,
+IndexWriteUtilities::writeSourceSelector(FixedSourceSelector::SaveInfo & saveInfo,
                                          uint32_t sourceId,
-                                         const TuneFileAttributes &
-                                         tuneFileAttributes,
-                                         const FileHeaderContext &
-                                         fileHeaderContext,
+                                         const TuneFileAttributes & tuneFileAttributes,
+                                         const FileHeaderContext & fileHeaderContext,
                                          SerialNum serialNum)
 {
-    SerialNumFileHeaderContext snFileHeaderContext(fileHeaderContext,
-                                                   serialNum);
+    SerialNumFileHeaderContext snFileHeaderContext(fileHeaderContext, serialNum);
     if (!saveInfo.save(tuneFileAttributes, snFileHeaderContext)) {
         std::ostringstream msg;
         msg << "Flush of sourceselector failed. Source id = " << sourceId;
@@ -122,20 +117,16 @@ IndexWriteUtilities::writeSourceSelector(FixedSourceSelector::SaveInfo &
 }
 
 void
-IndexWriteUtilities::updateDiskIndexSchema(const vespalib::string &indexDir,
-                                           const Schema &schema,
-                                           SerialNum serialNum)
+IndexWriteUtilities::updateDiskIndexSchema(const vespalib::string &indexDir, const Schema &schema, SerialNum serialNum)
 {
     vespalib::string schemaName = IndexDiskLayout::getSchemaFileName(indexDir);
     Schema oldSchema;
     if (!oldSchema.loadFromFile(schemaName)) {
-        LOG(error, "Could not open schema '%s'",
-            schemaName.c_str());
+        LOG(error, "Could not open schema '%s'", schemaName.c_str());
         return;
     }
     if (!SchemaUtil::validateSchema(oldSchema)) {
-        LOG(error, "Could not validate schema loaded from '%s'",
-            schemaName.c_str());
+        LOG(error, "Could not validate schema loaded from '%s'", schemaName.c_str());
         return;
     }
     Schema::UP newSchema = Schema::intersect(oldSchema, schema);
@@ -152,8 +143,7 @@ IndexWriteUtilities::updateDiskIndexSchema(const vespalib::string &indexDir,
     vespalib::string schemaOrigName = schemaName + ".orig";
     fs::remove(fs::path(schemaTmpName));
     if (!newSchema->saveToFile(schemaTmpName)) {
-        LOG(error, "Could not save schema to '%s'",
-            schemaTmpName.c_str());
+        LOG(error, "Could not save schema to '%s'", schemaTmpName.c_str());
     }
     FastOS_StatInfo statInfo;
     bool statres;
@@ -161,15 +151,12 @@ IndexWriteUtilities::updateDiskIndexSchema(const vespalib::string &indexDir,
     if (!statres) {
         if (statInfo._error != FastOS_StatInfo::FileNotFound) {
             LOG(error, "Failed to stat orig schema '%s': %s",
-                schemaOrigName.c_str(),
-                FastOS_File::getLastErrorString().c_str());
+                schemaOrigName.c_str(), FastOS_File::getLastErrorString().c_str());
         }
         int linkres = ::link(schemaName.c_str(), schemaOrigName.c_str());
         if (linkres != 0) {
             LOG(error, "Could not link '%s' to '%s': %s",
-                schemaOrigName.c_str(),
-                schemaName.c_str(),
-                FastOS_File::getLastErrorString().c_str());
+                schemaOrigName.c_str(), schemaName.c_str(), FastOS_File::getLastErrorString().c_str());
         }
         vespalib::File::sync(indexDir);
     }
@@ -178,9 +165,7 @@ IndexWriteUtilities::updateDiskIndexSchema(const vespalib::string &indexDir,
         int error = errno;
         std::string errString = FastOS_File::getErrorString(error);
         LOG(error, "Could not rename '%s' to '%s': %s",
-            schemaTmpName.c_str(),
-            schemaName.c_str(),
-            errString.c_str());
+            schemaTmpName.c_str(), schemaName.c_str(), errString.c_str());
     }
     vespalib::File::sync(indexDir);
 }
diff --git a/searchlib/src/vespa/searchlib/attribute/attributevector.cpp b/searchlib/src/vespa/searchlib/attribute/attributevector.cpp
index 4654cf435b1..dcf627b0ce2 100644
--- a/searchlib/src/vespa/searchlib/attribute/attributevector.cpp
+++ b/searchlib/src/vespa/searchlib/attribute/attributevector.cpp
@@ -328,7 +328,7 @@ bool
 AttributeVector::isEnumeratedSaveFormat() const
 {
     vespalib::string datName(fmt("%s.dat", getBaseFileName().c_str()));
-    Fast_BufferedFile   datFile;
+    Fast_BufferedFile   datFile(16_Ki);
     vespalib::FileHeader datHeader(FileSettings::DIRECTIO_ALIGNMENT);
     if ( ! datFile.OpenReadOnly(datName.c_str()) ) {
         LOG(error, "could not open %s: %s", datFile.GetFileName(), getLastErrorString().c_str());
diff --git a/searchlib/src/vespa/searchlib/attribute/sourceselector.cpp b/searchlib/src/vespa/searchlib/attribute/sourceselector.cpp
index 907d54467c1..77c86e21b2a 100644
--- a/searchlib/src/vespa/searchlib/attribute/sourceselector.cpp
+++ b/searchlib/src/vespa/searchlib/attribute/sourceselector.cpp
@@ -81,7 +81,7 @@ void
 SourceSelector::LoadInfo::load()
 {
     const vespalib::string fileName = _header._baseFileName + ".dat";
-    Fast_BufferedFile file;
+    Fast_BufferedFile file(16_Ki);
     // XXX no checking for success
     file.ReadOpen(fileName.c_str());
 
diff --git a/searchlib/src/vespa/searchlib/common/documentsummary.cpp b/searchlib/src/vespa/searchlib/common/documentsummary.cpp
index f004e5cc4cf..9341cf92b89 100644
--- a/searchlib/src/vespa/searchlib/common/documentsummary.cpp
+++ b/searchlib/src/vespa/searchlib/common/documentsummary.cpp
@@ -40,7 +40,7 @@ bool
 DocumentSummary::writeDocIdLimit(const vespalib::string &dir, uint32_t count)
 {
     vespalib::string qcntname = dir + "/docsum.qcnt";
-    Fast_BufferedFile qcntfile(new FastOS_File);
+    Fast_BufferedFile qcntfile(4_Ki);
 
     qcntfile.WriteOpen(qcntname.c_str());
     if (!qcntfile.IsOpened()) {
diff --git a/searchlib/src/vespa/searchlib/diskindex/bitvectorfile.cpp b/searchlib/src/vespa/searchlib/diskindex/bitvectorfile.cpp
index fc7fd9c2fb7..8c47e5c193e 100644
--- a/searchlib/src/vespa/searchlib/diskindex/bitvectorfile.cpp
+++ b/searchlib/src/vespa/searchlib/diskindex/bitvectorfile.cpp
@@ -49,7 +49,7 @@ BitVectorFileWrite::open(const vespalib::string &name, uint32_t docIdLimit,
 
     Parent::open(name, docIdLimit, tuneFileWrite, fileHeaderContext);
 
-    _datFile = std::make_unique<Fast_BufferedFile>(new FastOS_File);
+    _datFile = std::make_unique<Fast_BufferedFile>();
     if (tuneFileWrite.getWantSyncWrites()) {
         _datFile->EnableSyncWrites();
     }
diff --git a/searchlib/src/vespa/searchlib/diskindex/bitvectoridxfile.cpp b/searchlib/src/vespa/searchlib/diskindex/bitvectoridxfile.cpp
index 7e3f0f5f258..cec3db35d60 100644
--- a/searchlib/src/vespa/searchlib/diskindex/bitvectoridxfile.cpp
+++ b/searchlib/src/vespa/searchlib/diskindex/bitvectoridxfile.cpp
@@ -59,7 +59,7 @@ BitVectorIdxFileWrite::open(const vespalib::string &name, uint32_t docIdLimit,
     vespalib::string idxname = name + getBitVectorKeyScopeSuffix(_scope);
 
     assert( !_idxFile);
-    _idxFile = std::make_unique<Fast_BufferedFile>(new FastOS_File());
+    _idxFile = std::make_unique<Fast_BufferedFile>();
     if (tuneFileWrite.getWantSyncWrites()) {
         _idxFile->EnableSyncWrites();
     }
diff --git a/searchlib/src/vespa/searchlib/diskindex/dictionarywordreader.cpp b/searchlib/src/vespa/searchlib/diskindex/dictionarywordreader.cpp
index 1392f47525e..19741b3b166 100644
--- a/searchlib/src/vespa/searchlib/diskindex/dictionarywordreader.cpp
+++ b/searchlib/src/vespa/searchlib/diskindex/dictionarywordreader.cpp
@@ -6,6 +6,8 @@
 #include <vespa/fastlib/io/bufferedfile.h>
 
 #include <vespa/log/log.h>
+
+#include <memory>
 LOG_SETUP(".diskindex.dictionarywordreader");
 
 namespace search::diskindex {
@@ -21,17 +23,15 @@ DictionaryWordReader::DictionaryWordReader()
 {
 }
 
-
 DictionaryWordReader::~DictionaryWordReader() = default;
 
-
 bool
 DictionaryWordReader::open(const vespalib::string & dictionaryName,
                            const vespalib::string & wordMapName,
                            const TuneFileSeqRead &tuneFileRead)
 {
-    _old2newwordfile.reset(new Fast_BufferedFile(new FastOS_File));
-    _dictFile.reset(new PageDict4FileSeqRead);
+    _old2newwordfile = std::make_unique<Fast_BufferedFile>();
+    _dictFile = std::make_unique<PageDict4FileSeqRead>();
     if (!_dictFile->open(dictionaryName, tuneFileRead)) {
         LOG(error, "Could not open dictionary %s: %s",
             dictionaryName.c_str(), getLastErrorString().c_str());
diff --git a/searchlib/src/vespa/searchlib/diskindex/diskindex.cpp b/searchlib/src/vespa/searchlib/diskindex/diskindex.cpp
index bf295acec75..105151d8132 100644
--- a/searchlib/src/vespa/searchlib/diskindex/diskindex.cpp
+++ b/searchlib/src/vespa/searchlib/diskindex/diskindex.cpp
@@ -121,26 +121,20 @@ DiskIndex::openField(const vespalib::string &fieldDir,
                    DiskPostingFileReal::getSubIdentifier()) {
             dynamicK = false;
         } else {
-            LOG(warning,
-                "Could not detect format for posocc file read %s",
-                postingName.c_str());
+            LOG(warning, "Could not detect format for posocc file read %s", postingName.c_str());
         }
     }
-    pFile.reset(dynamicK ?
-                new DiskPostingFileDynamicKReal() :
-                new DiskPostingFileReal());
+    pFile.reset(dynamicK
+                ? new DiskPostingFileDynamicKReal()
+                : new DiskPostingFileReal());
     if (!pFile->open(postingName, tuneFileSearch._read)) {
-        LOG(warning,
-            "Could not open posting list file '%s'",
-            postingName.c_str());
+        LOG(warning, "Could not open posting list file '%s'", postingName.c_str());
         return false;
     }
 
     bDict.reset(new BitVectorDictionary());
     if (!bDict->open(fieldDir, tuneFileSearch._read, BitVectorKeyScope::PERFIELD_WORDS)) {
-        LOG(warning,
-            "Could not open bit vector dictionary in '%s'",
-            fieldDir.c_str());
+        LOG(warning, "Could not open bit vector dictionary in '%s'", fieldDir.c_str());
         return false;
     }
     _postingFiles.push_back(pFile);
@@ -158,8 +152,7 @@ DiskIndex::setup(const TuneFileSearch &tuneFileSearch)
         return false;
     }
     for (SchemaUtil::IndexIterator itr(_schema); itr.isValid(); ++itr) {
-        vespalib::string fieldDir =
-            _indexDir + "/" + itr.getName() + "/";
+        vespalib::string fieldDir = _indexDir + "/" + itr.getName() + "/";
         if (!openField(fieldDir, tuneFileSearch)) {
             return false;
         }
@@ -169,8 +162,7 @@ DiskIndex::setup(const TuneFileSearch &tuneFileSearch)
 }
 
 bool
-DiskIndex::setup(const TuneFileSearch &tuneFileSearch,
-                 const DiskIndex &old)
+DiskIndex::setup(const TuneFileSearch &tuneFileSearch, const DiskIndex &old)
 {
     if (tuneFileSearch != old._tuneFileSearch) {
         return setup(tuneFileSearch);
@@ -180,8 +172,7 @@ DiskIndex::setup(const TuneFileSearch &tuneFileSearch,
     }
     const Schema &oldSchema = old._schema;
     for (SchemaUtil::IndexIterator itr(_schema); itr.isValid(); ++itr) {
-        vespalib::string fieldDir =
-            _indexDir + "/" + itr.getName() + "/";
+        vespalib::string fieldDir = _indexDir + "/" + itr.getName() + "/";
         SchemaUtil::IndexSettings settings = itr.getIndexSettings();
         if (settings.hasError()) {
             return false;
@@ -336,12 +327,11 @@ DiskIndex::LookupResult G_nothing;
 
 class LookupCache {
 public:
-    LookupCache(DiskIndex & diskIndex, const std::vector<uint32_t> & fieldIds) :
-        _diskIndex(diskIndex),
-        _fieldIds(fieldIds),
-        _cache()
-    {
-    }
+    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) {
         auto it = _cache.find(word);
@@ -473,7 +463,7 @@ DiskIndex::get_field_length_info(const vespalib::string& field_name) const
     if (fieldId != Schema::UNKNOWN_FIELD_ID) {
         return _postingFiles[fieldId]->get_field_length_info();
     } else {
-        return FieldLengthInfo();
+        return {};
     }
 }
 
diff --git a/searchlib/src/vespa/searchlib/diskindex/indexbuilder.cpp b/searchlib/src/vespa/searchlib/diskindex/indexbuilder.cpp
index 5cf80d06c87..ae1e5594320 100644
--- a/searchlib/src/vespa/searchlib/diskindex/indexbuilder.cpp
+++ b/searchlib/src/vespa/searchlib/diskindex/indexbuilder.cpp
@@ -180,10 +180,10 @@ FileHandle::close()
 FieldHandle::FieldHandle(const Schema &schema, uint32_t fieldId, IndexBuilder &builder, uint32_t docIdLimit,
                          uint64_t numWordIds, const IFieldLengthInspector & field_length_inspector,
                          const TuneFileSeqWrite &tuneFileWrite, const FileHeaderContext &fileHeaderContext)
-        : _schema(schema),
-          _builder(builder),
-          _file(),
-          _fieldId(fieldId)
+    : _schema(schema),
+      _builder(builder),
+      _file(),
+      _fieldId(fieldId)
 {
     std::filesystem::create_directory(std::filesystem::path(getDir()));
     _file.open(getDir(), SchemaUtil::IndexIterator(_schema, getIndexId()), docIdLimit, numWordIds,
@@ -251,7 +251,6 @@ IndexBuilder::IndexBuilder(const Schema &schema, vespalib::stringref prefix, uin
                            uint64_t numWordIds, const index::IFieldLengthInspector &field_length_inspector,
                            const TuneFileIndexing &tuneFileIndexing, const search::common::FileHeaderContext &fileHeaderContext)
     : index::IndexBuilder(schema),
-      _schema(schema),
       _fields(extractFields(schema)),
       _prefix(prefix),
       _docIdLimit(docIdLimit),
diff --git a/searchlib/src/vespa/searchlib/diskindex/indexbuilder.h b/searchlib/src/vespa/searchlib/diskindex/indexbuilder.h
index 4ef6ab4a813..3417f595faa 100644
--- a/searchlib/src/vespa/searchlib/diskindex/indexbuilder.h
+++ b/searchlib/src/vespa/searchlib/diskindex/indexbuilder.h
@@ -30,7 +30,6 @@ public:
     std::unique_ptr<index::FieldIndexBuilder> startField(uint32_t fieldId) override;
     vespalib::string appendToPrefix(vespalib::stringref name) const;
 private:
-    const index::Schema      &_schema;
     std::vector<int>          _fields;
     const vespalib::string    _prefix;
     const uint32_t            _docIdLimit;
diff --git a/searchlib/src/vespa/searchlib/diskindex/wordnummapper.cpp b/searchlib/src/vespa/searchlib/diskindex/wordnummapper.cpp
index 83033b137f8..bda0a0594b7 100644
--- a/searchlib/src/vespa/searchlib/diskindex/wordnummapper.cpp
+++ b/searchlib/src/vespa/searchlib/diskindex/wordnummapper.cpp
@@ -18,7 +18,7 @@ WordNumMapping::readMappingFile(const vespalib::string &name,
                                 const TuneFileSeqRead &tuneFileRead)
 {
     // Open word mapping file
-    Fast_BufferedFile old2newwordfile(new FastOS_File);
+    Fast_BufferedFile old2newwordfile;
     if (tuneFileRead.getWantDirectIO()) {
         old2newwordfile.EnableDirectIO();
     }
diff --git a/vespalib/src/vespa/fastlib/io/bufferedfile.cpp b/vespalib/src/vespa/fastlib/io/bufferedfile.cpp
index 0fa62aca295..4d46427ed33 100644
--- a/vespalib/src/vespa/fastlib/io/bufferedfile.cpp
+++ b/vespalib/src/vespa/fastlib/io/bufferedfile.cpp
@@ -202,7 +202,7 @@ Fast_BufferedFile::ReadLine(char *line, size_t buflen)
 
     p = line;
     ep = line + buflen - 1;
-    while (1) {
+    while (true) {
         while (_bufi < _bufe && *_bufi != '\n' && p < ep)
             *p++ = *_bufi++;
         if (p >= ep) {
@@ -258,7 +258,7 @@ Fast_BufferedFile::Read(void *dst, size_t dstlen)
 {
     char * p = static_cast<char *>(dst);
     char * pe = p + dstlen;
-    while (1) {
+    while (true) {
         int64_t sz = std::min(_bufe - _bufi, pe - p);
         memcpy(p, _bufi, sz);
         p += sz;
@@ -334,11 +334,6 @@ Fast_BufferedFile::WriteOpen(const char *name)
         _openFlags = FASTOS_FILE_OPEN_WRITE;
 }
 
-Fast_BufferedFile::Fast_BufferedFile(FastOS_FileInterface *file) :
-    Fast_BufferedFile(file, DEFAULT_BUF_SIZE)
-{
-}
-
 Fast_BufferedFile::Fast_BufferedFile() :
     Fast_BufferedFile(DEFAULT_BUF_SIZE) 
 {
diff --git a/vespalib/src/vespa/fastlib/io/bufferedfile.h b/vespalib/src/vespa/fastlib/io/bufferedfile.h
index 8a22ec89bd7..16153b79171 100644
--- a/vespalib/src/vespa/fastlib/io/bufferedfile.h
+++ b/vespalib/src/vespa/fastlib/io/bufferedfile.h
@@ -28,30 +28,40 @@ private:
 
     char * buf() { return static_cast<char *>(_buf.get()); }
     const char * buf() const { return static_cast<const char *>(_buf.get()); }
-protected:
     /** The file instance used for low-level file access. */
     std::unique_ptr<FastOS_FileInterface> _file;
 
-public:
-    /**
-     * Create buffered file.
-     * @param file file instance that should be used for low-level
-     *             file access. If this is NULL, an instance of
-     *             FastOS_File will be created. NOTE: the file
-     *             instance given here will be deleted by
-     *             the destructor.
-     **/
     Fast_BufferedFile(FastOS_FileInterface *file, size_t bufferSize);
-    Fast_BufferedFile(FastOS_FileInterface *file);
+    /**
+     * Reset the internal start and end pointers to the
+     * head of the buffer, thus "emptying" it.
+     */
+    void ResetBuf();
+    /**
+     * Write the buffer to the file. Caution: Uses obsolete
+     * FastOS_FileInterface::WriteBuf.
+     * Allocates a 32kB buffer if not previously allocated.
+     */
+    void flushWriteBuf();
+    /**
+     * Read from the file into the buffer. Allocates a 32kB
+     * buffer if not previously allocated. Fills the buffer,
+     * or reads as much as possible if the (rest of) the file
+     * is smaller than the buffer.
+     * Caution: If the amount read is smaller than the expected
+     * amount, the method will abort.
+     */
+    void fillReadBuf();
+public:
     Fast_BufferedFile();
-    Fast_BufferedFile(size_t bufferSize);
+    explicit Fast_BufferedFile(size_t bufferSize);
     Fast_BufferedFile(const Fast_BufferedFile &) = delete;
     Fast_BufferedFile & operator = (const Fast_BufferedFile &) = delete;
 
     /**
      * Delete the file instance used for low-level file access.
      **/
-    virtual ~Fast_BufferedFile();
+    ~Fast_BufferedFile() override;
     /**
      * Open an existing file for reading.
      *
@@ -71,26 +81,7 @@ public:
      * @param name The name of the file to open.
      */
     void WriteOpen(const char *name);
-    /**
-     * Reset the internal start and end pointers to the
-     * head of the buffer, thus "emptying" it.
-     */
-    void ResetBuf();
-    /**
-     * Write the buffer to the file. Caution: Uses obsolete
-     * FastOS_FileInterface::WriteBuf.
-     * Allocates a 32kB buffer if not previously allocated.
-     */
-    void flushWriteBuf();
-    /**
-     * Read from the file into the buffer. Allocates a 32kB
-     * buffer if not previously allocated. Fills the buffer,
-     * or reads as much as possible if the (rest of) the file
-     * is smaller than the buffer.
-     * Caution: If the amount read is smaller than the expected
-     * amount, the method will abort.
-     */
-    void fillReadBuf();
+
     /**
      * Read the next line of the buffered file into a buffer,
      * reading from the file as necessary.
diff --git a/vespalib/src/vespa/vespalib/util/mmap_file_allocator.cpp b/vespalib/src/vespa/vespalib/util/mmap_file_allocator.cpp
index a663c6a601b..e6a00f4b86d 100644
--- a/vespalib/src/vespa/vespalib/util/mmap_file_allocator.cpp
+++ b/vespalib/src/vespa/vespalib/util/mmap_file_allocator.cpp
@@ -75,7 +75,7 @@ PtrAndSize
 MmapFileAllocator::alloc(size_t sz) const
 {
     if (sz == 0) {
-        return PtrAndSize(); // empty allocation
+        return {}; // empty allocation
     }
     static constexpr size_t alignment = 128;
     sz = (sz + alignment - 1) & -alignment; // round sz to a multiple of alignment
@@ -107,7 +107,7 @@ MmapFileAllocator::alloc_large(size_t sz) const
     retval = madvise(buf, sz, MADV_DONTDUMP);
     assert(retval == 0);
 #endif
-    return PtrAndSize(buf, sz);
+    return {buf, sz};
 }
 
 void*
diff --git a/vespalib/src/vespa/vespalib/util/mmap_file_allocator.h b/vespalib/src/vespa/vespalib/util/mmap_file_allocator.h
index 96a69f50e43..f568a14572a 100644
--- a/vespalib/src/vespa/vespalib/util/mmap_file_allocator.h
+++ b/vespalib/src/vespa/vespalib/util/mmap_file_allocator.h
@@ -24,15 +24,11 @@ class MmapFileAllocator : public MemoryAllocator {
     struct SizeAndOffset {
         size_t   size;
         uint64_t offset;
-        SizeAndOffset()
-            : SizeAndOffset(0u, 0u)
-        {
-        }
-        SizeAndOffset(size_t size_in, uint64_t offset_in)
+        SizeAndOffset() noexcept : SizeAndOffset(0u, 0u) { }
+        SizeAndOffset(size_t size_in, uint64_t offset_in) noexcept
             : size(size_in),
               offset(offset_in)
-        {
-        }
+        { }
     };
     using Allocations = hash_map<void *, SizeAndOffset>;
     const vespalib::string _dir_name;
@@ -55,9 +51,9 @@ class MmapFileAllocator : public MemoryAllocator {
 public:
     static constexpr uint32_t default_small_limit =  128_Ki;
     static constexpr uint32_t default_premmap_size = 1_Mi;
-    MmapFileAllocator(const vespalib::string& dir_name);
+    explicit MmapFileAllocator(const vespalib::string& dir_name);
     MmapFileAllocator(const vespalib::string& dir_name, uint32_t small_limit, uint32_t premmap_size);
-    ~MmapFileAllocator();
+    ~MmapFileAllocator() override;
     PtrAndSize alloc(size_t sz) const override;
     void free(PtrAndSize alloc) const noexcept override;
     size_t resize_inplace(PtrAndSize, size_t) const override;