SERVER-65481 Bulk shredding and loading for column store indexes

2 files changed, 13 insertions, 6 deletions

diff --git a/src/mongo/db/sorter/sorter.cpp b/src/mongo/db/sorter/sorter.cpp
index c23c2695afd..ecb9e10118e 100644
--- a/src/mongo/db/sorter/sorter.cpp
+++ b/src/mongo/db/sorter/sorter.cpp
@@ -1291,11 +1291,11 @@ void SortedFileWriter<Key, Value>::addAlreadySorted(const Key& key, const Value&
         addDataToChecksum(_buffer.buf() + _nextObjPos, _buffer.len() - _nextObjPos, _checksum);
 
     if (_buffer.len() > static_cast<int>(kSortedFileBufferSize))
-        spill();
+        writeChunk();
 }
 
 template <typename Key, typename Value>
-void SortedFileWriter<Key, Value>::spill() {
+void SortedFileWriter<Key, Value>::writeChunk() {
     int32_t size = _buffer.len();
     char* outBuffer = _buffer.buf();
 
@@ -1340,7 +1340,7 @@ void SortedFileWriter<Key, Value>::spill() {
 
 template <typename Key, typename Value>
 SortIteratorInterface<Key, Value>* SortedFileWriter<Key, Value>::done() {
-    spill();
+    writeChunk();
 
     return new sorter::FileIterator<Key, Value>(
         _file, _fileStartOffset, _file->currentOffset(), _settings, _dbName, _checksum);
diff --git a/src/mongo/db/sorter/sorter.h b/src/mongo/db/sorter/sorter.h
index 12bccee1178..85c0f279ac2 100644
--- a/src/mongo/db/sorter/sorter.h
+++ b/src/mongo/db/sorter/sorter.h
@@ -592,16 +592,23 @@ public:
     void addAlreadySorted(const Key&, const Value&);
 
     /**
-     * Spills any data remaining in the buffer to disk and then closes the file to which data was
+     * Writes any data remaining in the buffer to disk and then closes the file to which data was
      * written.
      *
      * No more data can be added via addAlreadySorted() after calling done().
      */
     Iterator* done();
 
-private:
-    void spill();
+    /**
+     * The SortedFileWriter organizes data into chunks, with a chunk getting written to the output
+     * file when it exceends a maximum chunks size. A SortedFilerWriter client can produce a short
+     * chunk by manually calling this function.
+     *
+     * If no new data has been added since the last chunk was written, this function is a no-op.
+     */
+    void writeChunk();
 
+private:
     const Settings _settings;
     std::shared_ptr<typename Sorter<Key, Value>::File> _file;
     BufBuilder _buffer;