Include title in indexes to avoid a per-record disk read

GOTTA GO FAST

3 files changed, 20 insertions, 22 deletions

diff --git a/src/database/database.cpp b/src/database/database.cpp
index 0d1c43e2..d0011abe 100644
--- a/src/database/database.cpp
+++ b/src/database/database.cpp
@@ -600,20 +600,12 @@ auto Database::ParseRecord<IndexRecord>(const leveldb::Slice& key,
     return {};
   }
 
-  // If there was a track id included for this key, then this is a leaf record.
-  // Fetch the actual track data instead of relying on the information in the
-  // key.
-  std::optional<Track> track;
-  if (data->track) {
-    std::optional<TrackData> track_data = dbGetTrackData(*data->track);
-    TrackTags track_tags;
-    if (track_data &&
-        tag_parser_->ReadAndParseTags(track_data->filepath(), &track_tags)) {
-      track.emplace(*track_data, track_tags);
-    }
+  std::optional<std::string> title;
+  if (!val.empty()) {
+    title = val.ToString();
   }
 
-  return IndexRecord(*data, track);
+  return IndexRecord(*data, title, data->track);
 }
 
 template <>
@@ -663,17 +655,17 @@ auto Database::ParseRecord<std::string>(const leveldb::Slice& key,
   return stream.str();
 }
 
-IndexRecord::IndexRecord(const IndexKey& key, std::optional<Track> track)
-    : key_(key), track_(track) {}
+IndexRecord::IndexRecord(const IndexKey& key, std::optional<shared_string> title, std::optional<TrackId> track)
+    : key_(key), override_text_(title), track_(track) {}
 
 auto IndexRecord::text() const -> std::optional<shared_string> {
-  if (track_) {
-    return track_->TitleOrFilename();
+  if (override_text_) {
+    return override_text_;
   }
   return key_.item;
 }
 
-auto IndexRecord::track() const -> std::optional<Track> {
+auto IndexRecord::track() const -> std::optional<TrackId> {
   return track_;
 }
 
diff --git a/src/database/include/database.hpp b/src/database/include/database.hpp
index 7ffc15b0..f7e44299 100644
--- a/src/database/include/database.hpp
+++ b/src/database/include/database.hpp
@@ -70,16 +70,17 @@ class Result {
 
 class IndexRecord {
  public:
-  explicit IndexRecord(const IndexKey&, std::optional<Track>);
+   explicit IndexRecord(const IndexKey&, std::optional<shared_string>, std::optional<TrackId>);
 
   auto text() const -> std::optional<shared_string>;
-  auto track() const -> std::optional<Track>;
+  auto track() const -> std::optional<TrackId>;
 
   auto Expand(std::size_t) const -> std::optional<Continuation<IndexRecord>>;
 
  private:
   IndexKey key_;
-  std::optional<Track> track_;
+  std::optional<shared_string> override_text_;
+  std::optional<TrackId> track_;
 };
 
 class Database {
diff --git a/src/database/index.cpp b/src/database/index.cpp
index a828578d..84d00bcd 100644
--- a/src/database/index.cpp
+++ b/src/database/index.cpp
@@ -52,15 +52,20 @@ auto Index(const IndexInfo& info, const Track& t, leveldb::WriteBatch* batch)
       key.item = {};
     }
 
-    // If this is the last component, then we should also fill in the track id.
+    // If this is the last component, then we should also fill in the track id
+    // and title.
+    std::optional<std::string> title;
     if (i == info.components.size() - 1) {
       key.track = t.data().id();
+      if (info.components.at(i) != Tag::kTitle) {
+        title = t.TitleOrFilename();
+      }
     } else {
       key.track = {};
     }
 
     auto encoded = EncodeIndexKey(key);
-    batch->Put(encoded.slice, leveldb::Slice{});
+    batch->Put(encoded.slice, title.value_or(""));
 
     // If there are more components after this, then we need to finish by
     // narrowing the header with the current title.