indexer/store: avoid completed callback

This cause havoc / race conditions.

lib/index/mu-indexer.cc

@@ -43,7 +43,8 @@ struct IndexState {
 	enum State { Idle,
 		     Scanning,
 		     Finishing,
-		     Cleaning };
+		     Cleaning
+	};
 	static const char* name(State s) {
 		switch (s) {
 		case Idle:
@@ -65,7 +66,6 @@ struct IndexState {
 	bool operator!=(State rhs) const {
 		return state_.load() != rhs;
 	}
-
 	void change_to(State new_state) {
 		g_debug("changing indexer state %s->%s", name((State)state_),
 			name((State)new_state));
@@ -128,6 +128,8 @@ struct Indexer::Private {
 	Progress   progress_;
 	IndexState state_;
 	std::mutex lock_, w_lock_;
+
+	std::atomic<time_t> completed_;
 };
 
 bool
@@ -339,7 +341,7 @@ Indexer::Private::scan_worker()
 		g_debug("cleanup finished");
 	}
 
-	store_.index_complete();
+	completed_ = ::time({});
 	state_.change_to(IndexState::Idle);
 }
 
@@ -380,7 +382,6 @@ Indexer::Private::stop()
 	if (scanner_worker_.joinable())
 		scanner_worker_.join();
 
-	store_.index_complete();
 	state_.change_to(IndexState::Idle);
 	for (auto&& w : workers_)
 		if (w.joinable())
@@ -392,8 +393,7 @@ Indexer::Private::stop()
 
 Indexer::Indexer(Store& store)
     : priv_{std::make_unique<Private>(store)}
-{
-}
+{}
 
 Indexer::~Indexer() = default;
 
@@ -438,3 +438,9 @@ Indexer::progress() const
 
 	return priv_->progress_;
 }
+
+time_t
+Indexer::completed() const
+{
+	return priv_->completed_;
+}

lib/index/mu-indexer.hh

@@ -110,6 +110,13 @@ public:
 	 */
 	const Progress& progress() const;
 
+	/**
+	 * Last time indexing was completed.
+	 *
+	 * @return the time or 0
+	 */
+	time_t completed() const;
+
 private:
 	struct Private;
 	std::unique_ptr<Private> priv_;

lib/mu-store.cc

@@ -103,8 +103,6 @@ struct Store::Private {
 
 	~Private() try {
 
-		indexer_.reset(); // reset so it cannot call us back
-
 		g_debug("closing store @ %s", properties_.database_path.c_str());
 		if (!read_only_) {
 			transaction_maybe_commit(true /*force*/);
@@ -173,6 +171,13 @@ struct Store::Private {
 								   contacts_cache_.serialize());
 				});
 			}
+
+			if (indexer_) { // save last index time.
+				if (auto&& t{indexer_->completed()}; t != 0)
+					writable_db().set_metadata(
+						IndexedKey, tstamp_to_string(t));
+			}
+
 			if (transaction_size_ == 0)
 				return; // nothing more to do here.
 
@@ -642,16 +647,6 @@ Store::commit()
 }
 
 
-void
-Store::index_complete()
-{
-	std::lock_guard lock{priv_->lock_};
-
-	g_debug("marking index complete");
-	priv_->writable_db().set_metadata(IndexedKey, tstamp_to_string(::time({})));
-}
-
-
 std::size_t
 Store::for_each_term(Field::Id field_id, Store::ForEachTermFunc func) const
 {

lib/mu-store.hh

@@ -456,12 +456,6 @@ private:
 	      const Config&      conf);
 
 
-	/**
-	 * Call with indexing has completed to update metadata.
-	 */
-	friend class Indexer;
-	void index_complete();
-
 	std::unique_ptr<Private> priv_;
 };