Revert "Rewrite optimistic scheduler in terms of ledger sets and add …

…ledger set height(account) overload."

This reverts commit 9512140.

# Conflicts:
#	nano/node/backlog_population.cpp
#	nano/node/node.cpp

nano/node/scheduler/optimistic.cpp

@@ -55,31 +55,30 @@ void nano::scheduler::optimistic::notify ()
 	condition.notify_all ();
 }
 
-bool nano::scheduler::optimistic::activate_predicate (nano::secure::transaction const & transaction, nano::account const & account) const
+bool nano::scheduler::optimistic::activate_predicate (const nano::account_info & account_info, const nano::confirmation_height_info & conf_info) const
 {
-	auto unconfirmed_height = ledger.any.account_height (transaction, account);
-	auto confirmed_height = ledger.confirmed.account_height (transaction, account);
-	// Account with nothing confirmed yet
-	if (confirmed_height == 0)
+	// Chain with a big enough gap between account frontier and confirmation frontier
+	if (account_info.block_count - conf_info.height > config.gap_threshold)
 	{
 		return true;
 	}
-	// Chain with a big enough gap between account frontier and confirmation frontier
-	if (unconfirmed_height - confirmed_height > config.gap_threshold)
+	// Account with nothing confirmed yet
+	if (conf_info.height == 0)
 	{
 		return true;
 	}
 	return false;
 }
 
-bool nano::scheduler::optimistic::activate (nano::secure::transaction const & transaction, nano::account const & account)
+bool nano::scheduler::optimistic::activate (const nano::account & account, const nano::account_info & account_info, const nano::confirmation_height_info & conf_info)
 {
 	if (!config.enabled)
 	{
 		return false;
 	}
 
-	if (activate_predicate (transaction, account))
+	debug_assert (account_info.block_count >= conf_info.height);
+	if (activate_predicate (account_info, conf_info))
 	{
 		{
 			nano::lock_guard<nano::mutex> lock{ mutex };

nano/node/scheduler/optimistic.hpp

@@ -60,7 +60,7 @@ class optimistic final
 	/**
 	 * Called from backlog population to process accounts with unconfirmed blocks
 	 */
-	bool activate (nano::secure::transaction const & transaction, nano::account const & account);
+	bool activate (nano::account const &, nano::account_info const &, nano::confirmation_height_info const &);
 
 	/**
 	 * Notify about changes in AEC vacancy
@@ -70,7 +70,7 @@ class optimistic final
 	std::unique_ptr<container_info_component> collect_container_info (std::string const & name) const;
 
 private:
-	bool activate_predicate (nano::secure::transaction const & transaction, nano::account const & account) const;
+	bool activate_predicate (nano::account_info const &, nano::confirmation_height_info const &) const;
 
 	bool predicate () const;
 	void run ();