From fc06ea8ded8a8ba92a363226d017ed2c7a7a395b Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Mon, 27 Feb 2023 19:58:11 -0800
Subject: [PATCH] ircd::db::options::map: Add merge suite for adding to
 existing options.

---
 include/ircd/db/opts.h |  8 ++++-
 ircd/db.cc             | 80 +++++++++++++++++++++++++++++-------------
 2 files changed, 63 insertions(+), 25 deletions(-)

diff --git a/include/ircd/db/opts.h b/include/ircd/db/opts.h
index 702211fbe..4633e3729 100644
--- a/include/ircd/db/opts.h
+++ b/include/ircd/db/opts.h
@@ -110,6 +110,12 @@ struct ircd::db::options
 struct ircd::db::options::map
 :std::unordered_map<std::string, std::string>
 {
+	// Merge output of options structures from map (map takes precedence).
+	rocksdb::DBOptions merge(const rocksdb::DBOptions &) const;
+	rocksdb::ColumnFamilyOptions merge(const rocksdb::ColumnFamilyOptions &) const;
+	rocksdb::PlainTableOptions merge(const rocksdb::PlainTableOptions &) const;
+	rocksdb::BlockBasedTableOptions merge(const rocksdb::BlockBasedTableOptions &) const;
+
 	// Output of options structures from map
 	operator rocksdb::DBOptions() const;
 	operator rocksdb::ColumnFamilyOptions() const;
@@ -120,7 +126,7 @@ struct ircd::db::options::map
 	map(const options &);
 
 	// Input of options map from user
-	map(std::unordered_map<std::string, std::string> m)
+	map(std::unordered_map<std::string, std::string> m = {})
 	:std::unordered_map<std::string, std::string>{std::move(m)}
 	{}
 };
diff --git a/ircd/db.cc b/ircd/db.cc
index a5f9c902b..18e7d87e2 100644
--- a/ircd/db.cc
+++ b/ircd/db.cc
@@ -3920,49 +3920,81 @@ ircd::db::options::map::map(const options &o)
 	};
 }
 
-ircd::db::options::map::operator rocksdb::PlainTableOptions()
-const
-{
-	rocksdb::PlainTableOptions ret;
-	throw_on_error
-	{
-		rocksdb::GetPlainTableOptionsFromMap(ret, *this, &ret)
-	};
-
-	return ret;
-}
-
 ircd::db::options::map::operator rocksdb::BlockBasedTableOptions()
 const
 {
 	rocksdb::BlockBasedTableOptions ret;
-	throw_on_error
-	{
-		rocksdb::GetBlockBasedTableOptionsFromMap(ret, *this, &ret)
-	};
+	return merge(ret);
+}
 
-	return ret;
+ircd::db::options::map::operator rocksdb::PlainTableOptions()
+const
+{
+	rocksdb::PlainTableOptions ret;
+	return merge(ret);
 }
 
 ircd::db::options::map::operator rocksdb::ColumnFamilyOptions()
 const
 {
 	rocksdb::ColumnFamilyOptions ret;
-	throw_on_error
-	{
-		rocksdb::GetColumnFamilyOptionsFromMap(ret, *this, &ret)
-	};
-
-	return ret;
+	return merge(ret);
 }
 
 ircd::db::options::map::operator rocksdb::DBOptions()
 const
 {
 	rocksdb::DBOptions ret;
+	return merge(ret);
+}
+
+rocksdb::BlockBasedTableOptions
+ircd::db::options::map::merge(const rocksdb::BlockBasedTableOptions &opts)
+const
+{
+	rocksdb::BlockBasedTableOptions ret;
 	throw_on_error
 	{
-		rocksdb::GetDBOptionsFromMap(ret, *this, &ret)
+		rocksdb::GetBlockBasedTableOptionsFromMap(opts, *this, &ret, true, true)
+	};
+
+	return ret;
+}
+
+rocksdb::PlainTableOptions
+ircd::db::options::map::merge(const rocksdb::PlainTableOptions &opts)
+const
+{
+	rocksdb::PlainTableOptions ret;
+	throw_on_error
+	{
+		rocksdb::GetPlainTableOptionsFromMap(opts, *this, &ret, true, true)
+	};
+
+	return ret;
+}
+
+rocksdb::ColumnFamilyOptions
+ircd::db::options::map::merge(const rocksdb::ColumnFamilyOptions &opts)
+const
+{
+	rocksdb::ColumnFamilyOptions ret;
+	throw_on_error
+	{
+		rocksdb::GetColumnFamilyOptionsFromMap(opts, *this, &ret, true, true)
+	};
+
+	return ret;
+}
+
+rocksdb::DBOptions
+ircd::db::options::map::merge(const rocksdb::DBOptions &opts)
+const
+{
+	rocksdb::DBOptions ret;
+	throw_on_error
+	{
+		rocksdb::GetDBOptionsFromMap(opts, *this, &ret, true, true)
 	};
 
 	return ret;