ircd::db: Add preliminary tuple specific interface.

include/ircd/db.h

@@ -108,6 +108,7 @@ namespace ircd::db
 #include "db/cell.h"
 #include "db/row.h"
 #include "db/value.h"
+#include "db/tuple.h"
 
 namespace ircd::db
 {

include/ircd/db/row.h

@@ -73,10 +73,6 @@ struct ircd::db::row
 	const cell &operator[](const string_view &column) const;
 	cell &operator[](const string_view &column);
 
-	// [GET] Object conversion
-	template<class tuple> explicit operator tuple() const;
-	template<class tuple> explicit operator tuple();
-
     // [SET] Perform operation
 	void operator()(const op &, const string_view &col, const string_view &val = {}, const sopts & = {});
 
@@ -206,27 +202,6 @@ ircd::db::row::row(database &d,
 {
 }
 
-template<class tuple>
-ircd::db::row::operator tuple()
-{
-	tuple ret;
-	for(auto &cell : *this)
-		json::set(ret, cell.col(), cell.val());
-
-	return ret;
-}
-
-template<class tuple>
-ircd::db::row::operator tuple()
-const
-{
-	tuple ret;
-	for(const auto &cell : *this)
-		json::set(ret, cell.col(), cell.val());
-
-	return ret;
-}
-
 inline ircd::db::cell &
 ircd::db::row::operator[](const string_view &column)
 {

include/ircd/db/tuple.h

@@ -0,0 +1,105 @@
+/*
+ * Copyright (C) 2016 Charybdis Development Team
+ * Copyright (C) 2016 Jason Volk <jason@zemos.net>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice is present in all copies.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#pragma once
+#define HAVE_IRCD_DB_TUPLE_H
+
+namespace ircd::db
+{
+	template<class... T> json::tuple<T...> &set(json::tuple<T...> &, const row &r);
+	template<class tuple> tuple make_tuple(const row &r);
+
+	//template<class it, class... T> void deltas(const json::tuple<T...> &tuple, it i);
+	template<class it> void set_index(it begin, it end, const string_view &index);
+	template<class... T> void write(database &, const string_view &index, const json::tuple<T...> &, const gopts & = {});
+}
+
+//
+// Commit a json::tuple to the database as a single transaction.
+//
+template<class it>
+void
+ircd::db::set_index(it b,
+                    it e,
+                    const string_view &index)
+{
+	std::for_each(b, e, [&index]
+	(auto &delta)
+	{
+		std::get<2>(delta) = index;
+	});
+}
+
+/*
+template<class it,
+         class... T>
+void
+ircd::db::deltas(const json::tuple<T...> &tuple,
+                 it i)
+{
+	for_each(tuple, [&i]
+	(const string_view &key, const auto &val)
+	{
+		*i = delta
+		{
+			key,              // col
+			string_view{},    // key  (set_index)
+			byte_view<>(val)  // val
+		};
+
+		++i;
+	});
+}
+*/
+
+template<class... T>
+void
+ircd::db::write(database &database,
+                const string_view &index,
+                const json::tuple<T...> &tuple,
+                const gopts &opts)
+{
+	std::array<delta, tuple.size()> deltas;
+	deltas(index, tuple, begin(deltas));
+	database(begin(deltas), end(deltas));
+}
+
+template<class tuple>
+tuple
+ircd::db::make_tuple(const row &row)
+{
+	tuple ret;
+	set(ret, row);
+	return ret;
+}
+
+template<class... T>
+ircd::json::tuple<T...> &
+ircd::db::set(json::tuple<T...> &tuple,
+              const row &row)
+{
+	for(auto &cell : row)
+		if(cell.valid())
+			json::set(tuple, cell.col(), cell.val());
+
+	return tuple;
+}