[tarantool-patches] [PATCH v9 6/7] sql: create box.execute()

[imeevma@tarantool.org]

This patch creates the method dump_lua() for port_sql and uses it
in the new function box.execute(). The function box.execute()
replaces box.sql.execute() in the next patch.

Part of #3505
---
 src/box/execute.c    | 83 +++++++++++++++++++++++++++++++++++++++++++++++++++-
 src/box/lua/init.c   | 23 +++++++++++++++
 test/box/misc.result |  1 +
 3 files changed, 106 insertions(+), 1 deletion(-)

diff --git a/src/box/execute.c b/src/box/execute.c
index 460eebc..ae3f7a4 100644
--- a/src/box/execute.c
+++ b/src/box/execute.c
@@ -43,6 +43,7 @@
 #include "port.h"
 #include "tuple.h"
 #include "sql/vdbe.h"
+#include "lua/utils.h"
 
 const char *sql_type_strs[] = {
 	NULL,
@@ -145,6 +146,16 @@ static_assert(sizeof(struct port_sql) <= sizeof(struct port),
 static int
 port_sql_dump_msgpack(struct port *port, struct obuf *out);
 
+/**
+ * Dump data from port to Lua stack. Data in port contains tuples,
+ * metadata, or information obtained from an executed SQL query.
+ *
+ * @param port Port that contains SQL response.
+ * @param L Lua stack.
+ */
+static void
+port_sql_dump_lua(struct port *port, struct lua_State *L);
+
 static void
 port_sql_destroy(struct port *base)
 {
@@ -155,7 +166,7 @@ port_sql_destroy(struct port *base)
 static const struct port_vtab port_sql_vtab = {
 	/* .dump_msgpack = */ port_sql_dump_msgpack,
 	/* .dump_msgpack_16 = */ NULL,
-	/* .dump_lua = */ NULL,
+	/* .dump_lua = */ port_sql_dump_lua,
 	/* .dump_plain = */ NULL,
 	/* .destroy = */ port_sql_destroy,
 };
@@ -671,6 +682,76 @@ port_sql_dump_msgpack(struct port *port, struct obuf *out)
 }
 
 /**
+ * Serialize a description of the prepared statement.
+ *
+ * @param stmt Prepared statement.
+ * @param L Lua stack.
+ * @param column_count Statement's column count.
+ */
+static inline void
+lua_sql_get_description(struct sql_stmt *stmt, struct lua_State *L,
+			int column_count)
+{
+	assert(column_count > 0);
+	lua_createtable(L, column_count, 0);
+	for (int i = 0; i < column_count; ++i) {
+		lua_createtable(L, 0, 2);
+		const char *name = sql_column_name(stmt, i);
+		const char *type = sql_column_datatype(stmt, i);
+		/*
+		 * Can not fail, since all column names are
+		 * preallocated during prepare phase and the
+		 * column_name simply returns them.
+		 */
+		assert(name != NULL);
+		assert(type != NULL);
+		lua_pushstring(L, name);
+		lua_setfield(L, -2, "name");
+		lua_pushstring(L, type);
+		lua_setfield(L, -2, "type");
+		lua_rawseti(L, -2, i + 1);
+	}
+}
+
+static void
+port_sql_dump_lua(struct port *port, struct lua_State *L)
+{
+	assert(port->vtab == &port_sql_vtab);
+	struct sql *db = sql_get();
+	struct sql_stmt *stmt = ((struct port_sql *)port)->stmt;
+	int column_count = sql_column_count(stmt);
+	if (column_count > 0) {
+		lua_createtable(L, 0, 2);
+		lua_sql_get_description(stmt, L, column_count);
+		lua_setfield(L, -2, "metadata");
+		port_tuple_vtab.dump_lua(port, L);
+		lua_setfield(L, -2, "rows");
+	} else {
+		assert(((struct port_tuple *)port)->size == 0);
+		struct stailq *autoinc_id_list =
+			vdbe_autoinc_id_list((struct Vdbe *)stmt);
+		lua_createtable(L, 0, stailq_empty(autoinc_id_list) ? 1 : 2);
+
+		luaL_pushuint64(L, db->nChange);
+		lua_setfield(L, -2, "rowcount");
+
+		if (!stailq_empty(autoinc_id_list)) {
+			lua_newtable(L);
+			int i = 1;
+			struct autoinc_id_entry *id_entry;
+			stailq_foreach_entry(id_entry, autoinc_id_list, link) {
+				if (id_entry->id >= 0)
+					luaL_pushuint64(L, id_entry->id);
+				else
+					luaL_pushint64(L, id_entry->id);
+				lua_rawseti(L, -2, i++);
+			}
+			lua_setfield(L, -2, "autoincrement_ids");
+		}
+	}
+}
+
+/**
  * Execute prepared SQL statement.
  *
  * This function uses region to allocate memory for temporary
diff --git a/src/box/lua/init.c b/src/box/lua/init.c
index 744b2c8..eb2ca31 100644
--- a/src/box/lua/init.c
+++ b/src/box/lua/init.c
@@ -40,6 +40,7 @@
 #include "box/box.h"
 #include "box/txn.h"
 #include "box/vclock.h"
+#include "box/execute.h"
 
 #include "box/lua/error.h"
 #include "box/lua/tuple.h"
@@ -266,12 +267,34 @@ lbox_backup_stop(struct lua_State *L)
 	return 0;
 }
 
+static int
+lbox_execute(struct lua_State *L)
+{
+	struct sql_bind *bind = NULL;
+	int bind_count = 0;
+	size_t length;
+	struct port port;
+	int top = lua_gettop(L);
+
+	if (top != 1 || ! lua_isstring(L, 1))
+		return luaL_error(L, "Usage: box.execute(sqlstring)");
+
+	const char *sql = lua_tolstring(L, 1, &length);
+	if (sql_prepare_and_execute(sql, length, bind, bind_count, &port,
+				    &fiber()->gc) != 0)
+		return luaT_error(L);
+	port_dump_lua(&port, L);
+	port_destroy(&port);
+	return 1;
+}
+
 static const struct luaL_Reg boxlib[] = {
 	{"commit", lbox_commit},
 	{"rollback", lbox_rollback},
 	{"on_commit", lbox_on_commit},
 	{"on_rollback", lbox_on_rollback},
 	{"snapshot", lbox_snapshot},
+	{"execute", lbox_execute},
 	{NULL, NULL}
 };
 
diff --git a/test/box/misc.result b/test/box/misc.result
index 4f1116e..714d5de 100644
--- a/test/box/misc.result
+++ b/test/box/misc.result
@@ -63,6 +63,7 @@ t
   - commit
   - ctl
   - error
+  - execute
   - feedback
   - index
   - info
-- 
2.7.4