[PATCH v5 1/3] box: introduce opts.is_multikey function option

[Kirill Shcherbatov <kshcherbatov@tarantool.org>]

Needed for #1260

@TarantoolBot document
Title: A new option is_multikey for function definition

A new option is_multikey allows to specify wether new function
returns multiple values packed in a table object. This is a
native way to define multikey func_index.
---
 src/box/func_def.h          | 22 ++++++++++++++++++++++
 src/box/func_def.c          | 19 ++++++++++++++++++-
 src/box/lua/call.c          |  3 +++
 src/box/alter.cc            |  6 ++++++
 src/box/lua/schema.lua      |  3 ++-
 test/box/function1.result   | 14 ++++++++++++++
 test/box/function1.test.lua |  5 +++++
 7 files changed, 70 insertions(+), 2 deletions(-)

diff --git a/src/box/func_def.h b/src/box/func_def.h
index 2eed710e7..d99d89190 100644
--- a/src/box/func_def.h
+++ b/src/box/func_def.h
@@ -33,6 +33,7 @@
 
 #include "trivia/util.h"
 #include "field_def.h"
+#include "opt_def.h"
 #include <stdbool.h>
 
 #ifdef __cplusplus
@@ -60,6 +61,25 @@ enum func_aggregate {
 
 extern const char *func_aggregate_strs[];
 
+/** Function options. */
+struct func_opts {
+	/**
+	 * True when a function returns multiple values
+	 * packed in array.
+	 */
+	bool is_multikey;
+};
+
+extern const struct func_opts func_opts_default;
+extern const struct opt_def func_opts_reg[];
+
+/** Create index options using default values. */
+static inline void
+func_opts_create(struct func_opts *opts)
+{
+	*opts = func_opts_default;
+}
+
 /**
  * Definition of a function. Function body is not stored
  * or replicated (yet).
@@ -109,6 +129,8 @@ struct func_def {
 		};
 		uint8_t all;
 	} exports;
+	/** The function options. */
+	struct func_opts opts;
 	/** Function name. */
 	char name[0];
 };
diff --git a/src/box/func_def.c b/src/box/func_def.c
index 41bef2ac7..11d2bdb84 100644
--- a/src/box/func_def.c
+++ b/src/box/func_def.c
@@ -29,6 +29,7 @@
  * SUCH DAMAGE.
  */
 #include "func_def.h"
+#include "opt_def.h"
 #include "string.h"
 #include "diag.h"
 #include "error.h"
@@ -37,6 +38,22 @@ const char *func_language_strs[] = {"LUA", "C", "SQL", "SQL_BUILTIN"};
 
 const char *func_aggregate_strs[] = {"none", "group"};
 
+const struct func_opts func_opts_default = {
+	/* .is_multikey = */ false,
+};
+
+const struct opt_def func_opts_reg[] = {
+	OPT_DEF("is_multikey", OPT_BOOL, struct func_opts, is_multikey),
+};
+
+int
+func_opts_cmp(struct func_opts *o1, struct func_opts *o2)
+{
+	if (o1->is_multikey != o2->is_multikey)
+		return o1->is_multikey - o2->is_multikey;
+	return 0;
+}
+
 int
 func_def_cmp(struct func_def *def1, struct func_def *def2)
 {
@@ -70,7 +87,7 @@ func_def_cmp(struct func_def *def1, struct func_def *def2)
 		return def1->comment - def2->comment;
 	if (def1->comment != NULL && strcmp(def1->comment, def2->comment) != 0)
 		return strcmp(def1->comment, def2->comment);
-	return 0;
+	return func_opts_cmp(&def1->opts, &def2->opts);
 }
 
 /**
diff --git a/src/box/lua/call.c b/src/box/lua/call.c
index 81f7f5bd9..0ac2eb7a6 100644
--- a/src/box/lua/call.c
+++ b/src/box/lua/call.c
@@ -900,6 +900,9 @@ lbox_func_new(struct lua_State *L, struct func *func)
 	lua_pushstring(L, "is_deterministic");
 	lua_pushboolean(L, func->def->is_deterministic);
 	lua_settable(L, top);
+	lua_pushstring(L, "is_multikey");
+	lua_pushboolean(L, func->def->opts.is_multikey);
+	lua_settable(L, top);
 	lua_pushstring(L, "is_sandboxed");
 	if (func->def->body != NULL)
 		lua_pushboolean(L, func->def->is_sandboxed);
diff --git a/src/box/alter.cc b/src/box/alter.cc
index df699bb87..9b064286c 100644
--- a/src/box/alter.cc
+++ b/src/box/alter.cc
@@ -2652,6 +2652,7 @@ func_def_new_from_tuple(struct tuple *tuple)
 		tnt_raise(ClientError, ER_CREATE_FUNCTION,
 			  tt_cstr(name, name_len), "function id is too big");
 	}
+	func_opts_create(&def->opts);
 	memcpy(def->name, name, name_len);
 	def->name[name_len] = '\0';
 	def->name_len = name_len;
@@ -2750,6 +2751,11 @@ func_def_new_from_tuple(struct tuple *tuple)
 			}
 		}
 		def->param_count = argc;
+		const char *opts = tuple_field(tuple, BOX_FUNC_FIELD_OPTS);
+		if (opts_decode(&def->opts, func_opts_reg, &opts,
+				ER_WRONG_SPACE_OPTIONS, BOX_FUNC_FIELD_OPTS,
+				NULL) != 0)
+			diag_raise();
 	} else {
 		def->is_deterministic = false;
 		def->is_sandboxed = false;
diff --git a/src/box/lua/schema.lua b/src/box/lua/schema.lua
index aadcd3fa9..334f49d51 100644
--- a/src/box/lua/schema.lua
+++ b/src/box/lua/schema.lua
@@ -2109,7 +2109,8 @@ box.schema.func.create = function(name, opts)
                               if_not_exists = 'boolean',
                               language = 'string', body = 'string',
                               is_deterministic = 'boolean',
-                              is_sandboxed = 'boolean', comment = 'string' })
+                              is_sandboxed = 'boolean', comment = 'string',
+                              opts = 'table' })
     local _func = box.space[box.schema.FUNC_ID]
     local _vfunc = box.space[box.schema.VFUNC_ID]
     local func = _vfunc.index.name:get{name}
diff --git a/test/box/function1.result b/test/box/function1.result
index 45db8ac7e..00e5880cd 100644
--- a/test/box/function1.result
+++ b/test/box/function1.result
@@ -99,6 +99,7 @@ box.func["function1.args"]
     sql: false
   id: 66
   setuid: false
+  is_multikey: false
   is_deterministic: false
   name: function1.args
   language: C
@@ -418,6 +419,7 @@ func
     sql: false
   id: 66
   setuid: false
+  is_multikey: false
   is_deterministic: false
   comment: Divide two values
   name: divide
@@ -489,6 +491,7 @@ func
     sql: false
   id: 66
   setuid: false
+  is_multikey: false
   is_deterministic: false
   name: function1.divide
   language: C
@@ -822,3 +825,14 @@ box.func.LUA:call({"return 1 + 1"})
 ---
 - 2
 ...
+-- Introduce function options
+box.schema.func.create('test', {body = "function(tuple) return tuple end", is_deterministic = true, opts = {is_multikey = true}})
+---
+...
+box.func['test'].is_multikey == true
+---
+- true
+...
+box.func['test']:drop()
+---
+...
diff --git a/test/box/function1.test.lua b/test/box/function1.test.lua
index d22cffb46..5eb597d16 100644
--- a/test/box/function1.test.lua
+++ b/test/box/function1.test.lua
@@ -293,3 +293,8 @@ for _, v in pairs(sql_builtin_list) do ok = ok and (box.space._func.index.name:g
 ok == true
 
 box.func.LUA:call({"return 1 + 1"})
+
+-- Introduce function options
+box.schema.func.create('test', {body = "function(tuple) return tuple end", is_deterministic = true, opts = {is_multikey = true}})
+box.func['test'].is_multikey == true
+box.func['test']:drop()
-- 
2.22.0