MDEV-32885 VEC_DISTANCE() function

libmysqld/CMakeLists.txt

@@ -101,7 +101,7 @@ SET(SQL_EMBEDDED_SOURCES emb_qcache.cc libmysqld.c lib_sql.cc
            ../sql/sql_show.cc ../sql/sql_state.c 
            ../sql/sql_statistics.cc ../sql/sql_string.cc
            ../sql/sql_table.cc ../sql/sql_test.cc
-           ../sql/ddl_log.cc
+           ../sql/ddl_log.cc ../sql/item_vectorfunc.cc
            ../sql/sql_trigger.cc ../sql/sql_udf.cc ../sql/sql_union.cc
            ../sql/sql_update.cc ../sql/sql_view.cc ../sql/sql_profile.cc
            ../sql/gcalc_tools.cc ../sql/gcalc_slicescan.cc

sql/CMakeLists.txt

@@ -103,7 +103,7 @@ SET (SQL_SOURCE
                filesort_utils.cc
                filesort.cc gstream.cc
                signal_handler.cc
-               handler.cc
+               handler.cc item_vectorfunc.cc
                hostname.cc init.cc item.cc item_buff.cc item_cmpfunc.cc
                item_create.cc item_func.cc item_geofunc.cc item_row.cc
                item_strfunc.cc item_subselect.cc item_sum.cc item_timefunc.cc

sql/item.h

@@ -6619,6 +6619,7 @@ class Item_int_with_ref :public Item_int
 #include "item_subselect.h"
 #include "item_xmlfunc.h"
 #include "item_jsonfunc.h"
+#include "item_vectorfunc.h"
 #include "item_create.h"
 #include "item_vers.h"
 #endif

sql/item_create.cc

@@ -6235,6 +6235,29 @@ Create_func_year_week::create_native(THD *thd, const LEX_CSTRING *name,
   return func;
 }
 
+
+class Create_func_vec_distance: public Create_func_arg2
+{
+public:
+  Item *create_2_arg(THD *thd, Item *arg1, Item *arg2) override;
+
+  static Create_func_vec_distance s_singleton;
+
+protected:
+  Create_func_vec_distance() = default;
+  virtual ~Create_func_vec_distance() = default;
+};
+
+
+Create_func_vec_distance Create_func_vec_distance::s_singleton;
+
+Item*
+Create_func_vec_distance::create_2_arg(THD *thd, Item *arg1, Item *arg2)
+{
+  return new (thd->mem_root) Item_func_vec_distance(thd, arg1, arg2);
+}
+
+
 #define BUILDER(F) & F::s_singleton
 
 /*
@@ -6461,6 +6484,7 @@ const Native_func_registry func_array[] =
   { { STRING_WITH_LEN("UPDATEXML") }, BUILDER(Create_func_xml_update)},
   { { STRING_WITH_LEN("UPPER") }, BUILDER(Create_func_ucase)},
   { { STRING_WITH_LEN("UUID_SHORT") }, BUILDER(Create_func_uuid_short)},
+  { { STRING_WITH_LEN("VEC_DISTANCE") }, BUILDER(Create_func_vec_distance)},
   { { STRING_WITH_LEN("VERSION") }, BUILDER(Create_func_version)},
   { { STRING_WITH_LEN("WEEK") }, BUILDER(Create_func_week)},
   { { STRING_WITH_LEN("WEEKDAY") }, BUILDER(Create_func_weekday)},

sql/item_vectorfunc.cc

+/* Copyright (c) 2023, MariaDB
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335  USA */
+
+
+/**
+  @file
+
+  @brief
+  This file defines all vector functions
+*/
+
+#include <my_global.h>
+#include "item.h"
+
+
+double Item_func_vec_distance::val_real()
+{
+  String *r1= args[0]->val_str();
+  String *r2= args[1]->val_str();
+  null_value= !r1 || !r2 || r1->length() != r2->length() ||
+              r1->length() % sizeof(float);
+  if (null_value)
+    return 0;
+  float *v1= (float*)r1->ptr();
+  float *v2= (float*)r2->ptr();
+  double d= 0;
+  for (uint i=0; i < r1->length() / sizeof(float); i++)
+    d+= (v1[i] - v2[i])*(v1[i] - v2[i]);
+  return sqrt(d);
+}

sql/item_vectorfunc.h

+#ifndef ITEM_VECTORFUNC_INCLUDED
+#define ITEM_VECTORFUNC_INCLUDED
+
+/* Copyright (C) 2023, MariaDB
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1335  USA */
+
+/* This file defines all vector functions */
+#include "lex_string.h"
+#include "item_func.h"
+
+class Item_func_vec_distance: public Item_real_func
+{
+protected:
+  bool check_arguments() const override
+  {
+    return check_argument_types_or_binary(NULL, 0, arg_count);
+  }
+public:
+  Item_func_vec_distance(THD *thd, Item *a, Item *b)
+   :Item_real_func(thd, a, b) {}
+  bool fix_length_and_dec(THD *thd) override
+  {
+    set_maybe_null();
+    return Item_real_func::fix_length_and_dec(thd);
+  }
+  double val_real() override;
+  LEX_CSTRING func_name_cstring() const override
+  {
+    static LEX_CSTRING name= {STRING_WITH_LEN("vec_distance") };
+    return name;
+  }
+  Item *do_get_copy(THD *thd) const override
+  { return get_item_copy<Item_func_vec_distance>(thd, this); }
+};
+
+#endif