Added make_tmp_table_name() to simplify creating temporary table names

sql/opt_subselect.cc

@@ -28,6 +28,7 @@
 #include "sql_select.h"
 #include "sql_update.h"  // class Sql_cmd_update
 #include "sql_delete.h"  // class Sql_cmd_delete
+#include "sql_table.h"   // make_tmp_table_name
 #include "filesort.h"
 #include "opt_subselect.h"
 #include "sql_test.h"
@@ -4780,8 +4781,8 @@ SJ_TMP_TABLE::create_sj_weedout_tmp_table(THD *thd)
   else
   {
     /* if we run out of slots or we are not using tempool */
-    sprintf(path,"%s-subquery-%lx-%lx-%x", tmp_file_prefix,current_pid,
-            (ulong) thd->thread_id, thd->tmp_table++);
+    LEX_STRING tmp= { path, sizeof(path) };
+    make_tmp_table_name(thd, &tmp, "subquery");
   }
   fn_format(path, path, mysql_tmpdir, "", MY_REPLACE_EXT|MY_UNPACK_FILENAME);
 

sql/sql_alter.cc

@@ -454,15 +454,8 @@ Alter_table_ctx::Alter_table_ctx(THD *thd, TABLE_LIST *table_list,
   }
 
   tmp_name.str= tmp_name_buff;
-  tmp_name.length= my_snprintf(tmp_name_buff, sizeof(tmp_name_buff),
-                               "%s-alter-%lx-%llx",
-                               tmp_file_prefix, current_pid, thd->thread_id);
-  /* Safety fix for InnoDB */
-  if (lower_case_table_names)
-  {
-    // Ok to latin1, as the file name is in the form '#sql-alter-abc-def'
-    tmp_name.length= my_casedn_str_latin1(tmp_name_buff);
-  }
+  tmp_name.length= sizeof(tmp_name_buff);
+  make_tmp_table_name(thd, (LEX_STRING*) &tmp_name, "alter");
 
   if (table_list->table->s->tmp_table == NO_TMP_TABLE)
   {

sql/sql_partition_admin.cc

@@ -654,14 +654,10 @@ bool Sql_cmd_alter_table_exchange_partition::
                        swap_table_list->db.str,
                        swap_table_list->table_name.str,
                        "", 0);
-  /* create a unique temp name */
-  my_snprintf(temp_name, sizeof(temp_name), "%s-exchange-%lx-%llx",
-              tmp_file_prefix, current_pid, thd->thread_id);
-  if (lower_case_table_names)
-  {
-    // Ok to use latin1 as the file name is in the form '#sql-exchange-abc-def'
-    my_casedn_str_latin1(temp_name);
-  }
+
+  LEX_STRING tmp= { temp_name, sizeof(temp_name) };
+  make_tmp_table_name(thd, &tmp, "exchange");
+
   build_table_filename(temp_file_name, sizeof(temp_file_name),
                        table_list->next_local->db.str,
                        temp_name, "", FN_IS_TMP);

sql/sql_select.cc

@@ -21807,8 +21807,8 @@ TABLE *Create_tmp_table::start(THD *thd,
   else
   {
     /* if we run out of slots or we are not using tempool */
-    sprintf(path, "%s-%s-%lx-%llx-%x", tmp_file_prefix, param->tmp_name,
-            current_pid, thd->thread_id, thd->tmp_table++);
+    LEX_STRING tmp= {path, sizeof(path) };
+    make_tmp_table_name(thd, &tmp, param->tmp_name);
   }
 
   /*

sql/sql_table.cc

@@ -635,6 +635,25 @@ uint build_table_filename(char *buff, size_t bufflen, const char *db,
 }
 
 
+/**
+  Create a temporary table name
+
+  @param to string. Note that to->length should contain buffer length
+*/
+
+void make_tmp_table_name(THD *thd, LEX_STRING *to, const char *prefix)
+{
+  to->length= my_snprintf((char*) to->str, to->length, "%s-%s-%lx-%llx-%x",
+                          tmp_file_prefix, prefix, current_pid,
+                          thd->thread_id, thd->tmp_table++);
+  if (lower_case_table_names)
+  {
+    // Ok to use latin1 as the file name is in the form '#sql-exchange-abc-def'
+    my_casedn_str_latin1(to->str);
+  }
+}
+
+
 /**
   Create path to a temporary table mysql_tmpdir/#sql-temptable-1234-12-1
   (i.e. to its .FRM file but without an extension).
@@ -652,18 +671,15 @@ uint build_table_filename(char *buff, size_t bufflen, const char *db,
 
 uint build_tmptable_filename(THD* thd, char *buff, size_t bufflen)
 {
+  LEX_STRING name;
   DBUG_ENTER("build_tmptable_filename");
 
-  char *p= strnmov(buff, mysql_tmpdir, bufflen);
-  my_snprintf(p, bufflen - (p - buff), "/%s-temptable-%lx-%llx-%x",
-              tmp_file_prefix, current_pid,
-              thd->thread_id, thd->tmp_table++);
+  char *p= strnmov(buff, mysql_tmpdir, bufflen-2);
+  *p++= '/';
 
-  if (lower_case_table_names)
-  {
-    /* Convert all except tmpdir to lower case */
-    my_casedn_str_latin1(p);
-  }
+  name= {p, bufflen - (p - buff) };
+
+  make_tmp_table_name(thd, &name, "temptable");
 
   size_t length= unpack_filename(buff, buff);
   DBUG_PRINT("exit", ("buff: '%s'", buff));
@@ -707,9 +723,10 @@ uint build_table_shadow_filename(char *buff, size_t bufflen,
                                  bool backup)
 {
   char tmp_name[FN_REFLEN];
-  my_snprintf(tmp_name, sizeof (tmp_name), "%s-%s-%lx-%s", tmp_file_prefix,
+
+  my_snprintf(tmp_name, sizeof(tmp_name), "%s-%s-%lx-%s", tmp_file_prefix,
               backup ? "backup" : "shadow",
-              (ulong) current_thd->thread_id, lpt->alter_info->table_name.str);
+              (ulong) lpt->thd->thread_id, lpt->alter_info->table_name.str);
   return build_table_filename(buff, bufflen, lpt->alter_info->db.str, tmp_name,
                               "", FN_IS_TMP);
 }

sql/sql_table.h

@@ -95,6 +95,7 @@ void build_lower_case_table_filename(char *buff, size_t bufflen,
                                      const LEX_CSTRING *table,
                                      uint flags);
 uint build_tmptable_filename(THD* thd, char *buff, size_t bufflen);
+void make_tmp_table_name(THD *thd, LEX_STRING *to, const char *prefix);
 bool add_keyword_to_query(THD *thd, String *result, const LEX_CSTRING *keyword,
                           const LEX_CSTRING *add);