Bug#16194302: SUPPORT FOR FLOATING-POINT SYSTEM VARIABLES

              USING THE PLUGIN INTERFACE.

ISSUE: No support for floating-point plugin
       system variables.

SOLUTION: Allowing plugins to define and expose floating-point
          system variables of type double. MYSQL_SYSVAR_DOUBLE
          and MYSQL_THDVAR_DOUBLE are added.

ISSUE: Fractional part of the def, min, max values of system
       variables are ignored.

SOLUTION: Adding functions that are used to store the raw
          representation of a double in the raw bits of unsigned
          longlong in a way that the binary representation
          remains the same.

2 files changed, 133 insertions, 1 deletions

diff --git a/mysql-test/r/plugin.result b/mysql-test/r/plugin.result
index 0d5bc29fc8c..2b96dc4f3ac 100644
--- a/mysql-test/r/plugin.result
+++ b/mysql-test/r/plugin.result
@@ -16,9 +16,11 @@ set global example_ulong_var=500;
 set global example_enum_var= e1;
 show status like 'example%';
 Variable_name	Value
-example_func_example	enum_var is 0, ulong_var is 500, really
+example_func_example	enum_var is 0, ulong_var is 500, double_var is 8.500000, really
 show variables like 'example%';
 Variable_name	Value
+example_double_thdvar	8.500000
+example_double_var	8.500000
 example_enum_var	e1
 example_ulong_var	500
 UNINSTALL PLUGIN example;
@@ -63,3 +65,81 @@ set session sql_mode=@old_sql_mode;
 set session old=bla;
 ERROR HY000: Variable 'old' is a read only variable
 UNINSTALL PLUGIN example;
+#
+# Bug #16194302  SUPPORT FOR FLOATING-POINT SYSTEM
+#                VARIABLES USING THE PLUGIN INTERFACE.
+#
+INSTALL PLUGIN example SONAME 'ha_example.so';
+SET GLOBAL example_double_var = -0.1;
+Warnings:
+Warning	1292	Truncated incorrect example_double_var value: '-0.1'
+SELECT @@GLOBAL.example_double_var;
+@@GLOBAL.example_double_var
+0.500000
+SET GLOBAL example_double_var = 0.000001;
+Warnings:
+Warning	1292	Truncated incorrect example_double_var value: '0.000001'
+SELECT @@GLOBAL.example_double_var;
+@@GLOBAL.example_double_var
+0.500000
+SET GLOBAL example_double_var = 0.4;
+Warnings:
+Warning	1292	Truncated incorrect example_double_var value: '0.4'
+SELECT @@GLOBAL.example_double_var;
+@@GLOBAL.example_double_var
+0.500000
+SET GLOBAL example_double_var = 123.456789;
+SELECT @@GLOBAL.example_double_var;
+@@GLOBAL.example_double_var
+123.456789
+SET GLOBAL example_double_var = 500;
+SELECT @@GLOBAL.example_double_var;
+@@GLOBAL.example_double_var
+500.000000
+SET GLOBAL example_double_var = 999.999999;
+SELECT @@GLOBAL.example_double_var;
+@@GLOBAL.example_double_var
+999.999999
+SET GLOBAL example_double_var = 1000.51;
+Warnings:
+Warning	1292	Truncated incorrect example_double_var value: '1000.51'
+SELECT @@GLOBAL.example_double_var;
+@@GLOBAL.example_double_var
+1000.500000
+SET SESSION example_double_thdvar = -0.1;
+Warnings:
+Warning	1292	Truncated incorrect example_double_thdvar value: '-0.1'
+SELECT @@SESSION.example_double_thdvar;
+@@SESSION.example_double_thdvar
+0.500000
+SET SESSION example_double_thdvar = 0.000001;
+Warnings:
+Warning	1292	Truncated incorrect example_double_thdvar value: '0.000001'
+SELECT @@SESSION.example_double_thdvar;
+@@SESSION.example_double_thdvar
+0.500000
+SET SESSION example_double_thdvar = 0.4;
+Warnings:
+Warning	1292	Truncated incorrect example_double_thdvar value: '0.4'
+SELECT @@SESSION.example_double_thdvar;
+@@SESSION.example_double_thdvar
+0.500000
+SET SESSION example_double_thdvar = 123.456789;
+SELECT @@SESSION.example_double_thdvar;
+@@SESSION.example_double_thdvar
+123.456789
+SET SESSION example_double_thdvar = 500;
+SELECT @@SESSION.example_double_thdvar;
+@@SESSION.example_double_thdvar
+500.000000
+SET SESSION example_double_thdvar = 999.999999;
+SELECT @@SESSION.example_double_thdvar;
+@@SESSION.example_double_thdvar
+999.999999
+SET SESSION example_double_thdvar = 1000.51;
+Warnings:
+Warning	1292	Truncated incorrect example_double_thdvar value: '1000.51'
+SELECT @@SESSION.example_double_thdvar;
+@@SESSION.example_double_thdvar
+1000.500000
+UNINSTALL PLUGIN example;
diff --git a/mysql-test/t/plugin.test b/mysql-test/t/plugin.test
index 117eaf1e19b..f3a3b0cc068 100644
--- a/mysql-test/t/plugin.test
+++ b/mysql-test/t/plugin.test
@@ -85,3 +85,55 @@ set session sql_mode=@old_sql_mode;
 set session old=bla;
 
 UNINSTALL PLUGIN example;
+
+--echo #
+--echo # Bug #16194302  SUPPORT FOR FLOATING-POINT SYSTEM
+--echo #                VARIABLES USING THE PLUGIN INTERFACE.
+--echo #
+
+--replace_regex /\.dll/.so/
+eval INSTALL PLUGIN example SONAME '$EXAMPLE_PLUGIN';
+
+SET GLOBAL example_double_var = -0.1;
+SELECT @@GLOBAL.example_double_var;
+
+SET GLOBAL example_double_var = 0.000001;
+SELECT @@GLOBAL.example_double_var;
+
+SET GLOBAL example_double_var = 0.4;
+SELECT @@GLOBAL.example_double_var;
+
+SET GLOBAL example_double_var = 123.456789;
+SELECT @@GLOBAL.example_double_var;
+
+SET GLOBAL example_double_var = 500;
+SELECT @@GLOBAL.example_double_var;
+
+SET GLOBAL example_double_var = 999.999999;
+SELECT @@GLOBAL.example_double_var;
+
+SET GLOBAL example_double_var = 1000.51;
+SELECT @@GLOBAL.example_double_var;
+
+SET SESSION example_double_thdvar = -0.1;
+SELECT @@SESSION.example_double_thdvar;
+
+SET SESSION example_double_thdvar = 0.000001;
+SELECT @@SESSION.example_double_thdvar;
+
+SET SESSION example_double_thdvar = 0.4;
+SELECT @@SESSION.example_double_thdvar;
+
+SET SESSION example_double_thdvar = 123.456789;
+SELECT @@SESSION.example_double_thdvar;
+
+SET SESSION example_double_thdvar = 500;
+SELECT @@SESSION.example_double_thdvar;
+
+SET SESSION example_double_thdvar = 999.999999;
+SELECT @@SESSION.example_double_thdvar;
+
+SET SESSION example_double_thdvar = 1000.51;
+SELECT @@SESSION.example_double_thdvar;
+
+UNINSTALL PLUGIN example;