Call BigDecimal(num) instead of BigDecimal.new(num) (#928)

Call BigDecimal(num) instead of BigDecimal.new(num) to be ready for
this deprecation in Ruby 2.6, and eliminate a deprecation warning now.

Reduce the number of extern classes - while developing this change,
I was chasing a NULL pointer on cBigDecimal from statement.c
because I removed the class lookup from result.c, but extern meant the
compiler did not flag it as an uninitialized value.

Author: sodabrew

benchmark/query_with_mysql_casting.rb

@@ -21,7 +21,7 @@ def mysql_cast(type, value)
       Mysql::Field::TYPE_INT24, Mysql::Field::TYPE_LONGLONG, Mysql::Field::TYPE_YEAR
     value.to_i
   when Mysql::Field::TYPE_DECIMAL, Mysql::Field::TYPE_NEWDECIMAL
-    BigDecimal.new(value)
+    BigDecimal(value)
   when Mysql::Field::TYPE_DOUBLE, Mysql::Field::TYPE_FLOAT
     value.to_f
   when Mysql::Field::TYPE_DATE

ext/mysql2/result.c

@@ -32,14 +32,14 @@ typedef struct {
   VALUE block_given;
 } result_each_args;
 
-VALUE cBigDecimal, cDateTime, cDate;
-static VALUE cMysql2Result;
-static VALUE opt_decimal_zero, opt_float_zero, opt_time_year, opt_time_month, opt_utc_offset;
 extern VALUE mMysql2, cMysql2Client, cMysql2Error;
-static ID intern_new, intern_utc, intern_local, intern_localtime, intern_local_offset, intern_civil, intern_new_offset;
-static VALUE sym_symbolize_keys, sym_as, sym_array, sym_database_timezone, sym_application_timezone,
-          sym_local, sym_utc, sym_cast_booleans, sym_cache_rows, sym_cast, sym_stream, sym_name;
-static ID intern_merge;
+static VALUE cMysql2Result, cDateTime, cDate;
+static VALUE opt_decimal_zero, opt_float_zero, opt_time_year, opt_time_month, opt_utc_offset;
+static ID intern_new, intern_utc, intern_local, intern_localtime, intern_local_offset,
+  intern_civil, intern_new_offset, intern_merge, intern_BigDecimal;
+static VALUE sym_symbolize_keys, sym_as, sym_array, sym_database_timezone,
+  sym_application_timezone, sym_local, sym_utc, sym_cast_booleans,
+  sym_cache_rows, sym_cast, sym_stream, sym_name;
 
 /* Mark any VALUEs that are only referenced in C, so the GC won't get them. */
 static void rb_mysql_result_mark(void * wrapper) {
@@ -444,7 +444,7 @@ static VALUE rb_mysql_result_fetch_row_stmt(VALUE self, MYSQL_FIELD * fields, co
         }
         case MYSQL_TYPE_DECIMAL:      // char[]
         case MYSQL_TYPE_NEWDECIMAL:   // char[]
-          val = rb_funcall(cBigDecimal, intern_new, 1, rb_str_new(result_buffer->buffer, *(result_buffer->length)));
+          val = rb_funcall(rb_mKernel, intern_BigDecimal, 1, rb_str_new(result_buffer->buffer, *(result_buffer->length)));
           break;
         case MYSQL_TYPE_STRING:       // char[]
         case MYSQL_TYPE_VAR_STRING:   // char[]
@@ -546,9 +546,9 @@ static VALUE rb_mysql_result_fetch_row(VALUE self, MYSQL_FIELD * fields, const r
           if (fields[i].decimals == 0) {
             val = rb_cstr2inum(row[i], 10);
           } else if (strtod(row[i], NULL) == 0.000000){
-            val = rb_funcall(cBigDecimal, intern_new, 1, opt_decimal_zero);
+            val = rb_funcall(rb_mKernel, intern_BigDecimal, 1, opt_decimal_zero);
           }else{
-            val = rb_funcall(cBigDecimal, intern_new, 1, rb_str_new(row[i], fieldLengths[i]));
+            val = rb_funcall(rb_mKernel, intern_BigDecimal, 1, rb_str_new(row[i], fieldLengths[i]));
           }
           break;
         case MYSQL_TYPE_FLOAT:      /* FLOAT field */
@@ -959,7 +959,6 @@ VALUE rb_mysql_result_to_obj(VALUE client, VALUE encoding, VALUE options, MYSQL_
 }
 
 void init_mysql2_result() {
-  cBigDecimal = rb_const_get(rb_cObject, rb_intern("BigDecimal"));
   cDate = rb_const_get(rb_cObject, rb_intern("Date"));
   cDateTime = rb_const_get(rb_cObject, rb_intern("DateTime"));
 
@@ -978,6 +977,7 @@ void init_mysql2_result() {
   intern_local_offset = rb_intern("local_offset");
   intern_civil        = rb_intern("civil");
   intern_new_offset   = rb_intern("new_offset");
+  intern_BigDecimal   = rb_intern("BigDecimal");
 
   sym_symbolize_keys  = ID2SYM(rb_intern("symbolize_keys"));
   sym_as              = ID2SYM(rb_intern("as"));

ext/mysql2/statement.c

@@ -1,7 +1,7 @@
 #include <mysql2_ext.h>
 
-VALUE cMysql2Statement;
-extern VALUE mMysql2, cMysql2Error, cMysql2TimeoutError, cBigDecimal, cDateTime, cDate;
+extern VALUE mMysql2, cMysql2Error;
+static VALUE cMysql2Statement, cBigDecimal, cDateTime, cDate;
 static VALUE sym_stream, intern_new_with_args, intern_each, intern_to_s, intern_merge_bang;
 static VALUE intern_sec_fraction, intern_usec, intern_sec, intern_min, intern_hour, intern_day, intern_month, intern_year;
 
@@ -547,8 +547,11 @@ static VALUE rb_mysql_stmt_close(VALUE self) {
 }
 
 void init_mysql2_statement() {
-  cMysql2Statement = rb_define_class_under(mMysql2, "Statement", rb_cObject);
+  cDate = rb_const_get(rb_cObject, rb_intern("Date"));
+  cDateTime = rb_const_get(rb_cObject, rb_intern("DateTime"));
+  cBigDecimal = rb_const_get(rb_cObject, rb_intern("BigDecimal"));
 
+  cMysql2Statement = rb_define_class_under(mMysql2, "Statement", rb_cObject);
   rb_define_method(cMysql2Statement, "param_count", rb_mysql_stmt_param_count, 0);
   rb_define_method(cMysql2Statement, "field_count", rb_mysql_stmt_field_count, 0);
   rb_define_method(cMysql2Statement, "_execute", rb_mysql_stmt_execute, -1);

ext/mysql2/statement.h

@@ -1,8 +1,6 @@
 #ifndef MYSQL2_STATEMENT_H
 #define MYSQL2_STATEMENT_H
 
-extern VALUE cMysql2Statement;
-
 typedef struct {
   VALUE client;
   MYSQL_STMT *stmt;

spec/mysql2/statement_spec.rb

@@ -183,7 +183,7 @@ def stmt_count
 
   it "should handle as a decimal binding a BigDecimal" do
     stmt = @client.prepare('SELECT ? AS decimal_test')
-    test_result = stmt.execute(BigDecimal.new("123.45")).first
+    test_result = stmt.execute(BigDecimal("123.45")).first
     expect(test_result['decimal_test']).to be_an_instance_of(BigDecimal)
     expect(test_result['decimal_test']).to eql(123.45)
   end
@@ -193,7 +193,7 @@ def stmt_count
     @client.query 'DROP TABLE IF EXISTS mysql2_stmt_decimal_test'
     @client.query 'CREATE TABLE mysql2_stmt_decimal_test (decimal_test DECIMAL(10,3))'
 
-    @client.prepare("INSERT INTO mysql2_stmt_decimal_test VALUES (?)").execute(BigDecimal.new("123.45"))
+    @client.prepare("INSERT INTO mysql2_stmt_decimal_test VALUES (?)").execute(BigDecimal("123.45"))
 
     test_result = @client.query("SELECT * FROM mysql2_stmt_decimal_test").first
     expect(test_result['decimal_test']).to eql(123.45)