Revert "Fix #microseconds conversion and #fast_string_to_time"

This reverts commit 717a2941e15b32d07cc456bb0d81742ecfc5b4a3. Bunch of failures when running postgresql tests.

2 files changed, 6 insertions, 50 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
index 5e8a01644d..520f3c8c0c 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
@@ -13,7 +13,6 @@ module ActiveRecord
       module Format
         ISO_DATE = /\A(\d{4})-(\d\d)-(\d\d)\z/
         ISO_DATETIME = /\A(\d{4})-(\d\d)-(\d\d) (\d\d):(\d\d):(\d\d)(\.\d+)?\z/
-        NEW_ISO_DATETIME = /\A(\d{4})-(\d\d)-(\d\d) (\d\d):(\d\d):(\d\d)(?:\.(\d+))?\z/
       end
 
       attr_reader :name, :default, :type, :limit, :null, :sql_type, :precision, :scale
@@ -168,11 +167,10 @@ module ActiveRecord
         end
 
         protected
-          # Rational(123456, 1_000_000) -> 123456
-          # The sec_fraction component returned by Date._parse is a Rational fraction of a second or nil
-          # NB: This method is optimized for performance by immediately converting away from Rational.
+          # '0.123456' -> 123456
+          # '1.123456' -> 123456
           def microseconds(time)
-            ((time[:sec_fraction].to_f % 1) * 1_000_000).round
+            ((time[:sec_fraction].to_f % 1) * 1_000_000).to_i
           end
 
           def new_date(year, mon, mday)
@@ -196,8 +194,9 @@ module ActiveRecord
 
           # Doesn't handle time zones.
           def fast_string_to_time(string)
-            if md = Format::NEW_ISO_DATETIME.match(string)
-              new_time *md.to_a[1..7].map(&:to_i)
+            if string =~ Format::ISO_DATETIME
+              microsec = ($7.to_f * 1_000_000).to_i
+              new_time $1.to_i, $2.to_i, $3.to_i, $4.to_i, $5.to_i, $6.to_i, microsec
             end
           end
 
diff --git a/activerecord/test/cases/schema_definitions_test.rb b/activerecord/test/cases/schema_definitions_test.rb
deleted file mode 100644
index d90a95cf58..0000000000
--- a/activerecord/test/cases/schema_definitions_test.rb
+++ /dev/null
@@ -1,43 +0,0 @@
-require "cases/helper"
-
-class SchemaDefinitionsTest < ActiveRecord::TestCase
-
-  REGRESSION_SAMPLES = %w{000249 125014 003912 256051 524287}
-
-  test 'fast_string_to_time converts properly' do
-    converted = ActiveRecord::ConnectionAdapters::Column.send('fast_string_to_time', "2010-01-12 12:34:56.000249")
-    assert_equal Time.mktime(2010, 01, 12, 12, 34, 56, 249), converted
-  end
-
-  test 'fallback_string_to_time converts properly' do
-    converted = ActiveRecord::ConnectionAdapters::Column.send('fallback_string_to_time', "2010-01-12 12:34:56.000249")
-    assert_equal Time.mktime(2010, 01, 12, 12, 34, 56, 249), converted
-  end
-
-  test 'fallback_string_to_time converts properly with no microseconds' do
-    converted = ActiveRecord::ConnectionAdapters::Column.send('fallback_string_to_time', "2010-01-12 12:34:56")
-    assert_equal Time.mktime(2010, 01, 12, 12, 34, 56, 0), converted
-  end
-
-  test "fast_string_to_time can handle problematic microseconds" do
-    REGRESSION_SAMPLES.each do |u|
-      converted = ActiveRecord::ConnectionAdapters::Column.send('fast_string_to_time', "2010-01-12 12:34:56.#{u}")
-      assert_equal u.to_i, converted.usec
-    end
-  end
-
-  test "microseconds can handle problematic microseconds" do
-    REGRESSION_SAMPLES.each do |u|
-      i = u.to_i
-      converted = ActiveRecord::ConnectionAdapters::Column.send('microseconds', {:sec_fraction => Rational(i, 1_000_000)})
-      assert_equal i, converted
-
-      converted = ActiveRecord::ConnectionAdapters::Column.send('microseconds', {:sec_fraction => Rational(i, 1_000_000)})
-      assert_equal i, converted
-    end
-  end
-
-  test 'fast constant is equally restrictive' do
-    assert_match ActiveRecord::ConnectionAdapters::Column::Format::NEW_ISO_DATETIME, "2010-01-12 12:34:56.555493"
-  end
-end