From f185e0ebc9cc18c596eb9cab1a9cd99e26a20500 Mon Sep 17 00:00:00 2001
From: Ryuta Kamizono <kamipo@gmail.com>
Date: Mon, 8 Apr 2019 18:57:05 +0900
Subject: Except `table_name` from column objects

The `table_name` was added at #23677 to detect whether serial column or
not correctly.

We can do that detection before initialize column object, it makes
column object size smaller, and it probably helps column object
de-duplication.
---
 .../connection_adapters/postgresql/column.rb       | 45 ++++++----------------
 .../postgresql/schema_statements.rb                | 27 +++++++++++--
 2 files changed, 35 insertions(+), 37 deletions(-)

(limited to 'activerecord/lib/active_record/connection_adapters/postgresql')

diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/column.rb b/activerecord/lib/active_record/connection_adapters/postgresql/column.rb
index 3ccc7271ab..ef98d2b37a 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/column.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/column.rb
@@ -2,42 +2,21 @@
 
 module ActiveRecord
   module ConnectionAdapters
-    # PostgreSQL-specific extensions to column definitions in a table.
-    class PostgreSQLColumn < Column #:nodoc:
-      delegate :array, :oid, :fmod, to: :sql_type_metadata
-      alias :array? :array
-
-      def initialize(*, max_identifier_length: 63, **)
-        super
-        @max_identifier_length = max_identifier_length
-      end
-
-      def serial?
-        return unless default_function
-
-        if %r{\Anextval\('"?(?<sequence_name>.+_(?<suffix>seq\d*))"?'::regclass\)\z} =~ default_function
-          sequence_name_from_parts(table_name, name, suffix) == sequence_name
+    module PostgreSQL
+      class Column < ConnectionAdapters::Column # :nodoc:
+        delegate :array, :oid, :fmod, to: :sql_type_metadata
+        alias :array? :array
+
+        def initialize(*, serial: nil, **)
+          super
+          @serial = serial
         end
-      end
 
-      private
-        attr_reader :max_identifier_length
-
-        def sequence_name_from_parts(table_name, column_name, suffix)
-          over_length = [table_name, column_name, suffix].map(&:length).sum + 2 - max_identifier_length
-
-          if over_length > 0
-            column_name_length = [(max_identifier_length - suffix.length - 2) / 2, column_name.length].min
-            over_length -= column_name.length - column_name_length
-            column_name = column_name[0, column_name_length - [over_length, 0].min]
-          end
-
-          if over_length > 0
-            table_name = table_name[0, table_name.length - over_length]
-          end
-
-          "#{table_name}_#{column_name}_#{suffix}"
+        def serial?
+          @serial
         end
+      end
     end
+    PostgreSQLColumn = PostgreSQL::Column # :nodoc:
   end
 end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
index 41d1a8e4ab..5f27cb0793 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
@@ -650,16 +650,19 @@ module ActiveRecord
             default_value = extract_value_from_default(default)
             default_function = extract_default_function(default_value, default)
 
-            PostgreSQLColumn.new(
+            if match = default_function&.match(/\Anextval\('"?(?<sequence_name>.+_(?<suffix>seq\d*))"?'::regclass\)\z/)
+              serial = sequence_name_from_parts(table_name, column_name, match[:suffix]) == match[:sequence_name]
+            end
+
+            PostgreSQL::Column.new(
               column_name,
               default_value,
               type_metadata,
               !notnull,
-              table_name,
               default_function,
-              collation,
+              collation: collation,
               comment: comment.presence,
-              max_identifier_length: max_identifier_length
+              serial: serial
             )
           end
 
@@ -675,6 +678,22 @@ module ActiveRecord
             PostgreSQLTypeMetadata.new(simple_type, oid: oid, fmod: fmod)
           end
 
+          def sequence_name_from_parts(table_name, column_name, suffix)
+            over_length = [table_name, column_name, suffix].sum(&:length) + 2 - max_identifier_length
+
+            if over_length > 0
+              column_name_length = [(max_identifier_length - suffix.length - 2) / 2, column_name.length].min
+              over_length -= column_name.length - column_name_length
+              column_name = column_name[0, column_name_length - [over_length, 0].min]
+            end
+
+            if over_length > 0
+              table_name = table_name[0, table_name.length - over_length]
+            end
+
+            "#{table_name}_#{column_name}_#{suffix}"
+          end
+
           def extract_foreign_key_action(specifier)
             case specifier
             when "c"; :cascade
-- 
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