Class: ActiveRecord::ConnectionAdapters::PostgreSQL::Branched::Shadow

Inherits:
Object
  • Object
show all
Defined in:
lib/active_record/connection_adapters/postgresql/branched/shadow.rb

Constant Summary collapse

DROPPED_SUFFIX = 
"__dropped"

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(connection, branch_schema) ⇒ Shadow

Returns a new instance of Shadow.



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# File 'lib/active_record/connection_adapters/postgresql/branched/shadow.rb', line 8

def initialize(connection, branch_schema)
  @connection = connection
  @branch_schema = branch_schema
  @dropped_schema = "#{branch_schema}#{DROPPED_SUFFIX}"
end

Instance Attribute Details

#dropped_schema ⇒ Object (readonly)

Returns the value of attribute dropped_schema.



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# File 'lib/active_record/connection_adapters/postgresql/branched/shadow.rb', line 14

def dropped_schema
  @dropped_schema
end

Instance Method Details

#call(table_name) ⇒ Object 



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# File 'lib/active_record/connection_adapters/postgresql/branched/shadow.rb', line 16

def call(table_name)
  table = table_name.to_s
  return unless exists_in_public?(table)
  return if already_shadowed?(table)
  return if dropped?(table)

  create_shadow(table)
end

#drop_table(table) ⇒ Object 



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# File 'lib/active_record/connection_adapters/postgresql/branched/shadow.rb', line 46

def drop_table(table)
  table = table.to_s
  return unless exists_in_public?(table)

  ensure_dropped_schema
  quoted_dropped = @connection.quote_column_name(@dropped_schema)
  quoted_table = @connection.quote_column_name(table)
  @connection.execute(<<~SQL)
    CREATE TABLE #{quoted_dropped}.#{quoted_table}
      (LIKE public.#{quoted_table})
  SQL
end

#dropped?(table_name) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_record/connection_adapters/postgresql/branched/shadow.rb', line 67

def dropped?(table_name)
  @connection.select_value(<<~SQL) == 1
    SELECT 1 FROM information_schema.tables
    WHERE table_schema = #{@connection.quote(@dropped_schema)}
      AND table_name = #{@connection.quote(table_name.to_s)}
  SQL
end

#shadow_enum(name) ⇒ Object 



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# File 'lib/active_record/connection_adapters/postgresql/branched/shadow.rb', line 25

def shadow_enum(name)
  name = name.to_s
  return unless enum_exists_in_public?(name)
  return if enum_exists_in_branch?(name)

  labels = @connection.select_values(<<~SQL)
    SELECT e.enumlabel FROM pg_enum e
      JOIN pg_type t ON t.oid = e.enumtypid
      JOIN pg_namespace n ON n.oid = t.typnamespace
    WHERE n.nspname = 'public' AND t.typname = #{@connection.quote(name)}
    ORDER BY e.enumsortorder
  SQL

  quoted_branch = @connection.quote_column_name(@branch_schema)
  quoted_labels = labels.map { |l| @connection.quote(l) }.join(", ")
  @connection.execute(<<~SQL)
    CREATE TYPE #{quoted_branch}.#{@connection.quote_column_name(name)}
      AS ENUM (#{quoted_labels})
  SQL
end

#undrop_table(table) ⇒ Object 



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# File 'lib/active_record/connection_adapters/postgresql/branched/shadow.rb', line 59

def undrop_table(table)
  table = table.to_s
  return unless dropped?(table)
  quoted_dropped = @connection.quote_column_name(@dropped_schema)
  quoted_table = @connection.quote_column_name(table)
  @connection.execute("DROP TABLE #{quoted_dropped}.#{quoted_table}")
end