Patch to support ibm_db in rake create and drop database tasks

active_record.rb

#--
# Copyright (c) 2004-2014 David Heinemeier Hansson
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
#++

require 'active_support'
require 'active_support/rails'
require 'active_model'
require 'arel'

require 'active_record/version'

module ActiveRecord
  extend ActiveSupport::Autoload

  autoload :Base
  autoload :Callbacks
  autoload :Core
  autoload :ConnectionHandling
  autoload :CounterCache
  autoload :DynamicMatchers
  autoload :Enum
  autoload :Explain
  autoload :Inheritance
  autoload :Integration
  autoload :Migration
  autoload :Migrator, 'active_record/migration'
  autoload :ModelSchema
  autoload :NestedAttributes
  autoload :NoTouching
  autoload :Persistence
  autoload :QueryCache
  autoload :Querying
  autoload :ReadonlyAttributes
  autoload :Reflection
  autoload :RuntimeRegistry
  autoload :Sanitization
  autoload :Schema
  autoload :SchemaDumper
  autoload :SchemaMigration
  autoload :Scoping
  autoload :Serialization
  autoload :StatementCache
  autoload :Store
  autoload :Timestamp
  autoload :Transactions
  autoload :Translation
  autoload :Validations

  eager_autoload do
    autoload :ActiveRecordError, 'active_record/errors'
    autoload :ConnectionNotEstablished, 'active_record/errors'
    autoload :ConnectionAdapters, 'active_record/connection_adapters/abstract_adapter'

    autoload :Aggregations
    autoload :Associations
    autoload :AttributeAssignment
    autoload :AttributeMethods
    autoload :AutosaveAssociation

    autoload :Relation
    autoload :AssociationRelation
    autoload :NullRelation

    autoload_under 'relation' do
      autoload :QueryMethods
      autoload :FinderMethods
      autoload :Calculations
      autoload :PredicateBuilder
      autoload :SpawnMethods
      autoload :Batches
      autoload :Delegation
    end

    autoload :Result
  end

  module Coders
    autoload :YAMLColumn, 'active_record/coders/yaml_column'
    autoload :JSON, 'active_record/coders/json'
  end

  module AttributeMethods
    extend ActiveSupport::Autoload

    eager_autoload do
      autoload :BeforeTypeCast
      autoload :Dirty
      autoload :PrimaryKey
      autoload :Query
      autoload :Read
      autoload :TimeZoneConversion
      autoload :Write
      autoload :Serialization
    end
  end

  module Locking
    extend ActiveSupport::Autoload

    eager_autoload do
      autoload :Optimistic
      autoload :Pessimistic
    end
  end

  module ConnectionAdapters
    extend ActiveSupport::Autoload

    eager_autoload do
      autoload :AbstractAdapter
      autoload :ConnectionManagement, "active_record/connection_adapters/abstract/connection_pool"
    end
  end

  module Scoping
    extend ActiveSupport::Autoload

    eager_autoload do
      autoload :Named
      autoload :Default
    end
  end

  module Tasks
    extend ActiveSupport::Autoload

    autoload :DatabaseTasks
    autoload :SQLiteDatabaseTasks, 'active_record/tasks/sqlite_database_tasks'
    autoload :MySQLDatabaseTasks,  'active_record/tasks/mysql_database_tasks'
    autoload :PostgreSQLDatabaseTasks,
      'active_record/tasks/postgresql_database_tasks'
    autoload :IBMDBDatabaseTasks, 'active_record/tasks/ibm_db_database_tasks'
  end

  autoload :TestFixtures, 'active_record/fixtures'

  def self.eager_load!
    super
    ActiveRecord::Locking.eager_load!
    ActiveRecord::Scoping.eager_load!
    ActiveRecord::Associations.eager_load!
    ActiveRecord::AttributeMethods.eager_load!
    ActiveRecord::ConnectionAdapters.eager_load!
  end
end

ActiveSupport.on_load(:active_record) do
  Arel::Table.engine = self
end

ActiveSupport.on_load(:i18n) do
  I18n.load_path << File.dirname(__FILE__) + '/active_record/locale/en.yml'
end

database_tasks.rb

module ActiveRecord
  module Tasks # :nodoc:
    class DatabaseAlreadyExists < StandardError; end # :nodoc:
    class DatabaseNotSupported < StandardError; end # :nodoc:

    # <tt>ActiveRecord::Tasks::DatabaseTasks</tt> is a utility class, which encapsulates
    # logic behind common tasks used to manage database and migrations.
    #
    # The tasks defined here are used in rake tasks provided by Active Record.
    #
    # In order to use DatabaseTasks, a few config values need to be set. All the needed
    # config values are set by Rails already, so it's necessary to do it only if you
    # want to change the defaults or when you want to use Active Record outside of Rails
    # (in such case after configuring the database tasks, you can also use the rake tasks
    # defined in Active Record).
    #
    #
    # The possible config values are:
    #
    #   * +env+: current environment (like Rails.env).
    #   * +database_configuration+: configuration of your databases (as in +config/database.yml+).
    #   * +db_dir+: your +db+ directory.
    #   * +fixtures_path+: a path to fixtures directory.
    #   * +migrations_paths+: a list of paths to directories with migrations.
    #   * +seed_loader+: an object which will load seeds, it needs to respond to the +load_seed+ method.
    #   * +root+: a path to the root of the application.
    #
    # Example usage of +DatabaseTasks+ outside Rails could look as such:
    #
    #   include ActiveRecord::Tasks
    #   DatabaseTasks.database_configuration = YAML.load(File.read('my_database_config.yml'))
    #   DatabaseTasks.db_dir = 'db'
    #   # other settings...
    #
    #   DatabaseTasks.create_current('production')
    module DatabaseTasks
      extend self

      attr_writer :current_config, :db_dir, :migrations_paths, :fixtures_path, :root, :env, :seed_loader
      attr_accessor :database_configuration

      LOCAL_HOSTS    = ['127.0.0.1', 'localhost']

      def register_task(pattern, task)
        @tasks ||= {}
        @tasks[pattern] = task
      end

      register_task(/mysql/,        ActiveRecord::Tasks::MySQLDatabaseTasks)
      register_task(/postgresql/,   ActiveRecord::Tasks::PostgreSQLDatabaseTasks)
      register_task(/sqlite/,       ActiveRecord::Tasks::SQLiteDatabaseTasks)
      register_task(/ibm_db/,       ActiveRecord::Tasks::IBMDBDatabaseTasks)

      def db_dir
        @db_dir ||= Rails.application.config.paths["db"].first
      end

      def migrations_paths
        @migrations_paths ||= Rails.application.paths['db/migrate'].to_a
      end

      def fixtures_path
        @fixtures_path ||= File.join(root, 'test', 'fixtures')
      end

      def root
        @root ||= Rails.root
      end

      def env
        @env ||= Rails.env
      end

      def seed_loader
        @seed_loader ||= Rails.application
      end

      def current_config(options = {})
        options.reverse_merge! :env => env
        if options.has_key?(:config)
          @current_config = options[:config]
        else
          @current_config ||= ActiveRecord::Base.configurations[options[:env]]
        end
      end

      def create(*arguments)
        configuration = arguments.first
        class_for_adapter(configuration['adapter']).new(*arguments).create
      rescue DatabaseAlreadyExists
        $stderr.puts "#{configuration['database']} already exists"
      rescue Exception => error
        $stderr.puts error, *(error.backtrace)
        $stderr.puts "Couldn't create database for #{configuration.inspect}"
      end

      def create_all
        each_local_configuration { |configuration| create configuration }
      end

      def create_current(environment = env)
        each_current_configuration(environment) { |configuration|
          create configuration
        }
        ActiveRecord::Base.establish_connection(environment.to_sym)
      end

      def drop(*arguments)
        configuration = arguments.first
        class_for_adapter(configuration['adapter']).new(*arguments).drop
      rescue Exception => error
        $stderr.puts error, *(error.backtrace)
        $stderr.puts "Couldn't drop #{configuration['database']}"
      end

      def drop_all
        each_local_configuration { |configuration| drop configuration }
      end

      def drop_current(environment = env)
        each_current_configuration(environment) { |configuration|
          drop configuration
        }
      end

      def charset_current(environment = env)
        charset ActiveRecord::Base.configurations[environment]
      end

      def charset(*arguments)
        configuration = arguments.first
        class_for_adapter(configuration['adapter']).new(*arguments).charset
      end

      def collation_current(environment = env)
        collation ActiveRecord::Base.configurations[environment]
      end

      def collation(*arguments)
        configuration = arguments.first
        class_for_adapter(configuration['adapter']).new(*arguments).collation
      end

      def purge(configuration)
        class_for_adapter(configuration['adapter']).new(configuration).purge
      end

      def structure_dump(*arguments)
        configuration = arguments.first
        filename = arguments.delete_at 1
        class_for_adapter(configuration['adapter']).new(*arguments).structure_dump(filename)
      end

      def structure_load(*arguments)
        configuration = arguments.first
        filename = arguments.delete_at 1
        class_for_adapter(configuration['adapter']).new(*arguments).structure_load(filename)
      end

      def load_schema(format = ActiveRecord::Base.schema_format, file = nil)
        load_schema_current(format, file)
      end

      # This method is the successor of +load_schema+. We should rename it
      # after +load_schema+ went through a deprecation cycle. (Rails > 4.2)
      def load_schema_for(configuration, format = ActiveRecord::Base.schema_format, file = nil) # :nodoc:
        case format
        when :ruby
          file ||= File.join(db_dir, "schema.rb")
          check_schema_file(file)
          purge(configuration)
          ActiveRecord::Base.establish_connection(configuration)
          load(file)
        when :sql
          file ||= File.join(db_dir, "structure.sql")
          check_schema_file(file)
          purge(configuration)
          structure_load(configuration, file)
        else
          raise ArgumentError, "unknown format #{format.inspect}"
        end
      end

      def load_schema_current(format = ActiveRecord::Base.schema_format, file = nil, environment = env)
        each_current_configuration(environment) { |configuration|
          load_schema_for configuration, format, file
        }
        ActiveRecord::Base.establish_connection(environment.to_sym)
      end

      def check_schema_file(filename)
        unless File.exist?(filename)
          message = %{#{filename} doesn't exist yet. Run `rake db:migrate` to create it, then try again.}
          message << %{ If you do not intend to use a database, you should instead alter #{Rails.root}/config/application.rb to limit the frameworks that will be loaded.} if defined?(::Rails)
          Kernel.abort message
        end
      end

      def load_seed
        if seed_loader
          seed_loader.load_seed
        else
          raise "You tried to load seed data, but no seed loader is specified. Please specify seed " +
                "loader with ActiveRecord::Tasks::DatabaseTasks.seed_loader = your_seed_loader\n" +
                "Seed loader should respond to load_seed method"
        end
      end

      private

      def class_for_adapter(adapter)
        key = @tasks.keys.detect { |pattern| adapter[pattern] }
        unless key
          raise DatabaseNotSupported, "Rake tasks not supported by '#{adapter}' adapter"
        end
        @tasks[key]
      end

      def each_current_configuration(environment)
        environments = [environment]
        # add test environment only if no RAILS_ENV was specified.
        environments << 'test' if environment == 'development' && ENV['RAILS_ENV'].nil?

        configurations = ActiveRecord::Base.configurations.values_at(*environments)
        configurations.compact.each do |configuration|
          yield configuration unless configuration['database'].blank?
        end
      end

      def each_local_configuration
        ActiveRecord::Base.configurations.each_value do |configuration|
          next unless configuration['database']

          if local_database?(configuration)
            yield configuration
          else
            $stderr.puts "This task only modifies local databases. #{configuration['database']} is on a remote host."
          end
        end
      end

      def local_database?(configuration)
        configuration['host'].blank? || LOCAL_HOSTS.include?(configuration['host'])
      end
    end
  end
end

ibm_db_database_tasks.rb

module ActiveRecord
  module Tasks # :nodoc:
    class IBMDBDatabaseTasks # :nodoc:
      delegate :connection, :establish_connection, to: ActiveRecord::Base

      def initialize(configuration, root = ActiveRecord::Tasks::DatabaseTasks.root)
        @configuration, @root = configuration, root
      end

      def create
         silence_warnings do
           begin
              ActiveRecord::Base.establish_connection configuration.merge('dbops' => true)
              $stderr.puts "Create database #{configuration['database']} in progress. Will take few minutes..."
              crtSuccessful = ActiveRecord::Base.connection.create_database(configuration['database'],configuration['codeSet'], configuration['mode'])
              $stderr.puts "#{configuration['database']} creation successful" if crtSuccessful
              establish_connection(configuration)
           rescue StandardError => error
               $stderr.puts "#{configuration['database']} creation process failed: #{error}"
               raise
           end
         end
      end

      def drop
         silence_warnings do
           begin
               ActiveRecord::Base.establish_connection(configuration.merge('dbops' => true))
               $stderr.puts "Drop database #{configuration['database']} in progress. Will take few minutes..."
               drpSuccessful = ActiveRecord::Base.connection.drop_database configuration['database']
               $stderr.puts "#{configuration['database']} drop successful" if drpSuccessful
               ActiveRecord::Base.connection.disconnect!
               drpSuccessful 
           rescue StandardError => error
               $stderr.puts "#{configuration['database']} drop failed: #{error}"
               return false
           end
         end
      end

      def purge
        drop
        create
      end

      def charset
        connection.encoding
      end

      private

      def configuration
        @configuration
      end

      def root
        @root
      end
    end
  end
end