Change public interface

README.md

@@ -42,22 +42,17 @@ twitter solution [1], it does not require the presence of an indexed
 
 ## Usage
 
-After extending Lhm, `hadron_change_table` becomes available
-with the following methods:
-
     class MigrateArbitrary < ActiveRecord::Migration
-      extend Lhm
-
       def self.up
-        hadron_change_table(:users) do |t|
+        Lhm.change_table(:users) do |t|
           t.add_column(:arbitrary, "INT(12)")
           t.add_index([:arbitrary, :created_at])
           t.ddl("alter table %s add column flag tinyint(1)" % t.name)
         end
       end
 
       def self.down
-        hadron_change_table(:users) do |t|
+        Lhm.change_table(:users) do |t|
           t.remove_index([:arbitrary, :created_at])
           t.remove_column(:arbitrary)
         end

lhm.gemspec

@@ -3,7 +3,7 @@
 lib = File.expand_path('../lib', __FILE__)
 $:.unshift(lib) unless $:.include?(lib)
 
-require 'lhm'
+require 'lhm/version'
 
 Gem::Specification.new do |s|
   s.name          = "lhm"

lib/lhm.rb

@@ -3,18 +3,19 @@
 #  Schmidt
 #
 
+require 'active_record'
 require 'lhm/table'
 require 'lhm/invoker'
-require 'lhm/migration'
+require 'lhm/version'
 
 module Lhm
-  VERSION = "1.0.0.rc2"
+  extend self
 
-  def hadron_change_table(table_name, chunk_options = {}, &block)
+  def change_table(table_name, chunk_options = {}, &block)
+    connection = ActiveRecord::Base.connection
     origin = Table.parse(table_name, connection)
     invoker = Invoker.new(origin, connection)
     block.call(invoker.migrator)
     invoker.run(chunk_options)
   end
 end
-

lib/lhm/chunker.rb

@@ -3,7 +3,6 @@
 #  Schmidt
 #
 
-require 'lhm/migration'
 require 'lhm/command'
 
 module Lhm

lib/lhm/invoker.rb

@@ -12,7 +12,6 @@
 require 'lhm/chunker'
 require 'lhm/entangler'
 require 'lhm/locked_switcher'
-require 'lhm/migration'
 require 'lhm/migrator'
 
 module Lhm

lib/lhm/migration.rb

@@ -3,7 +3,6 @@
 #  Schmidt
 #
 
-require 'lhm/table'
 require 'lhm/intersection'
 
 module Lhm

lib/lhm/migrator.rb

@@ -8,6 +8,7 @@
 
 require 'lhm/command'
 require 'lhm/migration'
+require 'lhm/table'
 
 module Lhm
   class Migrator
@@ -29,7 +30,7 @@ def ddl(statement)
     #
     # Add a column to a table:
     #
-    #   hadron_change_table("users") do |t|
+    #   Lhm.change_table("users") do |t|
     #     t.add_column(:logins, "INT(12) DEFAULT '0'")
     #   end
     #
@@ -42,7 +43,7 @@ def add_column(name, definition = "")
     #
     # Remove a column from a table:
     #
-    #   hadron_change_table("users") do |t|
+    #   Lhm.change_table("users") do |t|
     #     t.remove_column(:comment)
     #   end
     #
@@ -55,7 +56,7 @@ def remove_column(name)
     #
     # Add an index to a table:
     #
-    #  hadron_change_table("users") do |t|
+    #  Lhm.change_table("users") do |t|
     #    t.add_index([:comment, :created_at])
     #  end
     #
@@ -68,7 +69,7 @@ def add_index(cols)
     #
     # Add a unique index to a table:
     #
-    #  hadron_change_table("users") do |t|
+    #  Lhm.change_table("users") do |t|
     #    t.add_unique_index([:comment, :created_at])
     #  end
     #
@@ -81,7 +82,7 @@ def add_unique_index(cols)
     #
     # Remove an index from a table
     #
-    #   hadron_change_table("users") do |t|
+    #   Lhm.change_table("users") do |t|
     #     t.remove_index(:username, :created_at)
     #   end
     #
@@ -91,9 +92,7 @@ def remove_index(cols)
       statements << ddl.strip
     end
 
-    #
-    # Command implementation
-    #
+  private
 
     def validate
       unless table?(@origin.name)
@@ -111,8 +110,6 @@ def validate
       end
     end
 
-  private
-
     def execute
       destination_create
       sql(@statements)

lib/lhm/version.rb

@@ -0,0 +1,8 @@
+#
+#  Copyright (c) 2011, SoundCloud Ltd., Rany Keddo, Tobias Bielohlawek, Tobias
+#  Schmidt
+#
+
+module Lhm
+  VERSION = "1.0.0.rc2"
+end

spec/integration/lhm_spec.rb

@@ -6,76 +6,6 @@
 require 'lhm'
 require File.expand_path(File.dirname(__FILE__)) + '/integration_helper'
 
-class AddColumnTestMigration < ActiveRecord::Migration
-  extend Lhm
-
-  def self.up
-    hadron_change_table(:users) do |t|
-      t.add_column(:logins, "INT(12) DEFAULT '0'")
-    end
-  end
-end
-
-class RemoveColumnTestMigration < ActiveRecord::Migration
-  extend Lhm
-
-  def self.up
-    hadron_change_table(:users) do |t|
-      t.remove_column(:comment)
-    end
-  end
-end
-
-class AddIndexTestMigration < ActiveRecord::Migration
-  extend Lhm
-
-  def self.up
-    hadron_change_table(:users) do |t|
-      t.add_index([:comment, :created_at])
-    end
-  end
-end
-
-class AddUniqueIndexTestMigration < ActiveRecord::Migration
-  extend Lhm
-
-  def self.up
-    hadron_change_table(:users) do |t|
-      t.add_unique_index(:comment)
-    end
-  end
-end
-
-class RemoveIndexTestMigration < ActiveRecord::Migration
-  extend Lhm
-
-  def self.up
-    hadron_change_table(:users) do |t|
-      t.remove_index([:username, :created_at])
-    end
-  end
-end
-
-class DdlTestMigration < ActiveRecord::Migration
-  extend Lhm
-
-  def self.up
-    hadron_change_table(:users) do |t|
-      t.ddl("alter table %s add column flag tinyint(1)" % t.name)
-    end
-  end
-end
-
-class ParallelTestMigration < ActiveRecord::Migration
-  extend Lhm
-
-  def self.up
-    hadron_change_table(:users, :stride => 10, :throttle => 97) do |t|
-      t.add_column(:parallel, "INT(10) DEFAULT '0'")
-    end
-  end
-end
-
 describe Lhm do
   include IntegrationHelper
 
@@ -87,7 +17,9 @@ def self.up
     end
 
     it "should add a column" do
-      AddColumnTestMigration.up
+      Lhm.change_table(:users) do |t|
+        t.add_column(:logins, "INT(12) DEFAULT '0'")
+      end
 
       table_read(:users).columns["logins"].must_equal({
         :type => "int(12)",
@@ -98,37 +30,49 @@ def self.up
     it "should copy all rows" do
       23.times { |n| execute("insert into users set reference = '#{ n }'") }
 
-      AddColumnTestMigration.up
+      Lhm.change_table(:users) do |t|
+        t.add_column(:logins, "INT(12) DEFAULT '0'")
+      end
 
       count_all("users").must_equal(23)
     end
 
     it "should remove a column" do
-      RemoveColumnTestMigration.up
+      Lhm.change_table(:users) do |t|
+        t.remove_column(:comment)
+      end
 
       table_read(:users).columns["comment"].must_equal nil
     end
 
     it "should add an index" do
-      AddIndexTestMigration.up
+      Lhm.change_table(:users) do |t|
+        t.add_index([:comment, :created_at])
+      end
 
       key?(table_read(:users), [:comment, :created_at]).must_equal(true)
     end
 
     it "should add a unqiue index" do
-      AddUniqueIndexTestMigration.up
+      Lhm.change_table(:users) do |t|
+        t.add_unique_index(:comment)
+      end
 
       key?(table_read(:users), :comment, :unique).must_equal(true)
     end
 
     it "should remove an index" do
-      RemoveIndexTestMigration.up
+      Lhm.change_table(:users) do |t|
+        t.remove_index([:username, :created_at])
+      end
 
       key?(table_read(:users), [:username, :created_at]).must_equal(false)
     end
 
     it "should apply a ddl statement" do
-      DdlTestMigration.up
+      Lhm.change_table(:users) do |t|
+        t.ddl("alter table %s add column flag tinyint(1)" % t.name)
+      end
 
       table_read(:users).columns["flag"].must_equal({
         :type => "tinyint(1)",
@@ -147,7 +91,9 @@ def self.up
           end
         end
 
-        ParallelTestMigration.up
+        Lhm.change_table(:users, :stride => 10, :throttle => 97) do |t|
+          t.add_column(:parallel, "INT(10) DEFAULT '0'")
+        end
 
         insert.join
 
@@ -164,7 +110,9 @@ def self.up
           end
         end
 
-        ParallelTestMigration.up
+        Lhm.change_table(:users, :stride => 10, :throttle => 97) do |t|
+          t.add_column(:parallel, "INT(10) DEFAULT '0'")
+        end
 
         delete.join