Module: HairTrigger::SchemaDumper

Defined in:
lib/hair_trigger/schema_dumper.rb

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.included(base) ⇒ Object 



82
83
84
85
86
87
88
89
 
# File 'lib/hair_trigger/schema_dumper.rb', line 82

def self.included(base)
  base.class_eval do
    alias_method_chain :trailer, :triggers
    class << self
      attr_accessor :previous_schema
    end
  end
end

Instance Method Details

#normalize_trigger(name, definition, type) ⇒ Object 



56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
 
# File 'lib/hair_trigger/schema_dumper.rb', line 56

def normalize_trigger(name, definition, type)
  @connection = ActiveRecord::Base.connection
  @adapter_name = @connection.adapter_name.downcase.to_sym

  return definition unless @adapter_name == :postgresql
  begin
    # because postgres does not preserve the original CREATE TRIGGER/
    # FUNCTION statements, its decompiled reconstruction will not match
    # ours. we work around it by creating our generated trigger/function,
    # asking postgres for its definition, and then rolling back.
    begin
      @connection.transaction do
        chars = ('a'..'z').to_a + ('0'..'9').to_a + ['_']
        test_name = '_hair_trigger_test_' + (0..43).map{ chars[(rand * chars.size).to_i] }.join
        test_name << (type == :function ? '()' : '')
        @connection.execute(definition.sub(name, test_name))
        definition = @connection.triggers(:only => [test_name], :simple_check => true).values.first
        definition.sub!(test_name, name)
        raise
      end
    rescue
    end
  end
  definition
end

#trailer_with_triggers(stream) ⇒ Object 



3
4
5
6
7
8
9
10
 
# File 'lib/hair_trigger/schema_dumper.rb', line 3

def trailer_with_triggers(stream)
  orig_show_warnings = Builder.show_warnings
  Builder.show_warnings = false # we already show them when running the migration
  triggers(stream)
  trailer_without_triggers(stream)
ensure
  Builder.show_warnings = orig_show_warnings
end

#triggers(stream) ⇒ Object 



12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
 
# File 'lib/hair_trigger/schema_dumper.rb', line 12

def triggers(stream)
  @connection = ActiveRecord::Base.connection
  @adapter_name = @connection.adapter_name.downcase.to_sym

  db_triggers = @connection.triggers; nil
  db_trigger_warnings = {}

  migration_triggers = HairTrigger.current_migrations(:in_rake_task => true, :previous_schema => self.class.previous_schema).map do |(name, builder)|
    definitions = []
    builder.generate.each do |statement|
      if statement =~ /\ACREATE(.*TRIGGER| FUNCTION) ([^ \n]+)/
        definitions << [$2, statement, $1 == ' FUNCTION' ? :function : :trigger]
      end
    end
    {:builder => builder, :definitions => definitions}
  end

  migration_triggers.each do |migration|
    next unless migration[:definitions].all? do |(name, definition, type)|
      db_triggers[name] && (db_trigger_warnings[name] = true) && db_triggers[name] == normalize_trigger(name, definition, type)
    end
    migration[:definitions].each do |(name, trigger, type)|
      db_triggers.delete(name)
      db_trigger_warnings.delete(name)
    end

    stream.print migration[:builder].to_ruby('  ', false) + "\n\n"
  end

  db_triggers.to_a.sort_by{ |t| (t.first + 'a').sub(/\(/, '_') }.each do |(name, definition)|
    if db_trigger_warnings[name]
      stream.puts "  # WARNING: generating adapter-specific definition for #{name} due to a mismatch."
      stream.puts "  # either there's a bug in hairtrigger or you've messed up your migrations and/or db :-/"
    else
      stream.puts "  # no candidate create_trigger statement could be found, creating an adapter-specific one"
    end
    if definition =~ /\n/
      stream.print "  execute(<<-TRIGGERSQL)\n#{definition.rstrip}\n  TRIGGERSQL\n\n"
    else
      stream.print "  execute(#{definition.inspect})\n\n"
    end
  end
end