Module: Switchman::ActiveRecord::StatementCache

Defined in:
lib/switchman/active_record/statement_cache.rb

Defined Under Namespace

Modules: BindMap, ClassMethods

Instance Method Summary collapse

Instance Method Details

#execute(params, klass, connection) ⇒ Object

since the StatememtCache is only implemented for basic relations in AR::Base#find, AR::Base#find_by and AR::Association#get_records, we can make some assumptions about the shard source (e.g. infer from the primary key or use the current shard)



25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
 
# File 'lib/switchman/active_record/statement_cache.rb', line 25

def execute(params, klass, connection)
  target_shard = nil
  if primary_index = bind_map.primary_value_index
    primary_value = params[primary_index]
    target_shard = Shard.local_id_for(primary_value)[1]
  end
  current_shard = Shard.current(klass.shard_category)
  target_shard ||= current_shard

  bind_values = bind_map.bind(params, current_shard, target_shard)

  target_shard.activate(klass.shard_category) do
    if connection.use_qualified_names?
      sql = qualified_query_builder(target_shard, klass).sql_for(bind_values, connection)
      klass.find_by_sql(sql, bind_values)
    else
      sql = generic_query_builder(connection).sql_for(bind_values, connection)
      klass.find_by_sql(sql, bind_values)
    end
  end
end

#generic_query_builder(connection) ⇒ Object 



47
48
49
 
# File 'lib/switchman/active_record/statement_cache.rb', line 47

def generic_query_builder(connection)
  @query_builder ||= connection.cacheable_query(@arel)
end

#initialize(arel, bind_map) ⇒ Object 



14
15
16
17
18
 
# File 'lib/switchman/active_record/statement_cache.rb', line 14

def initialize(arel, bind_map)
  @arel = arel
  @bind_map = bind_map
  @qualified_query_builders = {}
end

#qualified_query_builder(shard, klass) ⇒ Object 



51
52
53
 
# File 'lib/switchman/active_record/statement_cache.rb', line 51

def qualified_query_builder(shard, klass)
  @qualified_query_builders[shard.id] ||= klass.connection.cacheable_query(@arel)
end