diff options
Diffstat (limited to 'activerecord/lib/active_record/associations/alias_tracker.rb')
-rw-r--r-- | activerecord/lib/active_record/associations/alias_tracker.rb | 68 |
1 files changed, 39 insertions, 29 deletions
diff --git a/activerecord/lib/active_record/associations/alias_tracker.rb b/activerecord/lib/active_record/associations/alias_tracker.rb index 0c23029981..85109aee6c 100644 --- a/activerecord/lib/active_record/associations/alias_tracker.rb +++ b/activerecord/lib/active_record/associations/alias_tracker.rb @@ -5,16 +5,48 @@ module ActiveRecord # Keeps track of table aliases for ActiveRecord::Associations::ClassMethods::JoinDependency and # ActiveRecord::Associations::ThroughAssociationScope class AliasTracker # :nodoc: - attr_reader :aliases, :table_joins, :connection + attr_reader :aliases, :connection + + def self.empty(connection) + new connection, Hash.new(0) + end + + def self.create(connection, table_joins) + if table_joins.empty? + empty connection + else + aliases = Hash.new { |h,k| + h[k] = initial_count_for(connection, k, table_joins) + } + new connection, aliases + end + end + + def self.initial_count_for(connection, name, table_joins) + # quoted_name should be downcased as some database adapters (Oracle) return quoted name in uppercase + quoted_name = connection.quote_table_name(name).downcase + + counts = table_joins.map do |join| + if join.is_a?(Arel::Nodes::StringJoin) + # Table names + table aliases + join.left.downcase.scan( + /join(?:\s+\w+)?\s+(\S+\s+)?#{quoted_name}\son/ + ).size + else + join.left.table_name == name ? 1 : 0 + end + end + + counts.sum + end # table_joins is an array of arel joins which might conflict with the aliases we assign here - def initialize(connection = Base.connection, table_joins = []) - @aliases = Hash.new { |h,k| h[k] = initial_count_for(k) } - @table_joins = table_joins - @connection = connection + def initialize(connection, aliases) + @aliases = aliases + @connection = connection end - def aliased_table_for(table_name, aliased_name = nil) + def aliased_table_for(table_name, aliased_name) table_alias = aliased_name_for(table_name, aliased_name) if table_alias == table_name @@ -24,9 +56,7 @@ module ActiveRecord end end - def aliased_name_for(table_name, aliased_name = nil) - aliased_name ||= table_name - + def aliased_name_for(table_name, aliased_name) if aliases[table_name].zero? # If it's zero, we can have our table_name aliases[table_name] = 1 @@ -48,26 +78,6 @@ module ActiveRecord private - def initial_count_for(name) - return 0 if Arel::Table === table_joins - - # quoted_name should be downcased as some database adapters (Oracle) return quoted name in uppercase - quoted_name = connection.quote_table_name(name).downcase - - counts = table_joins.map do |join| - if join.is_a?(Arel::Nodes::StringJoin) - # Table names + table aliases - join.left.downcase.scan( - /join(?:\s+\w+)?\s+(\S+\s+)?#{quoted_name}\son/ - ).size - else - join.left.table_name == name ? 1 : 0 - end - end - - counts.sum - end - def truncate(name) name.slice(0, connection.table_alias_length - 2) end |