diff options
Diffstat (limited to 'activerecord/lib/active_record/connection_adapters/schema_cache.rb')
-rw-r--r-- | activerecord/lib/active_record/connection_adapters/schema_cache.rb | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/schema_cache.rb b/activerecord/lib/active_record/connection_adapters/schema_cache.rb new file mode 100644 index 0000000000..aad1f9a7ef --- /dev/null +++ b/activerecord/lib/active_record/connection_adapters/schema_cache.rb @@ -0,0 +1,82 @@ +module ActiveRecord + module ConnectionAdapters + class SchemaCache + attr_reader :columns, :columns_hash, :primary_keys, :tables, :version + attr_accessor :connection + + def initialize(conn) + @connection = conn + + @columns = {} + @columns_hash = {} + @primary_keys = {} + @tables = {} + prepare_default_proc + end + + # A cached lookup for table existence. + def table_exists?(name) + return @tables[name] if @tables.key? name + + @tables[name] = connection.table_exists?(name) + end + + # Add internal cache for table with +table_name+. + def add(table_name) + if table_exists?(table_name) + @primary_keys[table_name] + @columns[table_name] + @columns_hash[table_name] + end + end + + # Clears out internal caches + def clear! + @columns.clear + @columns_hash.clear + @primary_keys.clear + @tables.clear + @version = nil + end + + # Clear out internal caches for table with +table_name+. + def clear_table_cache!(table_name) + @columns.delete table_name + @columns_hash.delete table_name + @primary_keys.delete table_name + @tables.delete table_name + end + + def marshal_dump + # if we get current version during initialization, it happens stack over flow. + @version = ActiveRecord::Migrator.current_version + [@version] + [:@columns, :@columns_hash, :@primary_keys, :@tables].map do |val| + self.instance_variable_get(val).inject({}) { |h, v| h[v[0]] = v[1]; h } + end + end + + def marshal_load(array) + @version, @columns, @columns_hash, @primary_keys, @tables = array + prepare_default_proc + end + + private + + def prepare_default_proc + @columns.default_proc = Proc.new do |h, table_name| + h[table_name] = connection.columns(table_name) + end + + @columns_hash.default_proc = Proc.new do |h, table_name| + h[table_name] = Hash[columns[table_name].map { |col| + [col.name, col] + }] + end + + @primary_keys.default_proc = Proc.new do |h, table_name| + h[table_name] = table_exists?(table_name) ? connection.primary_key(table_name) : nil + end + end + end + end +end |