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 | 50 |
1 files changed, 50 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..962718da56 --- /dev/null +++ b/activerecord/lib/active_record/connection_adapters/schema_cache.rb @@ -0,0 +1,50 @@ +module ActiveRecord + module ConnectionAdapters + class SchemaCache + attr_reader :columns, :columns_hash, :primary_keys, :tables + attr_reader :connection + + def initialize(conn) + @connection = conn + @tables = {} + + @columns = Hash.new do |h, table_name| + h[table_name] = conn.columns(table_name) + end + + @columns_hash = Hash.new do |h, table_name| + h[table_name] = Hash[columns[table_name].map { |col| + [col.name, col] + }] + end + + @primary_keys = Hash.new do |h, table_name| + h[table_name] = table_exists?(table_name) ? conn.primary_key(table_name) : nil + end + 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 + + # Clears out internal caches + def clear! + @columns.clear + @columns_hash.clear + @primary_keys.clear + @tables.clear + 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 + end + end +end |