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module ActiveRecord
module ConnectionAdapters
class SchemaCache
attr_reader :version
attr_accessor :connection
def initialize(conn)
@connection = conn
@columns = {}
@columns_hash = {}
@primary_keys = {}
@data_sources = {}
end
def initialize_dup(other)
super
@columns = @columns.dup
@columns_hash = @columns_hash.dup
@primary_keys = @primary_keys.dup
@data_sources = @data_sources.dup
end
def primary_keys(table_name)
@primary_keys[table_name] ||= data_source_exists?(table_name) ? connection.primary_key(table_name) : nil
end
# A cached lookup for table existence.
def data_source_exists?(name)
prepare_data_sources if @data_sources.empty?
return @data_sources[name] if @data_sources.key? name
@data_sources[name] = connection.data_source_exists?(name)
end
alias table_exists? data_source_exists?
deprecate table_exists?: "use #data_source_exists? instead"
# Add internal cache for table with +table_name+.
def add(table_name)
if data_source_exists?(table_name)
primary_keys(table_name)
columns(table_name)
columns_hash(table_name)
end
end
def data_sources(name)
@data_sources[name]
end
alias tables data_sources
deprecate tables: "use #data_sources instead"
# Get the columns for a table
def columns(table_name)
@columns[table_name] ||= connection.columns(table_name)
end
# Get the columns for a table as a hash, key is the column name
# value is the column object.
def columns_hash(table_name)
@columns_hash[table_name] ||= Hash[columns(table_name).map { |col|
[col.name, col]
}]
end
# Clears out internal caches
def clear!
@columns.clear
@columns_hash.clear
@primary_keys.clear
@data_sources.clear
@version = nil
end
def size
[@columns, @columns_hash, @primary_keys, @data_sources].map(&:size).inject :+
end
# Clear out internal caches for the data source +name+.
def clear_data_source_cache!(name)
@columns.delete name
@columns_hash.delete name
@primary_keys.delete name
@data_sources.delete name
end
alias clear_table_cache! clear_data_source_cache!
deprecate clear_table_cache!: "use #clear_data_source_cache! instead"
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, @data_sources]
end
def marshal_load(array)
@version, @columns, @columns_hash, @primary_keys, @data_sources = array
end
private
def prepare_data_sources
connection.data_sources.each { |source| @data_sources[source] = true }
end
end
end
end
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