X-Git-Url: https://git.openstreetmap.org./rails.git/blobdiff_plain/34e3e51456774127d43408b7ab65c24f41373f62..7d4cc85a312cb79fd1c4b0f22626722bea1d736d:/lib/diff_reader.rb diff --git a/lib/diff_reader.rb b/lib/diff_reader.rb index 40b43c5cd..2784646af 100644 --- a/lib/diff_reader.rb +++ b/lib/diff_reader.rb @@ -4,14 +4,12 @@ # Uses the streaming LibXML "Reader" interface to cut down on memory # usage, so hopefully we can process fairly large diffs. class DiffReader - include ConsistencyValidations - # maps each element type to the model class which handles it MODELS = { - "node" => Node, - "way" => Way, + "node" => Node, + "way" => Way, "relation" => Relation - } + }.freeze ## # Construct a diff reader by giving it a bunch of XML +data+ to parse @@ -32,11 +30,9 @@ class DiffReader def read_or_die # NOTE: XML::Reader#read returns false for EOF and raises an # exception if an error occurs. - begin - @reader.read - rescue LibXML::XML::Error => ex - raise OSM::APIBadXMLError.new("changeset", xml, ex.message) - end + @reader.read + rescue LibXML::XML::Error => e + raise OSM::APIBadXMLError.new("changeset", xml, e.message) end ## @@ -52,19 +48,17 @@ class DiffReader # read the first element read_or_die - while @reader.node_type != 15 do # end element + while @reader.node_type != 15 # end element # because we read elements in DOM-style to reuse their DOM # parsing code, we don't always read an element on each pass # as the call to @reader.next in the innermost loop will take # care of that for us. if @reader.node_type == 1 # element name = @reader.name - attributes = {} + attributes = {} if @reader.has_attributes? - while @reader.move_to_next_attribute == 1 - attributes[@reader.name] = @reader.value - end + attributes[@reader.name] = @reader.value while @reader.move_to_next_attribute == 1 @reader.move_to_element end @@ -85,10 +79,12 @@ class DiffReader # elements, it would be better to DRY and do this in a block. This # could also help with error handling...? def with_model - with_element do |model_name,model_attributes| + with_element do |model_name, _model_attributes| model = MODELS[model_name] - raise OSM::APIBadUserInput.new("Unexpected element type #{model_name}, " + - "expected node, way or relation.") if model.nil? + if model.nil? + raise OSM::APIBadUserInput, "Unexpected element type #{model_name}, " \ + "expected node, way or relation." + end # new in libxml-ruby >= 2, expand returns an element not associated # with a document. this means that there's no encoding parameter, # which means basically nothing works. @@ -112,9 +108,7 @@ class DiffReader # such as save_ and delete_with_history. def check(model, xml, new) raise OSM::APIBadXMLError.new(model, xml) if new.nil? - unless new.changeset_id == @changeset.id - raise OSM::APIChangesetMismatchError.new(new.changeset_id, @changeset.id) - end + raise OSM::APIChangesetMismatchError.new(new.changeset_id, @changeset.id) unless new.changeset_id == @changeset.id end ## @@ -125,36 +119,35 @@ class DiffReader # On a failure to meet preconditions (e.g: optimistic locking fails) # an exception subclassing OSM::APIError will be thrown. def commit - # data structure used for mapping placeholder IDs to real IDs - node_ids, way_ids, rel_ids = {}, {}, {} - ids = { :node => node_ids, :way => way_ids, :relation => rel_ids} + ids = { :node => {}, :way => {}, :relation => {} } # take the first element and check that it is an osmChange element @reader.read - raise OSM::APIBadUserInput.new("Document element should be 'osmChange'.") if @reader.name != 'osmChange' + raise OSM::APIBadUserInput, "Document element should be 'osmChange'." if @reader.name != "osmChange" - result = OSM::API.new.get_xml_doc + result = OSM::API.new.xml_doc result.root.name = "diffResult" # loop at the top level, within the element - with_element do |action_name,action_attributes| - if action_name == 'create' + with_element do |action_name, action_attributes| + case action_name + when "create" # create a new element. this code is agnostic of the element type # because all the elements support the methods that we're using. with_model do |model, xml| - new = model.from_xml_node(xml, true) + new = model.from_xml_node(xml, :create => true) check(model, xml, new) # when this element is saved it will get a new ID, so we save it # to produce the mapping which is sent to other elements. - placeholder_id = xml['id'].to_i + placeholder_id = xml["id"].to_i raise OSM::APIBadXMLError.new(model, xml) if placeholder_id.nil? # check if the placeholder ID has been given before and throw # an exception if it has - we can't create the same element twice. model_sym = model.to_s.downcase.to_sym - raise OSM::APIBadUserInput.new("Placeholder IDs must be unique for created elements.") if ids[model_sym].include? placeholder_id + raise OSM::APIBadUserInput, "Placeholder IDs must be unique for created elements." if ids[model_sym].include? placeholder_id # some elements may have placeholders for other elements in the # diff, so we must fix these before saving the element. @@ -174,12 +167,12 @@ class DiffReader result.root << xml_result end - elsif action_name == 'modify' + when "modify" # modify an existing element. again, this code doesn't directly deal # with types, but uses duck typing to handle them transparently. with_model do |model, xml| # get the new element from the XML payload - new = model.from_xml_node(xml, false) + new = model.from_xml_node(xml, :create => false) check(model, xml, new) # if the ID is a placeholder then map it to the real ID @@ -206,13 +199,13 @@ class DiffReader result.root << xml_result end - elsif action_name == 'delete' + when "delete" # delete action. this takes a payload in API 0.6, so we need to do # most of the same checks that are done for the modify. with_model do |model, xml| # delete doesn't have to contain a full payload, according to # the wiki docs, so we just extract the things we need. - new_id = xml['id'].to_i + new_id = xml["id"].to_i raise OSM::APIBadXMLError.new(model, xml, "ID attribute is required") if new_id.nil? # if the ID is a placeholder then map it to the real ID @@ -222,8 +215,8 @@ class DiffReader # build the "new" element by modifying the existing one new = model.find(id) - new.changeset_id = xml['changeset'].to_i - new.version = xml['version'].to_i + new.changeset_id = xml["changeset"].to_i + new.version = xml["version"].to_i check(model, xml, new) # fetch the matching old element from the DB @@ -241,7 +234,7 @@ class DiffReader if action_attributes["if-unused"] begin old.delete_with_history!(new, @changeset.user) - rescue OSM::APIAlreadyDeletedError, OSM::APIPreconditionFailedError => ex + rescue OSM::APIAlreadyDeletedError, OSM::APIPreconditionFailedError xml_result["new_id"] = old.id.to_s xml_result["new_version"] = old.version.to_s end @@ -254,12 +247,11 @@ class DiffReader else # no other actions to choose from, so it must be the users fault! - raise OSM::APIChangesetActionInvalid.new(action_name) + raise OSM::APIChangesetActionInvalid, action_name end end # return the XML document to be rendered back to the client - return result + result end - end