# 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
# NOTE: XML::Reader#read returns false for EOF and raises an
# exception if an error occurs.
@reader.read
- rescue LibXML::XML::Error => ex
- raise OSM::APIBadXMLError.new("changeset", xml, ex.message)
+ rescue LibXML::XML::Error => e
+ raise OSM::APIBadXMLError.new("changeset", xml, e.message)
end
##
# 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
def with_model
with_element do |model_name, _model_attributes|
model = MODELS[model_name]
- fail 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.
# Checks a few invariants. Others are checked in the model methods
# such as save_ and delete_with_history.
def check(model, xml, new)
- fail OSM::APIBadXMLError.new(model, xml) if new.nil?
- unless new.changeset_id == @changeset.id
- fail OSM::APIChangesetMismatchError.new(new.changeset_id, @changeset.id)
- end
+ raise OSM::APIBadXMLError.new(model, xml) if new.nil?
+ raise OSM::APIChangesetMismatchError.new(new.changeset_id, @changeset.id) unless new.changeset_id == @changeset.id
end
##
# 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
- fail 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 <osmChange> element
with_element do |action_name, action_attributes|
- if action_name == 'create'
+ 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
- fail OSM::APIBadXMLError.new(model, xml) if placeholder_id.nil?
+ 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
- fail 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.
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
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
- fail OSM::APIBadXMLError.new(model, xml, "ID attribute is required") if new_id.nil?
+ 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
model_sym = model.to_s.downcase.to_sym
# 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
else
# no other actions to choose from, so it must be the users fault!
- fail OSM::APIChangesetActionInvalid.new(action_name)
+ raise OSM::APIChangesetActionInvalid, action_name
end
end
projects / rails.git / blobdiff