belongs_to :user
has_many :changeset_tags, :foreign_key => 'id'
+
+ has_many :nodes
+ has_many :ways
+ has_many :relations
+ has_many :old_nodes
+ has_many :old_ways
+ has_many :old_relations
+
+ validates_presence_of :id, :on => :update
+ validates_presence_of :user_id, :created_at, :closed_at, :num_changes
+ validates_uniqueness_of :id
+ validates_numericality_of :id, :on => :update, :integer_only => true
+ validates_numericality_of :min_lat, :max_lat, :min_lon, :max_lat, :allow_nil => true, :integer_only => true
+ validates_numericality_of :user_id, :integer_only => true
+ validates_numericality_of :num_changes, :integer_only => true, :greater_than_or_equal_to => 0
+ validates_associated :user
+
+ # over-expansion factor to use when updating the bounding box
+ EXPAND = 0.1
+
+ # maximum number of elements allowed in a changeset
+ MAX_ELEMENTS = 50000
+
+ # maximum time a changeset is allowed to be open for.
+ MAX_TIME_OPEN = 1.day
+
+ # idle timeout increment, one hour seems reasonable.
+ IDLE_TIMEOUT = 1.hour
+
+ # Use a method like this, so that we can easily change how we
+ # determine whether a changeset is open, without breaking code in at
+ # least 6 controllers
+ def is_open?
+ # a changeset is open (that is, it will accept further changes) when
+ # it has not yet run out of time and its capacity is small enough.
+ # note that this may not be a hard limit - due to timing changes and
+ # concurrency it is possible that some changesets may be slightly
+ # longer than strictly allowed or have slightly more changes in them.
+ return ((closed_at > Time.now.getutc) and (num_changes <= MAX_ELEMENTS))
+ end
+ def set_closed_time_now
+ if is_open?
+ self.closed_at = Time.now.getutc
+ end
+ end
+
def self.from_xml(xml, create=false)
begin
- p = XML::Parser.new
- p.string = xml
+ p = XML::Parser.string(xml)
doc = p.parse
cs = Changeset.new
doc.find('//osm/changeset').each do |pt|
if create
- cs.created_at = Time.now
+ cs.created_at = Time.now.getutc
+ # initial close time is 1h ahead, but will be increased on each
+ # modification.
+ cs.closed_at = cs.created_at + IDLE_TIMEOUT
+ # initially we have no changes in a changeset
+ cs.num_changes = 0
end
pt.find('tag').each do |tag|
end
end
rescue Exception => ex
- print "noes "+ ex.to_s + "\n"
cs = nil
end
return cs
end
+ ##
+ # returns the bounding box of the changeset. it is possible that some
+ # or all of the values will be nil, indicating that they are undefined.
+ def bbox
+ @bbox ||= [ min_lon, min_lat, max_lon, max_lat ]
+ end
+
+ def has_valid_bbox?
+ not bbox.include? nil
+ end
+
+ ##
+ # returns area of the changset bbox as a rough comparitive quantity for use of changset displays
+ def area
+ if has_valid_bbox?
+ (max_lon - min_lon) * (max_lat - min_lat)
+ else
+ 0
+ end
+ end
+
+ ##
+ # expand the bounding box to include the given bounding box. also,
+ # expand a little bit more in the direction of the expansion, so that
+ # further expansions may be unnecessary. this is an optimisation
+ # suggested on the wiki page by kleptog.
+ def update_bbox!(array)
+ # ensure that bbox is cached and has no nils in it. if there are any
+ # nils, just use the bounding box update to write over them.
+ @bbox = bbox.zip(array).collect { |a, b| a.nil? ? b : a }
+
+ # FIXME - this looks nasty and violates DRY... is there any prettier
+ # way to do this?
+ @bbox[0] = [-180 * GeoRecord::SCALE, array[0] + EXPAND * (@bbox[0] - @bbox[2])].max if array[0] < @bbox[0]
+ @bbox[1] = [ -90 * GeoRecord::SCALE, array[1] + EXPAND * (@bbox[1] - @bbox[3])].max if array[1] < @bbox[1]
+ @bbox[2] = [ 180 * GeoRecord::SCALE, array[2] + EXPAND * (@bbox[2] - @bbox[0])].min if array[2] > @bbox[2]
+ @bbox[3] = [ 90 * GeoRecord::SCALE, array[3] + EXPAND * (@bbox[3] - @bbox[1])].min if array[3] > @bbox[3]
+
+ # update active record. rails 2.1's dirty handling should take care of
+ # whether this object needs saving or not.
+ self.min_lon, self.min_lat, self.max_lon, self.max_lat = @bbox
+ end
+
+ ##
+ # the number of elements is also passed in so that we can ensure that
+ # a single changeset doesn't contain too many elements. this, of course,
+ # destroys the optimisation described in the bbox method above.
+ def add_changes!(elements)
+ self.num_changes += elements
+ end
+
+ def tags_as_hash
+ return tags
+ end
+
def tags
unless @tags
@tags = {}
end
def save_with_tags!
- t = Time.now
-
+ # do the changeset update and the changeset tags update in the
+ # same transaction to ensure consistency.
Changeset.transaction do
- # fixme update modified_at time?
self.save!
- end
- ChangesetTag.transaction do
tags = self.tags
ChangesetTag.delete_all(['id = ?', self.id])
end
end
end
+
+ ##
+ # set the auto-close time to be one hour in the future unless
+ # that would make it more than 24h long, in which case clip to
+ # 24h, as this has been decided is a reasonable time limit.
+ def before_save
+ if self.is_open?
+ if (closed_at - created_at) > (MAX_TIME_OPEN - IDLE_TIMEOUT)
+ self.closed_at = created_at + MAX_TIME_OPEN
+ else
+ self.closed_at = Time.now.getutc + IDLE_TIMEOUT
+ end
+ end
+ end
def to_xml
doc = OSM::API.new.get_xml_doc
doc.root << to_xml_node()
return doc
end
+
def to_xml_node(user_display_name_cache = nil)
el1 = XML::Node.new 'changeset'
el1['id'] = self.id.to_s
end
el1['user'] = user_display_name_cache[self.user_id] unless user_display_name_cache[self.user_id].nil?
+ el1['uid'] = self.user_id.to_s if self.user.data_public?
self.tags.each do |k,v|
el2 = XML::Node.new('tag')
end
el1['created_at'] = self.created_at.xmlschema
+ el1['closed_at'] = self.closed_at.xmlschema unless is_open?
+ el1['open'] = is_open?.to_s
- # FIXME FIXME FIXME: This does not include changes yet! There is
- # currently no changeset_id column in the tables as far as I can tell,
- # so this is just a scaffold to build on, not a complete to_xml
+ el1['min_lon'] = (bbox[0].to_f / GeoRecord::SCALE).to_s unless bbox[0].nil?
+ el1['min_lat'] = (bbox[1].to_f / GeoRecord::SCALE).to_s unless bbox[1].nil?
+ el1['max_lon'] = (bbox[2].to_f / GeoRecord::SCALE).to_s unless bbox[2].nil?
+ el1['max_lat'] = (bbox[3].to_f / GeoRecord::SCALE).to_s unless bbox[3].nil?
+
+ # NOTE: changesets don't include the XML of the changes within them,
+ # they are just structures for tagging. to get the osmChange of a
+ # changeset, see the download method of the controller.
return el1
end
+
+ ##
+ # update this instance from another instance given and the user who is
+ # doing the updating. note that this method is not for updating the
+ # bounding box, only the tags of the changeset.
+ def update_from(other, user)
+ # ensure that only the user who opened the changeset may modify it.
+ unless user.id == self.user_id
+ raise OSM::APIUserChangesetMismatchError.new
+ end
+
+ # can't change a closed changeset
+ unless is_open?
+ raise OSM::APIChangesetAlreadyClosedError.new(self)
+ end
+
+ # copy the other's tags
+ self.tags = other.tags
+
+ save_with_tags!
+ end
end