added comment for future generations

[rails.git] / app / models / way.rb

diff --git a/app/models/way.rb b/app/models/way.rb
index 92b69ed7dc15c472c6779c5d5673736cdc65c89d..8788bd671b1e2ffdd9b1c9bd82c8f371edabc45a 100644 (file)
--- a/app/models/way.rb
+++ b/app/models/way.rb
@@ -25,16 +25,16 @@ class Way < ActiveRecord::Base
   validates_numericality_of :id, :on => :update, :integer_only => true
   validates_associated :changeset
 
   validates_numericality_of :id, :on => :update, :integer_only => true
   validates_associated :changeset
 

+  # Read in xml as text and return it's Way object representation

   def self.from_xml(xml, create=false)
     begin
   def self.from_xml(xml, create=false)
     begin

-      p = XML::Parser.new
-      p.string = xml
+      p = XML::Parser.string(xml)

       doc = p.parse
 
       doc.find('//osm/way').each do |pt|
         return Way.from_xml_node(pt, create)
       end
       doc = p.parse
 
       doc.find('//osm/way').each do |pt|
         return Way.from_xml_node(pt, create)
       end

-    rescue LibXML::XML::Error => ex
+    rescue LibXML::XML::Error, ArgumentError => ex

       raise OSM::APIBadXMLError.new("way", xml, ex.message)
     end
   end
       raise OSM::APIBadXMLError.new("way", xml, ex.message)
     end
   end


@@ -42,27 +42,27 @@ class Way < ActiveRecord::Base
   def self.from_xml_node(pt, create=false)
     way = Way.new
 
   def self.from_xml_node(pt, create=false)
     way = Way.new
 

-    if !create and pt['id'] != '0'
-      way.id = pt['id'].to_i
-    end
-    
+    raise OSM::APIBadXMLError.new("way", pt, "Version is required when updating") unless create or not pt['version'].nil?

     way.version = pt['version']
     way.version = pt['version']

-    raise OSM::APIBadXMLError.new("node", pt, "Changeset is required") if pt['changeset'].nil?
+    raise OSM::APIBadXMLError.new("way", pt, "Changeset id is missing") if pt['changeset'].nil?

     way.changeset_id = pt['changeset']
 
     way.changeset_id = pt['changeset']
 

-    # This next section isn't required for the create, update, or delete of ways
-    if create
-      way.timestamp = Time.now
-      way.visible = true
-    else
-      if pt['timestamp']
-        way.timestamp = Time.parse(pt['timestamp'])
-      end
-      # if visible isn't present then it defaults to true
-      way.visible = (pt['visible'] or true)
+    unless create
+      raise OSM::APIBadXMLError.new("way", pt, "ID is required when updating") if pt['id'].nil?
+      way.id = pt['id'].to_i
+      # .to_i will return 0 if there is no number that can be parsed. 
+      # We want to make sure that there is no id with zero anyway
+      raise OSM::APIBadUserInput.new("ID of way cannot be zero when updating.") if way.id == 0

     end
 
     end
 

+    # We don't care about the timestamp nor the visibility as these are either
+    # set explicitly or implicit in the action. The visibility is set to true, 
+    # and manually set to false before the actual delete.
+    way.visible = true
+

     pt.find('tag').each do |tag|
     pt.find('tag').each do |tag|

+      raise OSM::APIBadXMLError.new("way", pt, "tag is missing key") if tag['k'].nil?
+      raise OSM::APIBadXMLError.new("way", pt, "tag is missing value") if tag['v'].nil?

       way.add_tag_keyval(tag['k'], tag['v'])
     end
 
       way.add_tag_keyval(tag['k'], tag['v'])
     end
 


@@ -90,7 +90,7 @@ class Way < ActiveRecord::Base
     return doc
   end
 
     return doc
   end
 

-  def to_xml_node(visible_nodes = nil, user_display_name_cache = nil)
+  def to_xml_node(visible_nodes = nil, changeset_cache = {}, user_display_name_cache = {})

     el1 = XML::Node.new 'way'
     el1['id'] = self.id.to_s
     el1['visible'] = self.visible.to_s
     el1 = XML::Node.new 'way'
     el1['id'] = self.id.to_s
     el1['visible'] = self.visible.to_s


@@ -98,19 +98,25 @@ class Way < ActiveRecord::Base
     el1['version'] = self.version.to_s
     el1['changeset'] = self.changeset_id.to_s
 
     el1['version'] = self.version.to_s
     el1['changeset'] = self.changeset_id.to_s
 

-    user_display_name_cache = {} if user_display_name_cache.nil?
+    if changeset_cache.key?(self.changeset_id)
+      # use the cache if available
+    else
+      changeset_cache[self.changeset_id] = self.changeset.user_id
+    end
+
+    user_id = changeset_cache[self.changeset_id]

 
 

-    if user_display_name_cache and user_display_name_cache.key?(self.changeset.user_id)
+    if user_display_name_cache.key?(user_id)

       # use the cache if available
     elsif self.changeset.user.data_public?
       # use the cache if available
     elsif self.changeset.user.data_public?

-      user_display_name_cache[self.changeset.user_id] = self.changeset.user.display_name
+      user_display_name_cache[user_id] = self.changeset.user.display_name

     else
     else

-      user_display_name_cache[self.changeset.user_id] = nil
+      user_display_name_cache[user_id] = nil

     end
 
     end
 

-    if not user_display_name_cache[self.changeset.user_id].nil?
-      el1['user'] = user_display_name_cache[self.changeset.user_id]
-      el1['uid'] = self.changeset.user_id.to_s
+    if not user_display_name_cache[user_id].nil?
+      el1['user'] = user_display_name_cache[user_id]
+      el1['uid'] = user_id.to_s

     end
 
     # make sure nodes are output in sequence_id order
     end
 
     # make sure nodes are output in sequence_id order


@@ -199,98 +205,77 @@ class Way < ActiveRecord::Base
   end
 
   def update_from(new_way, user)
   end
 
   def update_from(new_way, user)

-    check_consistency(self, new_way, user)
-    if !new_way.preconditions_ok?
-      raise OSM::APIPreconditionFailedError.new
+    Way.transaction do
+      self.lock!
+      check_consistency(self, new_way, user)
+      unless new_way.preconditions_ok?(self.nds)
+        raise OSM::APIPreconditionFailedError.new("Cannot update way #{self.id}: data is invalid.")
+      end
+      
+      self.changeset_id = new_way.changeset_id
+      self.changeset = new_way.changeset
+      self.tags = new_way.tags
+      self.nds = new_way.nds
+      self.visible = true
+      save_with_history!

     end
     end

-    self.changeset_id = new_way.changeset_id
-    self.tags = new_way.tags
-    self.nds = new_way.nds
-    self.visible = true
-    save_with_history!

   end
 
   def create_with_history(user)
     check_create_consistency(self, user)
   end
 
   def create_with_history(user)
     check_create_consistency(self, user)

-    if !self.preconditions_ok?
-      raise OSM::APIPreconditionFailedError.new
+    unless self.preconditions_ok?
+      raise OSM::APIPreconditionFailedError.new("Cannot create way: data is invalid.")

     end
     self.version = 0
     self.visible = true
     save_with_history!
   end
 
     end
     self.version = 0
     self.visible = true
     save_with_history!
   end
 

-  def preconditions_ok?
+  def preconditions_ok?(old_nodes = [])

     return false if self.nds.empty?
     if self.nds.length > APP_CONFIG['max_number_of_way_nodes']
     return false if self.nds.empty?
     if self.nds.length > APP_CONFIG['max_number_of_way_nodes']

-      raise OSM::APITooManyWayNodesError.new(self.nds.count, APP_CONFIG['max_number_of_way_nodes'])
+      raise OSM::APITooManyWayNodesError.new(self.nds.length, APP_CONFIG['max_number_of_way_nodes'])

     end
     end

-    self.nds.each do |n|
-      node = Node.find(:first, :conditions => ["id = ?", n])
-      unless node and node.visible
-        return false
+
+    # check only the new nodes, for efficiency - old nodes having been checked last time and can't
+    # be deleted when they're in-use.
+    new_nds = (self.nds - old_nodes).sort.uniq
+
+    unless new_nds.empty?
+      db_nds = Node.find(:all, :conditions => { :id => new_nds, :visible => true })
+
+      if db_nds.length < new_nds.length
+        missing = new_nds - db_nds.collect { |n| n.id }
+        raise OSM::APIPreconditionFailedError.new("Way #{self.id} requires the nodes with id in (#{missing.join(',')}), which either do not exist, or are not visible.")

       end
     end
       end
     end

+

     return true
   end
 
   def delete_with_history!(new_way, user)
     unless self.visible
     return true
   end
 
   def delete_with_history!(new_way, user)
     unless self.visible

-      raise OSM::APIAlreadyDeletedError
+      raise OSM::APIAlreadyDeletedError.new("way", new_way.id)

     end
     
     # need to start the transaction here, so that the database can 
     # provide repeatable reads for the used-by checks. this means it
     # shouldn't be possible to get race conditions.
     Way.transaction do
     end
     
     # need to start the transaction here, so that the database can 
     # provide repeatable reads for the used-by checks. this means it
     # shouldn't be possible to get race conditions.
     Way.transaction do

+      self.lock!

       check_consistency(self, new_way, user)
       check_consistency(self, new_way, user)

-      if RelationMember.find(:first, :joins => "INNER JOIN current_relations ON current_relations.id=current_relation_members.id",
-                             :conditions => [ "visible = ? AND member_type='way' and member_id=? ", true, self.id])
-        raise OSM::APIPreconditionFailedError.new("You need to make sure that this way is not a member of a relation.")
-      else
-        self.changeset_id = new_way.changeset_id
-        self.tags = []
-        self.nds = []
-        self.visible = false
-        save_with_history!
-      end
-    end
-  end
-
-  # delete a way and its nodes that aren't part of other ways, with history
-
-  # FIXME: merge the potlatch code to delete the relations
-  #        and refactor to use delete_with_history!
-  # This really needs the ids and versions of the nodes/relations to be passed in too
-  # so that we can do the version checking before the delete
-  def delete_with_relations_and_nodes_and_history(changeset_id)
-    # delete the nodes not used by other ways
-    self.unshared_node_ids.each do |node_id|
-      n = Node.find(node_id)
-      n.changeset_id = changeset_id
-      n.visible = false
-      # FIXME next line is bad
-      n.save_with_history!
-    end
-    
-    self.changeset_id = changeset_id
-    self.tags = []
-    self.nds = []
-    self.visible = false
-    # FIXME next line is bad
-    self.save_with_history!
-  end
-
-  # Find nodes that belong to this way only
-  def unshared_node_ids
-    node_ids = self.nodes.collect { |node| node.id }
-
-    unless node_ids.empty?
-      way_nodes = WayNode.find(:all, :conditions => "node_id in (#{node_ids.join(',')}) and id != #{self.id}")
-      node_ids = node_ids - way_nodes.collect { |way_node| way_node.node_id }
+      rel = RelationMember.find(:first, :joins => :relation,
+                             :conditions => [ "visible = ? AND member_type='Way' and member_id=? ", true, self.id])
+      raise OSM::APIPreconditionFailedError.new("Way #{self.id} still used by relation #{rel.relation.id}.") if rel
+      
+      self.changeset_id = new_way.changeset_id
+      self.changeset = new_way.changeset
+
+      self.tags = []
+      self.nds = []
+      self.visible = false
+      save_with_history!

     end
     end

-
-    return node_ids

   end
 
   # Temporary method to match interface to nodes
   end
 
   # Temporary method to match interface to nodes


@@ -302,11 +287,11 @@ class Way < ActiveRecord::Base
   # if any referenced nodes are placeholder IDs (i.e: are negative) then
   # this calling this method will fix them using the map from placeholders 
   # to IDs +id_map+. 
   # if any referenced nodes are placeholder IDs (i.e: are negative) then
   # this calling this method will fix them using the map from placeholders 
   # to IDs +id_map+. 

-  def fix_placeholders!(id_map)
+  def fix_placeholders!(id_map, placeholder_id = nil)

     self.nds.map! do |node_id|
       if node_id < 0
         new_id = id_map[:node][node_id]
     self.nds.map! do |node_id|
       if node_id < 0
         new_id = id_map[:node][node_id]

-        raise "invalid placeholder for #{node_id.inspect}: #{new_id.inspect}" if new_id.nil?
+        raise OSM::APIBadUserInput.new("Placeholder node not found for reference #{node_id} in way #{self.id.nil? ? placeholder_id : self.id}") if new_id.nil?

         new_id
       else
         node_id
         new_id
       else
         node_id


@@ -317,13 +302,14 @@ class Way < ActiveRecord::Base
   private
   
   def save_with_history!
   private
   
   def save_with_history!

-    t = Time.now
+    t = Time.now.getutc

 
 

-    # update the bounding box, but don't save it as the controller knows the 
-    # lifetime of the change better. note that this has to be done both before 
+    # update the bounding box, note that this has to be done both before 

     # and after the save, so that nodes from both versions are included in the 
     # and after the save, so that nodes from both versions are included in the 

-    # bbox.
-    changeset.update_bbox!(bbox) unless nodes.empty?
+    # bbox. we use a copy of the changeset so that it isn't reloaded
+    # later in the save.
+    cs = self.changeset
+    cs.update_bbox!(bbox) unless nodes.empty?

 
     Way.transaction do
       self.version += 1
 
     Way.transaction do
       self.version += 1


@@ -355,14 +341,18 @@ class Way < ActiveRecord::Base
       old_way.timestamp = t
       old_way.save_with_dependencies!
 
       old_way.timestamp = t
       old_way.save_with_dependencies!
 

+      # reload the way so that the nodes array points to the correct
+      # new set of nodes.
+      self.reload
+

       # update and commit the bounding box, now that way nodes 
       # have been updated and we're in a transaction.
       # update and commit the bounding box, now that way nodes 
       # have been updated and we're in a transaction.

-      changeset.update_bbox!(bbox) unless nodes.empty?
+      cs.update_bbox!(bbox) unless nodes.empty?

 
       # tell the changeset we updated one element only
 
       # tell the changeset we updated one element only

-      changeset.add_changes! 1
+      cs.add_changes! 1

 
 

-      changeset.save!
+      cs.save!

     end
   end
 
     end
   end