X-Git-Url: https://git.openstreetmap.org./rails.git/blobdiff_plain/137509534304be853ab01ca554111c524a9a1bca..b946779b845b298639c99e92407e8200d66814c1:/app/models/way.rb

diff --git a/app/models/way.rb b/app/models/way.rb
index e2e1ae302..639f4e69a 100644
--- a/app/models/way.rb
+++ b/app/models/way.rb
@@ -25,42 +25,45 @@ class Way < ActiveRecord::Base
   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
-      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
-    rescue
-      return nil
+      raise OSM::APIBadXMLError.new("node", xml, "XML doesn't contain an osm/way element.")
+    rescue LibXML::XML::Error, ArgumentError => ex
+      raise OSM::APIBadXMLError.new("way", xml, ex.message)
     end
   end
 
   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']
+    raise OSM::APIBadXMLError.new("way", pt, "Changeset id is missing") if pt['changeset'].nil?
     way.changeset_id = pt['changeset']
 
-    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
 
+    # 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|
+      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
 
@@ -88,7 +91,7 @@ class Way < ActiveRecord::Base
     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
@@ -96,19 +99,25 @@ class Way < ActiveRecord::Base
     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
 
-    if user_display_name_cache and user_display_name_cache.key?(self.changeset.user_id)
+    user_id = changeset_cache[self.changeset_id]
+
+    if user_display_name_cache.key?(user_id)
       # 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
-      user_display_name_cache[self.changeset.user_id] = nil
+      user_display_name_cache[user_id] = nil
     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
@@ -182,7 +191,7 @@ class Way < ActiveRecord::Base
 
     # duplicate tags are now forbidden, so we can't allow values
     # in the hash to be overwritten.
-    raise OSM::APIDuplicateTagsError.new if @tags.include? k
+    raise OSM::APIDuplicateTagsError.new("way", self.id, k) if @tags.include? k
 
     @tags[k] = v
   end
@@ -196,140 +205,78 @@ class Way < ActiveRecord::Base
     [ lons.min, lats.min, lons.max, lats.max ]
   end
 
-  def save_with_history!
-    t = Time.now
-
-    # 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 
-    # and after the save, so that nodes from both versions are included in the 
-    # bbox.
-    changeset.update_bbox!(bbox) unless nodes.empty?
-
+  def update_from(new_way, user)
     Way.transaction do
-      self.version += 1
-      self.timestamp = t
-      self.save!
-
-      tags = self.tags
-      WayTag.delete_all(['id = ?', self.id])
-      tags.each do |k,v|
-        tag = WayTag.new
-        tag.k = k
-        tag.v = v
-        tag.id = self.id
-        tag.save!
+      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
-
-      nds = self.nds
-      WayNode.delete_all(['id = ?', self.id])
-      sequence = 1
-      nds.each do |n|
-        nd = WayNode.new
-        nd.id = [self.id, sequence]
-        nd.node_id = n
-        nd.save!
-        sequence += 1
-      end
-
-      old_way = OldWay.from_way(self)
-      old_way.timestamp = t
-      old_way.save_with_dependencies!
-
-      # 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?
-
-      # tell the changeset we updated one element only
-      changeset.add_changes! 1
-
-      changeset.save!
-    end
-  end
-
-  def update_from(new_way, user)
-    check_consistency(self, new_way, user)
-    if !new_way.preconditions_ok?
-      raise OSM::APIPreconditionFailedError.new
+      
+      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
-    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)
-    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
 
-  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']
-      raise OSM::APITooManyWayNodesError.new(self.nds.count, APP_CONFIG['max_number_of_way_nodes'])
+      raise OSM::APITooManyWayNodesError.new(self.id, self.nds.length, APP_CONFIG['max_number_of_way_nodes'])
     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
+
     return true
   end
 
   def delete_with_history!(new_way, user)
-    check_consistency(self, new_way, user)
-    if self.visible
-      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
-      else
-        self.changeset_id = new_way.changeset_id
-        self.tags = []
-        self.nds = []
-        self.visible = false
-        self.save_with_history!
-      end
-    else
-      raise OSM::APIAlreadyDeletedError
-    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!
-  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
-      n.save_with_history!
+    unless self.visible
+      raise OSM::APIAlreadyDeletedError.new("way", new_way.id)
     end
     
-    self.changeset_id = changeset_id
-    self.tags = []
-    self.nds = []
-    self.visible = false
-    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 }
+    # 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)
+      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
-
-    return node_ids
   end
 
   # Temporary method to match interface to nodes
@@ -341,11 +288,11 @@ 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+. 
-  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]
-        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
@@ -353,4 +300,61 @@ class Way < ActiveRecord::Base
     end
   end
 
+  private
+  
+  def save_with_history!
+    t = Time.now.getutc
+
+    # 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 
+    # 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
+      self.timestamp = t
+      self.save!
+
+      tags = self.tags
+      WayTag.delete_all(['id = ?', self.id])
+      tags.each do |k,v|
+        tag = WayTag.new
+        tag.k = k
+        tag.v = v
+        tag.id = self.id
+        tag.save!
+      end
+
+      nds = self.nds
+      WayNode.delete_all(['id = ?', self.id])
+      sequence = 1
+      nds.each do |n|
+        nd = WayNode.new
+        nd.id = [self.id, sequence]
+        nd.node_id = n
+        nd.save!
+        sequence += 1
+      end
+
+      old_way = OldWay.from_way(self)
+      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.
+      cs.update_bbox!(bbox) unless nodes.empty?
+
+      # tell the changeset we updated one element only
+      cs.add_changes! 1
+
+      cs.save!
+    end
+  end
+
 end