Add a changeset cache to stop us looking up the same changeset over

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

diff --git a/app/models/way.rb b/app/models/way.rb
index 2773ecc7b87ed83faec5e871d95d34f95b14fb42..52d28020969f4e1d1ed51a70e21144ad2cf54eac 100644 (file)
--- a/app/models/way.rb
+++ b/app/models/way.rb
@@ -1,81 +1,359 @@
 class Way < ActiveRecord::Base
   require 'xml/libxml'
   
 class Way < ActiveRecord::Base
   require 'xml/libxml'
   

-  belongs_to :user
+  include ConsistencyValidations
+

   set_table_name 'current_ways'
   set_table_name 'current_ways'

+  
+  belongs_to :changeset
+
+  has_many :old_ways, :foreign_key => 'id', :order => 'version'
+
+  has_many :way_nodes, :foreign_key => 'id', :order => 'sequence_id'
+  has_many :nodes, :through => :way_nodes, :order => 'sequence_id'
+
+  has_many :way_tags, :foreign_key => 'id'
+
+  has_many :containing_relation_members, :class_name => "RelationMember", :as => :member
+  has_many :containing_relations, :class_name => "Relation", :through => :containing_relation_members, :source => :relation, :extend => ObjectFinder
+
+  validates_presence_of :id, :on => :update
+  validates_presence_of :changeset_id,:version,  :timestamp
+  validates_uniqueness_of :id
+  validates_inclusion_of :visible, :in => [ true, false ]
+  validates_numericality_of :changeset_id, :version, :integer_only => true
+  validates_numericality_of :id, :on => :update, :integer_only => true
+  validates_associated :changeset

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

-    p = XML::Parser.new
-    p.string = xml
-    doc = p.parse
+    begin
+      p = XML::Parser.string(xml)
+      doc = p.parse
+
+      doc.find('//osm/way').each do |pt|
+        return Way.from_xml_node(pt, create)
+      end
+    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
 
     way = Way.new
 

-    doc.find('//osm/way').each do |pt|
-      if !create and pt['id'] != '0'
-        way.id = pt['id'].to_i
+    if !create and pt['id'] != '0'
+      way.id = pt['id'].to_i
+    end
+    
+    way.version = pt['version']
+    raise OSM::APIBadXMLError.new("node", pt, "Changeset is required") if pt['changeset'].nil?
+    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.getutc
+      way.visible = true
+    else
+      if pt['timestamp']
+        way.timestamp = Time.parse(pt['timestamp'])

       end
       end

+      # if visible isn't present then it defaults to true
+      way.visible = (pt['visible'] or true)
+    end
+
+    pt.find('tag').each do |tag|
+      way.add_tag_keyval(tag['k'], tag['v'])
+    end
+
+    pt.find('nd').each do |nd|
+      way.add_nd_num(nd['ref'])
+    end
+
+    return way
+  end
+
+  # Find a way given it's ID, and in a single SQL call also grab its nodes
+  #
+  
+  # You can't pull in all the tags too unless we put a sequence_id on the way_tags table and have a multipart key
+  def self.find_eager(id)
+    way = Way.find(id, :include => {:way_nodes => :node})
+    #If waytag had a multipart key that was real, you could do this:
+    #way = Way.find(id, :include => [:way_tags, {:way_nodes => :node}])
+  end
+
+  # Find a way given it's ID, and in a single SQL call also grab its nodes and tags
+  def to_xml
+    doc = OSM::API.new.get_xml_doc
+    doc.root << to_xml_node()
+    return doc
+  end
+
+  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['timestamp'] = self.timestamp.xmlschema
+    el1['version'] = self.version.to_s
+    el1['changeset'] = self.changeset_id.to_s
+
+    if changeset_cache.key?(self.changeset_id)
+      # use the cache if available
+    else
+      changeset_cache[self.changeset_id] = self.changeset.user_id
+    end

 
 

-      if create
-        way.timestamp = Time.now
-        way.visible = true
+    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[user_id] = self.changeset.user.display_name
+    else
+      user_display_name_cache[user_id] = nil
+    end
+
+    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
+    ordered_nodes = []
+    self.way_nodes.each do |nd|
+      if visible_nodes
+        # if there is a list of visible nodes then use that to weed out deleted nodes
+        if visible_nodes[nd.node_id]
+          ordered_nodes[nd.sequence_id] = nd.node_id.to_s
+        end

       else
       else

-        if pt['timestamp']
-          way.timestamp = Time.parse(pt['timestamp'])
+        # otherwise, manually go to the db to check things
+        if nd.node and nd.node.visible?
+          ordered_nodes[nd.sequence_id] = nd.node_id.to_s

         end
       end
         end
       end

+    end

 
 

-      pt.find('tag').each do |tag|
-        way.add_tag_keyval(tag['k'], tag['v'])
+    ordered_nodes.each do |nd_id|
+      if nd_id and nd_id != '0'
+        e = XML::Node.new 'nd'
+        e['ref'] = nd_id
+        el1 << e

       end
       end

+    end

 
 

-      pt.find('seg').each do |seg|
-        way.add_seg_num(seg['id'])
-      end
- 
+    self.way_tags.each do |tag|
+      e = XML::Node.new 'tag'
+      e['k'] = tag.k
+      e['v'] = tag.v
+      el1 << e
+    end
+    return el1
+  end 

 
 

+  def nds
+    unless @nds
+      @nds = Array.new
+      self.way_nodes.each do |nd|
+        @nds += [nd.node_id]
+      end

     end
     end

+    @nds
+  end

 
 

-    return way
+  def tags
+    unless @tags
+      @tags = {}
+      self.way_tags.each do |tag|
+        @tags[tag.k] = tag.v
+      end
+    end
+    @tags

   end
 
   end
 

-  def segs
-    @segs = Array.new unless @segs
-    @segs
+  def nds=(s)
+    @nds = s

   end
 
   end
 

-  def tags
-    @tags = Hash.new unless @tags
-    @tags
+  def tags=(t)
+    @tags = t

   end
 
   end
 

-  def add_seg_num(n)
-    @segs = Array.new unless @segs
-    @segs << n.to_i
+  def add_nd_num(n)
+    @nds = Array.new unless @nds
+    @nds << n.to_i

   end
 
   def add_tag_keyval(k, v)
     @tags = Hash.new unless @tags
   end
 
   def add_tag_keyval(k, v)
     @tags = Hash.new unless @tags

+
+    # duplicate tags are now forbidden, so we can't allow values
+    # in the hash to be overwritten.
+    raise OSM::APIDuplicateTagsError.new("way", self.id, k) if @tags.include? k
+

     @tags[k] = v
   end
 
     @tags[k] = v
   end
 

-  def save_with_history
-    t = Time.now
-    self.timestamp = t
-    self.save
+  ##
+  # the integer coords (i.e: unscaled) bounding box of the way, assuming
+  # straight line segments.
+  def bbox
+    lons = nodes.collect { |n| n.longitude }
+    lats = nodes.collect { |n| n.latitude }
+    [ lons.min, lats.min, lons.max, lats.max ]
+  end
+
+  def update_from(new_way, user)
+    check_consistency(self, new_way, user)
+    unless new_way.preconditions_ok?
+      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
+
+  def create_with_history(user)
+    check_create_consistency(self, user)
+    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?
+    return false if self.nds.empty?
+    if self.nds.length > APP_CONFIG['max_number_of_way_nodes']
+      raise OSM::APITooManyWayNodesError.new(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
+        raise OSM::APIPreconditionFailedError.new("The node with id #{n} either does not exist, or is not visible")
+      end
+    end
+    return true
+  end
+
+  def delete_with_history!(new_way, user)
+    unless self.visible
+      raise OSM::APIAlreadyDeletedError.new("way", new_way.id)
+    end

     
     

-    WayTag.delete_all(['id = ?', self.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
+      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.changeset = new_way.changeset

 
 

-    self.tags.each do |k,v|
-      tag = WayTag.new
-      tag.k = k
-      tag.v = v
-      tag.id = self.id
-      tag.save
+        self.tags = []
+        self.nds = []
+        self.visible = false
+        save_with_history!
+      end

     end
     end

+  end
+
+  # Find nodes that belong to this way only
+  def unshared_node_ids
+    node_ids = self.nodes.collect { |node| node.id }

 
 

-    old_way = OldWay.from_way(self)
-    old_way.save
+    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 }
+    end
+
+    return node_ids
+  end
+
+  # Temporary method to match interface to nodes
+  def tags_as_hash
+    return self.tags
+  end
+
+  ##
+  # 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)
+    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?
+        new_id
+      else
+        node_id
+      end
+    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
   end
 
 end