List all objects that are blocking a delete, in a well defined order

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

diff --git a/app/models/way.rb b/app/models/way.rb
index a8724456374be2f339933c6201bcb2bdd8277fe2..23475785c88f1ecc069268f6df85dd2e76fd730c 100644 (file)
--- a/app/models/way.rb
+++ b/app/models/way.rb
@@ -1,128 +1,362 @@
 class Way < ActiveRecord::Base
   require 'xml/libxml'
   
 class Way < ActiveRecord::Base
   require 'xml/libxml'
   

-  belongs_to :user
+  include ConsistencyValidations
+
+  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_segments, :foreign_key => 'id'

   has_many :way_tags, :foreign_key => 'id'
 
   has_many :way_tags, :foreign_key => 'id'
 

-  set_table_name 'current_ways'
+  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

 
 

+  scope :visible, where(:visible => true)
+  scope :invisible, where(:visible => false)
+
+  # Read in xml as text and return it's Way object representation

   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
+      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
 
     way = Way.new
 

-    doc.find('//osm/way').each do |pt|
-      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
-      end
+    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

 
 

-      pt.find('tag').each do |tag|
-        way.add_tag_keyval(tag['k'], tag['v'])
-      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('seg').each do |seg|
-        way.add_seg_num(seg['id'])
-      end
+    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

 
 

+    pt.find('nd').each do |nd|
+      way.add_nd_num(nd['ref'])

     end
 
     return way
   end
 
     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
   def to_xml

-    doc = XML::Document.new
-    doc.encoding = 'UTF-8' 
-    root = XML::Node.new 'osm'
-    root['version'] = '0.4'
-    root['generator'] = 'OpenStreetMap server'
+    doc = OSM::API.new.get_xml_doc
+    doc.root << to_xml_node()
+    return doc
+  end

 
 

-    doc.root = root
-    
+  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 = XML::Node.new 'way'
     el1['id'] = self.id.to_s
     el1['visible'] = self.visible.to_s
     el1['timestamp'] = self.timestamp.xmlschema

-    
-    self.way_segments.each do |seg| # FIXME need to make sure they come back in the right order
-      e = XML::Node.new 'seg'
-      e['id'] = seg.segment_id.to_s
-      el1 << e
+    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
+
+    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
     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
+        # 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
+
+    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
+

     self.way_tags.each do |tag|
       e = XML::Node.new 'tag'
       e['k'] = tag.k
       e['v'] = tag.v
       el1 << e
     end
     self.way_tags.each do |tag|
       e = XML::Node.new 'tag'
       e['k'] = tag.k
       e['v'] = tag.v
       el1 << e
     end

-  
-    root << el1
-    return doc
-  end
+    return el1
+  end 

 
 

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

   end
 
   def tags
   end
 
   def tags

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

     @tags
   end
 
     @tags
   end
 

-  def add_seg_num(n)
-    @segs = Array.new unless @segs
-    @segs << n.to_i
+  def nds=(s)
+    @nds = s
+  end
+
+  def tags=(t)
+    @tags = t
+  end
+
+  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
-    
-    WayTag.delete_all(['id = ?', self.id])
+  ##
+  # 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

 
 

-    self.tags.each do |k,v|
-      tag = WayTag.new
-      tag.k = k
-      tag.v = v
-      tag.id = self.id
-      tag.save
+  def update_from(new_way, user)
+    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

+  end

 
 

-    WaySegment.delete_all(['id = ?', self.id])
+  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?(old_nodes = [])
+    return false if self.nds.empty?
+    if self.nds.length > MAX_NUMBER_OF_WAY_NODES
+      raise OSM::APITooManyWayNodesError.new(self.id, self.nds.length, MAX_NUMBER_OF_WAY_NODES)
+    end
+
+    # 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)
+    unless self.visible
+      raise OSM::APIAlreadyDeletedError.new("way", new_way.id)
+    end

     
     

-    i = 0
-    self.segs.each do |n|
-      seg = WaySegment.new
-      seg.id = self.id
-      seg.segment_id = n
-      seg.sequence_id = i
-      seg.save
-      i += 1
-    end
-
-    old_way = OldWay.from_way(self)
-    old_way.timestamp = t
-    old_way.save_with_dependencies
+    # 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)
+      rels = Relation.joins(:relation_members).where(:visible => true, :current_relation_members => { :member_type => "Way", :member_id => id }).order(:id)
+      raise OSM::APIPreconditionFailedError.new("Way #{self.id} is still used by relations #{rels.collect { |r| r.id }.join(",")}.") unless rels.empty?
+
+      self.changeset_id = new_way.changeset_id
+      self.changeset = new_way.changeset
+
+      self.tags = []
+      self.nds = []
+      self.visible = false
+      save_with_history!
+    end
+  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, placeholder_id = nil)
+    self.nds.map! do |node_id|
+      if node_id < 0
+        new_id = id_map[:node][node_id]
+        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
+      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