X-Git-Url: https://git.openstreetmap.org./rails.git/blobdiff_plain/740511066fcfaa910e0d9a9d86f6fefce85af343..98ad72c6eb999d787303ed2f7f335e228abe30b7:/app/models/relation.rb

diff --git a/app/models/relation.rb b/app/models/relation.rb
index 0d10b7728..f09647320 100644
--- a/app/models/relation.rb
+++ b/app/models/relation.rb
@@ -1,226 +1,382 @@
-class Relation < ActiveRecord::Base
-  require 'xml/libxml'
-  
-  belongs_to :user
+# == Schema Information
+#
+# Table name: current_relations
+#
+#  id           :bigint(8)        not null, primary key
+#  changeset_id :bigint(8)        not null
+#  timestamp    :datetime         not null
+#  visible      :boolean          not null
+#  version      :bigint(8)        not null
+#
+# Indexes
+#
+#  current_relations_timestamp_idx  (timestamp)
+#
+# Foreign Keys
+#
+#  current_relations_changeset_id_fkey  (changeset_id => changesets.id)
+#
+
+class Relation < ApplicationRecord
+  require "xml/libxml"
+
+  include ConsistencyValidations
+  include NotRedactable
+
+  self.table_name = "current_relations"
+
+  belongs_to :changeset
+
+  has_many :old_relations, -> { order(:version) }, :inverse_of => :current_relation
+
+  has_many :relation_members, -> { order(:sequence_id) }, :inverse_of => :relation
+  has_many :relation_tags
+
+  has_many :containing_relation_members, :class_name => "RelationMember", :as => :member
+  has_many :containing_relations, :class_name => "Relation", :through => :containing_relation_members, :source => :relation
+
+  validates :id, :uniqueness => true, :presence => { :on => :update },
+                 :numericality => { :on => :update, :only_integer => true }
+  validates :version, :presence => true,
+                      :numericality => { :only_integer => true }
+  validates :timestamp, :presence => true
+  validates :changeset, :associated => true
+  validates :visible, :inclusion => [true, false]
+
+  scope :visible, -> { where(:visible => true) }
+  scope :invisible, -> { where(:visible => false) }
+  scope :nodes, ->(*ids) { joins(:relation_members).where(:current_relation_members => { :member_type => "Node", :member_id => ids.flatten }) }
+  scope :ways, ->(*ids) { joins(:relation_members).where(:current_relation_members => { :member_type => "Way", :member_id => ids.flatten }) }
+  scope :relations, ->(*ids) { joins(:relation_members).where(:current_relation_members => { :member_type => "Relation", :member_id => ids.flatten }) }
+
+  TYPES = %w[node way relation].freeze
+
+  def self.from_xml(xml, create: false)
+    p = XML::Parser.string(xml, :options => XML::Parser::Options::NOERROR)
+    doc = p.parse
+    pt = doc.find_first("//osm/relation")
+
+    if pt
+      Relation.from_xml_node(pt, :create => create)
+    else
+      raise OSM::APIBadXMLError.new("node", xml, "XML doesn't contain an osm/relation element.")
+    end
+  rescue LibXML::XML::Error, ArgumentError => e
+    raise OSM::APIBadXMLError.new("relation", xml, e.message)
+  end
 
-  has_many :relation_members, :foreign_key => 'id'
-  has_many :relation_tags, :foreign_key => 'id'
+  def self.from_xml_node(pt, create: false)
+    relation = Relation.new
 
-  has_many :old_relations, :foreign_key => 'id', :order => 'version'
+    raise OSM::APIBadXMLError.new("relation", pt, "Version is required when updating") unless create || !pt["version"].nil?
 
-  set_table_name 'current_relations'
+    relation.version = pt["version"]
+    raise OSM::APIBadXMLError.new("relation", pt, "Changeset id is missing") if pt["changeset"].nil?
 
-  def self.from_xml(xml, create=false)
-    begin
-      p = XML::Parser.new
-      p.string = xml
-      doc = p.parse
+    relation.changeset_id = pt["changeset"]
 
-      relation = Relation.new
+    unless create
+      raise OSM::APIBadXMLError.new("relation", pt, "ID is required when updating") if pt["id"].nil?
 
-      doc.find('//osm/relation').each do |pt|
-        if !create and pt['id'] != '0'
-          relation.id = pt['id'].to_i
-        end
+      relation.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, "ID of relation cannot be zero when updating." if relation.id.zero?
+    end
 
-        if create
-          relation.timestamp = Time.now
-          relation.visible = true
-        else
-          if pt['timestamp']
-            relation.timestamp = Time.parse(pt['timestamp'])
-          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.
+    relation.visible = true
 
-        pt.find('tag').each do |tag|
-          relation.add_tag_keyval(tag['k'], tag['v'])
-        end
+    # Start with no tags
+    relation.tags = {}
 
-        pt.find('member').each do |member|
-          relation.add_member(member['type'], member['ref'], member['role'])
-        end
-      end
-    rescue
-      relation = nil
+    # Add in any tags from the XML
+    pt.find("tag").each do |tag|
+      raise OSM::APIBadXMLError.new("relation", pt, "tag is missing key") if tag["k"].nil?
+      raise OSM::APIBadXMLError.new("relation", pt, "tag is missing value") if tag["v"].nil?
+
+      relation.add_tag_keyval(tag["k"], tag["v"])
     end
 
-    return relation
-  end
+    # need to initialise the relation members array explicitly, as if this
+    # isn't done for a new relation then @members attribute will be nil,
+    # and the members will be loaded from the database instead of being
+    # empty, as intended.
+    relation.members = []
 
-  def to_xml
-    doc = OSM::API.new.get_xml_doc
-    doc.root << to_xml_node()
-    return doc
-  end
+    pt.find("member").each do |member|
+      # member_type =
+      raise OSM::APIBadXMLError.new("relation", pt, "The #{member['type']} is not allowed only, #{TYPES.inspect} allowed") unless TYPES.include? member["type"]
 
-  def to_xml_node(user_display_name_cache = nil)
-    el1 = XML::Node.new 'relation'
-    el1['id'] = self.id.to_s
-    el1['visible'] = self.visible.to_s
-    el1['timestamp'] = self.timestamp.xmlschema
-
-    user_display_name_cache = {} if user_display_name_cache.nil?
-    
-    if user_display_name_cache and user_display_name_cache.key?(self.user_id)
-      # use the cache if available
-    elsif self.user.data_public?
-      user_display_name_cache[self.user_id] = self.user.display_name
-    else
-      user_display_name_cache[self.user_id] = nil
+      # member_ref = member['ref']
+      # member_role
+      member["role"] ||= "" # Allow  the upload to not include this, in which case we default to an empty string.
+      relation.add_member(member["type"].classify, member["ref"], member["role"])
     end
+    raise OSM::APIBadUserInput, "Some bad xml in relation" if relation.nil?
 
-    el1['user'] = user_display_name_cache[self.user_id] unless user_display_name_cache[self.user_id].nil?
-
-    self.relation_members.each do |member|
-      p=0
-      #if visible_members
-      #  # if there is a list of visible members then use that to weed out deleted segments
-      #  if visible_members[member.member_type][member.member_id]
-      #    p=1
-      #  end
-      #else
-        # otherwise, manually go to the db to check things
-        if member.member.visible?
-          p=1
-        end
-      #end
-      if p
-        e = XML::Node.new 'member'
-        e['type'] = member.member_type
-        e['ref'] = member.member_id.to_s 
-        e['role'] = member.member_role
-        el1 << e
-       end
-    end
-
-    self.relation_tags.each do |tag|
-      e = XML::Node.new 'tag'
-      e['k'] = tag.k
-      e['v'] = tag.v
-      el1 << e
-    end
-    return el1
-  end 
-
-  def self.find_for_nodes_and_ways(node_ids, way_ids)
-    # collect relationships. currently done in one big block at the end;
-    # may need to move this upwards if people want automatic completion of
-    # relationships, i.e. deliver referenced objects like we do with ways...
-	return [] if node_ids.empty? and node_ids.empty?
-    relations = Array.new
-    if node_ids.length > 0
-        relations += Relation.find_by_sql("select e.* from current_relations e,current_relation_members em where " +
-            "e.visible=1 and " +
-            "em.id = e.id and em.member_type='node' and em.member_id in (#{node_ids.join(',')})")
-    end
-    if way_ids.length > 0
-        relations += Relation.find_by_sql("select e.* from current_relations e,current_relation_members em where " +
-            "e.visible=1 and " +
-            "em.id = e.id and em.member_type='way' and em.member_id in (#{way_ids.join(',')})")
-    end
+    relation
   end
 
-
-  # FIXME is this really needed?
+  # FIXME: is this really needed?
   def members
-    unless @members
-        @members = Array.new
-        self.relation_members.each do |member|
-            @members += [[member.member_type,member.member_id,member.member_role]]
-        end
+    @members ||= relation_members.map do |member|
+      [member.member_type, member.member_id, member.member_role]
     end
-    @members
   end
 
   def tags
-    unless @tags
-        @tags = Hash.new
-        self.relation_tags.each do |tag|
-            @tags[tag.k] = tag.v
-        end
-    end
-    @tags
+    @tags ||= relation_tags.to_h { |t| [t.k, t.v] }
   end
 
-  def members=(m)
-    @members = m
+  attr_writer :members, :tags
+
+  def add_member(type, id, role)
+    @members ||= []
+    @members << [type, id.to_i, role]
   end
 
-  def tags=(t)
-    @tags = t
+  def add_tag_keyval(k, v)
+    @tags ||= {}
+
+    # duplicate tags are now forbidden, so we can't allow values
+    # in the hash to be overwritten.
+    raise OSM::APIDuplicateTagsError.new("relation", id, k) if @tags.include? k
+
+    @tags[k] = v
   end
 
-  def add_member(type,id,role)
-    @members = Array.new unless @members
-    @members += [[type,id,role]]
+  ##
+  # updates the changeset bounding box to contain the bounding box of
+  # the element with given +type+ and +id+. this only works with nodes
+  # and ways at the moment, as they're the only elements to respond to
+  # the :bbox call.
+  def update_changeset_element(type, id)
+    element = Kernel.const_get(type.capitalize).find(id)
+    changeset.update_bbox! element.bbox
   end
 
-  def add_tag_keyval(k, v)
-    @tags = Hash.new unless @tags
-    @tags[k] = v
+  def delete_with_history!(new_relation, user)
+    raise OSM::APIAlreadyDeletedError.new("relation", new_relation.id) unless visible
+
+    # 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.
+    Relation.transaction do
+      lock!
+      check_update_element_consistency(self, new_relation, user)
+      # This will check to see if this relation is used by another relation
+      rel = RelationMember.joins(:relation).find_by("visible = ? AND member_type = 'Relation' and member_id = ? ", true, id)
+      raise OSM::APIPreconditionFailedError, "The relation #{new_relation.id} is used in relation #{rel.relation.id}." unless rel.nil?
+
+      self.changeset_id = new_relation.changeset_id
+      self.tags = {}
+      self.members = []
+      self.visible = false
+      save_with_history!
+    end
   end
 
-  def save_with_history!
+  def update_from(new_relation, user)
     Relation.transaction do
-      t = Time.now
-      self.timestamp = t
-      self.save!
+      lock!
+      check_update_element_consistency(self, new_relation, user)
+      raise OSM::APIPreconditionFailedError, "Cannot update relation #{id}: data or member data is invalid." unless new_relation.preconditions_ok?(members)
+
+      self.changeset_id = new_relation.changeset_id
+      self.changeset = new_relation.changeset
+      self.tags = new_relation.tags
+      self.members = new_relation.members
+      self.visible = true
+      save_with_history!
+    end
+  end
+
+  def create_with_history(user)
+    check_create_element_consistency(self, user)
+    raise OSM::APIPreconditionFailedError, "Cannot create relation: data or member data is invalid." unless preconditions_ok?
 
-      tags = self.tags
+    self.version = 0
+    self.visible = true
+    save_with_history!
+  end
+
+  def preconditions_ok?(good_members = [])
+    raise OSM::APITooManyRelationMembersError.new(id, members.length, Settings.max_number_of_relation_members) if members.length > Settings.max_number_of_relation_members
+
+    # These are hastables that store an id in the index of all
+    # the nodes/way/relations that have already been added.
+    # If the member is valid and visible then we add it to the
+    # relevant hash table, with the value true as a cache.
+    # Thus if you have nodes with the ids of 50 and 1 already in the
+    # relation, then the hash table nodes would contain:
+    # => {50=>true, 1=>true}
+    elements = { :node => {}, :way => {}, :relation => {} }
+
+    # pre-set all existing members to good
+    good_members.each { |m| elements[m[0].downcase.to_sym][m[1]] = true }
+
+    members.each do |m|
+      # find the hash for the element type or die
+      hash = elements[m[0].downcase.to_sym]
+      return false unless hash
 
-      RelationTag.delete_all(['id = ?', self.id])
+      # unless its in the cache already
+      next if hash.key? m[1]
 
-      tags.each do |k,v|
-	tag = RelationTag.new
-	tag.k = k
-	tag.v = v
-	tag.id = self.id
-	tag.save!
+      # use reflection to look up the appropriate class
+      model = Kernel.const_get(m[0].capitalize)
+      # get the element with that ID. and, if found, lock the element to
+      # ensure it can't be deleted until after the current transaction
+      # commits.
+      element = model.lock("for share").find_by(:id => m[1])
+
+      # and check that it is OK to use.
+      raise OSM::APIPreconditionFailedError, "Relation with id #{id} cannot be saved due to #{m[0]} with id #{m[1]}" unless element&.visible? && element&.preconditions_ok?
+
+      hash[m[1]] = true
+    end
+
+    true
+  end
+
+  ##
+  # if any members are referenced by placeholder IDs (i.e: 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)
+    members.map! do |type, id, role|
+      old_id = id.to_i
+      if old_id.negative?
+        new_id = id_map[type.downcase.to_sym][old_id]
+        raise OSM::APIBadUserInput, "Placeholder #{type} not found for reference #{old_id} in relation #{self.id.nil? ? placeholder_id : self.id}." if new_id.nil?
+
+        [type, new_id, role]
+      else
+        [type, id, role]
       end
+    end
+  end
 
-      members = self.members
+  private
+
+  def save_with_history!
+    t = Time.now.utc
+
+    self.version += 1
+    self.timestamp = t
+
+    Relation.transaction do
+      # have to be a little bit clever here - to detect if any tags
+      # changed then we have to monitor their before and after state.
+      tags_changed = false
+
+      # clone the object before saving it so that the original is
+      # still marked as dirty if we retry the transaction
+      clone.save!
+
+      tags = self.tags.clone
+      relation_tags.each do |old_tag|
+        key = old_tag.k
+        # if we can match the tags we currently have to the list
+        # of old tags, then we never set the tags_changed flag. but
+        # if any are different then set the flag and do the DB
+        # update.
+        if tags.key? key
+          tags_changed |= (old_tag.v != tags[key])
+
+          # remove from the map, so that we can expect an empty map
+          # at the end if there are no new tags
+          tags.delete key
+
+        else
+          # this means a tag was deleted
+          tags_changed = true
+        end
+      end
+      # if there are left-over tags then they are new and will have to
+      # be added.
+      tags_changed |= !tags.empty?
+      RelationTag.where(:relation_id => id).delete_all
+      self.tags.each do |k, v|
+        tag = RelationTag.new
+        tag.relation_id = id
+        tag.k = k
+        tag.v = v
+        tag.save!
+      end
 
-      RelationMember.delete_all(['id = ?', self.id])
+      # same pattern as before, but this time we're collecting the
+      # changed members in an array, as the bounding box updates for
+      # elements are per-element, not blanked on/off like for tags.
+      changed_members = []
+      members = self.members.clone
+      relation_members.each do |old_member|
+        key = [old_member.member_type, old_member.member_id, old_member.member_role]
+        i = members.index key
+        if i.nil?
+          changed_members << key
+        else
+          members.delete_at i
+        end
+      end
+      # any remaining members must be new additions
+      changed_members += members
 
-      members.each do |n|
-	mem = RelationMember.new
-	mem.id = self.id
-	mem.member_type = n[0];
-	mem.member_id = n[1];
-	mem.member_role = n[2];
-	mem.save!
+      # update the members. first delete all the old members, as the new
+      # members may be in a different order and i don't feel like implementing
+      # a longest common subsequence algorithm to optimise this.
+      members = self.members
+      RelationMember.where(:relation_id => id).delete_all
+      members.each_with_index do |m, i|
+        mem = RelationMember.new
+        mem.relation_id = id
+        mem.sequence_id = i
+        mem.member_type = m[0]
+        mem.member_id = m[1]
+        mem.member_role = m[2]
+        mem.save!
       end
 
       old_relation = OldRelation.from_relation(self)
       old_relation.timestamp = t
       old_relation.save_with_dependencies!
-    end
-  end
 
-  def preconditions_ok?
-    self.members.each do |m|
-      if (m[0] == "node")
-        n = Node.find(:first, :conditions => ["id = ?", m[1]])
-        unless n and n.visible 
-          return false
-        end
-      elsif (m[0] == "way")
-        w = Way.find(:first, :conditions => ["id = ?", m[1]])
-        unless w and w.visible and w.preconditions_ok?
-          return false
-        end
-      elsif (m[0] == "relation")
-        e = Relation.find(:first, :conditions => ["id = ?", m[1]])
-        unless e and e.visible and e.preconditions_ok?
-          return false
-        end
-      else
-        return false
+      # update the bbox of the changeset and save it too.
+      # discussion on the mailing list gave the following definition for
+      # the bounding box update procedure of a relation:
+      #
+      # adding or removing nodes or ways from a relation causes them to be
+      # added to the changeset bounding box. adding a relation member or
+      # changing tag values causes all node and way members to be added to the
+      # bounding box. this is similar to how the map call does things and is
+      # reasonable on the assumption that adding or removing members doesn't
+      # materially change the rest of the relation.
+      any_relations =
+        changed_members.collect { |type, _id, _role| type == "Relation" }
+                       .inject(false) { |acc, elem| acc || elem }
+
+      # if the relation is being deleted tags_changed will be true and members empty
+      # so we need to use changed_members to create a correct bounding box
+      update_members = if visible && (tags_changed || any_relations)
+                         # add all non-relation bounding boxes to the changeset
+                         # FIXME: check for tag changes along with element deletions and
+                         # make sure that the deleted element's bounding box is hit.
+                         self.members
+                       else
+                         changed_members
+                       end
+      update_members.each do |type, id, _role|
+        update_changeset_element(type, id) if type != "Relation"
       end
+
+      # tell the changeset we updated one element only
+      changeset.add_changes! 1
+
+      # save the (maybe updated) changeset bounding box
+      changeset.save!
     end
-    return true
-  rescue
-    return false
   end
-
 end