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

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

diff --git a/app/models/relation.rb b/app/models/relation.rb
index f74a149ec0b28c0de7b518afb6c572903a13bc00..d2602f497270c455d3d3a4b44062670eaac689bd 100644 (file)
--- a/app/models/relation.rb
+++ b/app/models/relation.rb
@@ -1,48 +1,82 @@
 class Relation < ActiveRecord::Base
   require 'xml/libxml'
   
 class Relation < ActiveRecord::Base
   require 'xml/libxml'
   

-  belongs_to :user
+  include ConsistencyValidations
+  
+  set_table_name 'current_relations'

 
 

-  has_many :relation_members, :foreign_key => 'id'
-  has_many :relation_tags, :foreign_key => 'id'
+  belongs_to :changeset

 
   has_many :old_relations, :foreign_key => 'id', :order => 'version'
 
 
   has_many :old_relations, :foreign_key => 'id', :order => 'version'
 

-  set_table_name 'current_relations'
+  has_many :relation_members, :foreign_key => 'id', :order => 'sequence_id'
+  has_many :relation_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 :timestamp,:version,  :changeset_id 
+  validates_uniqueness_of :id
+  validates_inclusion_of :visible, :in => [ true, false ]
+  validates_numericality_of :id, :on => :update, :integer_only => true
+  validates_numericality_of :changeset_id, :version, :integer_only => true
+  validates_associated :changeset
+  
+  TYPES = ["node", "way", "relation"]

 
   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 = p.parse
 

-      relation = Relation.new
-

       doc.find('//osm/relation').each do |pt|
       doc.find('//osm/relation').each do |pt|

-        if !create and pt['id'] != '0'
-          relation.id = pt['id'].to_i
-        end
+        return Relation.from_xml_node(pt, create)
+      end
+    rescue LibXML::XML::Error, ArgumentError => ex
+      raise OSM::APIBadXMLError.new("relation", xml, ex.message)
+    end
+  end

 
 

-        if create
-          relation.timestamp = Time.now
-          relation.visible = true
-        else
-          if pt['timestamp']
-            relation.timestamp = Time.parse(pt['timestamp'])
-          end
-        end
+  def self.from_xml_node(pt, create=false)
+    relation = Relation.new

 
 

-        pt.find('tag').each do |tag|
-          relation.add_tag_keyval(tag['k'], tag['v'])
-        end
+    if !create and pt['id'] != '0'
+      relation.id = pt['id'].to_i
+    end

 
 

-        pt.find('member').each do |member|
-          relation.add_member(member['type'], member['ref'], member['role'])
-        end
+    raise OSM::APIBadXMLError.new("relation", pt, "You are missing the required changeset in the relation") if pt['changeset'].nil?
+    relation.changeset_id = pt['changeset']
+
+    # The follow block does not need to be executed because they are dealt with 
+    # in create_with_history, update_from and delete_with_history
+    if create
+      relation.timestamp = Time.now.getutc
+      relation.visible = true
+      relation.version = 0
+    else
+      if pt['timestamp']
+        relation.timestamp = Time.parse(pt['timestamp'])

       end
       end

-    rescue
-      relation = nil
+      relation.version = pt['version']
+    end
+
+    pt.find('tag').each do |tag|
+      relation.add_tag_keyval(tag['k'], tag['v'])
+    end
+
+    pt.find('member').each do |member|
+      #member_type = 
+      logger.debug "each member"
+      raise OSM::APIBadXMLError.new("relation", pt, "The #{member['type']} is not allowed only, #{TYPES.inspect} allowed") unless TYPES.include? member['type']
+      logger.debug "after raise"
+      #member_ref = member['ref']
+      #member_role
+      member['role'] ||= "" # Allow  the upload to not include this, in which case we default to an empty string.
+      logger.debug member['role']
+      relation.add_member(member['type'].classify, member['ref'], member['role'])

     end
     end

+    raise OSM::APIBadUserInput.new("Some bad xml in relation") if relation.nil?

 
     return relation
   end
 
     return relation
   end


@@ -53,23 +87,34 @@ class Relation < ActiveRecord::Base
     return doc
   end
 
     return doc
   end
 

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

     el1 = XML::Node.new 'relation'
     el1['id'] = self.id.to_s
     el1['visible'] = self.visible.to_s
     el1['timestamp'] = self.timestamp.xmlschema
     el1 = XML::Node.new 'relation'
     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

 
 

-    user_display_name_cache = {} if user_display_name_cache.nil?
-    
-    if user_display_name_cache and user_display_name_cache.key?(self.user_id)
+    if changeset_cache.key?(self.changeset_id)

       # use the cache if available
       # use the cache if available

-    elsif self.user.data_public?
-      user_display_name_cache[self.user_id] = self.user.display_name

     else
     else

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

     end
 
     end
 

-    el1['user'] = user_display_name_cache[self.user_id] unless user_display_name_cache[self.user_id].nil?
+    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

 
     self.relation_members.each do |member|
       p=0
 
     self.relation_members.each do |member|
       p=0


@@ -86,7 +131,7 @@ class Relation < ActiveRecord::Base
       #end
       if p
         e = XML::Node.new 'member'
       #end
       if p
         e = XML::Node.new 'member'

-        e['type'] = member.member_type
+        e['type'] = member.member_type.downcase

         e['ref'] = member.member_id.to_s 
         e['role'] = member.member_role
         el1 << e
         e['ref'] = member.member_id.to_s 
         e['role'] = member.member_role
         el1 << e


@@ -102,23 +147,53 @@ class Relation < ActiveRecord::Base
     return el1
   end 
 
     return el1
   end 
 

+  def self.find_for_nodes(ids, options = {})
+    if ids.empty?
+      return []
+    else
+      self.with_scope(:find => { :joins => "INNER JOIN current_relation_members ON current_relation_members.id = current_relations.id", :conditions => "current_relation_members.member_type = 'Node' AND current_relation_members.member_id IN (#{ids.join(',')})" }) do
+        return self.find(:all, options)
+      end
+    end
+  end
+
+  def self.find_for_ways(ids, options = {})
+    if ids.empty?
+      return []
+    else
+      self.with_scope(:find => { :joins => "INNER JOIN current_relation_members ON current_relation_members.id = current_relations.id", :conditions => "current_relation_members.member_type = 'Way' AND current_relation_members.member_id IN (#{ids.join(',')})" }) do
+        return self.find(:all, options)
+      end
+    end
+  end
+
+  def self.find_for_relations(ids, options = {})
+    if ids.empty?
+      return []
+    else
+      self.with_scope(:find => { :joins => "INNER JOIN current_relation_members ON current_relation_members.id = current_relations.id", :conditions => "current_relation_members.member_type = 'Relation' AND current_relation_members.member_id IN (#{ids.join(',')})" }) do
+        return self.find(:all, options)
+      end
+    end
+  end
+

   # FIXME is this really needed?
   def members
     unless @members
   # 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 = Array.new
+      self.relation_members.each do |member|
+        @members += [[member.member_type,member.member_id,member.member_role]]
+      end

     end
     @members
   end
 
   def tags
     unless @tags
     end
     @members
   end
 
   def tags
     unless @tags

-        @tags = Hash.new
-        self.relation_tags.each do |tag|
-            @tags[tag.k] = tag.v
-        end
+      @tags = Hash.new
+      self.relation_tags.each do |tag|
+        @tags[tag.k] = tag.v
+      end

     end
     @tags
   end
     end
     @tags
   end


@@ -138,76 +213,244 @@ class Relation < ActiveRecord::Base
 
   def add_tag_keyval(k, v)
     @tags = Hash.new unless @tags
 
   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("relation", self.id, k) if @tags.include? k
+

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

-  def save_with_history
-    begin
-      Relation.transaction do
-        t = Time.now
-        self.timestamp = t
-        self.save!
+  ##
+  # 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 delete_with_history!(new_relation, user)
+    unless self.visible
+      raise OSM::APIAlreadyDeletedError.new("relation", new_relation.id)
+    end

 
 

-        tags = self.tags
+    # 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
+      check_consistency(self, new_relation, user)
+      # This will check to see if this relation is used by another relation
+      rel = RelationMember.find(:first, :joins => "INNER JOIN current_relations ON current_relations.id=current_relation_members.id", :conditions => [ "visible = ? AND member_type='Relation' and member_id=? ", true, self.id ])
+      raise OSM::APIPreconditionFailedError.new("The relation #{new_relation.id} is a used in relation #{rel.id}.") unless rel.nil?
+
+      self.changeset_id = new_relation.changeset_id
+      self.tags = {}
+      self.members = []
+      self.visible = false
+      save_with_history!
+    end
+  end

 
 

-        RelationTag.delete_all(['id = ?', self.id])
+  def update_from(new_relation, user)
+    check_consistency(self, new_relation, user)
+    unless new_relation.preconditions_ok?
+      raise OSM::APIPreconditionFailedError.new("Cannot update relation #{self.id}: data or member data is invalid.")
+    end
+    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
+  
+  def create_with_history(user)
+    check_create_consistency(self, user)
+    unless self.preconditions_ok?
+      raise OSM::APIPreconditionFailedError.new("Cannot create relation: data or member data is invalid.")
+    end
+    self.version = 0
+    self.visible = true
+    save_with_history!
+  end

 
 

-        tags.each do |k,v|
-          tag = RelationTag.new
-          tag.k = k
-          tag.v = v
-          tag.id = self.id
-          tag.save!
+  def preconditions_ok?
+    # 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 => Hash.new, :way => Hash.new, :relation => Hash.new }
+    self.members.each do |m|
+      # find the hash for the element type or die
+      logger.debug m[0]
+      hash = elements[m[0].downcase.to_sym] or return false
+      # unless its in the cache already
+      unless hash.key? m[1]
+        # use reflection to look up the appropriate class
+        model = Kernel.const_get(m[0].capitalize)
+        # get the element with that ID
+        element = model.find(m[1])
+
+        # and check that it is OK to use.
+        unless element and element.visible? and element.preconditions_ok?
+          return false

         end
         end

+        hash[m[1]] = true
+      end
+    end

 
 

-        members = self.members
-
-        RelationMember.delete_all(['id = ?', self.id])
+    return true
+  rescue
+    return false
+  end

 
 

-        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!
-        end
+  # Temporary method to match interface to nodes
+  def tags_as_hash
+    return self.tags
+  end

 
 

-        old_relation = OldRelation.from_relation(self)
-        old_relation.timestamp = t
-        old_relation.save_with_dependencies!
+  ##
+  # 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)
+    self.members.map! do |type, id, role|
+      old_id = id.to_i
+      if old_id < 0
+        new_id = id_map[type.downcase.to_sym][old_id]
+        raise "invalid placeholder" if new_id.nil?
+        [type, new_id, role]
+      else
+        [type, id, role]

       end
       end

-
-      return true
-    rescue Exception => ex
-      return nil

     end
   end
 
     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
+  private
+  
+  def save_with_history!
+    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
+
+      t = Time.now.getutc
+      self.version += 1
+      self.timestamp = t
+      self.save!
+
+      tags = self.tags.clone
+      self.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.has_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

-      elsif (m[0] == "way")
-        w = Way.find(:first, :conditions => ["id = ?", m[1]])
-        unless w and w.visible and w.preconditions_ok?
-          return false
+      end
+      # if there are left-over tags then they are new and will have to
+      # be added.
+      tags_changed |= (not tags.empty?)
+      RelationTag.delete_all(:id => self.id)
+      self.tags.each do |k,v|
+        tag = RelationTag.new
+        tag.k = k
+        tag.v = v
+        tag.id = self.id
+        tag.save!
+      end
+      
+      # 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 = Array.new
+      members = Hash.new
+      self.members.each do |m|
+        # should be: h[[m.id, m.type]] = m.role, but someone prefers arrays
+        members[[m[1], m[0]]] = m[2]
+      end
+      relation_members.each do |old_member|
+        key = [old_member.member_id.to_s, old_member.member_type]
+        if members.has_key? key
+          members.delete key
+        else
+          changed_members << key

         end
         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
+      # any remaining members must be new additions
+      changed_members += members.keys
+
+      # 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.delete_all(:id => self.id)
+      members.each_with_index do |m,i|
+        mem = RelationMember.new
+        mem.id = [self.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!
+
+      # 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 { |id,type| type == "relation" }.
+        inject(false) { |b,s| b or s }
+
+      if tags_changed or 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.each do |type, id, role|
+          if type != "Relation"
+            update_changeset_element(type, id)
+          end

         end
       else
         end
       else

-        return false
+        # add only changed members to the changeset
+        changed_members.each do |id, type|
+          if type != "Relation"
+            update_changeset_element(type, id)
+          end
+        end

       end
       end

+
+      # tell the changeset we updated one element only
+      changeset.add_changes! 1
+
+      # save the (maybe updated) changeset bounding box
+      changeset.save!

     end
     end

-    return true
-  rescue
-    return false

   end
 
 end
   end
 
 end