X-Git-Url: https://git.openstreetmap.org/rails.git/blobdiff_plain/6f1aad0d0431703cd834e2b29becf20fcbac4dab..c760891d634eff7b95b98d2bd88fc0d5535220bb:/app/controllers/changeset_controller.rb?ds=inline

diff --git a/app/controllers/changeset_controller.rb b/app/controllers/changeset_controller.rb
index 9994a6b1e..9152df816 100644
--- a/app/controllers/changeset_controller.rb
+++ b/app/controllers/changeset_controller.rb
@@ -2,10 +2,11 @@
 
 class ChangesetController < ApplicationController
   require 'xml/libxml'
+  require 'diff_reader'
 
-  before_filter :authorize, :only => [:create, :update, :delete, :upload]
-  before_filter :check_write_availability, :only => [:create, :update, :delete, :upload]
-  before_filter :check_read_availability, :except => [:create, :update, :delete, :upload]
+  before_filter :authorize, :only => [:create, :update, :delete, :upload, :include]
+  before_filter :check_write_availability, :only => [:create, :update, :delete, :upload, :include]
+  before_filter :check_read_availability, :except => [:create, :update, :delete, :upload, :download]
   after_filter :compress_output
 
   # Create a changeset from XML.
@@ -25,27 +26,6 @@ class ChangesetController < ApplicationController
     end
   end
 
-  def create_prim(ids, prim, nd)
-    prim.version = 0
-    prim.user_id = @user.id
-    prim.visible = true
-    prim.save_with_history!
-
-    ids[nd['id'].to_i] = prim.id
-  end
-
-  def fix_way(w, node_ids)
-    w.nds = w.instance_eval { @nds }.
-      map { |nd| node_ids[nd] || nd }
-    return w
-  end
-
-  def fix_rel(r, ids)
-    r.members = r.instance_eval { @members }.
-      map { |memb| [memb[0], ids[memb[0]][memb[1].to_i] || memb[1], memb[2]] }
-    return r
-  end
-  
   def read
     begin
       changeset = Changeset.find(params[:id])
@@ -57,132 +37,191 @@ class ChangesetController < ApplicationController
   
   def close 
     begin
-      if not request.put?
+      unless request.put?
         render :nothing => true, :status => :method_not_allowed
         return
       end
+
       changeset = Changeset.find(params[:id])
+
+      unless @user.id == changeset.user_id 
+        raise OSM::APIUserChangesetMismatchError 
+      end
+
       changeset.open = false
-      changeset.save
+      changeset.save!
       render :nothing => true
     rescue ActiveRecord::RecordNotFound
       render :nothing => true, :status => :not_found
     end
   end
 
-  def upload
-    if not request.put?
+  ##
+  # insert a (set of) points into a changeset bounding box. this can only
+  # increase the size of the bounding box. this is a hint that clients can
+  # set either before uploading a large number of changes, or changes that
+  # the client (but not the server) knows will affect areas further away.
+  def include
+    # only allow POST requests, because although this method is
+    # idempotent, there is no "document" to PUT really...
+    if request.post?
+      cs = Changeset.find(params[:id])
+
+      # check user credentials - only the user who opened a changeset
+      # may alter it.
+      unless @user.id == changeset.user_id 
+        raise OSM::APIUserChangesetMismatchError 
+      end
+
+      # keep an array of lons and lats
+      lon = Array.new
+      lat = Array.new
+
+      # the request is in pseudo-osm format... this is kind-of an
+      # abuse, maybe should change to some other format?
+      doc = XML::Parser.string(request.raw_post).parse
+      doc.find("//osm/node").each do |n|
+        lon << n['lon'].to_f * SCALE
+        lat << n['lat'].to_f * SCALE
+      end
+
+      # add the existing bounding box to the lon-lat array
+      lon << cs.min_lon unless cs.min_lon.nil?
+      lat << cs.min_lat unless cs.min_lat.nil?
+      lon << cs.max_lon unless cs.max_lon.nil?
+      lat << cs.max_lat unless cs.max_lat.nil?
+
+      # collapse the arrays to minimum and maximum
+      cs.min_lon, cs.min_lat, cs.max_lon, cs.max_lat = 
+        lon.min, lat.min, lon.max, lat.max
+
+      # save the larger bounding box and return the changeset, which
+      # will include the bigger bounding box.
+      cs.save!
+      render :text => cs.to_xml.to_s, :content_type => "text/xml"
+
+    else
       render :nothing => true, :status => :method_not_allowed
-      return
     end
 
-    # FIXME: this should really be done without loading the whole XML file
-    # into memory.
-    p = XML::Parser.new
-    p.string  = request.raw_post
-    doc = p.parse
-
-    node_ids, way_ids, rel_ids = {}, {}, {}
-    ids = {"node"=>node_ids, "way"=>way_ids, "relation"=>rel_ids}
+  rescue ActiveRecord::RecordNotFound
+    render :nothing => true, :status => :not_found
+  rescue OSM::APIError => ex
+    render ex.render_opts
+  end
 
-    res = XML::Document.new
-    res.encoding = 'UTF-8'
-    root = XML::Node.new 'osm'
-    root['version'] = '0.6'
-    root['creator'] = 'OpenStreetMap.org'
-    res.root = root
+  ##
+  # Upload a diff in a single transaction.
+  #
+  # This means that each change within the diff must succeed, i.e: that
+  # each version number mentioned is still current. Otherwise the entire
+  # transaction *must* be rolled back.
+  #
+  # Furthermore, each element in the diff can only reference the current
+  # changeset.
+  #
+  # Returns: a diffResult document, as described in 
+  # http://wiki.openstreetmap.org/index.php/OSM_Protocol_Version_0.6
+  def upload
+    # only allow POST requests, as the upload method is most definitely
+    # not idempotent, as several uploads with placeholder IDs will have
+    # different side-effects.
+    # see http://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html#sec9.1.2
+    unless request.post?
+      render :nothing => true, :status => :method_not_allowed
+      return
+    end
 
-    root << XML::Node.new_comment(" Warning: this is a 0.6 result document, " +
-      "not a normal OSM file. ")
+    # access control - only the user who created a changeset may
+    # upload to it.
+    unless @user.id == changeset.user_id 
+      raise OSM::APIUserChangesetMismatchError 
+    end
 
+    changeset = Changeset.find(params[:id])
+    
+    diff_reader = DiffReader.new(request.raw_post, changeset)
     Changeset.transaction do
-      doc.find('//osm/create/node').each do |nd|
-	elem = XML::Node.new 'node'
-	node = Node.from_xml_node(nd, true)
-	elem['old_id'] = nd['id']
-	create_prim node_ids, node, nd
-	elem['new_id'] = node.id.to_s
-	elem['new_version'] = node.version.to_s
-	root << elem
-      end
-      doc.find('//osm/create/way').each do |nd|
-	elem = XML::Node.new 'way'
-	way = Way.from_xml_node(nd, true)
-	elem['old_id'] = nd['id']
-	fix_way(way, node_ids)
-	raise OSM::APIPreconditionFailedError.new if !way.preconditions_ok?
-	create_prim way_ids, way, nd
-	elem['new_id'] = way.id.to_s
-	elem['new_version'] = way.version.to_s
-	root << elem
-      end
-      doc.find('//osm/create/relation').each do |nd|
-	elem = XML::Node.new 'relation'
-	relation = Relation.from_xml_node(nd, true)
-	elem['old_id'] = nd['id']
-	fix_rel(relation, ids)
-	raise OSM::APIPreconditionFailedError.new if !relation.preconditions_ok?
-	create_prim rel_ids, relation, nd
-	elem['new_id'] = relation.id.to_s
-	elem['new_version'] = relation.version.to_s
-	root << elem
-      end
-
-      doc.find('//osm/modify/relation').each do |nd|
-	elem = XML::Node.new 'relation'
-	new_relation = Relation.from_xml_node(nd)
-	relation = Relation.find(new_relation.id)
-	relation.update_from new_relation, @user
-	elem['old_id'] = elem['new_id'] = relation.id.to_s
-	elem['new_version'] = relation.version.to_s
-	root << elem
-      end
-      doc.find('//osm/modify/way').each do |nd|
-	elem = XML::Node.new 'way'
-	new_way = Way.from_xml_node(nd)
-	way = Way.find(new_way.id)
-	way.update_from new_way, @user
-	elem['old_id'] = elem['new_id'] = way.id.to_s
-	elem['new_version'] = way.version.to_s
-	root << elem
-      end
-      doc.find('//osm/modify/node').each do |nd|
-	elem = XML::Node.new 'node'
-	new_node = Node.from_xml_node(nd)
-	node = Node.find(new_node.id)
-	node.update_from new_node, @user
-	elem['old_id'] = elem['new_id'] = node.id.to_s
-	elem['new_version'] = node.version.to_s
-	root << elem
-      end
+      result = diff_reader.commit
+      render :text => result.to_s, :content_type => "text/xml"
+    end
+    
+  rescue ActiveRecord::RecordNotFound
+    render :nothing => true, :status => :not_found
+  rescue OSM::APIError => ex
+    render ex.render_opts
+  end
 
-      doc.find('//osm/delete/relation').each do |nd|
-	elem = XML::Node.new 'relation'
-	relation = Relation.find(nd['id'])
-	relation.delete_with_history(@user)
-	elem['old_id'] = elem['new_id'] = relation.id.to_s
-	elem['new_version'] = relation.version.to_s
-	root << elem
-      end
-      doc.find('//osm/delete/way').each do |nd|
-	elem = XML::Node.new 'way'
-	way = Way.find(nd['id'])
-	way.delete_with_relations_and_history(@user)
-	elem['old_id'] = elem['new_id'] = way.id.to_s
-	elem['new_version'] = way.version.to_s
-	root << elem
-      end
-      doc.find('//osm/delete/node').each do |nd|
-	elem = XML::Node.new 'node'
-	new_node = Node.from_xml_node(nd)
-	node = Node.find(nd['id'])
-	node.delete_with_history(@user)
-	elem['old_id'] = elem['new_id'] = node.id.to_s
-	elem['new_version'] = node.version.to_s
-	root << elem
+  ##
+  # download the changeset as an osmChange document.
+  #
+  # to make it easier to revert diffs it would be better if the osmChange
+  # format were reversible, i.e: contained both old and new versions of 
+  # modified elements. but it doesn't at the moment...
+  #
+  # this method cannot order the database changes fully (i.e: timestamp and
+  # version number may be too coarse) so the resulting diff may not apply
+  # to a different database. however since changesets are not atomic this 
+  # behaviour cannot be guaranteed anyway and is the result of a design
+  # choice.
+  def download
+    changeset = Changeset.find(params[:id])
+    
+    # get all the elements in the changeset and stick them in a big array.
+    elements = [changeset.old_nodes, 
+                changeset.old_ways, 
+                changeset.old_relations].flatten
+    
+    # sort the elements by timestamp and version number, as this is the 
+    # almost sensible ordering available. this would be much nicer if 
+    # global (SVN-style) versioning were used - then that would be 
+    # unambiguous.
+    elements.sort! do |a, b| 
+      if (a.timestamp == b.timestamp)
+        a.version <=> b.version
+      else
+        a.timestamp <=> b.timestamp 
       end
     end
+    
+    # create an osmChange document for the output
+    result = OSM::API.new.get_xml_doc
+    result.root.name = "osmChange"
+
+    # generate an output element for each operation. note: we avoid looking
+    # at the history because it is simpler - but it would be more correct to 
+    # check these assertions.
+    elements.each do |elt|
+      result.root <<
+        if (elt.version == 1) 
+          # first version, so it must be newly-created.
+          created = XML::Node.new "create"
+          created << elt.to_xml_node
+        else
+          # get the previous version from the element history
+          prev_elt = elt.class.find(:first, :conditions => 
+                                    ['id = ? and version = ?',
+                                     elt.id, elt.version])
+          unless elt.visible
+            # if the element isn't visible then it must have been deleted, so
+            # output the *previous* XML
+            deleted = XML::Node.new "delete"
+            deleted << prev_elt.to_xml_node
+          else
+            # must be a modify, for which we don't need the previous version
+            # yet...
+            modified = XML::Node.new "modify"
+            modified << elt.to_xml_node
+          end
+        end
+    end
 
-    render :text => res.to_s, :content_type => "text/xml"
+    render :text => result.to_s, :content_type => "text/xml"
+            
+  rescue ActiveRecord::RecordNotFound
+    render :nothing => true, :status => :not_found
+  rescue OSM::APIError => ex
+    render ex.render_opts
   end
+
 end