X-Git-Url: https://git.openstreetmap.org./rails.git/blobdiff_plain/8c5638d6968be3286414f04b8dee2261ada84e76..32b280eb8dfd11d03646cb89c339d2b938f06a6e:/app/controllers/changeset_controller.rb

diff --git a/app/controllers/changeset_controller.rb b/app/controllers/changeset_controller.rb
index 1041c7469..7ac4eb91a 100644
--- a/app/controllers/changeset_controller.rb
+++ b/app/controllers/changeset_controller.rb
@@ -2,10 +2,12 @@
 
 class ChangesetController < ApplicationController
   require 'xml/libxml'
+  require 'diff_reader'
 
-  before_filter :authorize, :only => [:create, :update, :delete]
-  before_filter :check_write_availability, :only => [:create, :update, :delete]
-  before_filter :check_read_availability, :except => [:create, :update, :delete]
+  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]
+  after_filter :compress_output
 
   # Create a changeset from XML.
   def create
@@ -23,4 +25,158 @@ class ChangesetController < ApplicationController
       render :nothing => true, :status => :method_not_allowed
     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])
+      render :text => changeset.to_xml.to_s, :content_type => "text/xml"
+    rescue ActiveRecord::RecordNotFound
+      render :nothing => true, :status => :not_found
+    end
+  end
+  
+  def close 
+    begin
+      unless request.put?
+        render :nothing => true, :status => :method_not_allowed
+        return
+      end
+      changeset = Changeset.find(params[:id])
+      changeset.open = false
+      changeset.save!
+      render :nothing => true
+    rescue ActiveRecord::RecordNotFound
+      render :nothing => true, :status => :not_found
+    end
+  end
+
+  ##
+  # 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
+
+    changeset = Changeset.find(params[:id])
+    
+    diff_reader = DiffReader.new(request.raw_post, changeset)
+    Changeset.transaction do
+      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
+
+  ##
+  # 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 => 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