X-Git-Url: https://git.openstreetmap.org./rails.git/blobdiff_plain/cf304fe60f05f48251a480d19ce3ea9440f8a10e..2ed84e26cdeaaa20b8f607624d65b7891fcf1fed:/app/controllers/changeset_controller.rb

diff --git a/app/controllers/changeset_controller.rb b/app/controllers/changeset_controller.rb
index 1041c7469..58bcd1020 100644
--- a/app/controllers/changeset_controller.rb
+++ b/app/controllers/changeset_controller.rb
@@ -3,9 +3,16 @@
 class ChangesetController < ApplicationController
   require 'xml/libxml'
 
-  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, :include, :close]
+  before_filter :check_write_availability, :only => [:create, :update, :delete, :upload, :include]
+  before_filter :check_read_availability, :except => [:create, :update, :delete, :upload, :download, :query]
+  after_filter :compress_output
+
+  # Help methods for checking boundary sanity and area size
+  include MapBoundary
+
+  # Helper methods for checking consistency
+  include ConsistencyValidations
 
   # Create a changeset from XML.
   def create
@@ -23,4 +30,352 @@ class ChangesetController < ApplicationController
       render :nothing => true, :status => :method_not_allowed
     end
   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
+  
+  ##
+  # marks a changeset as closed. this may be called multiple times
+  # on the same changeset, so is idempotent.
+  def close 
+    unless request.put?
+      render :nothing => true, :status => :method_not_allowed
+      return
+    end
+    
+    changeset = Changeset.find(params[:id])    
+    check_changeset_consistency(changeset, @user)
+
+    # to close the changeset, we'll just set its closed_at time to
+    # now. this might not be enough if there are concurrency issues, 
+    # but we'll have to wait and see.
+    changeset.set_closed_time_now
+
+    changeset.save!
+    render :nothing => true
+  rescue ActiveRecord::RecordNotFound
+    render :nothing => true, :status => :not_found
+  rescue OSM::APIError => ex
+    render ex.render_opts
+  end
+
+  ##
+  # 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 expand_bbox
+    # 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_changeset_consistency(cs, @user)
+
+      # 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 * GeoRecord::SCALE
+        lat << n['lat'].to_f * GeoRecord::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
+    end
+
+  rescue ActiveRecord::RecordNotFound
+    render :nothing => true, :status => :not_found
+  rescue OSM::APIError => ex
+    render ex.render_opts
+  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])
+    check_changeset_consistency(changeset, @user)
+    
+    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
+
+  ##
+  # query changesets by bounding box, time, user or open/closed status.
+  def query
+    # create the conditions that the user asked for. some or all of
+    # these may be nil.
+    conditions = conditions_bbox(params['bbox'])
+    conditions = cond_merge conditions, conditions_user(params['user'])
+    conditions = cond_merge conditions, conditions_time(params['time'])
+    conditions = cond_merge conditions, conditions_open(params['open'])
+
+    # create the results document
+    results = OSM::API.new.get_xml_doc
+
+    # add all matching changesets to the XML results document
+    Changeset.find(:all, 
+                   :conditions => conditions, 
+                   :limit => 100,
+                   :order => 'created_at desc').each do |cs|
+      results.root << cs.to_xml_node
+    end
+
+    render :text => results.to_s, :content_type => "text/xml"
+
+  rescue ActiveRecord::RecordNotFound
+    render :nothing => true, :status => :not_found
+  rescue OSM::APIError => ex
+    render ex.render_opts
+  end
+  
+  ##
+  # updates a changeset's tags. none of the changeset's attributes are
+  # user-modifiable, so they will be ignored.
+  #
+  # changesets are not (yet?) versioned, so we don't have to deal with
+  # history tables here. changesets are locked to a single user, however.
+  #
+  # after succesful update, returns the XML of the changeset.
+  def update
+    # request *must* be a PUT.
+    unless request.put?
+      render :nothing => true, :status => :method_not_allowed
+      return
+    end
+    
+    changeset = Changeset.find(params[:id])
+    new_changeset = Changeset.from_xml(request.raw_post)
+
+    unless new_changeset.nil?
+      check_changeset_consistency(changeset, @user)
+      changeset.update_from(new_changeset, @user)
+      render :text => changeset.to_xml, :mime_type => "text/xml"
+    else
+      
+      render :nothing => true, :status => :bad_request
+    end
+      
+  rescue ActiveRecord::RecordNotFound
+    render :nothing => true, :status => :not_found
+  rescue OSM::APIError => ex
+    render ex.render_opts
+  end
+
+private
+  #------------------------------------------------------------
+  # utility functions below.
+  #------------------------------------------------------------  
+
+  ##
+  # merge two conditions
+  def cond_merge(a, b)
+    if a and b
+      a_str = a.shift
+      b_str = b.shift
+      return [ a_str + " and " + b_str ] + a + b
+    elsif a 
+      return a
+    else b
+      return b
+    end
+  end
+
+  ##
+  # if a bounding box was specified then parse it and do some sanity 
+  # checks. this is mostly the same as the map call, but without the 
+  # area restriction.
+  def conditions_bbox(bbox)
+    unless bbox.nil?
+      raise OSM::APIBadUserInput.new("Bounding box should be min_lon,min_lat,max_lon,max_lat") unless bbox.count(',') == 3
+      bbox = sanitise_boundaries(bbox.split(/,/))
+      raise OSM::APIBadUserInput.new("Minimum longitude should be less than maximum.") unless bbox[0] <= bbox[2]
+      raise OSM::APIBadUserInput.new("Minimum latitude should be less than maximum.") unless bbox[1] <= bbox[3]
+      return ['min_lon < ? and max_lon > ? and min_lat < ? and max_lat > ?',
+              bbox[2] * GeoRecord::SCALE, bbox[0] * GeoRecord::SCALE, bbox[3]* GeoRecord::SCALE, bbox[1] * GeoRecord::SCALE]
+    else
+      return nil
+    end
+  end
+
+  ##
+  # restrict changesets to those by a particular user
+  def conditions_user(user)
+    unless user.nil?
+      # user input checking, we don't have any UIDs < 1
+      raise OSM::APIBadUserInput.new("invalid user ID") if user.to_i < 1
+
+      u = User.find(user.to_i)
+      # should be able to get changesets of public users only, or 
+      # our own changesets regardless of public-ness.
+      unless u.data_public?
+        # get optional user auth stuff so that users can see their own
+        # changesets if they're non-public
+        setup_user_auth
+        
+        raise OSM::APINotFoundError if @user.nil? or @user.id != u.id
+      end
+      return ['user_id = ?', u.id]
+    else
+      return nil
+    end
+  end
+
+  ##
+  # restrict changes to those during a particular time period
+  def conditions_time(time) 
+    unless time.nil?
+      # if there is a range, i.e: comma separated, then the first is 
+      # low, second is high - same as with bounding boxes.
+      if time.count(',') == 1
+        # check that we actually have 2 elements in the array
+        times = time.split(/,/)
+        raise OSM::APIBadUserInput.new("bad time range") if times.size != 2 
+
+        from, to = times.collect { |t| DateTime.parse(t) }
+        return ['closed_at >= ? and created_at <= ?', from, to]
+      else
+        # if there is no comma, assume its a lower limit on time
+        return ['closed_at >= ?', DateTime.parse(time)]
+      end
+    else
+      return nil
+    end
+    # stupid DateTime seems to throw both of these for bad parsing, so
+    # we have to catch both and ensure the correct code path is taken.
+  rescue ArgumentError => ex
+    raise OSM::APIBadUserInput.new(ex.message.to_s)
+  rescue RuntimeError => ex
+    raise OSM::APIBadUserInput.new(ex.message.to_s)
+  end
+
+  ##
+  # restrict changes to those which are open
+  def conditions_open(open)
+    return open.nil? ? nil : ['closed_at >= ?', DateTime.now]
+  end
+
 end