]> git.openstreetmap.org Git - rails.git/blobdiff - app/controllers/amf_controller.rb
emit last-modified headers on nodes and ways
[rails.git] / app / controllers / amf_controller.rb
index 38c567734ff6a5905ef2e23bfeee7d5828cc0308..c8377991a9a26cb2a32ec638ffece4366804cfef 100644 (file)
 class AmfController < ApplicationController
   require 'stringio'
 
-  # Still to do:
-  # - all db interaction
-  # - user authentication
-  # - (also pass lat/lon through from view tab to edit tab)
-
-# to log:
-# RAILS_DEFAULT_LOGGER.error("Args: #{args[0]}, #{args[1]}, #{args[2]}, #{args[3]}")
+  session :off
+  before_filter :check_write_availability
 
+  # AMF controller for Potlatch
+  # ---------------------------
+  # All interaction between Potlatch (as a .SWF application) and the 
+  # OSM database takes place using this controller. Messages are 
+  # encoded in the Actionscript Message Format (AMF).
+  #
+  # Public domain. Set your tab width to 4 to read this document. :)
+  # editions Systeme D / Richard Fairhurst 2004-2008
+  
+  # to trap errors (getway_old,putway,putpoi,deleteway only):
+  #   return(-1,"message")             <-- just puts up a dialogue
+  #   return(-2,"message")             <-- also asks the user to e-mail me
+  # to log:
+  #   RAILS_DEFAULT_LOGGER.error("Args: #{args[0]}, #{args[1]}, #{args[2]}, #{args[3]}")
 
   # ====================================================================
   # Main AMF handler
-  
+
   # ---- talk  process AMF request
 
   def talk
-       req=StringIO.new(request.raw_post)      # Get POST data as request
-       req.read(2)                                                     # Skip version indicator and client ID
-       results={}                                                      # Results of each body
-
-       # -------------
-       # Parse request
-
-       headers=getint(req)                                     # Read number of headers
-       for i in (1..headers)                           # Read each header
-               name=getstring(req)                             #  |
-               req.getc                                                #  | skip boolean
-               value=getvalue(req)                             #  |
-               header["name"]=value                    #  |
-       end
+    req=StringIO.new(request.raw_post+0.chr)   # Get POST data as request
+                                                                                       # (cf http://www.ruby-forum.com/topic/122163)
+    req.read(2)                                                                        # Skip version indicator and client ID
+    results={}                                                                 # Results of each body
+    renumberednodes={}                                                 # Shared across repeated putways
 
-       bodies=getint(req)                                      # Read number of bodies
-       for i in (1..bodies)                            # Read each body
-               message=getstring(req)                  #  | get message name
-               index=getstring(req)                    #  | get index in response sequence
-               bytes=getlong(req)                              #  | get total size in bytes
-               args=getvalue(req)                              #  | get response (probably an array)
-       
-               case message
-                       when 'getpresets';      results[index]=putdata(index,getpresets)
-                       when 'whichways';       results[index]=putdata(index,whichways(args))
-                       when 'getway';          results[index]=putdata(index,getway(args))
-                       when 'putway';          results[index]=putdata(index,putway(args))
-                       when 'deleteway';       results[index]=putdata(index,deleteway(args))
-               end
-       end
+    # -------------
+    # Parse request
 
-       # ------------------
-       # Write out response
+    headers=getint(req)                                        # Read number of headers
 
-       response.headers["Content-Type"]="application/x-amf"
-       a,b=results.length.divmod(256)
-       ans=0.chr+0.chr+0.chr+0.chr+a.chr+b.chr
-       results.each do |k,v|
-               ans+=v
-       end
-       render :text=>ans
+    headers.times do                               # Read each header
+      name=getstring(req)                              #  |
+      req.getc                                         #  | skip boolean
+      value=getvalue(req)                              #  |
+      header["name"]=value                             #  |
+    end
 
-  end
+    bodies=getint(req)                                 # Read number of bodies
+    bodies.times do                                    # Read each body
+      message=getstring(req)                   #  | get message name
+      index=getstring(req)                             #  | get index in response sequence
+      bytes=getlong(req)                               #  | get total size in bytes
+      args=getvalue(req)                               #  | get response (probably an array)
 
+      case message
+                 when 'getpresets';            results[index]=putdata(index,getpresets)
+                 when 'whichways';                     results[index]=putdata(index,whichways(args))
+                 when 'whichways_deleted';     results[index]=putdata(index,whichways_deleted(args))
+                 when 'getway';                        results[index]=putdata(index,getway(args))
+                 when 'getway_old';            results[index]=putdata(index,getway_old(args))
+                 when 'getway_history';        results[index]=putdata(index,getway_history(args))
+                 when 'putway';                        r=putway(args,renumberednodes)
+                                                                       renumberednodes=r[3]
+                                                                       results[index]=putdata(index,r)
+                 when 'deleteway';                     results[index]=putdata(index,deleteway(args))
+                 when 'putpoi';                        results[index]=putdata(index,putpoi(args))
+                 when 'getpoi';                        results[index]=putdata(index,getpoi(args))
+      end
+    end
 
-       # ====================================================================
-       # Remote calls
-
-       def getpresets
-               presets={}
-               presetmenus={}; presetmenus['point']=[]; presetmenus['way']=[]
-               presetnames={}; presetnames['point']={}; presetnames['way']={}
-               presettype=''
-               presetcategory=''
-               
-               File.open("config/potlatch/presets.txt") do |file|
-                       file.each_line {|line|
-                               t=line.chomp
-                               if (t=~/(\w+)\/(\w+)/) then
-                                       presettype=$1
-                                       presetcategory=$2
-                                       presetmenus[presettype].push(presetcategory)
-                                       presetnames[presettype][presetcategory]=["(no preset)"]
-                               elsif (t=~/^(.+):\s?(.+)$/) then
-                                       pre=$1; kv=$2
-                                       presetnames[presettype][presetcategory].push(pre)
-                                       presets[pre]={}
-                                       kv.split(',').each {|a|
-                                               if (a=~/^(.+)=(.*)$/) then presets[pre][$1]=$2 end
-                                       }
-                               end
-                       }
+    # ------------------
+    # Write out response
+
+    RAILS_DEFAULT_LOGGER.info("  Response: start")
+    a,b=results.length.divmod(256)
+       render :content_type => "application/x-amf", :text => proc { |response, output| 
+        output.write 0.chr+0.chr+0.chr+0.chr+a.chr+b.chr
+               results.each do |k,v|
+                 output.write(v)
                end
-               [presets,presetmenus,presetnames]
-       end
+       }
+    RAILS_DEFAULT_LOGGER.info("  Response: end")
 
-       def whichways(args)
-               waylist=WaySegment.find_by_sql("SELECT DISTINCT current_way_segments.id AS wayid"+
-                        "  FROM current_way_segments,current_segments,current_nodes "+
-                        " WHERE segment_id=current_segments.id "+
-                        "   AND node_a=current_nodes.id "+
-                        "   AND (latitude  BETWEEN "+(args[1].to_f-0.01).to_s+" AND "+(args[3].to_f+0.01).to_s+") "+
-                        "   AND (longitude BETWEEN "+(args[0].to_f-0.01).to_s+" AND "+(args[2].to_f+0.01).to_s+")")
-               ways=[]
-               waylist.each {|a|
-                       ways<<a.wayid.to_i
-RAILS_DEFAULT_LOGGER.error("Found #{a.wayid.to_i}")
-               }
-               ways
-       end
-       
-       def getway(args)
-               objname,wayid,$baselong,$basey,$masterscale=args
-               wayid=wayid.to_i
-               points=[]
-               lastid=-1
-               xmin=999999; xmax=-999999
-               ymin=999999; ymax=-999999
-
-RAILS_DEFAULT_LOGGER.error("Looking for way #{wayid}")
-               nodelist=ActiveRecord::Base.connection.select_all "SELECT n1.latitude AS lat1,n1.longitude AS long1,n1.id AS id1,n1.tags as tags1, "+
-                       "                 n2.latitude AS lat2,n2.longitude AS long2,n2.id AS id2,n2.tags as tags2,segment_id "+
-                       "    FROM current_way_segments,current_segments,current_nodes AS n1,current_nodes AS n2 "+
-                       "   WHERE current_way_segments.id=#{wayid} "+
-                       "     AND segment_id=current_segments.id "+
-                       "     AND n1.id=node_a and n2.id=node_b "+
-                       "   ORDER BY sequence_id"
-               nodelist.each {|row|
-                       xs1=long2coord(row['long1'].to_f); ys1=lat2coord(row['lat1'].to_f)
-                       xs2=long2coord(row['long2'].to_f); ys2=lat2coord(row['lat2'].to_f)
-                       if (row['id1'].to_i!=lastid)
-                               points<<[xs1,ys1,row['id1'].to_i,0,tag2array(row['tags1']),0]
-                       end
-                       lastid=row['id2'].to_i
-                       points<<[xs2,ys2,row['id2'].to_i,1,tag2array(row['tags2']),row['segment_id'].to_i]
-                       xmin=[xmin,row['long1'].to_f,row['long2'].to_f].min
-                       xmax=[xmax,row['long1'].to_f,row['long2'].to_f].max
-                       ymin=[ymin,row['lat1'].to_f,row['lat2'].to_f].min
-                       ymax=[ymax,row['lat1'].to_f,row['lat2'].to_f].max
-               }
-                       
-               attributes={}
-               attrlist=ActiveRecord::Base.connection.select_all "SELECT k,v FROM current_way_tags WHERE id=#{wayid}"
-               attrlist.each {|a| attributes[a['k']]=a['v'] }
+  end
 
-RAILS_DEFAULT_LOGGER.error("Way #{wayid} #{xmin},#{xmax},#{ymin},#{ymax}")
-               [objname,points,attributes,xmin,xmax,ymin,ymax]
-       end
-       
-       def putway(args)
-               # to do
-       end
-       
-       def deleteway(args)
-               # to do
-       end
-       
-       # need support functions here too:
-       #       database support functions (readwayquery, createuniquesegments)
-       #       tag2array, array2tag
-       #       getuserid
-
-       def tag2array(a)
-               tags={}
-               a.gsub('\;','#%').split(';').each do |b|
-                       b.gsub!('#%',';')
-                       k,v=b.split('=')
-                       tags[k]=v
-               end
-               tags
-       end
-       
+  private
 
-       # ====================================================================
-       # AMF read subroutines
-       
-       # ----- getint          return two-byte integer
-       # ----- getlong         return four-byte long
-       # ----- getstring       return string with two-byte length
-       # ----- getdouble       return eight-byte double-precision float
-       # ----- getobject       return object/hash
-       # ----- getarray        return numeric array
-       
-       def getint(s)
-               s.getc*256+s.getc
-       end
-       
-       def getlong(s)
-               ((s.getc*256+s.getc)*256+s.getc)*256+s.getc
-       end
-       
-       def getstring(s)
-               len=s.getc*256+s.getc
-               s.read(len)
-       end
-       
-       def getdouble(s)
-               a=s.read(8).unpack('G')                 # G big-endian, E little-endian
-               a[0]
-       end
-       
-       def getarray(s)
-               len=getlong(s)
-               arr=[]
-               for i in (0..len-1)
-                       arr[i]=getvalue(s)
+
+  # ====================================================================
+  # Remote calls
+
+  # ----- getpresets
+  #              in:   none
+  #              does: reads tag preset menus, colours, and autocomplete config files
+  #          out:  [0] presets, [1] presetmenus, [2] presetnames,
+  #                            [3] colours, [4] casing, [5] areas, [6] autotags (all hashes)
+
+  def getpresets
+    RAILS_DEFAULT_LOGGER.info("  Message: getpresets")
+
+       # Read preset menus
+    presets={}
+    presetmenus={}; presetmenus['point']=[]; presetmenus['way']=[]; presetmenus['POI']=[]
+    presetnames={}; presetnames['point']={}; presetnames['way']={}; presetnames['POI']={}
+    presettype=''
+    presetcategory=''
+#      StringIO.open(txt) do |file|
+       File.open("#{RAILS_ROOT}/config/potlatch/presets.txt") do |file|
+      file.each_line {|line|
+        t=line.chomp
+        if (t=~/(\w+)\/(\w+)/) then
+          presettype=$1
+          presetcategory=$2
+          presetmenus[presettype].push(presetcategory)
+          presetnames[presettype][presetcategory]=["(no preset)"]
+        elsif (t=~/^(.+):\s?(.+)$/) then
+          pre=$1; kv=$2
+          presetnames[presettype][presetcategory].push(pre)
+          presets[pre]={}
+          kv.split(',').each {|a|
+            if (a=~/^(.+)=(.*)$/) then presets[pre][$1]=$2 end
+          }
+        end
+      }
+    end
+    
+    # Read colours/styling
+       colours={}; casing={}; areas={}
+       File.open("#{RAILS_ROOT}/config/potlatch/colours.txt") do |file|
+         file.each_line {|line|
+               t=line.chomp
+               if (t=~/(\w+)\s+([^\s]+)\s+([^\s]+)\s+([^\s]+)/) then
+                 tag=$1
+                 if ($2!='-') then colours[tag]=$2.hex end
+                 if ($3!='-') then casing[tag]=$3.hex end
+                 if ($4!='-') then areas[tag]=$4.hex end
                end
-               arr
+         }
        end
        
-       def getobject(s)
-               arr={}
-               while (key=getstring(s))
-                       if (key=='') then break end
-                       arr[key]=getvalue(s)
-               end
-               s.getc          # skip the 9 'end of object' value
-               arr
+       # Read auto-complete
+       autotags={}; autotags['point']={}; autotags['way']={}; autotags['POI']={};
+       File.open("#{RAILS_ROOT}/config/potlatch/autocomplete.txt") do |file|
+               file.each_line {|line|
+                       t=line.chomp
+                       if (t=~/^(\w+)\/(\w+)\s+(.+)$/) then
+                               tag=$1; type=$2; values=$3
+                               if values=='-' then autotags[type][tag]=[]
+                                                          else autotags[type][tag]=values.split(',').sort.reverse end
+                       end
+               }
        end
        
-       # ----- getvalue        parse and get value
+    [presets,presetmenus,presetnames,colours,casing,areas,autotags]
+  end
+
+  # ----- whichways
+  #              return array of ways in current bounding box
+
+  #              in:   [0] xmin, [1] ymin, [2] xmax, [3] ymax (bbox in degrees)
+  #                            [4] baselong (longitude of SWF map origin),
+  #                            [5] basey (projected latitude of SWF map origin),
+  #                            [6] masterscale (SWF map scale)
+  #              does: finds all ways and POI nodes in bounding box
+  #                            at present, instead of using correct (=more complex) SQL to find
+  #                            corner-crossing ways, it simply enlarges the bounding box
+  #              out:  [0] array of way ids,
+  #                            [1] array of POIs
+  #                            (where each POI is an array containing:
+  #                             [0] id, [1] projected long, [2] projected lat, [3] hash of tags)
+
+  def whichways(args)
+    xmin = args[0].to_f-0.01
+    ymin = args[1].to_f-0.01
+    xmax = args[2].to_f+0.01
+    ymax = args[3].to_f+0.01
+    baselong    = args[4]
+    basey       = args[5]
+    masterscale = args[6]
+
+    RAILS_DEFAULT_LOGGER.info("  Message: whichways, bbox=#{xmin},#{ymin},#{xmax},#{ymax}")
+
+    waylist = ActiveRecord::Base.connection.select_all("SELECT DISTINCT current_way_nodes.id AS wayid"+
+       "  FROM current_way_nodes,current_nodes,current_ways "+
+       " WHERE current_nodes.id=current_way_nodes.node_id "+
+       "   AND current_nodes.visible=1 "+
+       "   AND current_ways.id=current_way_nodes.id "+
+       "   AND current_ways.visible=1 "+
+       "   AND "+OSM.sql_for_area(ymin, xmin, ymax, xmax, "current_nodes."))
+
+    ways = waylist.collect {|a| a['wayid'].to_i } # get an array of way IDs
+
+    pointlist = ActiveRecord::Base.connection.select_all("SELECT current_nodes.id,current_nodes.latitude*0.0000001 AS lat,current_nodes.longitude*0.0000001 AS lng,current_nodes.tags "+
+       "  FROM current_nodes "+
+       "  LEFT OUTER JOIN current_way_nodes cwn ON cwn.node_id=current_nodes.id "+
+       " WHERE "+OSM.sql_for_area(ymin, xmin, ymax, xmax, "current_nodes.")+
+       "   AND cwn.id IS NULL "+
+       "   AND current_nodes.visible=1")
+
+    points = pointlist.collect {|a| [a['id'],long2coord(a['lng'].to_f,baselong,masterscale),lat2coord(a['lat'].to_f,basey,masterscale),tag2array(a['tags'])]   } # get a list of node ids and their tags
+
+    [ways,points]
+  end
+
+  # ----- whichways_deleted
+  #              return array of deleted ways in current bounding box
+
+  #              in:   as whichways
+  #              does: finds all deleted ways with a deleted node in bounding box
+  #              out:  [0] array of way ids
+  
+  def whichways_deleted(args)
+    xmin = args[0].to_f-0.01
+    ymin = args[1].to_f-0.01
+    xmax = args[2].to_f+0.01
+    ymax = args[3].to_f+0.01
+    baselong    = args[4]
+    basey       = args[5]
+    masterscale = args[6]
+
+       sql=<<-EOF
+                SELECT DISTINCT current_ways.id 
+                  FROM current_nodes,way_nodes,current_ways 
+                 WHERE #{OSM.sql_for_area(ymin, xmin, ymax, xmax, "current_nodes.")} 
+                       AND way_nodes.node_id=current_nodes.id 
+                       AND way_nodes.id=current_ways.id 
+                       AND current_nodes.visible=0 
+                       AND current_ways.visible=0 
+       EOF
+    waylist = ActiveRecord::Base.connection.select_all(sql)
+    ways = waylist.collect {|a| a['id'].to_i }
+       [ways]
+  end
+  
+  # ----- getway
+  #              in:   [0] SWF object name, [1] way id, [2] baselong, [3] basey,
+  #                            [4] masterscale
+  #              does: gets way and all nodes
+  #              out:  [0] SWF object name (unchanged),
+  #                            [1] array of points
+  #                                    (where each point is an array containing
+  #                                     [0] projected long, [1] projected lat, [2] node id,
+  #                                     [3] null, [4] hash of node tags),
+  #                            [2] xmin, [3] xmax, [4] ymin, [5] ymax (unprojected bbox)
+
+  def getway(args)
+    objname,wayid,baselong,basey,masterscale=args
+    wayid = wayid.to_i
+    points = []
+    xmin = ymin =  999999
+    xmax = ymax = -999999
+
+    RAILS_DEFAULT_LOGGER.info("  Message: getway, id=#{wayid}")
+
+    readwayquery(wayid,true).each {|row|
+      points<<[long2coord(row['longitude'].to_f,baselong,masterscale),lat2coord(row['latitude'].to_f,basey,masterscale),row['id'].to_i,nil,tag2array(row['tags'])]
+      xmin = [xmin,row['longitude'].to_f].min
+      xmax = [xmax,row['longitude'].to_f].max
+      ymin = [ymin,row['latitude'].to_f].min
+      ymax = [ymax,row['latitude'].to_f].max
+    }
+
+    attributes={}
+    attrlist=ActiveRecord::Base.connection.select_all "SELECT k,v FROM current_way_tags WHERE id=#{wayid}"
+    attrlist.each {|a| attributes[a['k'].gsub(':','|')]=a['v'] }
+
+    [objname,points,attributes,xmin,xmax,ymin,ymax]
+  end
+  
+  # ----- getway_old
+  #              returns old version of way
+
+  #              in:   [0] SWF object name, [1] way id,
+  #                            [2] way version to get (or -1 for "last deleted version")
+  #                            [3] baselong, [4] basey, [5] masterscale
+  #              does: gets old version of way and all constituent nodes
+  #                            for undelete, always uses the most recent version of each node
+  #                              (even if it's moved)
+  #                            for revert, uses the historic version of each node, but if that node is
+  #                              still visible and has been changed since, generates a new node id
+  #              out:  [0] 0 (code for success), [1] SWF object name,
+  #                            [2] array of points (as getway _except_ [3] is node.visible?, 0 or 1),
+  #                            [4] xmin, [5] xmax, [6] ymin, [7] ymax (unprojected bbox),
+  #                            [8] way version
+
+  def getway_old(args)
+    RAILS_DEFAULT_LOGGER.info("  Message: getway_old (server is #{SERVER_URL})")
+#      if SERVER_URL=="www.openstreetmap.org" then return -1,"Revert is not currently enabled on the OpenStreetMap server." end
        
-       def getvalue(s)
-               case s.getc
-                       when 0; return getdouble(s)                     # number
-                       when 1; return s.getc                           # boolean
-                       when 2; return getstring(s)                     # string
-                       when 3; return getobject(s)                     # object/hash
-                       when 5; return nil                                      # null
-                       when 6; return nil                                      # undefined
-                       when 8; s.read(4)                                       # mixedArray
-                                       return getobject(s)                     #  |
-                       when 10;return getarray(s)                      # array
-                       else;   return nil                                      # error
-               end
+    objname,wayid,version,baselong,basey,masterscale=args
+    wayid = wayid.to_i
+    version = version.to_i
+    xmin = ymin =  999999
+    xmax = ymax = -999999
+       points=[]
+       if version<0
+         historic=false
+         version=getlastversion(wayid,version)
+       else
+         historic=true
        end
+       readwayquery_old(wayid,version,historic).each { |row|
+      points<<[long2coord(row['longitude'].to_f,baselong,masterscale),lat2coord(row['latitude'].to_f,basey,masterscale),row['id'].to_i,row['visible'].to_i,tag2array(row['tags'].to_s)]
+      xmin=[xmin,row['longitude'].to_f].min
+      xmax=[xmax,row['longitude'].to_f].max
+      ymin=[ymin,row['latitude' ].to_f].min
+      ymax=[ymax,row['latitude' ].to_f].max
+       }
+
+       # get tags from this version
+    attributes={}
+    attrlist=ActiveRecord::Base.connection.select_all "SELECT k,v FROM way_tags WHERE id=#{wayid} AND version=#{version}"
+    attrlist.each {|a| attributes[a['k'].gsub(':','|')]=a['v'] }
+       attributes['history']="Retrieved from v"+version.to_s
 
-       # ====================================================================
-       # AMF write subroutines
+    [0,objname,points,attributes,xmin,xmax,ymin,ymax,version]
+  end
+
+  # ----- getway_history
+  #              find history of a way
+
+  #              in:   [0] way id
+  #              does: finds history of a way
+  #              out:  [0] array of previous versions (where each is
+  #                                    [0] version, [1] db timestamp, [2] visible 0 or 1,
+  #                                    [3] username or 'anonymous')
+
+  def getway_history(wayid)
+       history=[]
+       sql=<<-EOF
+       SELECT version,timestamp,visible,display_name,data_public
+         FROM ways,users
+        WHERE ways.id=#{wayid}
+          AND ways.user_id=users.id
+          AND ways.visible=1
+        ORDER BY version DESC
+       EOF
+       histlist=ActiveRecord::Base.connection.select_all(sql)
+       histlist.each { |row|
+               if row['data_public'].to_i==1 then user=row['display_name'] else user='anonymous' end
+               history<<[row['version'],row['timestamp'],row['visible'],user]
+       }
+       [history]
+  end
+
+  # ----- putway
+  #              saves a way to the database
+  
+  #              in:   [0] user token, [1] original way id (may be negative), 
+  #                            [2] array of points (as getway/getway_old), [3] hash of way tags,
+  #                            [4] original way version (0 if not a reverted/undeleted way),
+  #                            [5] baselong, [6] basey, [7] masterscale
+  #              does: saves way to the database
+  #                            all constituent nodes are created/updated as necessary
+  #                            (or deleted if they were in the old version and are otherwise unused)
+  #              out:  [0] 0 (code for success), [1] original way id (unchanged),
+  #                            [2] new way id, [3] hash of renumbered nodes (old id=>new id),
+  #                            [4] xmin, [5] xmax, [6] ymin, [7] ymax (unprojected bbox)
+
+  def putway(args,renumberednodes)
+    RAILS_DEFAULT_LOGGER.info("  putway started")
+    usertoken,originalway,points,attributes,oldversion,baselong,basey,masterscale=args
+    uid=getuserid(usertoken)
+    if !uid then return -1,"You are not logged in, so the way could not be saved." end
+
+    RAILS_DEFAULT_LOGGER.info("  putway authenticated happily")
+    db_uqn='unin'+(rand*100).to_i.to_s+uid.to_s+originalway.to_i.abs.to_s+Time.new.to_i.to_s   # temp uniquenodes table name, typically 51 chars
+    db_now='@now'+(rand*100).to_i.to_s+uid.to_s+originalway.to_i.abs.to_s+Time.new.to_i.to_s   # 'now' variable name, typically 51 chars
+    ActiveRecord::Base.connection.execute("SET #{db_now}=NOW()")
+    originalway=originalway.to_i
+       oldversion=oldversion.to_i
        
-       # ----- putdata         envelope data into AMF writeable form
-       # ----- encodevalue     pack variables as AMF
+    RAILS_DEFAULT_LOGGER.info("  Message: putway, id=#{originalway}")
+
+       # -- Temporary check for null IDs
        
-       def putdata(index,n)
-               d =encodestring(index+"/onResult")
-               d+=encodestring("null")
-               d+=[-1].pack("N")
-               d+=encodevalue(n)
+       points.each do |a|
+         if a[2]==0 or a[2].nil? then return -2,"Server error - node with id 0 found in way #{originalway}." end
        end
-       
-       def encodevalue(n)
-               case n.class.to_s
-                       when 'Array'
-                               a=10.chr+encodelong(n.length)
-                               n.each do |b|
-                                       a+=encodevalue(b)
-                               end
-                               a
-                       when 'Hash'
-                               a=3.chr
-                               n.each do |k,v|
-                                       a+=encodestring(k)+encodevalue(v)
-                               end
-                               a+0.chr+0.chr+9.chr
-                       when 'String'
-                               2.chr+encodestring(n)
-                       when 'Bignum','Fixnum','Float'
-                               0.chr+encodedouble(n)
-                       when 'NilClass'
-                               5.chr
-                       else
-                               RAILS_DEFAULT_LOGGER.error("Unexpected Ruby type for AMF conversion: "+n.class.to_s)
+
+    # -- 3.    read original way into memory
+
+    xc={}; yc={}; tagc={}; vc={}
+    if originalway>0
+      way=originalway
+         if oldversion==0 then r=readwayquery(way,false)
+                                          else r=readwayquery_old(way,oldversion,true) end
+         r.each { |row|
+               id=row['id'].to_i
+               if (id>0) then
+                 xc[id]=row['longitude'].to_f
+                 yc[id]=row['latitude' ].to_f
+                 tagc[id]=row['tags']
+                 vc[id]=row['visible'].to_i
+           end
+         }
+      ActiveRecord::Base.connection.update("UPDATE current_ways SET timestamp=#{db_now},user_id=#{uid},visible=1 WHERE id=#{way}")
+    else
+      way=ActiveRecord::Base.connection.insert("INSERT INTO current_ways (user_id,timestamp,visible) VALUES (#{uid},#{db_now},1)")
+    end
+
+    # -- 4.    get version by inserting new row into ways
+
+    version=ActiveRecord::Base.connection.insert("INSERT INTO ways (id,user_id,timestamp,visible) VALUES (#{way},#{uid},#{db_now},1)")
+
+    # -- 5. compare nodes and update xmin,xmax,ymin,ymax
+
+    xmin=ymin= 999999
+    xmax=ymax=-999999
+    insertsql=''
+       nodelist=[]
+
+    points.each_index do |i|
+      xs=coord2long(points[i][0],masterscale,baselong)
+      ys=coord2lat(points[i][1],masterscale,basey)
+      xmin=[xs,xmin].min; xmax=[xs,xmax].max
+      ymin=[ys,ymin].min; ymax=[ys,ymax].max
+      node=points[i][2].to_i
+         tagstr=array2tag(points[i][4])
+      tagsql="'"+sqlescape(tagstr)+"'"
+      lat=(ys * 10000000).round
+      long=(xs * 10000000).round
+      tile=QuadTile.tile_for_point(ys, xs)
+
+      # compare node
+      if node<0
+        # new node - create
+               if renumberednodes[node.to_s].nil?
+          newnode=ActiveRecord::Base.connection.insert("INSERT INTO current_nodes (   latitude,longitude,timestamp,user_id,visible,tags,tile) VALUES (           #{lat},#{long},#{db_now},#{uid},1,#{tagsql},#{tile})")
+                  ActiveRecord::Base.connection.insert("INSERT INTO nodes         (id,latitude,longitude,timestamp,user_id,visible,tags,tile) VALUES (#{newnode},#{lat},#{long},#{db_now},#{uid},1,#{tagsql},#{tile})")
+          points[i][2]=newnode
+          nodelist.push(newnode)
+          renumberednodes[node.to_s]=newnode.to_s
+               else
+          points[i][2]=renumberednodes[node.to_s].to_i
                end
+
+      elsif xc.has_key?(node)
+               nodelist.push(node)
+        # old node from original way - update
+        if ((xs/0.0000001).round!=(xc[node]/0.0000001).round or (ys/0.0000001).round!=(yc[node]/0.0000001).round or tagstr!=tagc[node] or vc[node]==0)
+          ActiveRecord::Base.connection.insert("INSERT INTO nodes (id,latitude,longitude,timestamp,user_id,visible,tags,tile) VALUES (#{node},#{lat},#{long},#{db_now},#{uid},1,#{tagsql},#{tile})")
+          ActiveRecord::Base.connection.update("UPDATE current_nodes SET latitude=#{lat},longitude=#{long},timestamp=#{db_now},user_id=#{uid},tags=#{tagsql},visible=1,tile=#{tile} WHERE id=#{node}")
+        end
+      else
+        # old node, created in another way and now added to this way
+      end
+    end
+
+
+       # -- 6a. delete any nodes not in modified way
+
+    createuniquenodes(way,db_uqn,nodelist)     # nodes which appear in this way but no other
+
+    sql=<<-EOF
+       INSERT INTO nodes (id,latitude,longitude,timestamp,user_id,visible,tile)  
+       SELECT DISTINCT cn.id,cn.latitude,cn.longitude,#{db_now},#{uid},0,cn.tile
+         FROM current_nodes AS cn,#{db_uqn}
+        WHERE cn.id=node_id
+    EOF
+    ActiveRecord::Base.connection.insert(sql)
+
+    sql=<<-EOF
+      UPDATE current_nodes AS cn, #{db_uqn}
+         SET cn.timestamp=#{db_now},cn.visible=0,cn.user_id=#{uid} 
+       WHERE cn.id=node_id
+    EOF
+    ActiveRecord::Base.connection.update(sql)
+
+       deleteuniquenoderelations(db_uqn,uid,db_now)
+    ActiveRecord::Base.connection.execute("DROP TEMPORARY TABLE #{db_uqn}")
+
+       #       6b. insert new version of route into way_nodes
+
+    insertsql =''
+    currentsql=''
+    sequence  =1
+    points.each do |p|
+      if insertsql !='' then insertsql +=',' end
+      if currentsql!='' then currentsql+=',' end
+      insertsql +="(#{way},#{p[2]},#{sequence},#{version})"
+      currentsql+="(#{way},#{p[2]},#{sequence})"
+      sequence  +=1
+    end
+
+    ActiveRecord::Base.connection.execute("DELETE FROM current_way_nodes WHERE id=#{way}");
+    ActiveRecord::Base.connection.insert( "INSERT INTO         way_nodes (id,node_id,sequence_id,version) VALUES #{insertsql}");
+    ActiveRecord::Base.connection.insert( "INSERT INTO current_way_nodes (id,node_id,sequence_id        ) VALUES #{currentsql}");
+
+    # -- 7. insert new way tags
+
+    insertsql =''
+    currentsql=''
+    attributes.each do |k,v|
+      if v=='' or v.nil? then next end
+      if v[0,6]=='(type ' then next end
+      if insertsql !='' then insertsql +=',' end
+      if currentsql!='' then currentsql+=',' end
+      insertsql +="(#{way},'"+sqlescape(k.gsub('|',':'))+"','"+sqlescape(v)+"',#{version})"
+      currentsql+="(#{way},'"+sqlescape(k.gsub('|',':'))+"','"+sqlescape(v)+"')"
+    end
+
+    ActiveRecord::Base.connection.execute("DELETE FROM current_way_tags WHERE id=#{way}")
+    if (insertsql !='') then ActiveRecord::Base.connection.insert("INSERT INTO way_tags (id,k,v,version) VALUES #{insertsql}" ) end
+    if (currentsql!='') then ActiveRecord::Base.connection.insert("INSERT INTO current_way_tags (id,k,v) VALUES #{currentsql}") end
+
+    [0,originalway,way,renumberednodes,xmin,xmax,ymin,ymax]
+  end
+
+  # ----- putpoi
+  #              save POI to the database
+  
+  #              in:   [0] user token, [1] original node id (may be negative),
+  #                            [2] projected longitude, [3] projected latitude, [4] hash of tags,
+  #                            [5] visible (0 to delete, 1 otherwise), 
+  #                            [6] baselong, [7] basey, [8] masterscale
+  #              does: saves POI node to the database
+  #                            refuses save if the node has since become part of a way
+  #              out:  [0] 0 (success), [1] original node id (unchanged), [2] new node id
+
+  def putpoi(args)
+    usertoken,id,x,y,tags,visible,baselong,basey,masterscale=args
+    uid=getuserid(usertoken)
+    if !uid then return -1,"You are not logged in, so the point could not be saved." end
+
+    db_now='@now'+(rand*100).to_i.to_s+uid.to_s+id.to_i.abs.to_s+Time.new.to_i.to_s    # 'now' variable name, typically 51 chars
+    ActiveRecord::Base.connection.execute("SET #{db_now}=NOW()")
+
+    id=id.to_i
+    visible=visible.to_i
+       if visible==0 then
+               # if deleting, check node hasn't become part of a way 
+               inway=ActiveRecord::Base.connection.select_one("SELECT cw.id FROM current_ways cw,current_way_nodes cwn WHERE cw.id=cwn.id AND cw.visible=1 AND cwn.node_id=#{id} LIMIT 1")
+               unless inway.nil? then return -1,"The point has since become part of a way, so you cannot save it as a POI." end
+               deleteitemrelations(id,'node',uid,db_now)
        end
+
+    x=coord2long(x.to_f,masterscale,baselong)
+    y=coord2lat(y.to_f,masterscale,basey)
+    tagsql="'"+sqlescape(array2tag(tags))+"'"
+    lat=(y * 10000000).round
+    long=(x * 10000000).round
+    tile=QuadTile.tile_for_point(y, x)
        
-       # ----- encodestring    encode string with two-byte length
-       # ----- encodedouble    encode number as eight-byte double precision float
-       # ----- encodelong              encode number as four-byte long
-       
-       def encodestring(n)
-               a,b=n.size.divmod(256)
-               a.chr+b.chr+n
-       end
-       
-       def encodedouble(n)
-               [n].pack('G')
-       end
-       
-       def encodelong(n)
-               [n].pack('N')
-       end
-       
-       # ====================================================================
-       # Co-ordinate conversion
-       
-       def lat2coord(a)
-               -(lat2y(a)-$basey)*$masterscale+250
-       end
-       
-       def long2coord(a)
-               (a-$baselong)*$masterscale+350
-       end
+    if (id>0) then
+        ActiveRecord::Base.connection.insert("INSERT INTO nodes (id,latitude,longitude,timestamp,user_id,visible,tags,tile) VALUES (#{id},#{lat},#{long},#{db_now},#{uid},#{visible},#{tagsql},#{tile})");
+        ActiveRecord::Base.connection.update("UPDATE current_nodes SET latitude=#{lat},longitude=#{long},timestamp=#{db_now},user_id=#{uid},visible=#{visible},tags=#{tagsql},tile=#{tile} WHERE id=#{id}");
+        newid=id
+    else
+        newid=ActiveRecord::Base.connection.insert("INSERT INTO current_nodes (latitude,longitude,timestamp,user_id,visible,tags,tile) VALUES (#{lat},#{long},#{db_now},#{uid},#{visible},#{tagsql},#{tile})");
+              ActiveRecord::Base.connection.update("INSERT INTO nodes (id,latitude,longitude,timestamp,user_id,visible,tags,tile) VALUES (#{newid},#{lat},#{long},#{db_now},#{uid},#{visible},#{tagsql},#{tile})");
+    end
+    [0,id,newid]
+  end
+
+  # ----- getpoi
+  #              read POI from database
+  #              (only called on revert: POIs are usually read by whichways)
+  
+  #              in:   [0] node id, [1] baselong, [2] basey, [3] masterscale
+  #              does: reads POI
+  #              out:  [0] id (unchanged), [1] projected long, [2] projected lat, [3] hash of tags
+  
+  def getpoi(args)
+       id,baselong,basey,masterscale=args; id=id.to_i
+       poi=ActiveRecord::Base.connection.select_one("SELECT latitude*0.0000001 AS lat,longitude*0.0000001 AS lng,tags "+
+               "FROM current_nodes WHERE visible=1 AND id=#{id}")
+       if poi.nil? then return [nil,nil,nil,''] end
+       [id,
+        long2coord(poi['lng'].to_f,baselong,masterscale),
+        lat2coord(poi['lat'].to_f,basey,masterscale),
+        tag2array(poi['tags'])]
+  end
+
+  # ----- deleteway
+  #              delete way and constituent nodes from database
+  
+  #              in:   [0] user token, [1] way id
+  #              does: deletes way from db and any constituent nodes not used elsewhere
+  #                            also removes ways/nodes from any relations they're in
+  #              out:  [0] 0 (success), [1] way id (unchanged)
+
+  def deleteway(args)
+    usertoken,way=args
+
+    RAILS_DEFAULT_LOGGER.info("  Message: deleteway, id=#{way}")
+    uid=getuserid(usertoken)
+    if !uid then return -1,"You are not logged in, so the way could not be deleted." end
+
+    way=way.to_i
+    db_uqn='unin'+(rand*100).to_i.to_s+uid.to_s+way.to_i.abs.to_s+Time.new.to_i.to_s   # temp uniquenodes table name, typically 51 chars
+    db_now='@now'+(rand*100).to_i.to_s+uid.to_s+way.to_i.abs.to_s+Time.new.to_i.to_s   # 'now' variable name, typically 51 chars
+    ActiveRecord::Base.connection.execute("SET #{db_now}=NOW()")
+
+    # - delete any otherwise unused nodes
+  
+    createuniquenodes(way,db_uqn,[])
+
+#      unless (preserve.empty?) then
+#              ActiveRecord::Base.connection.execute("DELETE FROM #{db_uqn} WHERE node_id IN ("+preserve.join(',')+")")
+#      end
+
+    sql=<<-EOF
+       INSERT INTO nodes (id,latitude,longitude,timestamp,user_id,visible,tile)
+       SELECT DISTINCT cn.id,cn.latitude,cn.longitude,#{db_now},#{uid},0,cn.tile
+         FROM current_nodes AS cn,#{db_uqn}
+        WHERE cn.id=node_id
+    EOF
+    ActiveRecord::Base.connection.insert(sql)
+
+    sql=<<-EOF
+      UPDATE current_nodes AS cn, #{db_uqn}
+         SET cn.timestamp=#{db_now},cn.visible=0,cn.user_id=#{uid} 
+       WHERE cn.id=node_id
+    EOF
+    ActiveRecord::Base.connection.update(sql)
+
+       deleteuniquenoderelations(db_uqn,uid,db_now)
+    ActiveRecord::Base.connection.execute("DROP TEMPORARY TABLE #{db_uqn}")
+
+    # - delete way
        
-       def lat2y(a)
-               180/Math::PI * Math.log(Math.tan(Math::PI/4+a*(Math::PI/180)/2))
+    ActiveRecord::Base.connection.insert("INSERT INTO ways (id,user_id,timestamp,visible) VALUES (#{way},#{uid},#{db_now},0)")
+    ActiveRecord::Base.connection.update("UPDATE current_ways SET user_id=#{uid},timestamp=#{db_now},visible=0 WHERE id=#{way}")
+    ActiveRecord::Base.connection.execute("DELETE FROM current_way_nodes WHERE id=#{way}")
+    ActiveRecord::Base.connection.execute("DELETE FROM current_way_tags WHERE id=#{way}")
+       deleteitemrelations(way,'way',uid,db_now)
+    [0,way]
+end
+
+
+
+# ====================================================================
+# Support functions for remote calls
+
+def readwayquery(id,insistonvisible)
+  sql=<<-EOF
+    SELECT latitude*0.0000001 AS latitude,longitude*0.0000001 AS longitude,current_nodes.id,tags,visible 
+      FROM current_way_nodes,current_nodes 
+     WHERE current_way_nodes.id=#{id} 
+       AND current_way_nodes.node_id=current_nodes.id 
+  EOF
+  if insistonvisible then sql+=" AND current_nodes.visible=1 " end
+  sql+=" ORDER BY sequence_id"
+  ActiveRecord::Base.connection.select_all(sql)
+end
+
+def getlastversion(id,version)
+  row=ActiveRecord::Base.connection.select_one("SELECT version FROM ways WHERE id=#{id} AND visible=1 ORDER BY version DESC LIMIT 1")
+  row['version']
+end
+
+def readwayquery_old(id,version,historic)
+  # Node handling on undelete (historic=false):
+  # - always use the node specified, even if it's moved
+  
+  # Node handling on revert (historic=true):
+  # - if it's a visible node, use a new node id (i.e. not mucking up the old one)
+  #   which means the SWF needs to allocate new ids
+  # - if it's an invisible node, we can reuse the old node id
+
+  # get node list from specified version of way,
+  # and the _current_ lat/long/tags of each node
+
+  row=ActiveRecord::Base.connection.select_one("SELECT timestamp FROM ways WHERE version=#{version} AND id=#{id}")
+  waytime=row['timestamp']
+
+  sql=<<-EOF
+       SELECT cn.id,visible,latitude*0.0000001 AS latitude,longitude*0.0000001 AS longitude,tags 
+         FROM way_nodes wn,current_nodes cn 
+        WHERE wn.version=#{version} 
+          AND wn.id=#{id} 
+          AND wn.node_id=cn.id 
+        ORDER BY sequence_id
+  EOF
+  rows=ActiveRecord::Base.connection.select_all(sql)
+
+  # if historic (full revert), get the old version of each node
+  # - if it's in another way now, generate a new id
+  # - if it's not in another way, use the old ID
+  if historic then
+       rows.each_index do |i|
+         sql=<<-EOF
+         SELECT latitude*0.0000001 AS latitude,longitude*0.0000001 AS longitude,tags,cwn.id AS currentway 
+           FROM nodes n
+   LEFT JOIN current_way_nodes cwn
+                 ON cwn.node_id=n.id
+          WHERE n.id=#{rows[i]['id']} 
+            AND n.timestamp<="#{waytime}" 
+                AND cwn.id!=#{id} 
+          ORDER BY n.timestamp DESC 
+          LIMIT 1
+         EOF
+         row=ActiveRecord::Base.connection.select_one(sql)
+         unless row.nil? then
+           nx=row['longitude'].to_f
+           ny=row['latitude'].to_f
+           if (row['currentway'] && (nx!=rows[i]['longitude'].to_f or ny!=rows[i]['latitude'].to_f or row['tags']!=rows[i]['tags'])) then rows[i]['id']=-1 end
+               rows[i]['longitude']=nx
+               rows[i]['latitude' ]=ny
+               rows[i]['tags'     ]=row['tags']
+         end
+    end
+  end
+  rows
+end
+
+def createuniquenodes(way,uqn_name,nodelist)
+       # Find nodes which appear in this way but no others
+       sql=<<-EOF
+       CREATE TEMPORARY TABLE #{uqn_name}
+                                       SELECT a.node_id
+                                         FROM (SELECT DISTINCT node_id FROM current_way_nodes
+                                                       WHERE id=#{way}) a
+                                LEFT JOIN current_way_nodes b
+                                               ON b.node_id=a.node_id
+                                          AND b.id!=#{way}
+                                        WHERE b.node_id IS NULL
+       EOF
+       unless nodelist.empty? then
+         sql+="AND a.node_id NOT IN ("+nodelist.join(',')+")"
        end
-       
-       def coord2lat(a)
-               y2lat((a-250)/-$masterscale+$basey)
+       ActiveRecord::Base.connection.execute(sql)
+end
+
+
+
+# ====================================================================
+# Relations handling
+# deleteuniquenoderelations(uqn_name,uid,db_now)
+# deleteitemrelations(way|node,'way'|'node',uid,db_now)
+
+def deleteuniquenoderelations(uqn_name,uid,db_now)
+       sql=<<-EOF
+       SELECT node_id,cr.id FROM #{uqn_name},current_relation_members crm,current_relations cr 
+        WHERE crm.member_id=node_id 
+          AND crm.member_type='node' 
+          AND crm.id=cr.id 
+          AND cr.visible=1
+       EOF
+
+       relnodes=ActiveRecord::Base.connection.select_all(sql)
+       relnodes.each do |a|
+               removefromrelation(a['node_id'],'node',a['id'],uid,db_now)
        end
+end
+
+def deleteitemrelations(objid,type,uid,db_now)
+       sql=<<-EOF
+       SELECT cr.id FROM current_relation_members crm,current_relations cr 
+        WHERE crm.member_id=#{objid} 
+          AND crm.member_type='#{type}' 
+          AND crm.id=cr.id 
+          AND cr.visible=1
+       EOF
        
-       def coord2long(a)
-               (a-350)/$masterscale+$baselong
+       relways=ActiveRecord::Base.connection.select_all(sql)
+       relways.each do |a|
+               removefromrelation(objid,type,a['id'],uid,db_now)
        end
+end
+
+def removefromrelation(objid,type,relation,uid,db_now)
+       rver=ActiveRecord::Base.connection.insert("INSERT INTO relations (id,user_id,timestamp,visible) VALUES (#{relation},#{uid},#{db_now},1)")
+
+       tagsql=<<-EOF
+       INSERT INTO relation_tags (id,k,v,version) 
+       SELECT id,k,v,#{rver} FROM current_relation_tags 
+        WHERE id=#{relation} 
+       EOF
+       ActiveRecord::Base.connection.insert(tagsql)
+
+       membersql=<<-EOF
+       INSERT INTO relation_members (id,member_type,member_id,member_role,version) 
+       SELECT id,member_type,member_id,member_role,#{rver} FROM current_relation_members 
+        WHERE id=#{relation} 
+          AND (member_id!=#{objid} OR member_type!='#{type}')
+       EOF
+       ActiveRecord::Base.connection.insert(membersql)
        
-       def y2lat(a)
-               180/Math::PI * (2*Math.atan(Math.exp(a*Math::PI/180))-Math::PI/2)
-       end
+       ActiveRecord::Base.connection.update("UPDATE current_relations SET user_id=#{uid},timestamp=#{db_now} WHERE id=#{relation}")
+       ActiveRecord::Base.connection.execute("DELETE FROM current_relation_members WHERE id=#{relation} AND member_type='#{type}' AND member_id=#{objid}")
+end
+
+
+def sqlescape(a)
+  a.gsub(/[\000-\037]/,"").gsub("'","''").gsub(92.chr) {92.chr+92.chr}
+end
 
+def tag2array(a)
+  tags={}
+  Tags.split(a) do |k, v|
+    tags[k.gsub(':','|')]=v
+  end
+  tags
+end
+
+def array2tag(a)
+  tags = []
+  a.each do |k,v|
+    if v=='' then next end
+    if v[0,6]=='(type ' then next end
+    tags << [k.gsub('|',':'), v]
+  end
+  return Tags.join(tags)
+end
+
+def getuserid(token)
+  if (token =~ /^(.+)\+(.+)$/) then
+    user = User.authenticate(:username => $1, :password => $2)
+  else
+    user = User.authenticate(:token => token)
+  end
+
+  return user ? user.id : nil;
+end
+
+
+
+# ====================================================================
+# AMF read subroutines
+
+# -----        getint          return two-byte integer
+# -----        getlong         return four-byte long
+# -----        getstring       return string with two-byte length
+# ----- getdouble      return eight-byte double-precision float
+# ----- getobject      return object/hash
+# ----- getarray       return numeric array
+
+def getint(s)
+  s.getc*256+s.getc
+end
+
+def getlong(s)
+  ((s.getc*256+s.getc)*256+s.getc)*256+s.getc
+end
+
+def getstring(s)
+  len=s.getc*256+s.getc
+  s.read(len)
+end
+
+def getdouble(s)
+  a=s.read(8).unpack('G')                      # G big-endian, E little-endian
+  a[0]
+end
+
+def getarray(s)
+  len=getlong(s)
+  arr=[]
+  for i in (0..len-1)
+    arr[i]=getvalue(s)
+  end
+  arr
+end
+
+def getobject(s)
+  arr={}
+  while (key=getstring(s))
+    if (key=='') then break end
+    arr[key]=getvalue(s)
+  end
+  s.getc               # skip the 9 'end of object' value
+  arr
+end
+
+# -----        getvalue        parse and get value
+
+def getvalue(s)
+  case s.getc
+       when 0; return getdouble(s)                     # number
+       when 1; return s.getc                           # boolean
+       when 2; return getstring(s)                     # string
+       when 3; return getobject(s)                     # object/hash
+       when 5; return nil                                      # null
+       when 6; return nil                                      # undefined
+       when 8; s.read(4)                                       # mixedArray
+                       return getobject(s)                     #  |
+       when 10;return getarray(s)                      # array
+       else;   return nil                                      # error
+  end
+end
+
+# ====================================================================
+# AMF write subroutines
+
+# -----        putdata         envelope data into AMF writeable form
+# -----        encodevalue     pack variables as AMF
+
+def putdata(index,n)
+  d =encodestring(index+"/onResult")
+  d+=encodestring("null")
+  d+=[-1].pack("N")
+  d+=encodevalue(n)
+end
+
+def encodevalue(n)
+  case n.class.to_s
+  when 'Array'
+    a=10.chr+encodelong(n.length)
+    n.each do |b|
+      a+=encodevalue(b)
+    end
+    a
+  when 'Hash'
+    a=3.chr
+    n.each do |k,v|
+      a+=encodestring(k)+encodevalue(v)
+    end
+    a+0.chr+0.chr+9.chr
+  when 'String'
+    2.chr+encodestring(n)
+  when 'Bignum','Fixnum','Float'
+    0.chr+encodedouble(n)
+  when 'NilClass'
+    5.chr
+  else
+    RAILS_DEFAULT_LOGGER.error("Unexpected Ruby type for AMF conversion: "+n.class.to_s)
+  end
+end
+
+# -----        encodestring    encode string with two-byte length
+# -----        encodedouble    encode number as eight-byte double precision float
+# -----        encodelong              encode number as four-byte long
+
+def encodestring(n)
+  a,b=n.size.divmod(256)
+  a.chr+b.chr+n
+end
+
+def encodedouble(n)
+  [n].pack('G')
+end
+
+def encodelong(n)
+  [n].pack('N')
+end
+
+# ====================================================================
+# Co-ordinate conversion
+
+def lat2coord(a,basey,masterscale)
+  -(lat2y(a)-basey)*masterscale+250
+end
+
+def long2coord(a,baselong,masterscale)
+  (a-baselong)*masterscale+350
+end
+
+def lat2y(a)
+  180/Math::PI * Math.log(Math.tan(Math::PI/4+a*(Math::PI/180)/2))
+end
+
+def coord2lat(a,masterscale,basey)
+  y2lat((a-250)/-masterscale+basey)
+end
+
+def coord2long(a,masterscale,baselong)
+  (a-350)/masterscale+baselong
+end
+
+def y2lat(a)
+  180/Math::PI * (2*Math.atan(Math.exp(a*Math::PI/180))-Math::PI/2)
+end
 
 end