app/controllers/amf_controller.rb

   1 class AmfController < ApplicationController
   2   require 'stringio'
   3
   4 # to log:
   5 # RAILS_DEFAULT_LOGGER.error("Args: #{args[0]}, #{args[1]}, #{args[2]}, #{args[3]}")
   6
   7   # ====================================================================
   8   # Main AMF handler
   9
  10   # ---- talk   process AMF request
  11
  12   def talk
  13         req=StringIO.new(request.raw_post)      # Get POST data as request
  14         req.read(2)                                                     # Skip version indicator and client ID
  15         results={}                                                      # Results of each body
  16
  17         # -------------
  18         # Parse request
  19
  20         headers=getint(req)                                     # Read number of headers
  21         for i in (1..headers)                           # Read each header
  22                 name=getstring(req)                             #  |
  23                 req.getc                                                #  | skip boolean
  24                 value=getvalue(req)                             #  |
  25                 header["name"]=value                    #  |
  26         end
  27
  28         bodies=getint(req)                                      # Read number of bodies
  29         for i in (1..bodies)                            # Read each body
  30                 message=getstring(req)                  #  | get message name
  31                 index=getstring(req)                    #  | get index in response sequence
  32                 bytes=getlong(req)                              #  | get total size in bytes
  33                 args=getvalue(req)                              #  | get response (probably an array)
  34
  35                 case message
  36                         when 'getpresets';      results[index]=putdata(index,getpresets)
  37                         when 'whichways';       results[index]=putdata(index,whichways(args))
  38                         when 'getway';          results[index]=putdata(index,getway(args))
  39                         when 'putway';          results[index]=putdata(index,putway(args))
  40                         when 'deleteway';       results[index]=putdata(index,deleteway(args))
  41                 end
  42         end
  43
  44         # ------------------
  45         # Write out response
  46
  47         response.headers["Content-Type"]="application/x-amf"
  48         a,b=results.length.divmod(256)
  49         ans=0.chr+0.chr+0.chr+0.chr+a.chr+b.chr
  50         results.each do |k,v|
  51                 ans+=v
  52         end
  53         render :text=>ans
  54
  55   end
  56
  57
  58         # ====================================================================
  59         # Remote calls
  60
  61         # ----- getpresets
  62         #               return presets,presetmenus and presetnames arrays
  63
  64         def getpresets
  65                 presets={}
  66                 presetmenus={}; presetmenus['point']=[]; presetmenus['way']=[]
  67                 presetnames={}; presetnames['point']={}; presetnames['way']={}
  68                 presettype=''
  69                 presetcategory=''
  70
  71                 File.open("config/potlatch/presets.txt") do |file|
  72                         file.each_line {|line|
  73                                 t=line.chomp
  74                                 if (t=~/(\w+)\/(\w+)/) then
  75                                         presettype=$1
  76                                         presetcategory=$2
  77                                         presetmenus[presettype].push(presetcategory)
  78                                         presetnames[presettype][presetcategory]=["(no preset)"]
  79                                 elsif (t=~/^(.+):\s?(.+)$/) then
  80                                         pre=$1; kv=$2
  81                                         presetnames[presettype][presetcategory].push(pre)
  82                                         presets[pre]={}
  83                                         kv.split(',').each {|a|
  84                                                 if (a=~/^(.+)=(.*)$/) then presets[pre][$1]=$2 end
  85                                         }
  86                                 end
  87                         }
  88                 end
  89                 [presets,presetmenus,presetnames]
  90         end
  91
  92         # ----- whichways(left,bottom,right,top)
  93         #               return array of ways in current bounding box
  94         #               at present, instead of using correct (=more complex) SQL to find
  95         #               corner-crossing ways, it simply enlarges the bounding box by +/- 0.01
  96
  97         def whichways(args)
  98                 waylist=WaySegment.find_by_sql("SELECT DISTINCT current_way_segments.id AS wayid"+
  99                          "  FROM current_way_segments,current_segments,current_nodes "+
 100                          " WHERE segment_id=current_segments.id "+
 101                          "   AND current_segments.visible=1 "+
 102                          "   AND node_a=current_nodes.id "+
 103                          "   AND (latitude  BETWEEN "+(args[1].to_f-0.01).to_s+" AND "+(args[3].to_f+0.01).to_s+") "+
 104                          "   AND (longitude BETWEEN "+(args[0].to_f-0.01).to_s+" AND "+(args[2].to_f+0.01).to_s+")")
 105                 ways=[]
 106                 waylist.each {|a|
 107                         ways<<a.wayid.to_i
 108                 }
 109                 ways
 110         end
 111
 112         # ----- getway (objectname, way, baselong, basey, masterscale)
 113         #               returns objectname, array of co-ordinates, attributes,
 114         #                               xmin,xmax,ymin,ymax
 115
 116         def getway(args)
 117                 objname,wayid,baselong,basey,masterscale=args
 118                 wayid=wayid.to_i
 119                 points=[]
 120                 lastid=-1
 121                 xmin=999999; xmax=-999999
 122                 ymin=999999; ymax=-999999
 123
 124                 readwayquery(wayid).each {|row|
 125                         xs1=long2coord(row['long1'].to_f,baselong,masterscale); ys1=lat2coord(row['lat1'].to_f,basey,masterscale)
 126                         xs2=long2coord(row['long2'].to_f,baselong,masterscale); ys2=lat2coord(row['lat2'].to_f,basey,masterscale)
 127                         if (row['id1'].to_i!=lastid)
 128                                 points<<[xs1,ys1,row['id1'].to_i,0,tag2array(row['tags1']),0]
 129                         end
 130                         lastid=row['id2'].to_i
 131                         points<<[xs2,ys2,row['id2'].to_i,1,tag2array(row['tags2']),row['segment_id'].to_i]
 132                         xmin=[xmin,row['long1'].to_f,row['long2'].to_f].min
 133                         xmax=[xmax,row['long1'].to_f,row['long2'].to_f].max
 134                         ymin=[ymin,row['lat1'].to_f,row['lat2'].to_f].min
 135                         ymax=[ymax,row['lat1'].to_f,row['lat2'].to_f].max
 136                 }
 137
 138                 attributes={}
 139                 attrlist=ActiveRecord::Base.connection.select_all "SELECT k,v FROM current_way_tags WHERE id=#{wayid}"
 140                 attrlist.each {|a| attributes[a['k']]=a['v'] }
 141
 142                 [objname,points,attributes,xmin,xmax,ymin,ymax]
 143         end
 144
 145         # ----- putway (user token, way, array of co-ordinates, array of attributes,
 146         #                               baselong, basey, masterscale)
 147         #               returns current way ID, new way ID, hash of renumbered nodes,
 148         #                               xmin,xmax,ymin,ymax
 149
 150         def putway(args)
 151                 usertoken,originalway,points,attributes,baselong,basey,masterscale=args
 152                 uid=getuserid(usertoken); if !uid then return end
 153                 db_uqs='uniq'+uid.to_s+originalway.to_i.abs.to_s+Time.new.to_i.to_s     # temp uniquesegments table name, typically 51 chars
 154                 db_now='@now'+uid.to_s+originalway.to_i.abs.to_s+Time.new.to_i.to_s     # 'now' variable name, typically 51 chars
 155                 ActiveRecord::Base.connection.execute("SET #{db_now}=NOW()")
 156                 originalway=originalway.to_i
 157
 158                 # -- 3. read original way into memory
 159
 160                 xc={}; yc={}; tagc={}; seg={}
 161                 if (originalway>0)
 162                         way=originalway
 163                         readwayquery(way).each { |row|
 164                                 id1=row['id1'].to_i; xc[id1]=row['long1'].to_f; yc[id1]=row['lat1'].to_f; tagc[id1]=row['tags1']
 165                                 id2=row['id2'].to_i; xc[id2]=row['long2'].to_f; yc[id2]=row['lat2'].to_f; tagc[id2]=row['tags2']
 166                                 seg[row['segment_id'].to_i]=id1.to_s+'-'+id2.to_s
 167                         }
 168                 else
 169                         way=ActiveRecord::Base.connection.insert("INSERT INTO current_ways (user_id,timestamp,visible) VALUES (#{uid},#{db_now},1)")
 170                 end
 171
 172                 # -- 4. get version by inserting new row into ways
 173
 174                 version=ActiveRecord::Base.connection.insert("INSERT INTO ways (id,user_id,timestamp,visible) VALUES (#{way},#{uid},#{db_now},1)")
 175
 176                 # -- 5. compare nodes and update xmin,xmax,ymin,ymax
 177
 178                 xmin=999999; xmax=-999999
 179                 ymin=999999; ymax=-999999
 180                 insertsql=''
 181                 nodelist=''
 182                 renumberednodes={}
 183
 184                 points.each_index do |i|
 185                         xs=coord2long(points[i][0],masterscale,baselong)
 186                         ys=coord2lat(points[i][1],masterscale,basey)
 187                         xmin=[xs,xmin].min; xmax=[xs,xmax].max
 188                         ymin=[ys,ymin].min; ymax=[ys,ymax].max
 189                         node=points[i][2].to_i
 190                         tagstr=array2tag(points[i][4])
 191                         tagsql="'"+sqlescape(tagstr)+"'"
 192
 193                         # compare node
 194                         if node<0
 195                                 # new node - create
 196                                 newnode=ActiveRecord::Base.connection.insert("INSERT INTO current_nodes (   latitude,longitude,timestamp,user_id,visible,tags) VALUES (           #{ys},#{xs},#{db_now},#{uid},1,#{tagsql})")
 197                                                 ActiveRecord::Base.connection.insert("INSERT INTO nodes         (id,latitude,longitude,timestamp,user_id,visible,tags) VALUES (#{newnode},#{ys},#{xs},#{db_now},#{uid},1,#{tagsql})")
 198                                 points[i][2]=newnode
 199                                 renumberednodes[node.to_s]=newnode.to_s
 200
 201                         elsif xc.has_key?(node)
 202                                 # old node from original way - update
 203                                 if (xs!=xc[node] or (ys/0.0000001).round!=(yc[node]/0.0000001).round or tagstr!=tagc[node])
 204                                         ActiveRecord::Base.connection.insert("INSERT INTO nodes (id,latitude,longitude,timestamp,user_id,visible,tags) VALUES (#{node},#{ys},#{xs},#{db_now},#{uid},1,#{tagsql})")
 205                                         ActiveRecord::Base.connection.update("UPDATE current_nodes SET latitude=#{ys},longitude=#{xs},timestamp=#{db_now},user_id=#{uid},tags=#{tagsql},visible=1 WHERE id=#{node}")
 206                                 else
 207                                         if (nodelist!='') then nodelist+=',' end; nodelist+=node.to_s
 208                                 end
 209                         else
 210                                 # old node, created in another way and now added to this way
 211                                 if (nodelist!='') then nodelist+=',' end; nodelist+=node.to_s
 212                         end
 213
 214                 end
 215
 216                 if nodelist!='' then
 217                         ActiveRecord::Base.connection.update("UPDATE current_nodes SET timestamp=#{db_now},user_id=#{uid},visible=1 WHERE id IN (#{nodelist})")
 218                 end
 219
 220                 # -- 6.i compare segments
 221
 222                 numberedsegments={}
 223                 seglist=''
 224                 for i in (0..(points.length-2))
 225                         if (points[i+1][3].to_i==0) then next end
 226                         segid=points[i+1][5].to_i
 227                         from =points[i  ][2].to_i
 228                         to   =points[i+1][2].to_i
 229                         if seg.has_key?(segid)
 230                                 if seg[segid]=="#{from}-#{to}" then
 231                                         if (seglist!='') then seglist+=',' end; seglist+=segid.to_s
 232                                         next
 233                                 end
 234                         end
 235                         segid=ActiveRecord::Base.connection.insert("INSERT INTO current_segments (   node_a,node_b,timestamp,user_id,visible,tags) VALUES (         #{from},#{to},#{db_now},#{uid},1,'')")
 236                                   ActiveRecord::Base.connection.insert("INSERT INTO segments         (id,node_a,node_b,timestamp,user_id,visible,tags) VALUES (#{segid},#{from},#{to},#{db_now},#{uid},1,'')")
 237                         points[i+1][5]=segid
 238                         numberedsegments[(i+1).to_s]=segid.to_s
 239                 end
 240                 # numberedsegments.each{|a,b| RAILS_DEFAULT_LOGGER.error("Sending back: seg no. #{a} -> id #{b}") }
 241
 242                 if seglist!='' then
 243                         ActiveRecord::Base.connection.update("UPDATE current_segments SET timestamp=#{db_now},user_id=#{uid},visible=1 WHERE id IN (#{seglist})")
 244                 end
 245
 246
 247                 # -- 6.ii insert new way segments
 248
 249                 createuniquesegments(way,db_uqs)
 250
 251                 # a=''
 252                 # ActiveRecord::Base.connection.select_values("SELECT segment_id FROM #{db_uqs}").each {|b| a+=b+',' }
 253                 # RAILS_DEFAULT_LOGGER.error("Unique segments are #{a}")
 254                 # a=ActiveRecord::Base.connection.select_value("SELECT #{db_now}")
 255                 # RAILS_DEFAULT_LOGGER.error("Timestamp of this edit is #{a}")
 256                 # RAILS_DEFAULT_LOGGER.error("Userid of this edit is #{uid}")
 257
 258                 #               delete nodes from uniquesegments (and not in modified way)
 259
 260                 sql=<<-EOF
 261                         INSERT INTO nodes (id,latitude,longitude,timestamp,user_id,visible)
 262                         SELECT DISTINCT cn.id,cn.latitude,cn.longitude,#{db_now},#{uid},0
 263                           FROM current_nodes AS cn,
 264                                    current_segments AS cs,
 265                                    #{db_uqs} AS us
 266                          WHERE(cn.id=cs.node_a OR cn.id=cs.node_b)
 267                            AND cs.id=us.segment_id AND cs.visible=1
 268                            AND (cn.timestamp!=#{db_now} OR cn.user_id!=#{uid})
 269                 EOF
 270                 ActiveRecord::Base.connection.insert(sql)
 271
 272                 sql=<<-EOF
 273                         UPDATE current_nodes AS cn,
 274                                    current_segments AS cs,
 275                                    #{db_uqs} AS us
 276                            SET cn.timestamp=#{db_now},cn.visible=0,cn.user_id=#{uid}
 277                          WHERE (cn.id=cs.node_a OR cn.id=cs.node_b)
 278                            AND cs.id=us.segment_id AND cs.visible=1
 279                            AND (cn.timestamp!=#{db_now} OR cn.user_id!=#{uid})
 280                 EOF
 281                 ActiveRecord::Base.connection.update(sql)
 282
 283                 #               delete segments from uniquesegments (and not in modified way)
 284
 285                 sql=<<-EOF
 286                         INSERT INTO segments (id,node_a,node_b,timestamp,user_id,visible)
 287                         SELECT DISTINCT segment_id,node_a,node_b,#{db_now},#{uid},0
 288                           FROM current_segments AS cs, #{db_uqs} AS us
 289                          WHERE cs.id=us.segment_id AND cs.visible=1
 290                            AND (cs.timestamp!=#{db_now} OR cs.user_id!=#{uid})
 291                 EOF
 292                 ActiveRecord::Base.connection.insert(sql)
 293
 294                 sql=<<-EOF
 295                            UPDATE current_segments AS cs, #{db_uqs} AS us
 296                                   SET cs.timestamp=#{db_now},cs.visible=0,cs.user_id=#{uid}
 297                                 WHERE cs.id=us.segment_id AND cs.visible=1
 298                                   AND (cs.timestamp!=#{db_now} OR cs.user_id!=#{uid})
 299                 EOF
 300                 ActiveRecord::Base.connection.update(sql)
 301                 ActiveRecord::Base.connection.execute("DROP TABLE #{db_uqs}")
 302
 303                 #               insert new version of route into way_segments
 304
 305                 insertsql =''
 306                 currentsql=''
 307                 sequence  =1
 308                 for i in (0..(points.length-2))
 309                         if (points[i+1][3].to_i==0) then next end
 310                         if insertsql !='' then insertsql +=',' end
 311                         if currentsql!='' then currentsql+=',' end
 312                         insertsql +="(#{way},#{points[i+1][5]},#{version})"
 313                         currentsql+="(#{way},#{points[i+1][5]},#{sequence})"
 314                         sequence  +=1
 315                 end
 316
 317                 ActiveRecord::Base.connection.execute("DELETE FROM current_way_segments WHERE id=#{way}");
 318                 ActiveRecord::Base.connection.insert("INSERT INTO         way_segments (id,segment_id,version    ) VALUES #{insertsql}");
 319                 ActiveRecord::Base.connection.insert("INSERT INTO current_way_segments (id,segment_id,sequence_id) VALUES #{currentsql}");
 320
 321                 # -- 7. insert new way tags
 322
 323                 insertsql =''
 324                 currentsql=''
 325                 attributes.each do |k,v|
 326                         if v=='' then next end
 327                         if v[0,6]=='(type ' then next end
 328                         if insertsql !='' then insertsql +=',' end
 329                         if currentsql!='' then currentsql+=',' end
 330                         insertsql +="(#{way},'"+sqlescape(k)+"','"+sqlescape(v)+"',version)"
 331                         currentsql+="(#{way},'"+sqlescape(k)+"','"+sqlescape(v)+"')"
 332                 end
 333
 334                 ActiveRecord::Base.connection.execute("DELETE FROM current_way_tags WHERE id=#{way}")
 335                 if (insertsql !='') then ActiveRecord::Base.connection.insert("INSERT INTO way_tags (id,k,v,version) VALUES #{insertsql}" ) end
 336                 if (currentsql!='') then ActiveRecord::Base.connection.insert("INSERT INTO current_way_tags (id,k,v) VALUES #{currentsql}") end
 337
 338                 [originalway,way,renumberednodes,numberedsegments,xmin,xmax,ymin,ymax]
 339         end
 340
 341         # ----- deleteway (user token, way)
 342         #               returns way ID only
 343
 344         def deleteway(args)
 345                 usertoken,way=args
 346                 uid=getuserid(usertoken); if !uid then return end
 347                 way=way.to_i
 348
 349                 db_uqs='uniq'+uid.to_s+way.to_i.abs.to_s+Time.new.to_i.to_s     # temp uniquesegments table name, typically 51 chars
 350                 db_now='@now'+uid.to_s+way.to_i.abs.to_s+Time.new.to_i.to_s     # 'now' variable name, typically 51 chars
 351                 ActiveRecord::Base.connection.execute("SET #{db_now}=NOW()")
 352                 createuniquesegments(way,db_uqs)
 353
 354                 sql=<<-EOF
 355                         INSERT INTO nodes (id,latitude,longitude,timestamp,user_id,visible)
 356                         SELECT DISTINCT cn.id,cn.latitude,cn.longitude,#{db_now},#{uid},0
 357                           FROM current_nodes AS cn,
 358                                    current_segments AS cs,
 359                                    #{db_uqs} AS us
 360                          WHERE (cn.id=cs.node_a OR cn.id=cs.node_b)
 361                            AND cs.id=us.segment_id
 362                 EOF
 363                 ActiveRecord::Base.connection.insert(sql)
 364
 365                 sql=<<-EOF
 366                         UPDATE current_nodes AS cn,
 367                                    current_segments AS cs,
 368                                    #{db_uqs} AS us
 369                            SET cn.timestamp=#{db_now},cn.visible=0,cn.user_id=#{uid}
 370                          WHERE (cn.id=cs.node_a OR cn.id=cs.node_b)
 371                            AND cs.id=us.segment_id
 372                 EOF
 373                 ActiveRecord::Base.connection.update(sql)
 374
 375                 # -     delete any otherwise unused segments
 376
 377                 sql=<<-EOF
 378                         INSERT INTO segments (id,node_a,node_b,timestamp,user_id,visible)
 379                         SELECT DISTINCT segment_id,node_a,node_b,#{db_now},#{uid},0
 380                           FROM current_segments AS cs, #{db_uqs} AS us
 381                          WHERE cs.id=us.segment_id
 382                 EOF
 383                 ActiveRecord::Base.connection.insert(sql)
 384
 385                 sql=<<-EOF
 386                         UPDATE current_segments AS cs, #{db_uqs} AS us
 387                            SET cs.timestamp=#{db_now},cs.visible=0,cs.user_id=#{uid}
 388                          WHERE cs.id=us.segment_id
 389                 EOF
 390                 ActiveRecord::Base.connection.update(sql)
 391                 ActiveRecord::Base.connection.execute("DROP TABLE #{db_uqs}")
 392
 393                 # - delete way
 394
 395                 ActiveRecord::Base.connection.insert("INSERT INTO ways (id,user_id,timestamp,visible) VALUES (#{way},#{uid},#{db_now},0)")
 396                 ActiveRecord::Base.connection.update("UPDATE current_ways SET user_id=#{uid},timestamp=#{db_now},visible=0 WHERE id=#{way}")
 397                 ActiveRecord::Base.connection.execute("DELETE FROM current_way_segments WHERE id=#{way}")
 398                 ActiveRecord::Base.connection.execute("DELETE FROM current_way_tags WHERE id=#{way}")
 399
 400                 way
 401         end
 402
 403         # ====================================================================
 404         # Support functions for remote calls
 405
 406         def readwayquery(id)
 407                 ActiveRecord::Base.connection.select_all "SELECT n1.latitude AS lat1,n1.longitude AS long1,n1.id AS id1,n1.tags as tags1, "+
 408                         "                 n2.latitude AS lat2,n2.longitude AS long2,n2.id AS id2,n2.tags as tags2,segment_id "+
 409                         "    FROM current_way_segments,current_segments,current_nodes AS n1,current_nodes AS n2 "+
 410                         "   WHERE current_way_segments.id=#{id} "+
 411                         "     AND segment_id=current_segments.id "+
 412                         "     AND n1.id=node_a and n2.id=node_b "+
 413                         "   ORDER BY sequence_id"
 414         end
 415
 416         def createuniquesegments(way,uqs_name)
 417                 sql=<<-EOF
 418                         CREATE TEMPORARY TABLE #{uqs_name}
 419                                                         SELECT a.segment_id,COUNT(a.segment_id) AS ct
 420                                                           FROM current_way_segments AS a, current_way_segments AS b
 421                                                          WHERE a.segment_id=b.segment_id
 422                                                            AND a.id=#{way}
 423                                                   GROUP BY a.segment_id
 424                                                         HAVING ct=1
 425                 EOF
 426                 ActiveRecord::Base.connection.execute(sql)
 427         end
 428
 429
 430         def sqlescape(a)
 431                 a.gsub("'","''").gsub(92.chr,92.chr+92.chr)
 432         end
 433
 434         def tag2array(a)
 435                 tags={}
 436                 a.gsub(';;;','#%').split(';').each do |b|
 437                         b.gsub!('#%',';;;')
 438                         b.gsub!('===','#%')
 439                         k,v=b.split('=')
 440                         tags[k.gsub('#%','=')]=v.gsub('#%','=')
 441                 end
 442                 tags
 443         end
 444
 445         def array2tag(a)
 446                 str=''
 447                 a.each do |k,v|
 448                         if v=='' then next end
 449                         if v[0,6]=='(type ' then next end
 450                         if str!='' then str+=';' end
 451                         str+=k.gsub(';',';;;').gsub('=','===')+'='+v.gsub(';',';;;').gsub('=','===')
 452                 end
 453                 str
 454         end
 455
 456         def getuserid(token)
 457                 token=sqlescape(token)
 458                 if (token=~/^(.+)\+(.+)$/) then
 459                         return ActiveRecord::Base.connection.select_value("SELECT id FROM users WHERE active=1 AND timeout>NOW() AND email='#{$1}' AND pass_crypt=MD5('#{$2}')")
 460                 else
 461                         return ActiveRecord::Base.connection.select_value("SELECT id FROM users WHERE active=1 AND timeout>NOW() AND token='#{token}'")
 462                 end
 463         end
 464
 465
 466
 467         # ====================================================================
 468         # AMF read subroutines
 469
 470         # ----- getint          return two-byte integer
 471         # ----- getlong         return four-byte long
 472         # ----- getstring       return string with two-byte length
 473         # ----- getdouble       return eight-byte double-precision float
 474         # ----- getobject       return object/hash
 475         # ----- getarray        return numeric array
 476
 477         def getint(s)
 478                 s.getc*256+s.getc
 479         end
 480
 481         def getlong(s)
 482                 ((s.getc*256+s.getc)*256+s.getc)*256+s.getc
 483         end
 484
 485         def getstring(s)
 486                 len=s.getc*256+s.getc
 487                 s.read(len)
 488         end
 489
 490         def getdouble(s)
 491                 a=s.read(8).unpack('G')                 # G big-endian, E little-endian
 492                 a[0]
 493         end
 494
 495         def getarray(s)
 496                 len=getlong(s)
 497                 arr=[]
 498                 for i in (0..len-1)
 499                         arr[i]=getvalue(s)
 500                 end
 501                 arr
 502         end
 503
 504         def getobject(s)
 505                 arr={}
 506                 while (key=getstring(s))
 507                         if (key=='') then break end
 508                         arr[key]=getvalue(s)
 509                 end
 510                 s.getc          # skip the 9 'end of object' value
 511                 arr
 512         end
 513
 514         # ----- getvalue        parse and get value
 515
 516         def getvalue(s)
 517                 case s.getc
 518                         when 0; return getdouble(s)                     # number
 519                         when 1; return s.getc                           # boolean
 520                         when 2; return getstring(s)                     # string
 521                         when 3; return getobject(s)                     # object/hash
 522                         when 5; return nil                                      # null
 523                         when 6; return nil                                      # undefined
 524                         when 8; s.read(4)                                       # mixedArray
 525                                         return getobject(s)                     #  |
 526                         when 10;return getarray(s)                      # array
 527                         else;   return nil                                      # error
 528                 end
 529         end
 530
 531         # ====================================================================
 532         # AMF write subroutines
 533
 534         # ----- putdata         envelope data into AMF writeable form
 535         # ----- encodevalue     pack variables as AMF
 536
 537         def putdata(index,n)
 538                 d =encodestring(index+"/onResult")
 539                 d+=encodestring("null")
 540                 d+=[-1].pack("N")
 541                 d+=encodevalue(n)
 542         end
 543
 544         def encodevalue(n)
 545                 case n.class.to_s
 546                         when 'Array'
 547                                 a=10.chr+encodelong(n.length)
 548                                 n.each do |b|
 549                                         a+=encodevalue(b)
 550                                 end
 551                                 a
 552                         when 'Hash'
 553                                 a=3.chr
 554                                 n.each do |k,v|
 555                                         a+=encodestring(k)+encodevalue(v)
 556                                 end
 557                                 a+0.chr+0.chr+9.chr
 558                         when 'String'
 559                                 2.chr+encodestring(n)
 560                         when 'Bignum','Fixnum','Float'
 561                                 0.chr+encodedouble(n)
 562                         when 'NilClass'
 563                                 5.chr
 564                         else
 565                                 RAILS_DEFAULT_LOGGER.error("Unexpected Ruby type for AMF conversion: "+n.class.to_s)
 566                 end
 567         end
 568
 569         # ----- encodestring    encode string with two-byte length
 570         # ----- encodedouble    encode number as eight-byte double precision float
 571         # ----- encodelong              encode number as four-byte long
 572
 573         def encodestring(n)
 574                 a,b=n.size.divmod(256)
 575                 a.chr+b.chr+n
 576         end
 577
 578         def encodedouble(n)
 579                 [n].pack('G')
 580         end
 581
 582         def encodelong(n)
 583                 [n].pack('N')
 584         end
 585
 586         # ====================================================================
 587         # Co-ordinate conversion
 588
 589         def lat2coord(a,basey,masterscale)
 590                 -(lat2y(a)-basey)*masterscale+250
 591         end
 592
 593         def long2coord(a,baselong,masterscale)
 594                 (a-baselong)*masterscale+350
 595         end
 596
 597         def lat2y(a)
 598                 180/Math::PI * Math.log(Math.tan(Math::PI/4+a*(Math::PI/180)/2))
 599         end
 600
 601         def coord2lat(a,masterscale,basey)
 602                 y2lat((a-250)/-masterscale+basey)
 603         end
 604
 605         def coord2long(a,masterscale,baselong)
 606                 (a-350)/masterscale+baselong
 607         end
 608
 609         def y2lat(a)
 610                 180/Math::PI * (2*Math.atan(Math.exp(a*Math::PI/180))-Math::PI/2)
 611         end
 612
 613
 614 end