app/controllers/amf_controller.rb

   1 class AmfController < ApplicationController
   2   require 'stringio'
   3
   4   # Still to do:
   5   # - all db interaction
   6   # - user authentication
   7   # - (also pass lat/lon through from view tab to edit tab)
   8
   9   # ====================================================================
  10   # Main AMF handler
  11
  12   # ---- talk   process AMF request
  13
  14   def talk
  15         req=StringIO.new(request.raw_post)      # Get POST data as request
  16         req.read(2)                                                     # Skip version indicator and client ID
  17         results={}                                                      # Results of each body
  18
  19         # -------------
  20         # Parse request
  21
  22         headers=getint(req)                                     # Read number of headers
  23         for i in (1..headers)                           # Read each header
  24                 name=getstring(req)                             #  |
  25                 req.getc                                                #  | skip boolean
  26                 value=getvalue(req)                             #  |
  27                 header["name"]=value                    #  |
  28         end
  29
  30         bodies=getint(req)                                      # Read number of bodies
  31         for i in (1..bodies)                            # Read each body
  32                 message=getstring(req)                  #  | get message name
  33                 index=getstring(req)                    #  | get index in response sequence
  34                 bytes=getlong(req)                              #  | get total size in bytes
  35                 args=getvalue(req)                              #  | get response (probably an array)
  36
  37                 case message
  38                         when 'getpresets';      results[index]=putdata(index,getpresets)
  39                         when 'whichways';       results[index]=putdata(index,whichways(args))
  40                         when 'getway';          results[index]=putdata(index,getway(args))
  41                         when 'putway';          results[index]=putdata(index,putway(args))
  42                         when 'deleteway';       results[index]=putdata(index,deleteway(args))
  43                 end
  44         end
  45
  46         # ------------------
  47         # Write out response
  48
  49         response.headers["Content-Type"]="application/x-amf"
  50         a,b=results.length.divmod(256)
  51         ans=0.chr+0.chr+0.chr+0.chr+a.chr+b.chr
  52         results.each do |k,v|
  53                 ans+=v
  54         end
  55         render :text=>ans
  56
  57   end
  58
  59
  60         # ====================================================================
  61         # Remote calls
  62
  63         def getpresets
  64                 presets={}
  65                 presetmenus={}; presetmenus['point']=[]; presetmenus['way']=[]
  66                 presetnames={}; presetnames['point']={}; presetnames['way']={}
  67                 presettype=''
  68                 presetcategory=''
  69
  70                 File.open("config/potlatch/presets.txt") do |file|
  71                         file.each_line {|line|
  72                                 t=line.chomp
  73                                 if (t=~/(\w+)\/(\w+)/) then
  74                                         presettype=$1
  75                                         presetcategory=$2
  76                                         presetmenus[presettype].push(presetcategory)
  77                                         presetnames[presettype][presetcategory]=["(no preset)"]
  78                                 elsif (t=~/^(.+):\s?(.+)$/) then
  79                                         pre=$1; kv=$2
  80                                         presetnames[presettype][presetcategory].push(pre)
  81                                         presets[pre]={}
  82                                         kv.split(',').each {|a|
  83                                                 if (a=~/^(.+)=(.*)$/) then presets[pre][$1]=$2 end
  84                                         }
  85                                 end
  86                         }
  87                 end
  88                 [presets,presetmenus,presetnames]
  89         end
  90
  91         def whichways(args)
  92                 # to do
  93         end
  94
  95         def getway(args)
  96                 # to do
  97         end
  98
  99         def putway(args)
 100                 # to do
 101         end
 102
 103         def deleteway(args)
 104                 # to do
 105         end
 106
 107         # need support functions here too:
 108         #       database support functions (readwayquery, createuniquesegments)
 109         #       tag2array, array2tag
 110         #       getuserid
 111
 112         # ====================================================================
 113         # AMF read subroutines
 114
 115         # ----- getint          return two-byte integer
 116         # ----- getlong         return four-byte long
 117         # ----- getstring       return string with two-byte length
 118         # ----- getdouble       return eight-byte double-precision float
 119         # ----- getobject       return object/hash
 120         # ----- getarray        return numeric array
 121
 122         def getint(s)
 123                 s.getc*256+s.getc
 124         end
 125
 126         def getlong(s)
 127                 ((s.getc*256+s.getc)*256+s.getc)*256+s.getc
 128         end
 129
 130         def getstring(s)
 131                 len=s.getc*256+s.getc
 132                 s.read(len)
 133         end
 134
 135         def getdouble(s)
 136                 a=s.read(8).unpack('G')                 # G big-endian, E little-endian
 137                 a[0]
 138         end
 139
 140         def getarray(s)
 141                 len=getlong(s)
 142                 arr=[]
 143                 for i in (0..len-1)
 144                         arr[i]=getvalue(s)
 145                 end
 146                 arr
 147         end
 148
 149         def getobject(s)
 150                 arr={}
 151                 while (key=getstring(s))
 152                         if (key=='') then break end
 153                         arr[key]=getvalue(s)
 154                 end
 155                 s.getc          # skip the 9 'end of object' value
 156                 arr
 157         end
 158
 159         # ----- getvalue        parse and get value
 160
 161         def getvalue(s)
 162                 case s.getc
 163                         when 0; return getdouble(s)                     # number
 164                         when 1; return s.getc                           # boolean
 165                         when 2; return getstring(s)                     # string
 166                         when 3; return getobject(s)                     # object/hash
 167                         when 5; return nil                                      # null
 168                         when 6; return nil                                      # undefined
 169                         when 8; s.read(4)                                       # mixedArray
 170                                         return getobject(s)                     #  |
 171                         when 10;return getarray(s)                      # array
 172                         else;   return nil                                      # error
 173                 end
 174         end
 175
 176         # ====================================================================
 177         # AMF write subroutines
 178
 179         # ----- putdata         envelope data into AMF writeable form
 180         # ----- encodevalue     pack variables as AMF
 181
 182         def putdata(index,n)
 183                 d =encodestring(index+"/onResult")
 184                 d+=encodestring("null")
 185                 d+=[-1].pack("N")
 186                 d+=encodevalue(n)
 187         end
 188
 189         def encodevalue(n)
 190                 case n.class.to_s
 191                         when 'Array'
 192                                 a=10.chr+encodelong(n.length)
 193                                 n.each do |b|
 194                                         a+=encodevalue(b)
 195                                 end
 196                                 a
 197                         when 'Hash'
 198                                 a=3.chr
 199                                 n.each do |k,v|
 200                                         a+=encodestring(k)+encodevalue(v)
 201                                 end
 202                                 a+0.chr+0.chr+9.chr
 203                         when 'String'
 204                                 2.chr+encodestring(n)
 205                         when 'Bignum','Fixnum','Float'
 206                                 0.chr+encodedouble(n)
 207                         when 'NilClass'
 208                                 5.chr
 209                 end
 210         end
 211
 212         # ----- encodestring    encode string with two-byte length
 213         # ----- encodedouble    encode number as eight-byte double precision float
 214         # ----- encodelong              encode number as four-byte long
 215
 216         def encodestring(n)
 217                 a,b=n.size.divmod(256)
 218                 a.chr+b.chr+n
 219         end
 220
 221         def encodedouble(n)
 222                 [n].pack('G')
 223         end
 224
 225         def encodelong(n)
 226                 [n].pack('N')
 227         end
 228
 229         # ====================================================================
 230         # Co-ordinate conversion
 231
 232         def lat2coord(a)
 233                 -(lat2y(a)-$basey)*$masterscale+250
 234         end
 235
 236         def long2coord(a)
 237                 (a-$baselong)*$masterscale+350
 238         end
 239
 240         def lat2y(a)
 241                 180/Math::PI * Math.log(Math.tan(Math::PI/4+a*(Math::PI/180)/2))
 242         end
 243
 244         def coord2lat(a)
 245                 y2lat((a-250)/-$masterscale+$basey)
 246         end
 247
 248         def coord2long(a)
 249                 (a-350)/$masterscale+$baselong
 250         end
 251
 252         def y2lat(a)
 253                 180/Math::PI * (2*Math.atan(Math.exp(a*Math::PI/180))-Math::PI/2)
 254         end
 255
 256
 257 end