util/httpstream.lua

   1
   2 local coroutine = coroutine;
   3 local tonumber = tonumber;
   4
   5 local deadroutine = coroutine.create(function() end);
   6 coroutine.resume(deadroutine);
   7
   8 module("httpstream")
   9
  10 local function parser(data, success_cb)
  11         local function readline()
  12                 local pos = data:find("\r\n", nil, true);
  13                 while not pos do
  14                         data = data..coroutine.yield();
  15                         pos = data:find("\r\n", nil, true);
  16                 end
  17                 local r = data:sub(1, pos-1);
  18                 data = data:sub(pos+2);
  19                 return r;
  20         end
  21         local function readlength(n)
  22                 while #data < n do
  23                         data = data..coroutine.yield();
  24                 end
  25                 local r = data:sub(1, n);
  26                 data = data:sub(n + 1);
  27                 return r;
  28         end
  29         local function readheaders()
  30                 local headers = {}; -- read headers
  31                 while true do
  32                         local line = readline();
  33                         if line == "" then break; end -- headers done
  34                         local key, val = line:match("^([^%s:]+): *(.*)$");
  35                         if not key then coroutine.yield("invalid-header-line"); end -- TODO handle multi-line and invalid headers
  36                         key = key:lower();
  37                         headers[key] = headers[key] and headers[key]..","..val or val;
  38                 end
  39         end
  40
  41         while true do
  42                 -- read status line
  43                 local status_line = readline();
  44                 local method, path, httpversion = status_line:match("^(%S+)%s+(%S+)%s+HTTP/(%S+)$");
  45                 if not method then coroutine.yield("invalid-status-line"); end
  46                 -- TODO parse url
  47                 local headers = readheaders();
  48
  49                 -- read body
  50                 local len = tonumber(headers["content-length"]);
  51                 len = len or 0; -- TODO check for invalid len
  52                 local body = readlength(len);
  53
  54                 success_cb({
  55                         method = method;
  56                         path = path;
  57                         httpversion = httpversion;
  58                         headers = headers;
  59                         body = body;
  60                 });
  61         end
  62 end
  63
  64 function new(success_cb, error_cb)
  65         local co = coroutine.create(parser);
  66         return {
  67                 feed = function(self, data)
  68                         if not data then
  69                                 co = deadroutine;
  70                                 return error_cb();
  71                         end
  72                         local success, result = coroutine.resume(co, data, success_cb);
  73                         if result then
  74                                 co = deadroutine;
  75                                 return error_cb(result);
  76                         end
  77                 end;
  78         };
  79 end
  80
  81 return _M;