util/httpstream.lua

   1
   2 local setmetatable = setmetatable;
   3 local coroutine = coroutine;
   4 local tonumber = tonumber;
   5
   6 local print = print;
   7 local error = error;
   8 local ser = require "util.serialization".serialize;
   9
  10 local deadroutine = coroutine.create(function() end);
  11 coroutine.resume(deadroutine);
  12
  13 module("httpstream")
  14
  15 local function parser(data, success_cb)
  16         local function readline()
  17                 if not data then coroutine.yield("Unexpected EOF"); end
  18                 local pos, line = (data:find("\r\n", nil, true));
  19                 if not pos then
  20                         local newdata = coroutine.yield();
  21                         if not newdata then data = nil; coroutine.yield("Unexpected EOF"); end
  22                         data = data..newdata;
  23                         return readline();
  24                 end
  25                 line, data = data:sub(1, pos-1), data:sub(pos+2);
  26                 return line;
  27         end
  28         local function readlength(n)
  29                 if not data then coroutine.yield("Unexpected EOF"); end
  30                 while #data < n do
  31                         local newdata = coroutine.yield();
  32                         if not newdata then data = nil; coroutine.yield("Unexpected EOF"); end
  33                         data = data..newdata;
  34                 end
  35                 local r = data:sub(1, n);
  36                 data = data:sub(n + 1);
  37                 return r;
  38         end
  39
  40         while true do
  41                 -- read status line
  42                 local status_line = readline();
  43                 local method, path, httpversion = status_line:match("^(%S+)%s+(%S+)%s+HTTP/(%S+)$");
  44                 if not method then coroutine.yield("invalid-status-line"); end
  45                 -- TODO parse url
  46
  47                 local headers = {}; -- read headers
  48                 while true do
  49                         local line = readline();
  50                         if line == "" then break; end -- headers done
  51                         local key, val = line:match("^([^%s:]+): *(.*)$");
  52                         if not key then coroutine.yield("invalid-header-line"); end -- TODO handle multi-line and invalid headers
  53                         key = key:lower();
  54                         headers[key] = headers[key] and headers[key]..","..val or val;
  55                 end
  56
  57                 -- read body
  58                 local len = tonumber(headers["content-length"]);
  59                 len = len or 0; -- TODO check for invalid len
  60                 local body = readlength(len);
  61
  62                 success_cb({
  63                         method = method;
  64                         path = path;
  65                         httpversion = httpversion;
  66                         headers = headers;
  67                         body = body;
  68                 });
  69         end
  70 end
  71
  72 function new(success_cb, error_cb)
  73         local co = coroutine.create(parser);
  74         return {
  75                 feed = function(self, data)
  76                         local success, result = coroutine.resume(co, data, success_cb);
  77                         if result then
  78                                 if result.method then
  79                                         success_cb(result);
  80                                 else -- error
  81                                         error_cb(result);
  82                                         co = deadroutine;
  83                                 end
  84                         end
  85                 end;
  86         };
  87 end
  88
  89 return _M;