--
-- sfive
--
-- sfive - spreadspace streaming statistics suite is a generic
-- statistic collection tool for streaming server infrastuctures.
-- The system collects and stores meta data like number of views
-- and throughput from a number of streaming servers and stores
-- it in a global data store.
-- The data acquisition is designed to be generic and extensible in
-- order to support different streaming software.
-- sfive also contains tools and applications to filter and visualize
-- live and recorded data.
--
--
-- Copyright (C) 2014 Christian Pointner <equinox@spreadspace.org>
--                    Markus Grueneis <gimpf@gimpf.org>
--
-- This file is part of sfive.
--
-- sfive is free software: you can redistribute it and/or modify
-- it under the terms of the GNU General Public License version 3
-- as published by the Free Software Foundation.
--
-- sfive is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-- GNU General Public License for more details.
--
-- You should have received a copy of the GNU General Public License
-- along with sfive. If not, see <http://www.gnu.org/licenses/>.
--
--
-- Install this by adding the following to your nginx.conf
--
-- location /sfive {
--   allow 127.0.0.1;
--   allow ::1;
--   deny  all;
--
--   content_by_lua_file '/path/to/s5-nginx-fetch.lua';
-- }
--

local lock = locks:new("sfive_locks", { exptime = nil, timeout = 0.001 })
local ok, err = lock:lock("fetch")
if not ok then
   if err == "timeout" then
      ngx.exit(ngx.HTTP_SERVICE_UNAVAILABLE)
   else
      ngx.log(ngx.ERR, "SFive(fetch): failed to acquire fetch lock: " .. err)
      ngx.exit(ngx.HTTP_INTERNAL_SERVER_ERROR)
   end
else
   ngx.log(ngx.INFO, "SFive(fetch): client connected")
   local sfive_data = ngx.shared.sfive_data
   while true do
      logs = sfive_data:get_keys()
      for i, k in ipairs(logs) do
         local ok, err = ngx.say(sfive_data:get(k))
         if not ok then
            ngx.log(ngx.ERR, "SFive(fetch): failed to send data set: ", err)
            break
         end
         sfive_data:delete(k)
      end
      ngx.flush()
      ngx.sleep(0.1)
   end
   ok, err = lock:unlock("fetch")
   if not ok then
      ngx.log(ngx.ERR, "SFive(fetch): unlock error: " .. err)
   end
end