# HG changeset patch
# User jbe
# Date 1434050249 -7200
# Node ID 6c1561547f79217bcb813828aabe4d2a504a680f
# Parent  d5b8295d035eb83aba97b8ccefe5a2f8ed610b42
Work on new HTTP module implementation

diff -r d5b8295d035e -r 6c1561547f79 moonbridge_http.lua
--- a/moonbridge_http.lua	Thu Jun 11 00:54:18 2015 +0200
+++ b/moonbridge_http.lua	Thu Jun 11 21:17:29 2015 +0200
@@ -176,20 +176,182 @@
         poll(nil, socket_set)
       end
     end
+    local function consume_all()
+      while consume do
+        consume()
+      end
+    end
     repeat
+      -- create a new request object:
       local request = {
         socket = socket,
         cookies = {}
       }
+      -- local variables to track the state:
+      local state = "init"        -- one of:
+      --  "init"                  (initial state)
+      --  "no_status_sent"        (configuration complete)
+      --  "info_status_sent"      (1xx status code has been sent)
+      --  "bodyless_status_sent"  (204/304 status code has been sent)
+      --  "status_sent"           (regular status code has been sent)
+      --  "headers_sent"          (headers have been terminated)
+      --  "finished"              (request has been answered completely)
+      local close_requested = false  -- "Connection: close" requested
+      local close_responded = false  -- "Connection: close" sent
+      local content_length = nil  -- value of Content-Length header sent
+      -- functions to send data to the browser:
       local function send(...)
         assert(socket:write_call(unblock, ...))
       end
+      local function send_flush(...)
+        assert(socket:flush_call(unblock, ...))
+      end
+      -- TODO:
+      local function prepare()
+        if state == "prepare" then
+          error("Unexpected internal status in HTTP engine")
+        elseif state ~= "init" then
+          return
+        end
+        state = "prepare"
+        -- TODO
+        state = "no_status_sent"
+      end
+      -- TODO:
+      local function finish_response()
+        if close_responded then
+          -- discard any input:
+          consume = drain
+          -- close output stream:
+          send_flush()
+          assert(socket:finish())
+          -- wait for EOF of peer to avoid immediate TCP RST condition:
+          consume_all()
+          -- fully close socket:
+          --socket_closed = true  -- avoid double close on error  -- TODO
+          assert(socket:close())
+        else
+          assert(socket:flush())
+          consume_all()
+        end
+      end
+      -- method to send a HTTP response status (e.g. "200 OK"):
+      function request:send_status(status)
+        prepare()
+        if state == "info_status_sent" then
+          send_flush("\r\n")
+        elseif state ~= "no_status_sent" then
+          error("HTTP status has already been sent")
+        end
+        local status1 = string.sub(status, 1, 1)
+        local status3 = string.sub(status, 1, 3)
+        send("HTTP/1.1 ", status, "\r\n", preamble)
+        local wrb = status_without_response_body[status3]
+        if wrb then
+          state = "bodyless_status_sent"
+          if wrb == "zero_content_length" then
+            request:send_header("Content-Length", 0)
+          end
+        elseif status1 == "1" then
+          state = "info_status_sent"
+        else
+          state = "status_sent"
+        end
+      end
+      -- method to send a HTTP response header:
+      -- (key and value must be provided as separate args)
+      function request:send_header(key, value)
+        prepare()
+        if state == "no_status_sent" then
+          error("HTTP status has not been sent yet")
+        elseif
+          state ~= "info_status_sent" and
+          state ~= "bodyless_status_sent" and
+          state ~= "status_sent"
+        then
+          error("All HTTP headers have already been sent")
+        end
+        local key_lower = string.lower(key)
+        if key_lower == "content-length" then
+          if state == "info_status_sent" then
+            error("Cannot set Content-Length for informational status response")
+          end
+          local cl = assert(tonumber(value), "Invalid content-length")
+          if content_length == nil then
+            content_length = cl
+          elseif content_length == cl then
+            return
+          else
+            error("Content-Length has been set multiple times with different values")
+          end
+        elseif key_lower == "connection" then
+          for entry in string.gmatch(string.lower(value), "[^,]+") do
+            if string.match(entry, "^[ \t]*close[ \t]*$") then
+              if state == "info_status_sent" then
+                error("Cannot set \"Connection: close\" for informational status response")
+              end
+              close_responded = true
+              break
+            end
+          end
+        end
+        assert_output(socket:write(key, ": ", value, "\r\n"))
+      end
+      -- method to close connection after sending the response:
+      function request:close_after_finish()
+        prepare()
+        if
+          state == "headers_sent" or
+          state == "finished"
+        then
+          error("All HTTP headers have already been sent")
+        end
+        close_requested = true
+      end
+      -- function to terminate header section in response, optionally flushing:
+      -- (may be called multiple times unless response is finished)
+      local function finish_headers(with_flush)
+        if state == "finished" then
+          error("Response has already been finished")
+        elseif state == "info_status_sent" then
+          send_flush("\r\n")
+          state = "no_status_sent"
+        elseif state == "bodyless_status_sent" then
+          if close_requested and not close_responded then
+            request:send_header("Connection", "close")
+          end
+          send("\r\n")
+          --finish_response() -- TODO
+          state = "finished"
+        elseif state == "status_sent" then
+          if not content_length then
+            request:send_header("Transfer-Encoding", "chunked")
+          end
+          if close_requested and not close_responded then
+            request:send_header("Connection", "close")
+          end
+          send("\r\n")
+          if request.method == "HEAD" then
+            --finish_response() -- TODO
+          elseif with_flush then
+            send_flush()
+          end
+          state = "headers_sent"
+        elseif state ~= "headers_sent" then
+          error("HTTP status has not been sent yet")
+        end
+      end
+      -- method to finish and flush headers:
+      function request:finish_headers()
+        prepare()
+        finish_headers(true)
+      end
       -- wait for input:
       if not poll(socket_set, nil, request_idle_timeout) then
         -- TODO: send error
         return survive
       end
-    until connection_close_responded
+    until close_responded
     return survive
   end
 end