]> git.scottworley.com Git - reliable-chat/blobdiff - server/server.go
/speak requests are permitted cross-origin
[reliable-chat] / server / server.go
index 9ca5e619c1a9d18cd53981af2157458e7caa5cac..963931f696d759459f6cb90512cd796100f88fcb 100644 (file)
@@ -1,3 +1,20 @@
+/*  reliable-chat - multipath chat
+ *  Copyright (C) 2012  Scott Worley <sworley@chkno.net>
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU Affero General Public License as
+ *  published by the Free Software Foundation, either version 3 of the
+ *  License, or (at your option) any later version.
+ *
+ *  This program 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 Affero General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Affero General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 package main
 
 import "container/list"
@@ -10,12 +27,15 @@ import "strconv"
 import "time"
 
 var port = flag.Int("port", 21059, "Port to listen on")
+var localaddress = flag.String("localaddress", "", "Local address to bind to")
+var max_messages = flag.Int("maxmessages", 1000, "Maximum number of messages to retain")
 
-var frame_count = expvar.NewInt("frame_count")
+var start_time = expvar.NewInt("start_time")
 var speak_count = expvar.NewInt("speak_count")
 var fetch_count = expvar.NewInt("fetch_count")
 var fetch_wait_count = expvar.NewInt("fetch_wait_count")
 var fetch_wake_count = expvar.NewInt("fetch_wake_count")
+var drop_due_to_limit_count = expvar.NewInt("drop_due_to_limit_count")
 
 type Message struct {
        Time time.Time
@@ -33,12 +53,43 @@ type Store struct {
        Get chan *StoreRequest
 }
 
-// TODO: Monotonic clock
+var monotonic_clock chan chan time.Time
+
+const minimum_clock_increment = time.Millisecond
+
+func start_clock() {
+       internal_monotonic_clock := make(chan chan time.Time, 1)
+       go func() {
+               last_time := time.Now()
+       main:
+               for {
+                       select {
+                       case request, ok := <-internal_monotonic_clock:
+                               if !ok {
+                                       break main
+                               }
+                               earliest_acceptable_time := last_time.Add(minimum_clock_increment)
+                               current_time := time.Now()
+                               if current_time.Before(earliest_acceptable_time) {
+                                       current_time = earliest_acceptable_time
+                               }
+                               request <- current_time
+                               last_time = current_time
+                       }
+               }
+       }()
+       monotonic_clock = internal_monotonic_clock
+}
+
+func now() time.Time {
+       c := make(chan time.Time, 0)
+       monotonic_clock <- c
+       return <-c
+}
 
 func manage_store(store Store) {
        messages := list.New()
        message_count := 0
-       max_messages := 1000
        waiting := list.New()
 main:
        for {
@@ -55,10 +106,11 @@ main:
                        }
                        waiting.Init()
                        messages.PushBack(new_message)
-                       if message_count < max_messages {
+                       if message_count < *max_messages {
                                message_count++
                        } else {
                                messages.Remove(messages.Front())
+                               drop_due_to_limit_count.Add(1)
                        }
                case request, ok := <-store.Get:
                        if !ok {
@@ -96,46 +148,8 @@ func start_store() Store {
        return store
 }
 
-const frame_html = `<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
-  "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
-
-<html xmlns="http://www.w3.org/1999/xhtml">
-<head>
- <script type="text/javascript"><!--//--><![CDATA[//><!--
-  var since;
-  function go() {
-   var delay = 10000;
-   var xhr = new XMLHttpRequest();
-   xhr.onreadystatechange = function() {
-    if (this.readyState == this.DONE) {
-     if (this.status == 200) {
-      var rtxt = this.responseText;
-      if (rtxt != null) {
-       var r = JSON.parse(rtxt);
-       if (r != null) {
-        window.parent.postMessage(rtxt, "*");
-        delay = 40;
-        if (r.length >= 1 && "Time" in r[r.length-1]) {
-         since = r[r.length-1]["Time"];
-        }
-       }
-      }
-     }
-     window.setTimeout(go, delay);
-    }
-   }
-   var uri = "/fetch";
-   if (since) {
-    uri += '?since="' + since + '"';
-   }
-   xhr.open("GET", uri);
-   xhr.send();
-  }
-  //--><!]]></script>
-</head>
-<body onload="go()">
-</body>
-</html>
+const robots_txt = `User-agent: *
+Disallow: /
 `
 
 func start_server(store Store) {
@@ -167,21 +181,23 @@ func start_server(store Store) {
 
        http.HandleFunc("/speak", func(w http.ResponseWriter, r *http.Request) {
                store.Add <- &Message{
-                       time.Now(),
+                       now(),
                        r.FormValue("id"),
                        r.FormValue("text")}
+               w.Header().Add("Access-Control-Allow-Origin", "*")
        })
 
-       http.HandleFunc("/frame", func(w http.ResponseWriter, r *http.Request) {
-               frame_count.Add(1)
-               w.Write([]byte(frame_html));
+       http.HandleFunc("/robots.txt", func(w http.ResponseWriter, r *http.Request) {
+               w.Write([]byte(robots_txt))
        })
 
-       log.Fatal(http.ListenAndServe(":"+strconv.Itoa(*port), nil))
+       log.Fatal(http.ListenAndServe(*localaddress+":"+strconv.Itoa(*port), nil))
 }
 
 func main() {
        flag.Parse()
+       start_clock()
+       start_time.Set(now().UnixNano())
        store := start_store()
        start_server(store)
 }