Don't send empty messages

[reliable-chat] / server / server.go

diff --git a/server/server.go b/server/server.go
index a8b1c5334f3a778370d4ed58f00a1503fe3bb23e..8dce69be6d77cfbbae9d73e9d96bfac4f9215445 100644 (file)
--- a/server/server.go
+++ b/server/server.go
@@ -1,29 +1,56 @@
+/*  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"
 import "encoding/json"
 package main
 
 import "container/list"
 import "encoding/json"

+import "expvar"
+import "flag"

 import "log"
 import "net/http"
 import "log"
 import "net/http"

+import "strconv"

 import "time"
 
 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 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
 type Message struct {
        Time time.Time

+       ID   string

        Text string
 }
 
        Text string
 }
 

-type FetchResponse struct {
-       Messages []Message
-       Time     time.Time
-}
-

 type StoreRequest struct {
        StartTime time.Time
        Messages  chan<- []Message
 }
 
 type Store struct {
 type StoreRequest struct {
        StartTime time.Time
        Messages  chan<- []Message
 }
 
 type Store struct {

-       Add chan Message
-       Get chan StoreRequest
+       Add chan *Message
+       Get chan *StoreRequest

 }
 
 // TODO: Monotonic clock
 }
 
 // TODO: Monotonic clock


@@ -31,40 +58,51 @@ type Store struct {
 func manage_store(store Store) {
        messages := list.New()
        message_count := 0
 func manage_store(store Store) {
        messages := list.New()
        message_count := 0

-       max_messages := 1000

        waiting := list.New()
        waiting := list.New()

+main:

        for {
                select {
        for {
                select {

-               case new_message := <-store.Add:
-                       messages.PushBack(new_message)
+               case new_message, ok := <-store.Add:
+                       if !ok {
+                               break main
+                       }
+                       speak_count.Add(1)

                        for waiter := waiting.Front(); waiter != nil; waiter = waiter.Next() {
                        for waiter := waiting.Front(); waiter != nil; waiter = waiter.Next() {

-                               waiter.Value.(StoreRequest).Messages <- []Message{new_message}
-                               close(waiter.Value.(StoreRequest).Messages)
+                               waiter.Value.(*StoreRequest).Messages <- []Message{*new_message}
+                               close(waiter.Value.(*StoreRequest).Messages)
+                               fetch_wake_count.Add(1)

                        }
                        waiting.Init()
                        }
                        waiting.Init()

-                       if message_count < max_messages {
+                       messages.PushBack(new_message)
+                       if message_count < *max_messages {

                                message_count++
                        } else {
                                messages.Remove(messages.Front())
                                message_count++
                        } else {
                                messages.Remove(messages.Front())

+                               drop_due_to_limit_count.Add(1)
+                       }
+               case request, ok := <-store.Get:
+                       if !ok {
+                               break main

                        }
                        }

-               case request := <-store.Get:
-                       if messages.Back() == nil || request.StartTime.After(messages.Back().Value.(Message).Time) {
+                       fetch_count.Add(1)
+                       if messages.Back() == nil || !request.StartTime.Before(messages.Back().Value.(*Message).Time) {

                                waiting.PushBack(request)
                                waiting.PushBack(request)

+                               fetch_wait_count.Add(1)

                        } else {
                                start := messages.Back()
                                response_size := 1
                        } else {
                                start := messages.Back()
                                response_size := 1

-                               if messages.Front().Value.(Message).Time.After(request.StartTime) {
+                               if messages.Front().Value.(*Message).Time.After(request.StartTime) {

                                        start = messages.Front()
                                        response_size = message_count
                                } else {
                                        start = messages.Front()
                                        response_size = message_count
                                } else {

-                                       for start.Prev().Value.(Message).Time.After(request.StartTime) {
+                                       for start.Prev().Value.(*Message).Time.After(request.StartTime) {

                                                start = start.Prev()
                                                response_size++
                                        }
                                }
                                response_messages := make([]Message, 0, response_size)
                                for m := start; m != nil; m = m.Next() {
                                                start = start.Prev()
                                                response_size++
                                        }
                                }
                                response_messages := make([]Message, 0, response_size)
                                for m := start; m != nil; m = m.Next() {

-                                       response_messages = append(response_messages, m.Value.(Message))
+                                       response_messages = append(response_messages, *m.Value.(*Message))

                                }
                                request.Messages <- response_messages
                        }
                                }
                                request.Messages <- response_messages
                        }


@@ -73,36 +111,59 @@ func manage_store(store Store) {
 }
 
 func start_store() Store {
 }
 
 func start_store() Store {

-       store := Store{make(chan Message, 20), make(chan StoreRequest, 20)}
+       store := Store{make(chan *Message, 20), make(chan *StoreRequest, 20)}

        go manage_store(store)
        return store
 }
 
        go manage_store(store)
        return store
 }
 

+const robots_txt = `User-agent: *
+Disallow: /
+`
+

 func start_server(store Store) {
        http.HandleFunc("/fetch", func(w http.ResponseWriter, r *http.Request) {
 func start_server(store Store) {
        http.HandleFunc("/fetch", func(w http.ResponseWriter, r *http.Request) {

-               var since time.Time // TODO: Get start time from URL
+               var since time.Time
+               url_since := r.FormValue("since")
+               if url_since != "" {
+                       err := json.Unmarshal([]byte(url_since), &since)
+                       if err != nil {
+                               log.Print("fetch: parse since: ", err)
+                               w.WriteHeader(http.StatusBadRequest)
+                               w.Write([]byte("Could not parse since as date"))
+                               return
+                       }
+               }

                messages_from_store := make(chan []Message, 1)
                messages_from_store := make(chan []Message, 1)

-               store.Get <- StoreRequest{since, messages_from_store}
+               store.Get <- &StoreRequest{since, messages_from_store}

 
 

-               json_encoded, err := json.Marshal(FetchResponse{<-messages_from_store, time.Now()})
+               json_encoded, err := json.Marshal(<-messages_from_store)

                if err != nil {
                        log.Print("json encode: ", err)
                        w.WriteHeader(http.StatusInternalServerError)
                        return
                }
                w.Header().Add("Content-Type", "application/json")
                if err != nil {
                        log.Print("json encode: ", err)
                        w.WriteHeader(http.StatusInternalServerError)
                        return
                }
                w.Header().Add("Content-Type", "application/json")

+               w.Header().Add("Access-Control-Allow-Origin", "*")

                w.Write(json_encoded)
        })
 
        http.HandleFunc("/speak", func(w http.ResponseWriter, r *http.Request) {
                w.Write(json_encoded)
        })
 
        http.HandleFunc("/speak", func(w http.ResponseWriter, r *http.Request) {

-               text := "woof" // TODO: Get text from URL
-               store.Add <- Message{time.Now(), text}
+               store.Add <- &Message{
+                       time.Now(),
+                       r.FormValue("id"),
+                       r.FormValue("text")}
+       })
+
+       http.HandleFunc("/robots.txt", func(w http.ResponseWriter, r *http.Request) {
+               w.Write([]byte(robots_txt))

        })
 
        })
 

-       log.Fatal(http.ListenAndServe(":8080", nil))
+       log.Fatal(http.ListenAndServe(*localaddress+":"+strconv.Itoa(*port), nil))

 }
 
 func main() {
 }
 
 func main() {

+       flag.Parse()
+       start_time.Set(time.Now().UnixNano())

        store := start_store()
        start_server(store)
 }
        store := start_store()
        start_server(store)
 }