tvheadend/ajaxui/ajaxui_mailbox.c

/*
 *  tvheadend, AJAX / HTML Mailboxes
 *  Copyright (C) 2008 Andreas <EFBFBD>man
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <pthread.h>
#include <assert.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>

#include "tvhead.h"
#include "dispatch.h"
#include "http.h"
#include "ajaxui.h"
#include "transports.h"

#define MAILBOX_UNUSED_TIMEOUT      15
#define MAILBOX_EMPTY_REPLY_TIMEOUT 10


static LIST_HEAD(, ajaxui_mailbox) mailboxes;

int mailbox_tally;

TAILQ_HEAD(ajaxui_letter_queue, ajaxui_letter);

typedef struct ajaxui_letter {
  TAILQ_ENTRY(ajaxui_letter) al_link;
  char *al_payload_a;
  char *al_payload_b;
} ajaxui_letter_t;


typedef struct ajaxui_mailbox {
  LIST_ENTRY(ajaxui_mailbox) amb_link;

  uint32_t amb_boxid;
  char *amb_subscriptionid;

  dtimer_t amb_timer;

  http_reply_t *amb_hr; /* Pending request */

  struct ajaxui_letter_queue amb_letters;

} ajaxui_mailbox_t;


/**
 *
 */
static void
al_destroy(ajaxui_mailbox_t *amb, ajaxui_letter_t *al)
{
  TAILQ_REMOVE(&amb->amb_letters, al, al_link);
  free(al->al_payload_a);
  free(al->al_payload_b);
  free(al);
}


/**
 *
 */
static void
amb_destroy(ajaxui_mailbox_t *amb)
{
  ajaxui_letter_t *al;

  while((al = TAILQ_FIRST(&amb->amb_letters)) != NULL)
    al_destroy(amb, al);

  LIST_REMOVE(amb, amb_link);

  dtimer_disarm(&amb->amb_timer);

  free(amb->amb_subscriptionid);
  free(amb);
}



/**
 *
 */
static void
ajax_mailbox_unused(void *opaque, int64_t now)
{
  ajaxui_mailbox_t *amb = opaque;
  assert(amb->amb_hr == NULL);
  amb_destroy(amb);
}

/**
 *
 */
static void
ajax_mailbox_connection_lost(http_reply_t *hr, void *opaque)
{
  ajaxui_mailbox_t *amb = opaque;
  assert(hr == amb->amb_hr);
  amb_destroy(amb);
}



/**
 *
 */
int
ajax_mailbox_create(const char *subscriptionid)
{
  ajaxui_mailbox_t *amb = calloc(1, sizeof(ajaxui_mailbox_t));

  mailbox_tally++;

  amb->amb_boxid = mailbox_tally;
  amb->amb_subscriptionid = strdup(subscriptionid);
  
  LIST_INSERT_HEAD(&mailboxes, amb, amb_link);

  TAILQ_INIT(&amb->amb_letters);

  dtimer_arm(&amb->amb_timer, ajax_mailbox_unused, amb,
	     MAILBOX_UNUSED_TIMEOUT);
  return amb->amb_boxid;
}

/**
 *
 */
void
ajax_mailbox_start(tcp_queue_t *tq, const char *identifier)
{
  int boxid = ajax_mailbox_create(identifier);

  /* We need to keep a hidden element in a part of the document that
     is directly mapped to this mailbox.

     This element is updated in every reply and if it fails,
     there will be no more updates.

     This avoid getting stale updaters that keeps on going if parts
     of the document is reloaded faster than the mailbox sees it */

  tcp_qprintf(tq, "<div style=\"display: none\" id=\"mbox_%d\"></div>", boxid);

  ajax_js(tq, "new Ajax.Request('/ajax/mailbox/%d')", boxid);
}


/**
 *
 */
static void
ajax_mailbox_reply(ajaxui_mailbox_t *amb, http_reply_t *hr)
{
  ajaxui_letter_t *al;

  /* Modify the hidden element (as described in ajax_mailbox_start()), 
     if this div no longer exist, the rest of the javascript will bail
     out and we will not be reloaded */

  tcp_qprintf(&hr->hr_tq, "$('mbox_%d').innerHTML='';\r\n", amb->amb_boxid);

  while((al = TAILQ_FIRST(&amb->amb_letters)) != NULL) {
    tcp_qprintf(&hr->hr_tq, "%s%s", al->al_payload_a, al->al_payload_b ?: "");
    al_destroy(amb, al);
  }

  tcp_qprintf(&hr->hr_tq, "new Ajax.Request('/ajax/mailbox/%d');\r\n",
	      amb->amb_boxid);

  http_output(hr->hr_connection, hr, "text/javascript", NULL, 0);
  amb->amb_hr = NULL;

  /* Arm a timer in case the browser won't call back */
  dtimer_arm(&amb->amb_timer, ajax_mailbox_unused, amb,
	     MAILBOX_UNUSED_TIMEOUT);
}

/**
 *
 */
static void
ajax_mailbox_empty_reply(void *opaque, int64_t now)
{
  ajaxui_mailbox_t *amb = opaque;
  http_reply_t *hr = amb->amb_hr;

  ajax_mailbox_reply(amb, hr);
  http_continue(hr->hr_connection);
}


/**
 * Poll callback
 *
 * Prepare the mailbox for reply
 */
static int
ajax_mailbox_poll(http_connection_t *hc, http_reply_t *hr, 
		  const char *remain, void *opaque)
{
  uint32_t boxid;
  ajaxui_mailbox_t *amb;

  if(remain == NULL)
    return HTTP_STATUS_NOT_FOUND;

  boxid = atoi(remain);
  LIST_FOREACH(amb, &mailboxes, amb_link)
    if(amb->amb_boxid == boxid)
      break;
  if(amb == NULL)
    return HTTP_STATUS_NOT_FOUND;

  if(amb->amb_hr != NULL)
    return 409;

  if(TAILQ_FIRST(&amb->amb_letters) != NULL) {
    /* Pending letters, direct reply */
    ajax_mailbox_reply(amb, hr);
    return 0;
  }

  amb->amb_hr = hr;

  hr->hr_opaque = amb;
  hr->hr_destroy = ajax_mailbox_connection_lost;

  dtimer_arm(&amb->amb_timer, ajax_mailbox_empty_reply, amb,
	     MAILBOX_EMPTY_REPLY_TIMEOUT);
  return 0;
}


/**
 *
 */
void
ajax_mailbox_init(void)
{
  http_path_add("/ajax/mailbox",  NULL, ajax_mailbox_poll);
}


/**
 * Delayed delivery of mailbox replies
 */
static void
ajax_mailbox_deliver(void *opaque, int64_t now)
{
  ajaxui_mailbox_t *amb = opaque;
  http_connection_t *hc;

  hc = amb->amb_hr->hr_connection;
  ajax_mailbox_reply(amb, amb->amb_hr);
  http_continue(hc);
}

/**
 *
 */
static void
ajax_mailbox_add_to_subscription(const char *subscription, 
				 const char *content_a, const char *content_b)
{
  ajaxui_mailbox_t *amb;
  ajaxui_letter_t *al;

  LIST_FOREACH(amb, &mailboxes, amb_link) {
    if(strcmp(subscription, amb->amb_subscriptionid))
      continue;

    /* Avoid inserting the same message twice */

    TAILQ_FOREACH(al, &amb->amb_letters, al_link) {
      if(!strcmp(al->al_payload_a, content_a))
	break;
    }

    if(al == NULL) {

      al = malloc(sizeof(ajaxui_letter_t));
      al->al_payload_a = strdup(content_a);
    } else {
      /* Already exist, just move to tail */

      TAILQ_REMOVE(&amb->amb_letters, al, al_link);
      free(al->al_payload_b);
    }

    al->al_payload_b = content_b ? strdup(content_b) : NULL;

    TAILQ_INSERT_TAIL(&amb->amb_letters, al, al_link);

    if(amb->amb_hr != NULL)
      dtimer_arm_hires(&amb->amb_timer, ajax_mailbox_deliver, amb, 
		       getclock_hires() + 100000);
  }
}



/**
 *
 */
static void
ajax_mailbox_update_div(const char *subscription, const char *prefix,
			const char *postfix, const char *content)
{
  char buf_a[500];
  char buf_b[500];

  snprintf(buf_a, sizeof(buf_a), "$('%s_%s').innerHTML=", prefix, postfix);
  snprintf(buf_b, sizeof(buf_b), "'%s';\n\r", content);

  ajax_mailbox_add_to_subscription(subscription, buf_a, buf_b);
}



static void
ajax_mailbox_reload_div(const char *subscription, const char *prefix,
			const char *postfix, const char *url)
{
  char buf[1000];

  snprintf(buf, sizeof(buf), "new Ajax.Updater('%s_%s', '%s', "
	   "{method: 'get', evalScripts: true});\r\n",
	   prefix, postfix, url);

  ajax_mailbox_add_to_subscription(subscription, buf, NULL);
}



void
ajax_mailbox_tdmi_state_change(th_dvb_mux_instance_t *tdmi)
{
  const char *txt;

  switch(tdmi->tdmi_state) {
  case TDMI_IDLE:      txt = "Idle";      break;
  case TDMI_IDLESCAN:  txt = "Scanning";  break;
  case TDMI_RUNNING:   txt = "Running";   break;
  default:             txt = "???";       break;
  }
  
  
  ajax_mailbox_update_div(tdmi->tdmi_adapter->tda_identifier,
			  "state", tdmi->tdmi_identifier,
			  txt);
}

void
ajax_mailbox_tdmi_name_change(th_dvb_mux_instance_t *tdmi)
{
  ajax_mailbox_update_div(tdmi->tdmi_adapter->tda_identifier,
			  "name", tdmi->tdmi_identifier,
			  tdmi->tdmi_network ?: "<noname>");
}


void
ajax_mailbox_tdmi_status_change(th_dvb_mux_instance_t *tdmi)
{
  ajax_mailbox_update_div(tdmi->tdmi_adapter->tda_identifier,
			  "status", tdmi->tdmi_identifier,
			  tdmi->tdmi_last_status);
}

void
ajax_mailbox_tdmi_services_change(th_dvb_mux_instance_t *tdmi)
{
  th_transport_t *t;
  char buf[20];
  int n, m;

  n = m = 0;
  LIST_FOREACH(t, &tdmi->tdmi_transports, tht_mux_link) {
    n++;
    if(transport_is_available(t))
      m++;
  }
  snprintf(buf, sizeof(buf), "%d / %d", m, n);
   
  ajax_mailbox_update_div(tdmi->tdmi_adapter->tda_identifier,
			  "nsvc", tdmi->tdmi_identifier,
			  buf);
}



void
ajax_mailbox_tda_change(th_dvb_adapter_t *tda)
{
  char buf[500];

  snprintf(buf, sizeof(buf), "/ajax/dvbadaptermuxlist/%s",
	   tda->tda_identifier);

  ajax_mailbox_reload_div(tda->tda_identifier,
			  "dvbmuxlist", tda->tda_identifier,
			  buf);
}