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// Copyright (C) 2021 Russell King.
// Licensed under GPL version 2. See COPYING.
#include <gio/gio.h>
#include "event-httpd.h"
#include "resource.h"
struct resource_object {
GList *client_list;
GString *string;
};
static struct resource_object position_object;
static struct resource_object signal_object;
static void object_v1_send(struct client *c, struct resource_object *obj)
{
GString *string = obj->string;
if (!string)
return;
respond_chunk(c, string);
}
static int object_v1_get(struct client *c, struct resource *r)
{
struct resource_object *obj = r->data;
respond_header(c, 200, "OK",
"Cache-Control: no-cache\r\n"
"Connection: keep-alive\r\n"
"Content-Type: text/event-stream; charset=UTF-8\r\n"
"Transfer-Encoding: chunked\r\n");
object_v1_send(c, obj);
// Add this client to the object list so it receives updates
obj->client_list = g_list_append(obj->client_list, c);
return 1;
}
// Update this client with the new resource object data
static void object_v1_client_update(gpointer data, gpointer user_data)
{
struct resource_object *obj = user_data;
struct client *c = data;
object_v1_send(c, obj);
}
// Update all attached clients with the new resource object data
static int object_v1_update(struct client *c, struct resource *r, const char *m)
{
struct resource_object *obj = r->data;
GString *string, *old;
char *n;
// Remove any trailing whitespace.
n = g_strchomp(g_strdup(m));
// Format the text/event-stream response
// We prefix the string with the "data:" tag in preparation for
// sending to via the text/event-stream connection.
// The double newline terminates this event
// See https://www.html5rocks.com/en/tutorials/eventsource/basics/
string = g_string_new(NULL);
g_string_printf(string, "data:%s\n\n", n);
old = obj->string;
obj->string = string;
g_string_free(old, TRUE);
g_free(n);
g_list_foreach(obj->client_list, object_v1_client_update, obj);
return 0;
}
static void object_v1_close(struct client *c, struct resource *r)
{
struct resource_object *obj = r->data;
// Remove this client from the object list
obj->client_list = g_list_remove(obj->client_list, c);
}
static struct resource resource_position1 = {
.get = object_v1_get,
.update = object_v1_update,
.close = object_v1_close,
.data = &position_object,
};
static struct resource resource_signal1 = {
.get = object_v1_get,
.update = object_v1_update,
.close = object_v1_close,
.data = &signal_object,
};
void resource_init(GHashTable *hash)
{
g_hash_table_insert(hash, "/api/1/position", &resource_position1);
g_hash_table_insert(hash, "/api/1/signal", &resource_signal1);
}
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