example_httpsrv_sse.c 3.9 KB

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  1. /* _
  2. * ___ __ _ __ _ _ _(_)
  3. * / __|/ _` |/ _` | | | | |
  4. * \__ \ (_| | (_| | |_| | |
  5. * |___/\__,_|\__, |\__,_|_|
  6. * |___/
  7. *
  8. * Cross-platform library which helps to develop web servers or frameworks.
  9. *
  10. * Copyright (C) 2016-2020 Silvio Clecio <[email protected]>
  11. *
  12. * Sagui library is free software; you can redistribute it and/or
  13. * modify it under the terms of the GNU Lesser General Public
  14. * License as published by the Free Software Foundation; either
  15. * version 2.1 of the License, or (at your option) any later version.
  16. *
  17. * Sagui library is distributed in the hope that it will be useful,
  18. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  20. * Lesser General Public License for more details.
  21. *
  22. * You should have received a copy of the GNU Lesser General Public
  23. * License along with Sagui library; if not, write to the Free Software
  24. * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  25. */
  26. #include <stdio.h>
  27. #include <stdlib.h>
  28. #include <stdint.h>
  29. #include <string.h>
  30. #ifdef _WIN32
  31. #include <windows.h>
  32. #else /* _WIN32 */
  33. #include <unistd.h>
  34. #endif /* _WIN32 */
  35. #include <sagui.h>
  36. /* NOTE: Error checking has been omitted to make it clear. */
  37. #define PAGE \
  38. "<html>\n" \
  39. "<head>\n" \
  40. "<title>SSE example</title>\n" \
  41. "</head><body><h2 id=\"counter\">Please wait ...</h2>\n" \
  42. "<script>\n" \
  43. "const es = new EventSource('/');\n" \
  44. "es.onmessage = function (ev) {\n" \
  45. " document.getElementById('counter').innerText = 'Counting: ' + ev.data;\n" \
  46. "};\n" \
  47. "</script>\n" \
  48. "</body>\n" \
  49. "</html>"
  50. static unsigned int COUNT = 0;
  51. #ifdef _WIN32
  52. #define sleep Sleep
  53. #endif /* _WIN32 */
  54. static ssize_t sse_read_cb(__SG_UNUSED void *handle, uint64_t offset, char *buf,
  55. size_t size) {
  56. char msg[20];
  57. if (offset == 0) {
  58. size = sprintf(msg, "retry: 1000\n");
  59. } else {
  60. size = sprintf(msg, "data: %d\n\n", ++COUNT);
  61. sleep(1);
  62. }
  63. memcpy(buf, msg, size);
  64. msg[size] = '\0';
  65. return size;
  66. }
  67. static void req_cb(__SG_UNUSED void *cls, struct sg_httpreq *req,
  68. struct sg_httpres *res) {
  69. struct sg_strmap *pair;
  70. struct sg_strmap **req_headers = sg_httpreq_headers(req);
  71. struct sg_strmap **res_headers = sg_httpres_headers(res);
  72. if (sg_strmap_find(*req_headers, "Accept", &pair) == 0 &&
  73. strstr(sg_strmap_val(pair), "text/event-stream")) {
  74. sg_strmap_set(res_headers, "Access-Control-Allow-Origin", "*");
  75. sg_strmap_set(res_headers, "Content-Type", "text/event-stream");
  76. sg_httpres_sendstream(res, 0, sse_read_cb, NULL, NULL, 200);
  77. return;
  78. }
  79. if (strcmp(sg_httpreq_path(req), "/favicon.ico") == 0) {
  80. sg_httpres_send(res, "", "", 204);
  81. return;
  82. }
  83. sg_httpres_send(res, PAGE, "text/html; charset=utf-8", 200);
  84. }
  85. int main(int argc, const char *argv[]) {
  86. struct sg_httpsrv *srv;
  87. if (argc != 2) {
  88. printf("%s <PORT>\n", argv[0]);
  89. return EXIT_FAILURE;
  90. }
  91. srv = sg_httpsrv_new(req_cb, NULL);
  92. if (!sg_httpsrv_listen(srv, strtol(argv[1], NULL, 10), true)) {
  93. sg_httpsrv_free(srv);
  94. return EXIT_FAILURE;
  95. }
  96. fprintf(stdout, "Server running at http://localhost:%d\n",
  97. sg_httpsrv_port(srv));
  98. fflush(stdout);
  99. getchar();
  100. sg_httpsrv_free(srv);
  101. return EXIT_SUCCESS;
  102. }