diff options
Diffstat (limited to 'main')
| -rw-r--r-- | main/http_api.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/main/http_api.c b/main/http_api.c index 69e555e..0192f7d 100644 --- a/main/http_api.c +++ b/main/http_api.c @@ -10,6 +10,7 @@ #include "esp_http_server.h" #include "esp_log.h" #include "esp_timer.h" +#include "lwip/sockets.h" // TCP_NODELAY setsockopt for /frame socket #include "display.h" #include "jpeg_decoder.h" @@ -334,6 +335,19 @@ static uint32_t s_last_painted_seq; static esp_err_t frame_post_handler(httpd_req_t *req) { + // Nagle off on this socket. /frame is a single large POST followed + // by a tiny (empty 204) response — the worst case for Nagle. The + // last partial-MTU packet of the body, and the response packet, + // both sit in the kernel send buffer up to 40ms waiting for an + // ACK that the peer's also delaying-ACKing. setsockopt is cheap + // and idempotent; if keep-alive is ever added the flag persists + // for the connection's life. + int sockfd = httpd_req_to_sockfd(req); + if (sockfd >= 0) { + int one = 1; + (void)setsockopt(sockfd, IPPROTO_TCP, TCP_NODELAY, &one, sizeof(one)); + } + // Content-Type must be image/jpeg. char ct[40] = {0}; if (httpd_req_get_hdr_value_str(req, "Content-Type", ct, sizeof(ct)) != ESP_OK || |