add dynamic tls record patch

src/event/ngx_event_openssl.c

@@ -1677,6 +1677,7 @@ ngx_ssl_create_connection(ngx_ssl_t *ssl, ngx_connection_t *c, ngx_uint_t flags)
 
     sc->buffer = ((flags & NGX_SSL_BUFFER) != 0);
     sc->buffer_size = ssl->buffer_size;
+    sc->dyn_rec = ssl->dyn_rec;
 
     sc->session_ctx = ssl->ctx;
 
@@ -2643,6 +2644,41 @@ ngx_ssl_send_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit)
 
     for ( ;; ) {
 
+        /* Dynamic record resizing:
+           We want the initial records to fit into one TCP segment
+           so we don't get TCP HoL blocking due to TCP Slow Start.
+           A connection always starts with small records, but after
+           a given amount of records sent, we make the records larger
+           to reduce header overhead.
+           After a connection has idled for a given timeout, begin
+           the process from the start. The actual parameters are
+           configurable. If dyn_rec_timeout is 0, we assume dyn_rec is off. */
+
+        if (c->ssl->dyn_rec.timeout > 0 ) {
+
+            if (ngx_current_msec - c->ssl->dyn_rec_last_write >
+                c->ssl->dyn_rec.timeout)
+            {
+                buf->end = buf->start + c->ssl->dyn_rec.size_lo;
+                c->ssl->dyn_rec_records_sent = 0;
+
+            } else {
+                if (c->ssl->dyn_rec_records_sent >
+                    c->ssl->dyn_rec.threshold * 2)
+                {
+                    buf->end = buf->start + c->ssl->buffer_size;
+
+                } else if (c->ssl->dyn_rec_records_sent >
+                           c->ssl->dyn_rec.threshold)
+                {
+                    buf->end = buf->start + c->ssl->dyn_rec.size_hi;
+
+                } else {
+                    buf->end = buf->start + c->ssl->dyn_rec.size_lo;
+                }
+            }
+        }
+
         while (in && buf->last < buf->end && send < limit) {
             if (in->buf->last_buf || in->buf->flush) {
                 flush = 1;
@@ -2782,6 +2818,9 @@ ngx_ssl_write(ngx_connection_t *c, u_char *data, size_t size)
 
     if (n > 0) {
 
+        c->ssl->dyn_rec_records_sent++;
+        c->ssl->dyn_rec_last_write = ngx_current_msec;
+
         if (c->ssl->saved_read_handler) {
 
             c->read->handler = c->ssl->saved_read_handler;

src/event/ngx_event_openssl.h

@@ -86,10 +86,19 @@
 typedef struct ngx_ssl_ocsp_s  ngx_ssl_ocsp_t;
 
 
+typedef struct {
+    ngx_msec_t                  timeout;
+    ngx_uint_t                  threshold;
+    size_t                      size_lo;
+    size_t                      size_hi;
+} ngx_ssl_dyn_rec_t;
+
+
 struct ngx_ssl_s {
     SSL_CTX                    *ctx;
     ngx_log_t                  *log;
     size_t                      buffer_size;
+    ngx_ssl_dyn_rec_t           dyn_rec;
 };
 
 
@@ -128,6 +137,10 @@ struct ngx_ssl_connection_s {
     unsigned                    in_ocsp:1;
     unsigned                    early_preread:1;
     unsigned                    write_blocked:1;
+
+    ngx_ssl_dyn_rec_t           dyn_rec;
+    ngx_msec_t                  dyn_rec_last_write;
+    ngx_uint_t                  dyn_rec_records_sent;
 };
 
 
@@ -137,7 +150,7 @@ struct ngx_ssl_connection_s {
 #define NGX_SSL_DFLT_BUILTIN_SCACHE  -5
 
 
-#define NGX_SSL_MAX_SESSION_SIZE  4096
+#define NGX_SSL_MAX_SESSION_SIZE  16384
 
 typedef struct ngx_ssl_sess_id_s  ngx_ssl_sess_id_t;