HTTP/3: refactored dynamic table implementation.

Previously dynamic table was not functional because of zero limit on its size
set by default.  Now the following changes enable it:

- new directives to set SETTINGS_QPACK_MAX_TABLE_CAPACITY and
  SETTINGS_QPACK_BLOCKED_STREAMS
- send settings with SETTINGS_QPACK_MAX_TABLE_CAPACITY and
  SETTINGS_QPACK_BLOCKED_STREAMS to the client
- send Insert Count Increment to the client
- send Header Acknowledgement to the client
- evict old dynamic table entries on overflow
- decode Required Insert Count from client
- block stream if Required Insert Count is not reached

1 files changed, 7 insertions, 1 deletions

diff --git a/src/http/v3/ngx_http_v3_request.c b/src/http/v3/ngx_http_v3_request.c
index 5747c8ee6..ae65ba9ea 100644
--- a/src/http/v3/ngx_http_v3_request.c
+++ b/src/http/v3/ngx_http_v3_request.c
@@ -64,12 +64,18 @@ ngx_http_v3_parse_request(ngx_http_request_t *r, ngx_buf_t *b)
     }
 
     while (b->pos < b->last) {
-        rc = ngx_http_v3_parse_headers(c, st, *b->pos++);
+        rc = ngx_http_v3_parse_headers(c, st, *b->pos);
 
         if (rc == NGX_ERROR) {
             goto failed;
         }
 
+        if (rc == NGX_BUSY) {
+            return NGX_BUSY;
+        }
+
+        b->pos++;
+
         if (rc == NGX_AGAIN) {
             continue;
         }