Added support for trailers in HTTP responses.

Example:

   ngx_table_elt_t  *h;

   h = ngx_list_push(&r->headers_out.trailers);
   if (h == NULL) {
       return NGX_ERROR;
   }

   ngx_str_set(&h->key, "Fun");
   ngx_str_set(&h->value, "with trailers");
   h->hash = ngx_hash_key_lc(h->key.data, h->key.len);

The code above adds "Fun: with trailers" trailer to the response.

Modules that want to emit trailers must set r->expect_trailers = 1
in header filter, otherwise they might not be emitted for HTTP/1.1
responses that aren't already chunked.

This change also adds $sent_trailer_* variables.

Signed-off-by: Piotr Sikora <piotrsikora@google.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/src/http/ngx_http_request.c b/src/http/ngx_http_request.c
index cc3722fb3..de1b20270 100644
--- a/src/http/ngx_http_request.c
+++ b/src/http/ngx_http_request.c
@@ -562,6 +562,14 @@ ngx_http_create_request(ngx_connection_t *c)
         return NULL;
     }
 
+    if (ngx_list_init(&r->headers_out.trailers, r->pool, 4,
+                      sizeof(ngx_table_elt_t))
+        != NGX_OK)
+    {
+        ngx_destroy_pool(r->pool);
+        return NULL;
+    }
+
     r->ctx = ngx_pcalloc(r->pool, sizeof(void *) * ngx_http_max_module);
     if (r->ctx == NULL) {
         ngx_destroy_pool(r->pool);