HTTP: filter: supporting a list of filter_handlers

Filter handlers are a new handler that takes place when a buffer is
about to be sent.  It filters (modifies) the contents of the buffer
in-place, so that the new contents will be sent.  Several filters can be
applied in a loop.

Signed-off-by: Alejandro Colomar <alx@nginx.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/src/nxt_http_request.c b/src/nxt_http_request.c
index 3bcf3d94..e72a7492 100644
--- a/src/nxt_http_request.c
+++ b/src/nxt_http_request.c
@@ -7,6 +7,8 @@
 #include <nxt_router.h>
 #include <nxt_http.h>
 
+#include "nxt_http_filter.h"
+
 
 static nxt_int_t nxt_http_validate_host(nxt_str_t *host, nxt_mp_t *mp);
 static void nxt_http_request_start(nxt_task_t *task, void *obj, void *data);
@@ -262,6 +264,11 @@ nxt_http_request_create(nxt_task_t *task)
         goto fail;
     }
 
+    r->response_filters = nxt_list_create(mp, 1, sizeof(nxt_http_filter_handler_t));
+    if (nxt_slow_path(r->response_filters == NULL)) {
+        goto fail;
+    }
+
     last = nxt_mp_zget(mp, NXT_BUF_SYNC_SIZE);
     if (nxt_slow_path(last == NULL)) {
         goto fail;
@@ -723,6 +730,12 @@ nxt_http_request_ws_frame_start(nxt_task_t *task, nxt_http_request_t *r,
 void
 nxt_http_request_send(nxt_task_t *task, nxt_http_request_t *r, nxt_buf_t *out)
 {
+    nxt_http_filter_handler_t  *filter;
+
+    nxt_list_each(filter, r->response_filters) {
+        filter->filter_handler(task, &out, filter->data);
+    } nxt_list_loop;
+
     if (nxt_fast_path(r->proto.any != NULL)) {
         nxt_http_proto[r->protocol].send(task, r, out);
     }