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>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

1 files changed, 53 insertions, 0 deletions

diff --git a/src/nxt_http_filter.h b/src/nxt_http_filter.h
new file mode 100644
index 00000000..d26ae1a9
--- /dev/null
+++ b/src/nxt_http_filter.h
@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) Alejandro Colomar
+ * Copyright (C) NGINX, Inc.
+ */
+
+#ifndef NXT_HTTP_FILTER_H_INCLUDED_
+#define NXT_HTTP_FILTER_H_INCLUDED_
+
+
+#include "nxt_router.h"
+
+#include "nxt_auto_config.h"
+
+#include <stddef.h>
+
+#include "nxt_clang.h"
+#include "nxt_errno.h"
+#include "nxt_list.h"
+#include "nxt_main.h"
+
+
+typedef struct nxt_http_filter_handler_s  nxt_http_filter_handler_t;
+
+
+struct nxt_http_filter_handler_s {
+    nxt_work_handler_t              filter_handler;
+    void                            *data;
+};
+
+
+nxt_inline nxt_int_t nxt_http_filter_handler_add(nxt_http_request_t *r,
+    nxt_work_handler_t filter_handler, void *data);
+
+
+nxt_inline nxt_int_t
+nxt_http_filter_handler_add(nxt_http_request_t *r,
+    nxt_work_handler_t filter_handler, void *data)
+{
+    nxt_http_filter_handler_t  *elem;
+
+    elem = nxt_list_add(r->response_filters);
+    if (nxt_slow_path(elem == NULL)) {
+        return NXT_ERROR;
+    }
+
+    elem->filter_handler = filter_handler;
+    elem->data = data;
+
+    return NXT_OK;
+}
+
+
+#endif  /* NXT_HTTP_FILTER_H_INCLUDED_ */