8 *#include <nghttp2/nghttp2.h>*
10 .. function:: int nghttp2_submit_trailer(nghttp2_session *session, int32_t stream_id, const nghttp2_nv *nva, size_t nvlen)
13 Submits trailer fields HEADERS against the stream *stream_id*.
15 The *nva* is an array of name/value pair :type:`nghttp2_nv` with
16 *nvlen* elements. The application must not include pseudo-header
17 fields (headers whose names starts with ":") in *nva*.
19 This function creates copies of all name/value pairs in *nva*. It
20 also lower-cases all names in *nva*. The order of elements in
21 *nva* is preserved. For header fields with
22 :macro:`nghttp2_nv_flag.NGHTTP2_NV_FLAG_NO_COPY_NAME` and
23 :macro:`nghttp2_nv_flag.NGHTTP2_NV_FLAG_NO_COPY_VALUE` are set,
24 header field name and value are not copied respectively. With
25 :macro:`nghttp2_nv_flag.NGHTTP2_NV_FLAG_NO_COPY_NAME`, application
26 is responsible to pass header field name in lowercase. The
27 application should maintain the references to them until
28 :type:`nghttp2_on_frame_send_callback` or
29 :type:`nghttp2_on_frame_not_send_callback` is called.
31 For server, trailer fields must follow response HEADERS or response
32 DATA without END_STREAM flat set. The library does not enforce
33 this requirement, and applications should do this for themselves.
34 If `nghttp2_submit_trailer()` is called before any response HEADERS
35 submission (usually by `nghttp2_submit_response()`), the content of
36 *nva* will be sent as response headers, which will result in error.
38 This function has the same effect with `nghttp2_submit_headers()`,
39 with flags = :macro:`nghttp2_flag.NGHTTP2_FLAG_END_STREAM` and both
40 pri_spec and stream_user_data to NULL.
42 To submit trailer fields after `nghttp2_submit_response()` is
43 called, the application has to specify
44 :type:`nghttp2_data_provider` to `nghttp2_submit_response()`.
45 Inside of :type:`nghttp2_data_source_read_callback`, when setting
46 :macro:`nghttp2_data_flag.NGHTTP2_DATA_FLAG_EOF`, also set
47 :macro:`nghttp2_data_flag.NGHTTP2_DATA_FLAG_NO_END_STREAM`. After
48 that, the application can send trailer fields using
49 `nghttp2_submit_trailer()`. `nghttp2_submit_trailer()` can be used
50 inside :type:`nghttp2_data_source_read_callback`.
52 This function returns 0 if it succeeds and *stream_id* is -1.
53 Otherwise, this function returns 0 if it succeeds, or one of the
54 following negative error codes:
56 :macro:`nghttp2_error.NGHTTP2_ERR_NOMEM`
58 :macro:`nghttp2_error.NGHTTP2_ERR_INVALID_ARGUMENT`