1
2nghttp2_submit_request
3======================
4
5Synopsis
6--------
7
8*#include <nghttp2/nghttp2.h>*
9
10.. function:: int32_t nghttp2_submit_request( nghttp2_session *session, const nghttp2_priority_spec *pri_spec, const nghttp2_nv *nva, size_t nvlen, const nghttp2_data_provider *data_prd, void *stream_user_data)
11
12
13    Submits HEADERS frame and optionally one or more DATA frames.
14
15    The *pri_spec* is priority specification of this request.  ``NULL``
16    means the default priority (see
17    `nghttp2_priority_spec_default_init()`).  To specify the priority,
18    use `nghttp2_priority_spec_init()`.  If *pri_spec* is not ``NULL``,
19    this function will copy its data members.
20
21    The ``pri_spec->weight`` must be in [:macro:`NGHTTP2_MIN_WEIGHT`,
22    :macro:`NGHTTP2_MAX_WEIGHT`], inclusive.  If ``pri_spec->weight``
23    is strictly less than :macro:`NGHTTP2_MIN_WEIGHT`, it becomes
24    :macro:`NGHTTP2_MIN_WEIGHT`.  If it is strictly greater than
25    :macro:`NGHTTP2_MAX_WEIGHT`, it becomes
26    :macro:`NGHTTP2_MAX_WEIGHT`.
27
28    The *nva* is an array of name/value pair :type:`nghttp2_nv` with
29    *nvlen* elements.  The application is responsible to include
30    required pseudo-header fields (header field whose name starts with
31    ":") in *nva* and must place pseudo-headers before regular header
32    fields.
33
34    This function creates copies of all name/value pairs in *nva*.  It
35    also lower-cases all names in *nva*.  The order of elements in
36    *nva* is preserved.  For header fields with
37    :macro:`nghttp2_nv_flag.NGHTTP2_NV_FLAG_NO_COPY_NAME` and
38    :macro:`nghttp2_nv_flag.NGHTTP2_NV_FLAG_NO_COPY_VALUE` are set,
39    header field name and value are not copied respectively.  With
40    :macro:`nghttp2_nv_flag.NGHTTP2_NV_FLAG_NO_COPY_NAME`, application
41    is responsible to pass header field name in lowercase.  The
42    application should maintain the references to them until
43    :type:`nghttp2_on_frame_send_callback` or
44    :type:`nghttp2_on_frame_not_send_callback` is called.
45
46    HTTP/2 specification has requirement about header fields in the
47    request HEADERS.  See the specification for more details.
48
49    If *data_prd* is not ``NULL``, it provides data which will be sent
50    in subsequent DATA frames.  In this case, a method that allows
51    request message bodies
52    (https://tools.ietf.org/html/rfc7231#section-4) must be specified
53    with ``:method`` key in *nva* (e.g. ``POST``).  This function does
54    not take ownership of the *data_prd*.  The function copies the
55    members of the *data_prd*.  If *data_prd* is ``NULL``, HEADERS have
56    END_STREAM set.  The *stream_user_data* is data associated to the
57    stream opened by this request and can be an arbitrary pointer,
58    which can be retrieved later by
59    `nghttp2_session_get_stream_user_data()`.
60
61    This function returns assigned stream ID if it succeeds, or one of
62    the following negative error codes:
63
64    :macro:`nghttp2_error.NGHTTP2_ERR_NOMEM`
65        Out of memory.
66    :macro:`nghttp2_error.NGHTTP2_ERR_STREAM_ID_NOT_AVAILABLE`
67        No stream ID is available because maximum stream ID was
68        reached.
69    :macro:`nghttp2_error.NGHTTP2_ERR_INVALID_ARGUMENT`
70        Trying to depend on itself (new stream ID equals
71        ``pri_spec->stream_id``).
72    :macro:`nghttp2_error.NGHTTP2_ERR_PROTO`
73        The *session* is server session.
74
75    .. warning::
76
77      This function returns assigned stream ID if it succeeds.  But
78      that stream is not created yet.  The application must not submit
79      frame to that stream ID before
80      :type:`nghttp2_before_frame_send_callback` is called for this
81      frame.  This means `nghttp2_session_get_stream_user_data()` does
82      not work before the callback.  But
83      `nghttp2_session_set_stream_user_data()` handles this situation
84      specially, and it can set data to a stream during this period.
85
86