nghttp3_conn_writev_stream
==========================

Synopsis
--------

*#include <nghttp3/nghttp3.h>*

.. function:: nghttp3_ssize nghttp3_conn_writev_stream(nghttp3_conn *conn, int64_t *pstream_id, int *pfin, nghttp3_vec *vec, size_t veccnt)

    
    `nghttp3_conn_writev_stream` stores stream data to send to *vec* of
    length *veccnt*, and returns the number of nghttp3_vec object in
    which it stored data.  It stores stream ID to *\*pstream_id*.  An
    application has to call `nghttp3_conn_add_write_offset` to inform
    *conn* of the actual number of bytes that underlying QUIC stack
    accepted.  *\*pfin* will be nonzero if this is the last data to
    send.  If there is no stream to write data or send fin, this
    function returns 0, and -1 is assigned to *\*pstream_id*.  This
    function may return 0, and *\*pstream_id* is not -1, and *\*pfin* is
    nonzero.  It means 0 length data to *\*pstream_id*, and it is the
    last data to the stream.  They must be passed to QUIC stack, and
    they are accepted, the application has to call
    `nghttp3_conn_add_write_offset` with 0 byte.
    
    This function returns the number of bytes consumed, or one of the
    following negative error codes:
    
    :macro:`NGHTTP3_ERR_NOMEM`
        Out of memory.
    :macro:`NGHTTP3_ERR_CALLBACK_FAILURE`
        User callback failed.
    
    It may return the other error codes.  In general, the negative
    error code means that *conn* encountered a connection error, and
    the connection should be closed.