QUIC: coalesce neighbouring stream send buffers. Previously a single STREAM frame was created for each buffer in stream output chain which is wasteful with respect to memory. The following changes were made in the stream send code: - ngx_quic_stream_send_chain() no longer calls ngx_quic_stream_send() and got a separate implementation that coalesces neighbouring buffers into a single frame - the new ngx_quic_stream_send_chain() respects the limit argument, which fixes sendfile_max_chunk and limit_rate - ngx_quic_stream_send() is reimplemented to call ngx_quic_stream_send_chain() - stream frame size limit is moved out to a separate function ngx_quic_max_stream_frame() - flow control is moved out to a separate function ngx_quic_max_stream_flow() - ngx_quic_stream_send_chain() is relocated next to ngx_quic_stream_send()

/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_SHMEM_H_INCLUDED_
#define _NGX_SHMEM_H_INCLUDED_


#include <ngx_config.h>
#include <ngx_core.h>


typedef struct {
    u_char      *addr;
    size_t       size;
    ngx_str_t    name;
    ngx_log_t   *log;
    ngx_uint_t   exists;   /* unsigned  exists:1;  */
} ngx_shm_t;


ngx_int_t ngx_shm_alloc(ngx_shm_t *shm);
void ngx_shm_free(ngx_shm_t *shm);


#endif /* _NGX_SHMEM_H_INCLUDED_ */