xref: /unit/src/nxt_sendbuf.h (revision 0:a63ceefd6ab0)
1 
2 /*
3  * Copyright (C) Igor Sysoev
4  * Copyright (C) NGINX, Inc.
5  */
6 
7 #ifndef _NXT_SENDBUF_H_INCLUDED_
8 #define _NXT_SENDBUF_H_INCLUDED_
9 
10 
11 /*
12  * The sendbuf interface is intended to send a buffer chain to a connection.
13  * It uses sendfile interface if available.  Otherwise it can send only
14  * memory buffers, so file buffers must be read in memory in advance.
15  *
16  * The sendbuf interface sets c->socket.write_ready to appropriate state
17  * and returns:
18  *
19  *   N > 0      if sendbuf sent N bytes.
20  *
21  *   0          if sendbuf was interrupted (EINTR and so on),
22  *              or sendbuf sent previously buffered data,
23  *              or single sync buffer has been encountered.
24  *              In all these cases sendbuf is ready to continue
25  *              operation, unless c->socket.write_ready is cleared.
26  *
27  *   NXT_AGAIN  if sendbuf did not send any bytes.
28  *
29  *   NXT_ERROR  if there was erorr.
30  *
31  * The sendbuf limit is size_t type since size_t is large enough and many
32  * sendfile implementations do not support anyway sending more than size_t
33  * at once.  The limit support is located at the sendbuf level otherwise
34  * an additional limited chain must be created on each sendbuf call.
35  */
36 
37 
38 typedef struct {
39     nxt_buf_t    *buf;
40     nxt_iobuf_t  *iobuf;
41 
42     uint32_t     nmax;
43     uint8_t      sync;   /* 1 bit */
44     uint8_t      last;   /* 1 bit */
45 
46     size_t       size;
47     size_t       limit;
48 } nxt_sendbuf_coalesce_t;
49 
50 
51 #if (NXT_HAVE_LINUX_SENDFILE)
52 #define NXT_HAVE_SENDFILE  1
53 ssize_t nxt_linux_event_conn_io_sendfile(nxt_event_conn_t *c, nxt_buf_t *b,
54     size_t limit);
55 #endif
56 
57 #if (NXT_HAVE_FREEBSD_SENDFILE)
58 #define NXT_HAVE_SENDFILE  1
59 ssize_t nxt_freebsd_event_conn_io_sendfile(nxt_event_conn_t *c, nxt_buf_t *b,
60     size_t limit);
61 #endif
62 
63 #if (NXT_HAVE_SOLARIS_SENDFILEV)
64 #define NXT_HAVE_SENDFILE  1
65 ssize_t nxt_solaris_event_conn_io_sendfilev(nxt_event_conn_t *c, nxt_buf_t *b,
66     size_t limit);
67 #endif
68 
69 #if (NXT_HAVE_MACOSX_SENDFILE)
70 #define NXT_HAVE_SENDFILE  1
71 ssize_t nxt_macosx_event_conn_io_sendfile(nxt_event_conn_t *c, nxt_buf_t *b,
72     size_t limit);
73 #endif
74 
75 #if (NXT_HAVE_AIX_SEND_FILE)
76 #define NXT_HAVE_SENDFILE  1
77 ssize_t nxt_aix_event_conn_io_send_file(nxt_event_conn_t *c, nxt_buf_t *b,
78     size_t limit);
79 #endif
80 
81 #if (NXT_HAVE_HPUX_SENDFILE)
82 #define NXT_HAVE_SENDFILE  1
83 ssize_t nxt_hpux_event_conn_io_sendfile(nxt_event_conn_t *c, nxt_buf_t *b,
84     size_t limit);
85 #endif
86 
87 ssize_t nxt_event_conn_io_sendbuf(nxt_event_conn_t *c, nxt_buf_t *b,
88     size_t limit);
89 
90 
91 nxt_uint_t nxt_sendbuf_mem_coalesce(nxt_sendbuf_coalesce_t *sb);
92 size_t nxt_sendbuf_file_coalesce(nxt_sendbuf_coalesce_t *sb);
93 
94 /*
95  * Auxiliary nxt_sendbuf_copy_coalesce() interface copies small memory
96  * buffers into internal buffer before output.  It is intended for
97  * SSL/TLS libraries which lack vector I/O interface yet add noticeable
98  * overhead to each SSL/TLS record.
99  */
100 ssize_t nxt_sendbuf_copy_coalesce(nxt_event_conn_t *c, nxt_buf_mem_t *bm,
101     nxt_buf_t *b, size_t limit);
102 
103 nxt_buf_t *nxt_sendbuf_update(nxt_buf_t *b, size_t sent);
104 nxt_buf_t *nxt_sendbuf_completion(nxt_thread_t *thr, nxt_work_queue_t *wq,
105     nxt_buf_t *b, size_t sent);
106 
107 
108 #endif /* _NXT_SENDBUF_H_INCLUDED_ */
109