ngx_buf.h revision e18a033b
1
2/*
3 * Copyright (C) Igor Sysoev
4 * Copyright (C) Nginx, Inc.
5 */
6
7
8#ifndef _NGX_BUF_H_INCLUDED_
9#define _NGX_BUF_H_INCLUDED_
10
11
12#include <ngx_config.h>
13#include <ngx_core.h>
14
15
16typedef void *            ngx_buf_tag_t;
17
18typedef struct ngx_buf_s  ngx_buf_t;
19
20struct ngx_buf_s {
21    u_char          *pos;
22    u_char          *last;
23    off_t            file_pos;
24    off_t            file_last;
25
26    u_char          *start;         /* start of buffer */
27    u_char          *end;           /* end of buffer */
28    ngx_buf_tag_t    tag;
29    ngx_file_t      *file;
30    ngx_buf_t       *shadow;
31
32
33    /* the buf's content could be changed */
34    unsigned         temporary:1;
35
36    /*
37     * the buf's content is in a memory cache or in a read only memory
38     * and must not be changed
39     */
40    unsigned         memory:1;
41
42    /* the buf's content is mmap()ed and must not be changed */
43    unsigned         mmap:1;
44
45    unsigned         recycled:1;
46    unsigned         in_file:1;
47    unsigned         flush:1;
48    unsigned         sync:1;
49    unsigned         last_buf:1;
50    unsigned         last_in_chain:1;
51
52    unsigned         last_shadow:1;
53    unsigned         temp_file:1;
54
55    /* STUB */ int   num;
56};
57
58
59struct ngx_chain_s {
60    ngx_buf_t    *buf;
61    ngx_chain_t  *next;
62};
63
64
65typedef struct {
66    ngx_int_t    num;
67    size_t       size;
68} ngx_bufs_t;
69
70
71typedef struct ngx_output_chain_ctx_s  ngx_output_chain_ctx_t;
72
73typedef ngx_int_t (*ngx_output_chain_filter_pt)(void *ctx, ngx_chain_t *in);
74
75typedef void (*ngx_output_chain_aio_pt)(ngx_output_chain_ctx_t *ctx,
76    ngx_file_t *file);
77
78struct ngx_output_chain_ctx_s {
79    ngx_buf_t                   *buf;
80    ngx_chain_t                 *in;
81    ngx_chain_t                 *free;
82    ngx_chain_t                 *busy;
83
84    unsigned                     sendfile:1;
85    unsigned                     directio:1;
86    unsigned                     unaligned:1;
87    unsigned                     need_in_memory:1;
88    unsigned                     need_in_temp:1;
89    unsigned                     aio:1;
90
91#if (NGX_HAVE_FILE_AIO || NGX_COMPAT)
92    ngx_output_chain_aio_pt      aio_handler;
93#if (NGX_HAVE_AIO_SENDFILE || NGX_COMPAT)
94    ssize_t                    (*aio_preload)(ngx_buf_t *file);
95#endif
96#endif
97
98#if (NGX_THREADS || NGX_COMPAT)
99    ngx_int_t                  (*thread_handler)(ngx_thread_task_t *task,
100                                                 ngx_file_t *file);
101    ngx_thread_task_t           *thread_task;
102#endif
103
104    off_t                        alignment;
105
106    ngx_pool_t                  *pool;
107    ngx_int_t                    allocated;
108    ngx_bufs_t                   bufs;
109    ngx_buf_tag_t                tag;
110
111    ngx_output_chain_filter_pt   output_filter;
112    void                        *filter_ctx;
113};
114
115
116typedef struct {
117    ngx_chain_t                 *out;
118    ngx_chain_t                **last;
119    ngx_connection_t            *connection;
120    ngx_pool_t                  *pool;
121    off_t                        limit;
122} ngx_chain_writer_ctx_t;
123
124
125#define NGX_CHAIN_ERROR     (ngx_chain_t *) NGX_ERROR
126
127
128#define ngx_buf_in_memory(b)        (b->temporary || b->memory || b->mmap)
129#define ngx_buf_in_memory_only(b)   (ngx_buf_in_memory(b) && !b->in_file)
130
131#define ngx_buf_special(b)                                                   \
132    ((b->flush || b->last_buf || b->sync)                                    \
133     && !ngx_buf_in_memory(b) && !b->in_file)
134
135#define ngx_buf_sync_only(b)                                                 \
136    (b->sync                                                                 \
137     && !ngx_buf_in_memory(b) && !b->in_file && !b->flush && !b->last_buf)
138
139#define ngx_buf_size(b)                                                      \
140    (ngx_buf_in_memory(b) ? (off_t) (b->last - b->pos):                      \
141                            (b->file_last - b->file_pos))
142
143ngx_buf_t *ngx_create_temp_buf(ngx_pool_t *pool, size_t size);
144ngx_chain_t *ngx_create_chain_of_bufs(ngx_pool_t *pool, ngx_bufs_t *bufs);
145
146
147#define ngx_alloc_buf(pool)  ngx_palloc(pool, sizeof(ngx_buf_t))
148#define ngx_calloc_buf(pool) ngx_pcalloc(pool, sizeof(ngx_buf_t))
149
150ngx_chain_t *ngx_alloc_chain_link(ngx_pool_t *pool);
151#define ngx_free_chain(pool, cl)                                             \
152    cl->next = pool->chain;                                                  \
153    pool->chain = cl
154
155
156
157ngx_int_t ngx_output_chain(ngx_output_chain_ctx_t *ctx, ngx_chain_t *in);
158ngx_int_t ngx_chain_writer(void *ctx, ngx_chain_t *in);
159
160ngx_int_t ngx_chain_add_copy(ngx_pool_t *pool, ngx_chain_t **chain,
161    ngx_chain_t *in);
162ngx_chain_t *ngx_chain_get_free_buf(ngx_pool_t *p, ngx_chain_t **free);
163void ngx_chain_update_chains(ngx_pool_t *p, ngx_chain_t **free,
164    ngx_chain_t **busy, ngx_chain_t **out, ngx_buf_tag_t tag);
165
166off_t ngx_chain_coalesce_file(ngx_chain_t **in, off_t limit);
167
168ngx_chain_t *ngx_chain_update_sent(ngx_chain_t *in, off_t sent);
169
170#endif /* _NGX_BUF_H_INCLUDED_ */
171