release/src/router/nginx/src/core/ngx_buf.h

   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
  16 typedef void *            ngx_buf_tag_t;
  17
  18 typedef struct ngx_buf_s  ngx_buf_t;
  19
  20 struct 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
  59 struct ngx_chain_s {
  60     ngx_buf_t    *buf;
  61     ngx_chain_t  *next;
  62 };
  63
  64
  65 typedef struct {
  66     ngx_int_t    num;
  67     size_t       size;
  68 } ngx_bufs_t;
  69
  70
  71 typedef struct ngx_output_chain_ctx_s  ngx_output_chain_ctx_t;
  72
  73 typedef ngx_int_t (*ngx_output_chain_filter_pt)(void *ctx, ngx_chain_t *in);
  74
  75 #if (NGX_HAVE_FILE_AIO)
  76 typedef void (*ngx_output_chain_aio_pt)(ngx_output_chain_ctx_t *ctx,
  77     ngx_file_t *file);
  78 #endif
  79
  80 struct ngx_output_chain_ctx_s {
  81     ngx_buf_t                   *buf;
  82     ngx_chain_t                 *in;
  83     ngx_chain_t                 *free;
  84     ngx_chain_t                 *busy;
  85
  86     unsigned                     sendfile:1;
  87     unsigned                     directio:1;
  88 #if (NGX_HAVE_ALIGNED_DIRECTIO)
  89     unsigned                     unaligned:1;
  90 #endif
  91     unsigned                     need_in_memory:1;
  92     unsigned                     need_in_temp:1;
  93 #if (NGX_HAVE_FILE_AIO)
  94     unsigned                     aio:1;
  95
  96     ngx_output_chain_aio_pt      aio_handler;
  97 #endif
  98
  99     off_t                        alignment;
 100
 101     ngx_pool_t                  *pool;
 102     ngx_int_t                    allocated;
 103     ngx_bufs_t                   bufs;
 104     ngx_buf_tag_t                tag;
 105
 106     ngx_output_chain_filter_pt   output_filter;
 107     void                        *filter_ctx;
 108 };
 109
 110
 111 typedef struct {
 112     ngx_chain_t                 *out;
 113     ngx_chain_t                **last;
 114     ngx_connection_t            *connection;
 115     ngx_pool_t                  *pool;
 116     off_t                        limit;
 117 } ngx_chain_writer_ctx_t;
 118
 119
 120 #define NGX_CHAIN_ERROR     (ngx_chain_t *) NGX_ERROR
 121
 122
 123 #define ngx_buf_in_memory(b)        (b->temporary || b->memory || b->mmap)
 124 #define ngx_buf_in_memory_only(b)   (ngx_buf_in_memory(b) && !b->in_file)
 125
 126 #define ngx_buf_special(b)                                                   \
 127     ((b->flush || b->last_buf || b->sync)                                    \
 128      && !ngx_buf_in_memory(b) && !b->in_file)
 129
 130 #define ngx_buf_sync_only(b)                                                 \
 131     (b->sync                                                                 \
 132      && !ngx_buf_in_memory(b) && !b->in_file && !b->flush && !b->last_buf)
 133
 134 #define ngx_buf_size(b)                                                      \
 135     (ngx_buf_in_memory(b) ? (off_t) (b->last - b->pos):                      \
 136                             (b->file_last - b->file_pos))
 137
 138 ngx_buf_t *ngx_create_temp_buf(ngx_pool_t *pool, size_t size);
 139 ngx_chain_t *ngx_create_chain_of_bufs(ngx_pool_t *pool, ngx_bufs_t *bufs);
 140
 141
 142 #define ngx_alloc_buf(pool)  ngx_palloc(pool, sizeof(ngx_buf_t))
 143 #define ngx_calloc_buf(pool) ngx_pcalloc(pool, sizeof(ngx_buf_t))
 144
 145 ngx_chain_t *ngx_alloc_chain_link(ngx_pool_t *pool);
 146 #define ngx_free_chain(pool, cl)                                             \
 147     cl->next = pool->chain;                                                  \
 148     pool->chain = cl
 149
 150
 151
 152 ngx_int_t ngx_output_chain(ngx_output_chain_ctx_t *ctx, ngx_chain_t *in);
 153 ngx_int_t ngx_chain_writer(void *ctx, ngx_chain_t *in);
 154
 155 ngx_int_t ngx_chain_add_copy(ngx_pool_t *pool, ngx_chain_t **chain,
 156     ngx_chain_t *in);
 157 ngx_chain_t *ngx_chain_get_free_buf(ngx_pool_t *p, ngx_chain_t **free);
 158 void ngx_chain_update_chains(ngx_pool_t *p, ngx_chain_t **free,
 159     ngx_chain_t **busy, ngx_chain_t **out, ngx_buf_tag_t tag);
 160
 161
 162 #endif /* _NGX_BUF_H_INCLUDED_ */