nginx/src/core/ngx_buf.h

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