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         last_buf:1;
  48
  49     unsigned         last_shadow:1;
  50     unsigned         temp_file:1;
  51
  52     unsigned         zerocopy_busy:1;
  53
  54     /* STUB */ int   num;
  55 };
  56
  57
  58 typedef struct ngx_chain_s       ngx_chain_t;
  59
  60 struct ngx_chain_s {
  61     ngx_buf_t    *buf;
  62     ngx_chain_t  *next;
  63 };
  64
  65
  66 typedef struct {
  67     ngx_int_t    num;
  68     size_t       size;
  69 } ngx_bufs_t;
  70
  71
  72 typedef int  (*ngx_output_chain_filter_pt)(void *ctx, ngx_chain_t *out);
  73
  74 typedef struct {
  75     ngx_buf_t                   *buf;
  76     ngx_chain_t                 *in;
  77     ngx_chain_t                 *free;
  78     ngx_chain_t                 *busy;
  79
  80     unsigned                     sendfile;
  81     unsigned                     need_in_memory;
  82     unsigned                     need_in_temp;
  83
  84     ngx_pool_t                  *pool;
  85     ngx_int_t                    allocated;
  86     ngx_bufs_t                   bufs;
  87     ngx_buf_tag_t                tag;
  88
  89     ngx_output_chain_filter_pt   output_filter;
  90     void                        *filter_ctx;
  91 } ngx_output_chain_ctx_t;
  92
  93
  94 typedef struct {
  95     ngx_chain_t                 *out;
  96     ngx_chain_t                **last;
  97     ngx_connection_t            *connection;
  98     ngx_pool_t                  *pool;
  99     off_t                        limit;
 100 } ngx_chain_writer_ctx_t;
 101
 102
 103 #define NGX_CHAIN_ERROR     (ngx_chain_t *) NGX_ERROR
 104
 105
 106 #define ngx_buf_in_memory(b)        (b->temporary || b->memory || b->mmap)
 107 #define ngx_buf_in_memory_only(b)   (ngx_buf_in_memory(b) && !b->in_file)
 108 #define ngx_buf_special(b)                                                   \
 109         ((b->flush || b->last_buf) && !ngx_buf_in_memory(b) && !b->in_file)
 110
 111 #define ngx_buf_size(b)                                                      \
 112         (ngx_buf_in_memory(b) ? (off_t) (b->last - b->pos):                  \
 113                                 (b->file_last - b->file_pos))
 114
 115 ngx_buf_t *ngx_create_temp_buf(ngx_pool_t *pool, size_t size);
 116 ngx_chain_t *ngx_create_chain_of_bufs(ngx_pool_t *pool, ngx_bufs_t *bufs);
 117
 118
 119 #define ngx_alloc_buf(pool)  ngx_palloc(pool, sizeof(ngx_buf_t))
 120 #define ngx_calloc_buf(pool) ngx_pcalloc(pool, sizeof(ngx_buf_t))
 121
 122
 123 #define ngx_alloc_chain_link(pool) ngx_palloc(pool, sizeof(ngx_chain_t))
 124
 125
 126 #define ngx_alloc_link_and_set_buf(chain, b, pool, error)                    \
 127             do {                                                             \
 128                 ngx_test_null(chain, ngx_alloc_chain_link(pool), error);     \
 129                 chain->buf = b;                                              \
 130                 chain->next = NULL;                                          \
 131             } while (0);
 132
 133
 134 #define ngx_chain_add_link(chain, last, cl)                                  \
 135             if (chain) {                                                     \
 136                 *last = cl;                                                  \
 137             } else {                                                         \
 138                 chain = cl;                                                  \
 139             }                                                                \
 140             last = &cl->next
 141
 142
 143 ngx_int_t ngx_output_chain(ngx_output_chain_ctx_t *ctx, ngx_chain_t *in);
 144 ngx_int_t ngx_chain_writer(void *data, ngx_chain_t *in);
 145
 146 ngx_int_t ngx_chain_add_copy(ngx_pool_t *pool, ngx_chain_t **chain,
 147                              ngx_chain_t *in);
 148 void ngx_chain_update_chains(ngx_chain_t **free, ngx_chain_t **busy,
 149                              ngx_chain_t **out, ngx_buf_tag_t tag);
 150
 151
 152 #endif /* _NGX_BUF_H_INCLUDED_ */