nginx/src/http/ngx_http_postpone_filter_module.c

   1
   2 /*
   3  * Copyright (C) Igor Sysoev
   4  */
   5
   6
   7 #include <ngx_config.h>
   8 #include <ngx_core.h>
   9 #include <ngx_http.h>
  10
  11
  12 static ngx_int_t ngx_http_postpone_filter_add(ngx_http_request_t *r,
  13     ngx_chain_t *in);
  14 static ngx_int_t ngx_http_postpone_filter_init(ngx_conf_t *cf);
  15
  16
  17 static ngx_http_module_t  ngx_http_postpone_filter_module_ctx = {
  18     NULL,                                  /* preconfiguration */
  19     ngx_http_postpone_filter_init,         /* postconfiguration */
  20
  21     NULL,                                  /* create main configuration */
  22     NULL,                                  /* init main configuration */
  23
  24     NULL,                                  /* create server configuration */
  25     NULL,                                  /* merge server configuration */
  26
  27     NULL,                                  /* create location configuration */
  28     NULL                                   /* merge location configuration */
  29 };
  30
  31
  32 ngx_module_t  ngx_http_postpone_filter_module = {
  33     NGX_MODULE_V1,
  34     &ngx_http_postpone_filter_module_ctx,  /* module context */
  35     NULL,                                  /* module directives */
  36     NGX_HTTP_MODULE,                       /* module type */
  37     NULL,                                  /* init master */
  38     NULL,                                  /* init module */
  39     NULL,                                  /* init process */
  40     NULL,                                  /* init thread */
  41     NULL,                                  /* exit thread */
  42     NULL,                                  /* exit process */
  43     NULL,                                  /* exit master */
  44     NGX_MODULE_V1_PADDING
  45 };
  46
  47
  48 static ngx_http_output_body_filter_pt    ngx_http_next_filter;
  49
  50
  51 static ngx_int_t
  52 ngx_http_postpone_filter(ngx_http_request_t *r, ngx_chain_t *in)
  53 {
  54     ngx_connection_t              *c;
  55     ngx_http_postponed_request_t  *pr;
  56
  57     c = r->connection;
  58
  59     ngx_log_debug3(NGX_LOG_DEBUG_HTTP, c->log, 0,
  60                    "http postpone filter \"%V?%V\" %p", &r->uri, &r->args, in);
  61
  62     if (r != c->data) {
  63
  64         if (in) {
  65             ngx_http_postpone_filter_add(r, in);
  66             return NGX_OK;
  67         }
  68
  69 #if 0
  70         /* TODO: SSI may pass NULL */
  71         ngx_log_error(NGX_LOG_ALERT, c->log, 0,
  72                       "http postpone filter NULL inactive request",
  73                       &r->uri, &r->args);
  74 #endif
  75
  76         return NGX_OK;
  77     }
  78
  79     if (r->postponed == NULL) {
  80
  81         if (in || c->buffered) {
  82             return ngx_http_next_filter(r->main, in);
  83         }
  84
  85         return NGX_OK;
  86     }
  87
  88     if (in) {
  89         ngx_http_postpone_filter_add(r, in);
  90     }
  91
  92     do {
  93         pr = r->postponed;
  94
  95         if (pr->request) {
  96
  97             ngx_log_debug2(NGX_LOG_DEBUG_HTTP, c->log, 0,
  98                            "http postpone filter wake \"%V?%V\"",
  99                            &pr->request->uri, &pr->request->args);
 100
 101             r->postponed = pr->next;
 102
 103             c->data = pr->request;
 104
 105             return ngx_http_post_request(pr->request);
 106         }
 107
 108         if (pr->out == NULL) {
 109             ngx_log_error(NGX_LOG_ALERT, c->log, 0,
 110                           "http postpone filter NULL output",
 111                           &r->uri, &r->args);
 112
 113         } else {
 114             ngx_log_debug2(NGX_LOG_DEBUG_HTTP, c->log, 0,
 115                            "http postpone filter output \"%V?%V\"",
 116                            &r->uri, &r->args);
 117
 118             if (ngx_http_next_filter(r->main, pr->out) == NGX_ERROR) {
 119                 return NGX_ERROR;
 120             }
 121         }
 122
 123         r->postponed = pr->next;
 124
 125     } while (r->postponed);
 126
 127     return NGX_OK;
 128 }
 129
 130
 131 static ngx_int_t
 132 ngx_http_postpone_filter_add(ngx_http_request_t *r, ngx_chain_t *in)
 133 {
 134     ngx_http_postponed_request_t  *pr, **ppr;
 135
 136     if (r->postponed) {
 137         for (pr = r->postponed; pr->next; pr = pr->next) { /* void */ }
 138
 139         if (pr->request == NULL) {
 140             goto found;
 141         }
 142
 143         ppr = &pr->next;
 144
 145     } else {
 146         ppr = &r->postponed;
 147     }
 148
 149     pr = ngx_palloc(r->pool, sizeof(ngx_http_postponed_request_t));
 150     if (pr == NULL) {
 151         return NGX_ERROR;
 152     }
 153
 154     *ppr = pr;
 155
 156     pr->request = NULL;
 157     pr->out = NULL;
 158     pr->next = NULL;
 159
 160 found:
 161
 162     if (ngx_chain_add_copy(r->pool, &pr->out, in) == NGX_OK) {
 163         return NGX_OK;
 164     }
 165
 166     return NGX_ERROR;
 167 }
 168
 169
 170 static ngx_int_t
 171 ngx_http_postpone_filter_init(ngx_conf_t *cf)
 172 {
 173     ngx_http_next_filter = ngx_http_top_body_filter;
 174     ngx_http_top_body_filter = ngx_http_postpone_filter;
 175
 176     return NGX_OK;
 177 }