Detailed analysis of each stage of nginx's http request processing

typedef enum {
 NGX_HTTP_POST_READ_PHASE = 0,
 
 NGX_HTTP_SERVER_REWRITE_PHASE,
 
 NGX_HTTP_FIND_CONFIG_PHASE,
 NGX_HTTP_REWRITE_PHASE,
 NGX_HTTP_POST_REWRITE_PHASE,
 
 NGX_HTTP_PREACCESS_PHASE,
 
 NGX_HTTP_ACCESS_PHASE,
 NGX_HTTP_POST_ACCESS_PHASE,
 
 NGX_HTTP_TRY_FILES_PHASE,
 NGX_HTTP_CONTENT_PHASE,
 
 NGX_HTTP_LOG_PHASE
} ngx_http_phases;

NGX_HTTP_POST_READ_PHASE = 0 //Read request phase NGX_HTTP_SERVER_REWRITE_PHASE //URI conversion phase NGX_HTTP_FIND_CONFIG_PHASE //Find the corresponding configuration to execute the phase NGX_HTTP_REWRITE_PHASE //URI conversion phase (not very clear here)
NGX_HTTP_POST_REWRITE_PHASE //The stage for processing the converted URL result NGX_HTTP_PREACCESS_PHASE //Permission check preparation stage NGX_HTTP_ACCESS_PHASE //Permission check stage NGX_HTTP_POST_ACCESS_PHASE //Permission check result processing stage NGX_HTTP_TRY_FILES_PHASE //Processing the try_files stage in the configuration NGX_HTTP_CONTENT_PHASE //Processing the generated return data stage (not considered too detailed here, of course, filters can be ignored)
NGX_HTTP_LOG_PHASE //Record the log processing phase, which should be processed after the request is completed and when the request is closed

static ngx_int_t
ngx_http_xxx_init(ngx_conf_t *cf)
{
 ngx_http_handler_pt *h;
 ngx_http_core_main_conf_t *cmcf;
 
 cmcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_core_module);
 
 h = ngx_array_push(&cmcf->phases[NGX_HTTP_CONTENT_PHASE].handlers);
 if (h == NULL) {
 return NGX_ERROR;
 }
 
 *h = ngx_http_xxx_handler;
 
 return NGX_OK;
}

NGX_OK //Processing successful, enter the next stageNGX_DECLINED //Abandon processingNGX_AGAIN || NGX_DONE //Processing completed, returning this value will trigger a requestNGX_ERROR || NGX_HTTP_.. //Processing error or other status values ​​of HTTP

static char *
ngx_http_xxx_server(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
 ngx_str_t *value;
 ngx_url_t u;
 ngx_http_core_loc_conf_t *clcf;
 
 clcf = ngx_http_conf_get_module_loc_conf(cf, ngx_http_core_module);
 
 clcf->handler = ngx_http_xxx_handler;
 
 if (clcf->name.data[clcf->name.len - 1] == '/') {
 clcf->auto_redirect = 1;
 }
 
 return NGX_CONF_OK;
}