static ngx_int_t ngx_http_set_expires(ngx_http_request_t *r, ngx_http_headers_conf_t *conf) { size_t len; time_t now, expires_time, max_age; ngx_uint_t i; ngx_table_elt_t *expires, *cc, **ccp; expires = r->headers_out.expires; if (expires == NULL) { expires = ngx_list_push(&r->headers_out.headers); if (expires == NULL) { return NGX_ERROR; } r->headers_out.expires = expires; expires->hash = 1; expires->key.len = sizeof("Expires") - 1; expires->key.data = (u_char *) "Expires"; } len = sizeof("Mon, 28 Sep 1970 06:00:00 GMT"); expires->value.len = len - 1; ccp = r->headers_out.cache_control.elts; if (ccp == NULL) { if (ngx_array_init(&r->headers_out.cache_control, r->pool, 1, sizeof(ngx_table_elt_t *)) != NGX_OK) { return NGX_ERROR; } ccp = ngx_array_push(&r->headers_out.cache_control); if (ccp == NULL) { return NGX_ERROR; } cc = ngx_list_push(&r->headers_out.headers); if (cc == NULL) { return NGX_ERROR; } cc->hash = 1; cc->key.len = sizeof("Cache-Control") - 1; cc->key.data = (u_char *) "Cache-Control"; *ccp = cc; } else { for (i = 1; i < r->headers_out.cache_control.nelts; i++) { ccp[i]->hash = 0; } cc = ccp[0]; } if (conf->expires == NGX_HTTP_EXPIRES_EPOCH) { expires->value.data = (u_char *) "Thu, 01 Jan 1970 00:00:01 GMT"; cc->value.len = sizeof("no-cache") - 1; cc->value.data = (u_char *) "no-cache"; return NGX_OK; } if (conf->expires == NGX_HTTP_EXPIRES_MAX) { expires->value.data = (u_char *) "Thu, 31 Dec 2037 23:55:55 GMT"; /* 10 years */ cc->value.len = sizeof("max-age=315360000") - 1; cc->value.data = (u_char *) "max-age=315360000"; return NGX_OK; } expires->value.data = ngx_pnalloc(r->pool, len); if (expires->value.data == NULL) { return NGX_ERROR; } if (conf->expires_time == 0) { ngx_memcpy(expires->value.data, ngx_cached_http_time.data, ngx_cached_http_time.len + 1); cc->value.len = sizeof("max-age=0") - 1; cc->value.data = (u_char *) "max-age=0"; return NGX_OK; } now = ngx_time(); if (conf->expires == NGX_HTTP_EXPIRES_ACCESS || r->headers_out.last_modified_time == -1) { expires_time = now + conf->expires_time; max_age = conf->expires_time; } else if (conf->expires == NGX_HTTP_EXPIRES_DAILY) { expires_time = ngx_next_time(conf->expires_time); max_age = expires_time - now; } else { expires_time = r->headers_out.last_modified_time + conf->expires_time; max_age = expires_time - now; } ngx_http_time(expires->value.data, expires_time); if (conf->expires_time < 0) { cc->value.len = sizeof("no-cache") - 1; cc->value.data = (u_char *) "no-cache"; return NGX_OK; } cc->value.data = ngx_pnalloc(r->pool, sizeof("max-age=") + NGX_TIME_T_LEN + 1); if (cc->value.data == NULL) { return NGX_ERROR; } cc->value.len = ngx_sprintf(cc->value.data, "max-age=%T", max_age) - cc->value.data; return NGX_OK; }
//expires配置解析,会触发创建设置r->headers_out.expires r->headers_out.cache_control static ngx_int_t //expires xx配置存储函数为ngx_http_headers_expires,真正组包生效函数为ngx_http_set_expires ngx_http_set_expires(ngx_http_request_t *r, ngx_http_headers_conf_t *conf) { char *err; size_t len; time_t now, expires_time, max_age; ngx_str_t value; ngx_int_t rc; ngx_uint_t i; ngx_table_elt_t *e, *cc, **ccp; ngx_http_expires_t expires; expires = conf->expires; expires_time = conf->expires_time; if (conf->expires_value != NULL) { //说明expires配置的是变量类型 if (ngx_http_complex_value(r, conf->expires_value, &value) != NGX_OK) { return NGX_ERROR; } rc = ngx_http_parse_expires(&value, &expires, &expires_time, &err); if (rc != NGX_OK) { return NGX_OK; } if (expires == NGX_HTTP_EXPIRES_OFF) { return NGX_OK; } } e = r->headers_out.expires; if (e == NULL) { e = ngx_list_push(&r->headers_out.headers); if (e == NULL) { return NGX_ERROR; } r->headers_out.expires = e; e->hash = 1; ngx_str_set(&e->key, "Expires"); } len = sizeof("Mon, 28 Sep 1970 06:00:00 GMT"); e->value.len = len - 1; ccp = r->headers_out.cache_control.elts; if (ccp == NULL) { if (ngx_array_init(&r->headers_out.cache_control, r->pool, 1, sizeof(ngx_table_elt_t *)) != NGX_OK) { return NGX_ERROR; } ccp = ngx_array_push(&r->headers_out.cache_control); if (ccp == NULL) { return NGX_ERROR; } cc = ngx_list_push(&r->headers_out.headers); if (cc == NULL) { return NGX_ERROR; } cc->hash = 1; ngx_str_set(&cc->key, "Cache-Control"); *ccp = cc; } else { for (i = 1; i < r->headers_out.cache_control.nelts; i++) { ccp[i]->hash = 0; } cc = ccp[0]; } if (expires == NGX_HTTP_EXPIRES_EPOCH) { e->value.data = (u_char *) "Thu, 01 Jan 1970 00:00:01 GMT"; ngx_str_set(&cc->value, "no-cache");//设置r->headers_out.cache_control return NGX_OK; } if (expires == NGX_HTTP_EXPIRES_MAX) { e->value.data = (u_char *) "Thu, 31 Dec 2037 23:55:55 GMT"; /* 10 years */ ngx_str_set(&cc->value, "max-age=315360000");//设置r->headers_out.cache_control return NGX_OK; } e->value.data = ngx_pnalloc(r->pool, len); if (e->value.data == NULL) { return NGX_ERROR; } if (expires_time == 0 && expires != NGX_HTTP_EXPIRES_DAILY) { ngx_memcpy(e->value.data, ngx_cached_http_time.data, ngx_cached_http_time.len + 1); ngx_str_set(&cc->value, "max-age=0");//设置r->headers_out.cache_control return NGX_OK; } now = ngx_time(); if (expires == NGX_HTTP_EXPIRES_DAILY) { expires_time = ngx_next_time(expires_time); max_age = expires_time - now; } else if (expires == NGX_HTTP_EXPIRES_ACCESS || r->headers_out.last_modified_time == -1) { max_age = expires_time; expires_time += now; } else { expires_time += r->headers_out.last_modified_time; max_age = expires_time - now; } ngx_http_time(e->value.data, expires_time); if (conf->expires_time < 0 || max_age < 0) { ngx_str_set(&cc->value, "no-cache");//设置r->headers_out.cache_control return NGX_OK; } //设置r->headers_out.cache_control cc->value.data = ngx_pnalloc(r->pool, sizeof("max-age=") + NGX_TIME_T_LEN + 1); if (cc->value.data == NULL) { return NGX_ERROR; } cc->value.len = ngx_sprintf(cc->value.data, "max-age=%T", max_age) - cc->value.data; return NGX_OK; }