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;
}
