Upstream: fixed X-Accel-Expires/Cache-Control/Expires handling. Previously, if caching was disabled due to Expires in the past, nginx failed to cache the response even if it was cacheable as per subsequently parsed Cache-Control header (ticket #964). Similarly, if caching was disabled due to Expires in the past, "Cache-Control: no-cache" or "Cache-Control: max-age=0", caching was not used if it was cacheable as per subsequently parsed X-Accel-Expires header. Fix is to avoid disabling caching immediately after parsing Expires in the past or Cache-Control, but rather set flags which are later checked by ngx_http_upstream_process_headers() (and cleared by "Cache-Control: max-age" and X-Accel-Expires). Additionally, now X-Accel-Expires does not prevent parsing of cache control extensions, notably stale-while-revalidate and stale-if-error. This ensures that order of the X-Accel-Expires and Cache-Control headers is not important. Prodded by Vadim Fedorenko and Yugo Horie.

/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_PARSE_H_INCLUDED_
#define _NGX_PARSE_H_INCLUDED_


#include <ngx_config.h>
#include <ngx_core.h>


ssize_t ngx_parse_size(ngx_str_t *line);
off_t ngx_parse_offset(ngx_str_t *line);
ngx_int_t ngx_parse_time(ngx_str_t *line, ngx_uint_t is_sec);


#endif /* _NGX_PARSE_H_INCLUDED_ */