Mercurial > hg > nginx
diff src/http/ngx_http_upstream.c @ 5441:43ccaf8e8728
Upstream: cache revalidation with conditional requests.
The following new directives are introduced: proxy_cache_revalidate,
fastcgi_cache_revalidate, scgi_cache_revalidate, uwsgi_cache_revalidate.
Default is off. When set to on, they enable cache revalidation using
conditional requests with If-Modified-Since for expired cache items.
As of now, no attempts are made to merge headers given in a 304 response
during cache revalidation with headers previously stored in a cache item.
Headers in a 304 response are only used to calculate new validity time
of a cache item.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 18 Nov 2013 20:48:22 +0400 |
parents | 16b68c724438 |
children | b7b8e2fa7ebd |
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--- a/src/http/ngx_http_upstream.c Mon Nov 11 18:49:35 2013 +0400 +++ b/src/http/ngx_http_upstream.c Mon Nov 18 20:48:22 2013 +0400 @@ -17,6 +17,8 @@ ngx_http_upstream_t *u); static ngx_int_t ngx_http_upstream_cache_status(ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data); +static ngx_int_t ngx_http_upstream_cache_last_modified(ngx_http_request_t *r, + ngx_http_variable_value_t *v, uintptr_t data); #endif static void ngx_http_upstream_init_request(ngx_http_request_t *r); @@ -358,6 +360,10 @@ ngx_http_upstream_cache_status, 0, NGX_HTTP_VAR_NOCACHEABLE, 0 }, + { ngx_string("upstream_cache_last_modified"), NULL, + ngx_http_upstream_cache_last_modified, 0, + NGX_HTTP_VAR_NOCACHEABLE|NGX_HTTP_VAR_NOHASH, 0 }, + #endif { ngx_null_string, NULL, NULL, 0, 0, 0 } @@ -1806,6 +1812,56 @@ #endif } +#if (NGX_HTTP_CACHE) + + if (status == NGX_HTTP_NOT_MODIFIED + && u->cache_status == NGX_HTTP_CACHE_EXPIRED + && u->conf->cache_revalidate) + { + time_t now, valid; + ngx_int_t rc; + + ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, + "http upstream not modified"); + + now = ngx_time(); + valid = r->cache->valid_sec; + + rc = u->reinit_request(r); + + if (rc != NGX_OK) { + ngx_http_upstream_finalize_request(r, u, rc); + return NGX_OK; + } + + u->cache_status = NGX_HTTP_CACHE_REVALIDATED; + rc = ngx_http_upstream_cache_send(r, u); + + if (valid == 0) { + valid = r->cache->valid_sec; + } + + if (valid == 0) { + valid = ngx_http_file_cache_valid(u->conf->cache_valid, + u->headers_in.status_n); + if (valid) { + valid = now + valid; + } + } + + if (valid) { + r->cache->valid_sec = valid; + r->cache->date = now; + + ngx_http_file_cache_update_header(r); + } + + ngx_http_upstream_finalize_request(r, u, rc); + return NGX_OK; + } + +#endif + return NGX_DECLINED; } @@ -4492,6 +4548,35 @@ return NGX_OK; } + +static ngx_int_t +ngx_http_upstream_cache_last_modified(ngx_http_request_t *r, + ngx_http_variable_value_t *v, uintptr_t data) +{ + u_char *p; + + if (!r->upstream->conf->cache_revalidate + || r->upstream->cache_status != NGX_HTTP_CACHE_EXPIRED + || r->cache->last_modified == -1) + { + v->not_found = 1; + return NGX_OK; + } + + p = ngx_pnalloc(r->pool, sizeof("Mon, 28 Sep 1970 06:00:00 GMT") - 1); + if (p == NULL) { + return NGX_ERROR; + } + + v->len = ngx_http_time(p, r->cache->last_modified) - p; + v->valid = 1; + v->no_cacheable = 0; + v->not_found = 0; + v->data = p; + + return NGX_OK; +} + #endif