Mercurial > hg > nginx
view src/os/unix/ngx_aio_read_chain.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 | d620f497c50f |
children | ec81934727a1 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> ssize_t ngx_aio_read_chain(ngx_connection_t *c, ngx_chain_t *cl) { int n; u_char *buf, *prev; size_t size; ssize_t total; if (c->read->pending_eof) { c->read->ready = 0; return 0; } total = 0; while (cl) { /* we can post the single aio operation only */ if (!c->read->ready) { return total ? total : NGX_AGAIN; } buf = cl->buf->last; prev = cl->buf->last; size = 0; /* coalesce the neighbouring bufs */ while (cl && prev == cl->buf->last) { size += cl->buf->end - cl->buf->last; prev = cl->buf->end; cl = cl->next; } n = ngx_aio_read(c, buf, size); ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "aio_read: %d", n); if (n == NGX_AGAIN) { return total ? total : NGX_AGAIN; } if (n == NGX_ERROR) { return NGX_ERROR; } if (n == 0) { c->read->pending_eof = 1; if (total) { c->read->eof = 0; c->read->ready = 1; } return total; } if (n > 0) { total += n; } ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, 0, "aio_read total: %d", total); } return total ? total : NGX_AGAIN; }