[nginx] Cache: c->reading flag introduced.

[Maxim Dounin]

details:   http://hg.nginx.org/nginx/rev/c525c0454aa5
branches:  
changeset: 5879:c525c0454aa5
user:      Maxim Dounin <mdounin at mdounin.ru>
date:      Mon Oct 27 21:14:07 2014 +0300
description:
Cache: c->reading flag introduced.

It replaces c->buf in checks in ngx_http_file_cache_open(), making it possible
to reopen the file without clearing c->buf.  No functional changes.

diffstat:

 src/http/ngx_http_cache.h      |  1 +
 src/http/ngx_http_file_cache.c |  5 ++++-
 2 files changed, 5 insertions(+), 1 deletions(-)

diffs (36 lines):

diff --git a/src/http/ngx_http_cache.h b/src/http/ngx_http_cache.h
--- a/src/http/ngx_http_cache.h
+++ b/src/http/ngx_http_cache.h
@@ -101,6 +101,7 @@ struct ngx_http_cache_s {
     unsigned                         updating:1;
     unsigned                         exists:1;
     unsigned                         temp_file:1;
+    unsigned                         reading:1;
 };
 
 
diff --git a/src/http/ngx_http_file_cache.c b/src/http/ngx_http_file_cache.c
--- a/src/http/ngx_http_file_cache.c
+++ b/src/http/ngx_http_file_cache.c
@@ -259,7 +259,7 @@ ngx_http_file_cache_open(ngx_http_reques
         return NGX_AGAIN;
     }
 
-    if (c->buf) {
+    if (c->reading) {
         return ngx_http_file_cache_read(r, c);
     }
 
@@ -620,9 +620,12 @@ ngx_http_file_cache_aio_read(ngx_http_re
     n = ngx_file_aio_read(&c->file, c->buf->pos, c->body_start, 0, r->pool);
 
     if (n != NGX_AGAIN) {
+        c->reading = 0;
         return n;
     }
 
+    c->reading = 1;
+
     c->file.aio->data = r;
     c->file.aio->handler = ngx_http_cache_aio_event_handler;