Modules compatibility: cache purge fields.

src/core/ngx_file.h

diff --git a/src/core/ngx_file.h b/src/core/ngx_file.h
index a723c3d..4240dc0 100644
--- a/src/core/ngx_file.h
+++ b/src/core/ngx_file.h
@@ -43,6 +43,7 @@
 
 
 typedef time_t (*ngx_path_manager_pt) (void *data);
+typedef ngx_msec_t (*ngx_path_purger_pt) (void *data);
 typedef void (*ngx_path_loader_pt) (void *data);
 
 
@@ -52,6 +53,7 @@
     size_t                     level[NGX_MAX_PATH_LEVEL];
 
     ngx_path_manager_pt        manager;
+    ngx_path_purger_pt         purger;
     ngx_path_loader_pt         loader;
     void                      *data;
 

src/http/ngx_http_cache.h

diff --git a/src/http/ngx_http_cache.h b/src/http/ngx_http_cache.h
index 2667cbb..4aa947f 100644
--- a/src/http/ngx_http_cache.h
+++ b/src/http/ngx_http_cache.h
@@ -50,7 +50,8 @@
     unsigned                         exists:1;
     unsigned                         updating:1;
     unsigned                         deleting:1;
-                                     /* 11 unused bits */
+    unsigned                         purged:1;
+                                     /* 10 unused bits */
 
     ngx_file_uniq_t                  uniq;
     time_t                           expire;
@@ -85,6 +86,7 @@
     ngx_uint_t                       min_uses;
     ngx_uint_t                       error;
     ngx_uint_t                       valid_msec;
+    ngx_uint_t                       vary_tag;
 
     ngx_buf_t                       *buf;
 
@@ -109,6 +111,7 @@
     unsigned                         updating:1;
     unsigned                         exists:1;
     unsigned                         temp_file:1;
+    unsigned                         purged:1;
     unsigned                         reading:1;
     unsigned                         secondary:1;
 };

src/http/ngx_http_upstream.h

diff --git a/src/http/ngx_http_upstream.h b/src/http/ngx_http_upstream.h
index 315f856..e079eae 100644
--- a/src/http/ngx_http_upstream.h
+++ b/src/http/ngx_http_upstream.h
@@ -205,6 +205,7 @@
 
     ngx_array_t                     *cache_valid;
     ngx_array_t                     *cache_bypass;
+    ngx_array_t                     *cache_purge;
     ngx_array_t                     *no_cache;
 #endif