Cache: prefix-based temporary files.

On Linux, the rename syscall can be slow due to a global file system lock,
acquired for the entire rename operation, unless both old and new files are
in the same directory.  To address this temporary files are now created
in the same directory as the expected resulting cache file when using the
"use_temp_path=off" parameter.

This change mostly reverts 99639bfdfa2a and 3281de8142f5, restoring the
behaviour as of a9138c35120d (with minor changes).

1 files changed, 13 insertions, 32 deletions

diff --git a/src/http/ngx_http_file_cache.c b/src/http/ngx_http_file_cache.c
index ac5c10374..3c8ad7dab 100644
--- a/src/http/ngx_http_file_cache.c
+++ b/src/http/ngx_http_file_cache.c
@@ -2112,6 +2112,17 @@ ngx_http_file_cache_add_file(ngx_tree_ctx_t *ctx, ngx_str_t *name)
         return NGX_ERROR;
     }
 
+    /*
+     * Temporary files in cache have a suffix consisting of a dot
+     * followed by 10 digits.
+     */
+
+    if (name->len >= 2 * NGX_HTTP_CACHE_KEY_LEN + 1 + 10
+        && name->data[name->len - 10 - 1] == '.')
+    {
+        return NGX_OK;
+    }
+
     if (ctx->size < (off_t) sizeof(ngx_http_file_cache_header_t)) {
         ngx_log_error(NGX_LOG_CRIT, ctx->log, 0,
                       "cache file \"%s\" is too small", name->data);
@@ -2256,7 +2267,6 @@ ngx_http_file_cache_set_slot(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
     off_t                   max_size;
     u_char                 *last, *p;
     time_t                  inactive;
-    size_t                  len;
     ssize_t                 size;
     ngx_str_t               s, name, *value;
     ngx_int_t               loader_files, manager_files;
@@ -2529,37 +2539,6 @@ ngx_http_file_cache_set_slot(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
         return NGX_CONF_ERROR;
     }
 
-    if (!use_temp_path) {
-        cache->temp_path = ngx_pcalloc(cf->pool, sizeof(ngx_path_t));
-        if (cache->temp_path == NULL) {
-            return NGX_CONF_ERROR;
-        }
-
-        len = cache->path->name.len + sizeof("/temp") - 1;
-
-        p = ngx_pnalloc(cf->pool, len + 1);
-        if (p == NULL) {
-            return NGX_CONF_ERROR;
-        }
-
-        cache->temp_path->name.len = len;
-        cache->temp_path->name.data = p;
-
-        p = ngx_cpymem(p, cache->path->name.data, cache->path->name.len);
-        ngx_memcpy(p, "/temp", sizeof("/temp"));
-
-        ngx_memcpy(&cache->temp_path->level, &cache->path->level,
-                   NGX_MAX_PATH_LEVEL * sizeof(size_t));
-
-        cache->temp_path->len = cache->path->len;
-        cache->temp_path->conf_file = cf->conf_file->file.name.data;
-        cache->temp_path->line = cf->conf_file->line;
-
-        if (ngx_add_path(cf, &cache->temp_path) != NGX_OK) {
-            return NGX_CONF_ERROR;
-        }
-    }
-
     cache->shm_zone = ngx_shared_memory_add(cf, &name, size, cmd->post);
     if (cache->shm_zone == NULL) {
         return NGX_CONF_ERROR;
@@ -2575,6 +2554,8 @@ ngx_http_file_cache_set_slot(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
     cache->shm_zone->init = ngx_http_file_cache_init;
     cache->shm_zone->data = cache;
 
+    cache->use_temp_path = use_temp_path;
+
     cache->inactive = inactive;
     cache->max_size = max_size;