Add option to clear cache

src/cache.c

@@ -9,6 +9,7 @@
 #include <dirent.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <ftw.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
@@ -144,6 +145,36 @@ void CacheSystem_init(const char *path, int url_supplied)
     CACHE_SYSTEM_INIT = 1;
 }
 
+static int ntfw_cb(const char *fpath, const struct stat *sb, int typeflag, struct FTW *ftwbuf)
+{
+    (void) sb;
+    (void) typeflag;
+    (void) ftwbuf;
+    return remove(fpath);
+}
+
+void CacheSystem_clear(const char *path)
+{
+    char *cache_root_dir;
+    if (path) {
+        cache_root_dir = strdup(path);
+    } else {
+        char *xdg_cache_home = getenv("XDG_CACHE_HOME");
+        if (!xdg_cache_home) {
+            char *home = getenv("HOME");
+            char *xdg_cache_home_default = "/.cache";
+            xdg_cache_home = path_append(home, xdg_cache_home_default);
+        }
+        cache_root_dir = path_append(xdg_cache_home, "/httpdirfs/");
+    }
+
+    lprintf(debug, "%s\n", path);
+
+    nftw(cache_root_dir, ntfw_cb, 64, FTW_DEPTH | FTW_PHYS | FTW_MOUNT);
+    exit(EXIT_SUCCESS);
+}
+
+
 /**
  * \brief read a metadata file
  * \return 0 on success, errno on error.

src/cache.h

@@ -92,6 +92,16 @@ extern char *META_DIR;
  */
 void CacheSystem_init(const char *path, int url_supplied);
 
+/**
+ * \brief clear the cache system directory
+ * \details This function basically clears these paths on disk:
+ *  - META_DIR
+ *  - DATA_DIR
+ *
+ * If these directories exist, they will be deleted.
+ */
+void CacheSystem_clear(const char *path);
+
 /**
  * \brief Create directories under the cache directory structure, if they do
  * not already exist

src/config.c

@@ -56,6 +56,8 @@ void Config_init(void)
     /*--------------- Cache related ---------------*/
     CONFIG.cache_enabled = 0;
 
+    CONFIG.cache_clear = 0;
+
     CONFIG.cache_dir = NULL;
 
     CONFIG.data_blksz = DEFAULT_DATA_BLKSZ;

src/config.h

@@ -72,8 +72,10 @@ typedef struct {
     /** \brief Refresh directory listing after refresh_timeout seconds*/
     int refresh_timeout;
     /*--------------- Cache related ---------------*/
-    /** \brief Whether cache mode is enabled */
+    /** \brief Whether to clear cache directory */
     int cache_enabled;
+    /** \brief Whether to clear any previous cache */
+    int cache_clear;
     /** \brief The cache location*/
     char *cache_dir;
     /** \brief The size of each download segment for cache mode */

src/main.c

@@ -203,6 +203,7 @@ parse_arg_list(int argc, char **argv, char ***fuse_argv, int *fuse_argc)
         { "proxy-cacert", required_argument, NULL, 'L' },       /* 24 */
         { "refresh-timeout", required_argument, NULL, 'L' },    /* 25 */
         { "http-header", required_argument, NULL, 'L' },        /* 26 */
+        { "cache-clear", no_argument, NULL, 'L' },     /* 27 */
         { 0, 0, 0, 0 }
     };
     while ((c =
@@ -314,6 +315,13 @@ parse_arg_list(int argc, char **argv, char ***fuse_argv, int *fuse_argc)
                 CONFIG.http_headers =
                     curl_slist_append(CONFIG.http_headers, strdup(optarg));
                 break;
+            case 27:
+                if (CONFIG.cache_dir) {
+                    CacheSystem_clear(CONFIG.cache_dir);
+                } else {
+                    CacheSystem_clear(NULL);
+                }
+                break;
             default:
                 fprintf(stderr, "see httpdirfs -h for usage\n");
                 return 1;
@@ -369,6 +377,7 @@ HTTPDirFS options:\n\
         --cache             Enable cache (default: off)\n\
         --cache-location    Set a custom cache location\n\
                             (default: \"${XDG_CACHE_HOME}/httpdirfs\")\n\
+        --cache-clear       Clear cache directory and exit\n\
         --cacert            Certificate authority for the server\n\
         --dl-seg-size       Set cache download segment size, in MB (default: 8)\n\
                             Note: this setting is ignored if previously\n\