Use dynamically-sized path buffer when scanning files

[wimlib] / src / scan.c

diff --git a/src/scan.c b/src/scan.c
index be651439bf2881a9927482aa6df1f7c1e98dafd2..cc86d808a13d3ba02a66aef7ad284b945ef0722a 100644 (file)
--- a/src/scan.c
+++ b/src/scan.c
@@ -3,7 +3,7 @@
  */
 
 /*
- * Copyright (C) 2013-2016 Eric Biggers
+ * Copyright (C) 2013-2017 Eric Biggers
  *
  * This file is free software; you can redistribute it and/or modify it under
  * the terms of the GNU Lesser General Public License as published by the Free
@@ -39,8 +39,8 @@
  * and possibly call the progress function provided by the library user.
  *
  * @params
- *     Flags, optional progress function, and progress data for the scan
- *     operation.
+ *     Current path, flags, optional progress function, and progress data for
+ *     the scan operation.
  * @status
  *     Status of the scanned file.
  * @inode
@@ -69,6 +69,7 @@ do_scan_progress(struct scan_params *params, int status,
                        return 0;
                break;
        }
+       params->progress.scan.cur_path = params->cur_path;
        params->progress.scan.status = status;
        if (status == WIMLIB_SCAN_DENTRY_OK) {
 
@@ -273,12 +274,11 @@ match_pattern_list(const tchar *path, const struct string_list *list)
  *     (1) The capture configuration file
  *     (2) The user-provided progress function
  *
- * The capture implementation must have set params->capture_root_nchars to an
- * appropriate value.  Example for UNIX:  if the capture root directory is
- * "foobar/subdir", then all paths will be provided starting with
- * "foobar/subdir", so params->capture_root_nchars must be set to
- * strlen("foobar/subdir") so that the appropriate path can be matched against
- * the patterns in the exclusion list.
+ * params->root_path_nchars must have been set beforehand.  Example for UNIX: if
+ * the capture root directory is "foobar/subdir", then all paths will be
+ * provided starting with "foobar/subdir", so params->root_path_nchars must have
+ * been set to strlen("foobar/subdir") so that the appropriate path suffix can
+ * be matched against the patterns in the exclusion list.
  *
  * Returns:
  *     < 0 if excluded
@@ -286,12 +286,12 @@ match_pattern_list(const tchar *path, const struct string_list *list)
  *     > 0 (wimlib error code) if error
  */
 int
-try_exclude(const tchar *full_path, const struct scan_params *params)
+try_exclude(const struct scan_params *params)
 {
        int ret;
 
        if (params->config) {
-               const tchar *path = full_path + params->capture_root_nchars;
+               const tchar *path = params->cur_path + params->root_path_nchars;
                if (match_pattern_list(path, &params->config->exclusion_pats) &&
                    !match_pattern_list(path, &params->config->exclusion_exception_pats))
                        return -1;
@@ -302,10 +302,10 @@ try_exclude(const tchar *full_path, const struct scan_params *params)
                union wimlib_progress_info info;
                tchar *cookie;
 
-               info.test_file_exclusion.path = full_path;
+               info.test_file_exclusion.path = params->cur_path;
                info.test_file_exclusion.will_exclude = false;
 
-               cookie = progress_get_win32_path(full_path);
+               cookie = progress_get_win32_path(info.test_file_exclusion.path);
 
                ret = call_progress(params->progfunc, WIMLIB_PROGRESS_MSG_TEST_FILE_EXCLUSION,
                                    &info, params->progctx);
@@ -368,3 +368,69 @@ attach_scanned_tree(struct wim_dentry *parent, struct wim_dentry *child,
                free_dentry_tree(child, blob_table);
        }
 }
+
+/* Set the path at which the directory tree scan is beginning. */
+int
+pathbuf_init(struct scan_params *params, const tchar *root_path)
+{
+       size_t nchars = tstrlen(root_path);
+       size_t alloc_nchars = nchars + 1 + 1024;
+
+       params->cur_path = MALLOC(alloc_nchars * sizeof(tchar));
+       if (!params->cur_path)
+               return WIMLIB_ERR_NOMEM;
+       tmemcpy(params->cur_path, root_path, nchars + 1);
+       params->cur_path_nchars = nchars;
+       params->cur_path_alloc_nchars = alloc_nchars;
+       params->root_path_nchars = nchars;
+       return 0;
+}
+
+/*
+ * Append a filename to the current path.
+ *
+ * If successful, returns a pointer to the filename component and sets
+ * *orig_path_nchars_ret to the old path length, which can be restored later
+ * using pathbuf_truncate().  Otherwise returns NULL (out of memory).
+ */
+const tchar *
+pathbuf_append_name(struct scan_params *params, const tchar *name,
+                   size_t name_nchars, size_t *orig_path_nchars_ret)
+{
+       size_t path_nchars = params->cur_path_nchars;
+       size_t required_nchars = path_nchars + 1 + name_nchars + 1;
+       tchar *buf = params->cur_path;
+
+       if (unlikely(required_nchars > params->cur_path_alloc_nchars)) {
+               required_nchars += 1024;
+               buf = REALLOC(buf, required_nchars * sizeof(tchar));
+               if (!buf)
+                       return NULL;
+               params->cur_path = buf;
+               params->cur_path_alloc_nchars = required_nchars;
+       }
+       *orig_path_nchars_ret = path_nchars;
+
+       /*
+        * Add the slash, but not if it will be a duplicate (which can happen if
+        * the path to the capture root directory ends in a slash), because
+        * on Windows duplicate slashes sometimes don't work as expected.
+        */
+       if (path_nchars && buf[path_nchars - 1] != OS_PREFERRED_PATH_SEPARATOR)
+               buf[path_nchars++] = OS_PREFERRED_PATH_SEPARATOR;
+
+       tmemcpy(&buf[path_nchars], name, name_nchars);
+       path_nchars += name_nchars;
+       buf[path_nchars] = T('\0');
+       params->cur_path_nchars = path_nchars;
+       return &buf[path_nchars - name_nchars];
+}
+
+/* Truncate the current path to the specified number of characters. */
+void
+pathbuf_truncate(struct scan_params *params, size_t nchars)
+{
+       wimlib_assert(nchars <= params->cur_path_nchars);
+       params->cur_path[nchars] = T('\0');
+       params->cur_path_nchars = nchars;
+}