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[PATCH v2 25/25] trim_last_path_elm(): replace last_path_elm()

From
Michael Haggerty <mhagger@alum.mit.edu>
Date
Apr 6, 2014, 23:34 UTC
Message-ID
<1396827247-28465-26-git-send-email-mhagger@alum.mit.edu>
In-Reply-To
<1396827247-28465-1-git-send-email-mhagger@alum.mit.edu>

Rewrite last_path_elm() to take a strbuf parameter and to trim off the last path name element in place rather than returning a pointer to the beginning of the last path name element. This simplifies the function a bit and makes it integrate better with its caller, which is also strbuf-based. Rename the function accordingly.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
---
 lockfile.c | 38 ++++++++++++++++----------------------
 1 file changed, 16 insertions(+), 22 deletions(-)
diff --git a/lockfile.c b/lockfile.c
index 8e7bcda..f9c8515 100644
--- a/lockfile.c
+++ b/lockfile.c
@@ -100,32 +100,28 @@ static void remove_lock_file_on_signal(int signo)
 }
 
 /*
- * p = absolute or relative path name
+ * path = absolute or relative path name
  *
- * Return a pointer into p showing the beginning of the last path name
- * element.  If p is empty or the root directory ("/"), just return p.
+ * Remove the last path name element from path (leaving the preceding
+ * "/", if any).  If path is empty or the root directory ("/"), set
+ * path to the empty string.
  */
-static char *last_path_elm(char *p)
+static void trim_last_path_elm(struct strbuf *path)
 {
-	/* r starts pointing to null at the end of the string */
-	char *r = strchr(p, '\0');
-
-	if (r == p)
-		return p; /* just return empty string */
-
-	r--; /* back up to last non-null character */
+	int i = path->len;
 
 	/* back up past trailing slashes, if any */
-	while (r > p && *r == '/')
-		r--;
+	while (i && path->buf[i - 1] == '/')
+		i--;
 
 	/*
-	 * then go backwards until I hit a slash, or the beginning of
-	 * the string
+	 * then go backwards until a slash, or the beginning of the
+	 * string
 	 */
-	while (r > p && *(r-1) != '/')
-		r--;
-	return r;
+	while (i && path->buf[i - 1] != '/')
+		i--;
+
+	strbuf_setlen(path, i);
 }
 
 
@@ -155,14 +151,12 @@ static void resolve_symlink(struct strbuf *path)
 		if (is_absolute_path(link.buf))
 			/* absolute path simply replaces p */
 			strbuf_reset(path);
-		else {
+		else
 			/*
 			 * link is a relative path, so replace the
 			 * last element of p with it.
 			 */
-			char *r = last_path_elm(path->buf);
-			strbuf_setlen(path, r - path->buf);
-		}
+			trim_last_path_elm(path);
 
 		strbuf_addbuf(path, &link);
 	}
-- 
1.9.1
Previous: Michael HaggertyNext: Jeff King
Message 36 of 37 in “Lockfile correctness and refactoring”
  1. 00/25 Lockfile correctness and refactoringMichael Haggerty, Apr 6, 2014
  2. 01/25 api-lockfile: expand the documentationMichael Haggerty, Apr 6, 2014
  3. Jeff KingApr 7, 2014
  4. 02/25 unable_to_lock_die(): rename function from unable_to_lock_index_die()Michael Haggerty, Apr 6, 2014
  5. Jeff KingApr 7, 2014
  6. Michael HaggertyApr 8, 2014
  7. 03/25 rollback_lock_file(): do not clear filename redundantlyMichael Haggerty, Apr 6, 2014
  8. 04/25 rollback_lock_file(): set fd to -1Michael Haggerty, Apr 6, 2014
  9. 05/25 lockfile: unlock file if lockfile permissions cannot be adjustedMichael Haggerty, Apr 6, 2014
  10. 06/25 hold_lock_file_for_append(): release lock on errorsMichael Haggerty, Apr 6, 2014
  11. 07/25 lock_file(): always add lock_file object to lock_file_listMichael Haggerty, Apr 6, 2014
  12. 08/25 struct lock_file: replace on_list field with flags fieldMichael Haggerty, Apr 6, 2014
  13. 09/25 lockfile.c: document the various states of lock_file objectsMichael Haggerty, Apr 6, 2014
  14. 10/25 lockfile: define a constant LOCK_SUFFIX_LENMichael Haggerty, Apr 6, 2014
  15. 11/25 delete_ref_loose(): don't muck around in the lock_file's filenameMichael Haggerty, Apr 6, 2014
  16. 12/25 prepare_index(): declare return value to be (const char *)Michael Haggerty, Apr 6, 2014
  17. 13/25 write_packed_entry_fn(): convert cb_data into a (const int *)Michael Haggerty, Apr 6, 2014
  18. 14/25 lock_file(): exit early if lockfile cannot be openedMichael Haggerty, Apr 6, 2014
  19. 15/25 remove_lock_file(): call rollback_lock_file()Michael Haggerty, Apr 6, 2014
  20. 16/25 commit_lock_file(): inline temporary variableMichael Haggerty, Apr 6, 2014
  21. 17/25 commit_lock_file(): make committing an unlocked lockfile a NOPMichael Haggerty, Apr 6, 2014
  22. Jeff KingApr 7, 2014
  23. Michael HaggertyApr 14, 2014
  24. 18/25 lockfile: avoid transitory invalid statesMichael Haggerty, Apr 6, 2014
  25. Johannes SixtApr 7, 2014
  26. Michael HaggertyApr 7, 2014
  27. Johannes SixtApr 7, 2014
  28. Michael HaggertyApr 7, 2014
  29. Jeff KingApr 7, 2014
  30. 19/25 try_merge_strategy(): remove redundant lock_file allocationMichael Haggerty, Apr 6, 2014
  31. 20/25 try_merge_strategy(): use a statically-allocated lock_file objectMichael Haggerty, Apr 6, 2014
  32. 21/25 commit_lock_file(): use a strbuf to manage temporary spaceMichael Haggerty, Apr 6, 2014
  33. 22/25 Change lock_file::filename into a strbufMichael Haggerty, Apr 6, 2014
  34. 23/25 resolve_symlink(): use a strbuf for internal scratch spaceMichael Haggerty, Apr 6, 2014
  35. 24/25 resolve_symlink(): take a strbuf parameterMichael Haggerty, Apr 6, 2014
  36. 25/25 trim_last_path_elm(): replace last_path_elm()Michael Haggerty, Apr 6, 2014
  37. Jeff KingApr 7, 2014

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