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[PATCH v7 31/38] trim_last_path_component(): replace last_path_elm()

From
Michael Haggerty <mhagger@alum.mit.edu>
Date
Oct 1, 2014, 10:28 UTC
Message-ID
<1412159322-2622-32-git-send-email-mhagger@alum.mit.edu>
In-Reply-To
<1412159322-2622-1-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 now also strbuf-based. Rename the function accordingly and a bit less tersely.

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 5f5bcff..56ad7e8 100644
--- a/lockfile.c
+++ b/lockfile.c
@@ -76,32 +76,28 @@ 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_component(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);
 }
 
 
@@ -131,14 +127,12 @@ 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_component(path);
 
 		strbuf_addbuf(path, &link);
 	}
-- 
2.1.0
Previous: Michael HaggertyNext: Michael Haggerty
Message 35 of 43 in “Lockfile correctness and refactoring”
  1. 00/38 Lockfile correctness and refactoringMichael Haggerty, Oct 1, 2014
  2. 01/38 unable_to_lock_die(): rename function from unable_to_lock_index_die()Michael Haggerty, Oct 1, 2014
  3. 02/38 api-lockfile: revise and expand the documentationMichael Haggerty, Oct 1, 2014
  4. 03/38 close_lock_file(): exit (successfully) if file is already closedMichael Haggerty, Oct 1, 2014
  5. 04/38 rollback_lock_file(): do not clear filename redundantlyMichael Haggerty, Oct 1, 2014
  6. 05/38 rollback_lock_file(): exit early if lock is not activeMichael Haggerty, Oct 1, 2014
  7. 06/38 rollback_lock_file(): set fd to -1Michael Haggerty, Oct 1, 2014
  8. 07/38 lockfile: unlock file if lockfile permissions cannot be adjustedMichael Haggerty, Oct 1, 2014
  9. 08/38 hold_lock_file_for_append(): release lock on errorsMichael Haggerty, Oct 1, 2014
  10. 09/38 lock_file(): always initialize and register lock_file objectMichael Haggerty, Oct 1, 2014
  11. René ScharfeOct 1, 2014
  12. Michael HaggertyOct 1, 2014
  13. Junio C HamanoOct 1, 2014
  14. 10/38 lockfile.c: document the various states of lock_file objectsMichael Haggerty, Oct 1, 2014
  15. 11/38 cache.h: define constants LOCK_SUFFIX and LOCK_SUFFIX_LENMichael Haggerty, Oct 1, 2014
  16. 12/38 delete_ref_loose(): don't muck around in the lock_file's filenameMichael Haggerty, Oct 1, 2014
  17. 13/38 prepare_index(): declare return value to be (const char *)Michael Haggerty, Oct 1, 2014
  18. 14/38 lock_file(): exit early if lockfile cannot be openedMichael Haggerty, Oct 1, 2014
  19. 15/38 remove_lock_file(): call rollback_lock_file()Michael Haggerty, Oct 1, 2014
  20. 16/38 commit_lock_file(): inline temporary variableMichael Haggerty, Oct 1, 2014
  21. 17/38 commit_lock_file(): die() if called for unlocked lockfile objectMichael Haggerty, Oct 1, 2014
  22. 18/38 close_lock_file(): if close fails, roll backMichael Haggerty, Oct 1, 2014
  23. 19/38 commit_lock_file(): rollback lock file on failure to renameMichael Haggerty, Oct 1, 2014
  24. 20/38 api-lockfile: document edge casesMichael Haggerty, Oct 1, 2014
  25. 21/38 dump_marks(): remove a redundant call to rollback_lock_file()Michael Haggerty, Oct 1, 2014
  26. 22/38 git_config_set_multivar_in_file(): avoid call to rollback_lock_file()Michael Haggerty, Oct 1, 2014
  27. 23/38 lockfile: avoid transitory invalid statesMichael Haggerty, Oct 1, 2014
  28. 24/38 struct lock_file: declare some fields volatileMichael Haggerty, Oct 1, 2014
  29. 25/38 try_merge_strategy(): remove redundant lock_file allocationMichael Haggerty, Oct 1, 2014
  30. 26/38 try_merge_strategy(): use a statically-allocated lock_file objectMichael Haggerty, Oct 1, 2014
  31. 27/38 commit_lock_file(): use a strbuf to manage temporary spaceMichael Haggerty, Oct 1, 2014
  32. 28/38 Change lock_file::filename into a strbufMichael Haggerty, Oct 1, 2014
  33. 29/38 resolve_symlink(): use a strbuf for internal scratch spaceMichael Haggerty, Oct 1, 2014
  34. 30/38 resolve_symlink(): take a strbuf parameterMichael Haggerty, Oct 1, 2014
  35. 31/38 trim_last_path_component(): replace last_path_elm()Michael Haggerty, Oct 1, 2014
  36. 32/38 Extract a function commit_lock_file_to()Michael Haggerty, Oct 1, 2014
  37. 33/38 Rename LOCK_NODEREF to LOCK_NO_DEREFMichael Haggerty, Oct 1, 2014
  38. 34/38 lockfile.c: rename static functionsMichael Haggerty, Oct 1, 2014
  39. 35/38 get_locked_file_path(): new functionMichael Haggerty, Oct 1, 2014
  40. 36/38 hold_lock_file_for_append(): restore errno before returningMichael Haggerty, Oct 1, 2014
  41. 37/38 Move read_index() definition to read-cache.cMichael Haggerty, Oct 1, 2014
  42. 38/38 lockfile.h: extract new header file for the functions in lockfile.cMichael Haggerty, Oct 1, 2014
  43. Junio C HamanoOct 1, 2014

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