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[PATCH v11 12/41] refs.c: change ref_transaction_update() to do error checking and return status

From
Ronnie Sahlberg <sahlberg@google.com>
Date
May 27, 2014, 20:25 UTC
Message-ID
<1401222360-21175-13-git-send-email-sahlberg@google.com>
In-Reply-To
<1401222360-21175-1-git-send-email-sahlberg@google.com>

Update ref_transaction_update() do some basic error checking and return non-zero on error. Update all callers to check ref_transaction_update() for error. There are currently no conditions in _update that will return error but there will be in the future. Add an err argument that will be updated on failure. In future patches we will start doing both locking and checking for name conflicts in _update instead of _commit at which time this function will start returning errors for these conditions.

Also check for BUGs during update and die(BUG:...) if we are calling _update with have_old but the old_sha1 pointer is NULL.

Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
---
 builtin/update-ref.c | 12 +++++++-----
 refs.c               | 18 ++++++++++++------
 refs.h               | 14 +++++++++-----
 3 files changed, 28 insertions(+), 16 deletions(-)
diff --git a/builtin/update-ref.c b/builtin/update-ref.c
index 88ab785..3067b11 100644
--- a/builtin/update-ref.c
+++ b/builtin/update-ref.c
@@ -16,6 +16,7 @@ static struct ref_transaction *transaction;
 
 static char line_termination = '\n';
 static int update_flags;
+static struct strbuf err = STRBUF_INIT;
 
 /*
  * Parse one whitespace- or NUL-terminated, possibly C-quoted argument
@@ -197,8 +198,9 @@ static const char *parse_cmd_update(struct strbuf *input, const char *next)
 	if (*next != line_termination)
 		die("update %s: extra input: %s", refname, next);
 
-	ref_transaction_update(transaction, refname, new_sha1, old_sha1,
-			       update_flags, have_old);
+	if (ref_transaction_update(transaction, refname, new_sha1, old_sha1,
+				   update_flags, have_old, &err))
+		die("%s", err.buf);
 
 	update_flags = 0;
 	free(refname);
@@ -286,8 +288,9 @@ static const char *parse_cmd_verify(struct strbuf *input, const char *next)
 	if (*next != line_termination)
 		die("verify %s: extra input: %s", refname, next);
 
-	ref_transaction_update(transaction, refname, new_sha1, old_sha1,
-			       update_flags, have_old);
+	if (ref_transaction_update(transaction, refname, new_sha1, old_sha1,
+				   update_flags, have_old, &err))
+		die("%s", err.buf);
 
 	update_flags = 0;
 	free(refname);
@@ -342,7 +345,6 @@ int cmd_update_ref(int argc, const char **argv, const char *prefix)
 	const char *refname, *oldval, *msg = NULL;
 	unsigned char sha1[20], oldsha1[20];
 	int delete = 0, no_deref = 0, read_stdin = 0, end_null = 0, flags = 0;
-	struct strbuf err = STRBUF_INIT;
 	struct option options[] = {
 		OPT_STRING( 'm', NULL, &msg, N_("reason"), N_("reason of the update")),
 		OPT_BOOL('d', NULL, &delete, N_("delete the reference")),
diff --git a/refs.c b/refs.c
index 00b6e9a..79a4477 100644
--- a/refs.c
+++ b/refs.c
@@ -3376,19 +3376,25 @@ static struct ref_update *add_update(struct ref_transaction *transaction,
 	return update;
 }
 
-void ref_transaction_update(struct ref_transaction *transaction,
-			    const char *refname,
-			    const unsigned char *new_sha1,
-			    const unsigned char *old_sha1,
-			    int flags, int have_old)
+int ref_transaction_update(struct ref_transaction *transaction,
+			   const char *refname,
+			   const unsigned char *new_sha1,
+			   const unsigned char *old_sha1,
+			   int flags, int have_old,
+			   struct strbuf *err)
 {
-	struct ref_update *update = add_update(transaction, refname);
+	struct ref_update *update;
+
+	if (have_old && !old_sha1)
+		die("BUG: have_old is true but old_sha1 is NULL");
 
+	update = add_update(transaction, refname);
 	hashcpy(update->new_sha1, new_sha1);
 	update->flags = flags;
 	update->have_old = have_old;
 	if (have_old)
 		hashcpy(update->old_sha1, old_sha1);
+	return 0;
 }
 
 void ref_transaction_create(struct ref_transaction *transaction,
diff --git a/refs.h b/refs.h
index 6ee9c9e..32edf3f 100644
--- a/refs.h
+++ b/refs.h
@@ -234,12 +234,16 @@ struct ref_transaction *ref_transaction_begin(void);
  * be deleted.  If have_old is true, then old_sha1 holds the value
  * that the reference should have had before the update, or zeros if
  * it must not have existed beforehand.
+ * Function returns 0 on success and non-zero on failure. A failure to update
+ * means that the transaction as a whole has failed and will need to be
+ * rolled back. On failure the err buffer will be updated.
  */
-void ref_transaction_update(struct ref_transaction *transaction,
-			    const char *refname,
-			    const unsigned char *new_sha1,
-			    const unsigned char *old_sha1,
-			    int flags, int have_old);
+int ref_transaction_update(struct ref_transaction *transaction,
+			   const char *refname,
+			   const unsigned char *new_sha1,
+			   const unsigned char *old_sha1,
+			   int flags, int have_old,
+			   struct strbuf *err);
 
 /*
  * Add a reference creation to transaction.  new_sha1 is the value

-- 
2.0.0.rc3.474.g0203784
Previous: Ronnie SahlbergNext: Ronnie Sahlberg
Message 22 of 89 in “Use ref transactions”
  1. 00/41 Use ref transactionsRonnie Sahlberg, May 27, 2014
  2. 01/41 refs.c: remove ref_transaction_rollbackRonnie Sahlberg, May 27, 2014
  3. 02/41 refs.c: ref_transaction_commit should not free the transactionRonnie Sahlberg, May 27, 2014
  4. Jonathan NiederMay 27, 2014
  5. 03/41 refs.c: constify the sha arguments for ref_transaction_create|delete|updateRonnie Sahlberg, May 27, 2014
  6. 04/41 refs.c: allow passing NULL to ref_transaction_freeRonnie Sahlberg, May 27, 2014
  7. 05/41 refs.c: add a strbuf argument to ref_transaction_commit for error loggingRonnie Sahlberg, May 27, 2014
  8. 06/41 refs.c: add an err argument to repack_without_refsRonnie Sahlberg, May 27, 2014
  9. Jonathan NiederMay 28, 2014
  10. Ronnie SahlbergMay 28, 2014
  11. Jonathan NiederMay 28, 2014
  12. 07/41 refs.c: make ref_update_reject_duplicates take a strbuf argument for errorsRonnie Sahlberg, May 27, 2014
  13. 08/41 refs.c: add an err argument to delete_ref_looseRonnie Sahlberg, May 27, 2014
  14. Jonathan NiederMay 28, 2014
  15. Ronnie SahlbergMay 28, 2014
  16. 09/41 refs.c: make update_ref_write update a strbuf on failureRonnie Sahlberg, May 27, 2014
  17. 10/41 update-ref.c: log transaction error from the update_refRonnie Sahlberg, May 27, 2014
  18. Jonathan NiederMay 28, 2014
  19. Ronnie SahlbergMay 28, 2014
  20. Jonathan NiederMay 28, 2014
  21. 11/41 refs.c: remove the onerr argument to ref_transaction_commitRonnie Sahlberg, May 27, 2014
  22. 12/41 refs.c: change ref_transaction_update() to do error checking and return statusRonnie Sahlberg, May 27, 2014
  23. 13/41 refs.c: change ref_transaction_create to do error checking and return statusRonnie Sahlberg, May 27, 2014
  24. Jonathan NiederMay 28, 2014
  25. Ronnie SahlbergMay 28, 2014
  26. Jonathan NiederMay 28, 2014
  27. Ronnie SahlbergMay 28, 2014
  28. Jonathan NiederMay 28, 2014
  29. Ronnie SahlbergMay 28, 2014
  30. Jonathan NiederMay 28, 2014
  31. 14/41 refs.c: update ref_transaction_delete to check for error and return statusRonnie Sahlberg, May 27, 2014
  32. Jonathan NiederMay 28, 2014
  33. 15/41 refs.c: make ref_transaction_begin take an err argumentRonnie Sahlberg, May 27, 2014
  34. 16/41 refs.c: add transaction.status and track OPEN/CLOSED/ERRORRonnie Sahlberg, May 27, 2014
  35. Jonathan NiederMay 28, 2014
  36. Ronnie SahlbergMay 28, 2014
  37. 17/41 tag.c: use ref transactions when doing updatesRonnie Sahlberg, May 27, 2014
  38. 18/41 replace.c: use the ref transaction functions for updatesRonnie Sahlberg, May 27, 2014
  39. 19/41 commit.c: use ref transactions for updatesRonnie Sahlberg, May 27, 2014
  40. 20/41 sequencer.c: use ref transactions for all ref updatesRonnie Sahlberg, May 27, 2014
  41. Jonathan NiederMay 28, 2014
  42. 21/41 fast-import.c: change update_branch to use ref transactionsRonnie Sahlberg, May 27, 2014
  43. Jonathan NiederMay 28, 2014
  44. 22/41 branch.c: use ref transaction for all ref updatesRonnie Sahlberg, May 27, 2014
  45. 23/41 refs.c: change update_ref to use a transactionRonnie Sahlberg, May 27, 2014
  46. Jonathan NiederMay 28, 2014
  47. Ronnie SahlbergMay 28, 2014
  48. 24/41 receive-pack.c: use a reference transaction for updating the refsRonnie Sahlberg, May 27, 2014
  49. 25/41 fast-import.c: use a ref transaction when dumping tagsRonnie Sahlberg, May 27, 2014
  50. Jonathan NiederMay 28, 2014
  51. Ronnie SahlbergMay 28, 2014
  52. Jonathan NiederMay 28, 2014
  53. Ronnie SahlbergMay 28, 2014
  54. Jonathan NiederMay 28, 2014
  55. Ronnie SahlbergMay 29, 2014
  56. Jonathan NiederMay 29, 2014
  57. Ronnie SahlbergJun 3, 2014
  58. 26/41 walker.c: use ref transaction for ref updatesRonnie Sahlberg, May 27, 2014
  59. Jonathan NiederMay 28, 2014
  60. Ronnie SahlbergMay 28, 2014
  61. 27/41 refs.c: make lock_ref_sha1 staticRonnie Sahlberg, May 27, 2014
  62. 28/41 refs.c: remove the update_ref_lock functionRonnie Sahlberg, May 27, 2014
  63. 29/41 refs.c: remove the update_ref_write functionRonnie Sahlberg, May 27, 2014
  64. Jonathan NiederMay 28, 2014
  65. 30/41 refs.c: remove lock_ref_sha1Ronnie Sahlberg, May 27, 2014
  66. 31/41 refs.c: make prune_ref use a transaction to delete the refRonnie Sahlberg, May 27, 2014
  67. Jonathan NiederMay 28, 2014
  68. Ronnie SahlbergMay 28, 2014
  69. 32/41 refs.c: make delete_ref use a transactionRonnie Sahlberg, May 27, 2014
  70. Jonathan NiederMay 30, 2014
  71. Ronnie SahlbergJun 3, 2014
  72. 33/41 refs.c: pass the ref log message to _create/delete/update instead of _commitRonnie Sahlberg, May 27, 2014
  73. Jonathan NiederMay 30, 2014
  74. Ronnie SahlbergJun 3, 2014
  75. 34/41 refs.c: pass NULL as *flags to read_ref_fullRonnie Sahlberg, May 27, 2014
  76. 35/41 refs.c: pack all refs before we start to rename a refRonnie Sahlberg, May 27, 2014
  77. Jonathan NiederMay 30, 2014
  78. Ronnie SahlbergJun 3, 2014
  79. 36/41 refs.c: move the check for valid refname to lock_ref_sha1_basicRonnie Sahlberg, May 27, 2014
  80. Jonathan NiederMay 30, 2014
  81. Ronnie SahlbergJun 3, 2014
  82. 37/41 refs.c: call lock_ref_sha1_basic directly from commitRonnie Sahlberg, May 27, 2014
  83. 38/41 refs.c: pass a skip list to name_conflict_fnRonnie Sahlberg, May 27, 2014
  84. 39/41 refs.c: propagate any errno==ENOTDIR from _commit back to the callersRonnie Sahlberg, May 27, 2014
  85. Jonathan NiederMay 31, 2014
  86. Ronnie SahlbergJun 3, 2014
  87. 40/41 fetch.c: change s_update_ref to use a ref transactionRonnie Sahlberg, May 27, 2014
  88. 41/41 refs.c: make write_ref_sha1 staticRonnie Sahlberg, May 27, 2014
  89. Jonathan NiederJun 3, 2014

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