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[PATCH v7 02/42] refs.c: allow passing NULL to ref_transaction_free

From
Ronnie Sahlberg <sahlberg@google.com>
Date
May 14, 2014, 21:16 UTC
Message-ID
<1400102236-30082-3-git-send-email-sahlberg@google.com>
In-Reply-To
<1400102236-30082-1-git-send-email-sahlberg@google.com>

Allow ref_transaction_free to be called with NULL and as a result allow ref_transaction_rollback to be called for a NULL transaction.

This allows us to write code that will
  if ( (!transaction ||
        ref_transaction_update(...))  ||
      (ref_transaction_commit(...) && !(transaction = NULL)) {
          ref_transaction_rollback(transaction);
          ...
  }

In this case transaction is reset to NULL IFF ref_transaction_commit() was invoked and thus the rollback becomes ref_transaction_rollback(NULL) which is safe. IF the conditional triggered prior to ref_transaction_commit() then transaction is untouched and then ref_transaction_rollback(transaction) will rollback the failed transaction.

Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
---
 refs.c | 3 +++
 1 file changed, 3 insertions(+)
diff --git a/refs.c b/refs.c
index 2114748..88d73c8 100644
--- a/refs.c
+++ b/refs.c
@@ -3312,6 +3312,9 @@ static void ref_transaction_free(struct ref_transaction *transaction)
 {
 	int i;
 
+	if (!transaction)
+		return;
+
 	for (i = 0; i < transaction->nr; i++)
 		free(transaction->updates[i]);
 

-- 
2.0.0.rc3.471.g2055d11.dirty
Previous: Ronnie SahlbergNext: Ronnie Sahlberg
Message 3 of 43 in “Use ref transactions for all ref updates”
  1. 00/42 Use ref transactions for all ref updatesRonnie Sahlberg, May 14, 2014
  2. 01/42 refs.c: constify the sha arguments for ref_transaction_create|delete|updateRonnie Sahlberg, May 14, 2014
  3. 02/42 refs.c: allow passing NULL to ref_transaction_freeRonnie Sahlberg, May 14, 2014
  4. 03/42 refs.c: add a strbuf argument to ref_transaction_commit for error loggingRonnie Sahlberg, May 14, 2014
  5. 04/42 refs.c: make ref_update_reject_duplicates take a strbuf argument for errorsRonnie Sahlberg, May 14, 2014
  6. 05/42 update-ref.c: log transaction error from the update_refRonnie Sahlberg, May 14, 2014
  7. 06/42 refs.c: make update_ref_write update a strbuf on failureRonnie Sahlberg, May 14, 2014
  8. 07/42 refs.c: remove the onerr argument to ref_transaction_commitRonnie Sahlberg, May 14, 2014
  9. 08/42 refs.c: change ref_transaction_update() to do error checking and return statusRonnie Sahlberg, May 14, 2014
  10. 09/42 refs.c: change ref_transaction_create to do error checking and return statusRonnie Sahlberg, May 14, 2014
  11. 10/42 refs.c: ref_transaction_delete to check for error and return statusRonnie Sahlberg, May 14, 2014
  12. 11/42 tag.c: use ref transactions when doing updatesRonnie Sahlberg, May 14, 2014
  13. 12/42 replace.c: use the ref transaction functions for updatesRonnie Sahlberg, May 14, 2014
  14. 13/42 commit.c: use ref transactions for updatesRonnie Sahlberg, May 14, 2014
  15. 14/42 sequencer.c: use ref transactions for all ref updatesRonnie Sahlberg, May 14, 2014
  16. 15/42 fast-import.c: change update_branch to use ref transactionsRonnie Sahlberg, May 14, 2014
  17. 16/42 branch.c: use ref transaction for all ref updatesRonnie Sahlberg, May 14, 2014
  18. 17/42 refs.c: change update_ref to use a transactionRonnie Sahlberg, May 14, 2014
  19. 18/42 refs.c: free the transaction before returning when number of updates is 0Ronnie Sahlberg, May 14, 2014
  20. 19/42 refs.c: ref_transaction_commit should not free the transactionRonnie Sahlberg, May 14, 2014
  21. 20/42 fetch.c: clear errno before calling functions that might set itRonnie Sahlberg, May 14, 2014
  22. 21/42 fetch.c: change s_update_ref to use a ref transactionRonnie Sahlberg, May 14, 2014
  23. 22/42 fetch.c: use a single ref transaction for all ref updatesRonnie Sahlberg, May 14, 2014
  24. 23/42 receive-pack.c: use a reference transaction for updating the refsRonnie Sahlberg, May 14, 2014
  25. 24/42 fast-import.c: use a ref transaction when dumping tagsRonnie Sahlberg, May 14, 2014
  26. 25/42 walker.c: use ref transaction for ref updatesRonnie Sahlberg, May 14, 2014
  27. 26/42 refs.c: make write_ref_sha1 staticRonnie Sahlberg, May 14, 2014
  28. 27/42 refs.c: make lock_ref_sha1 staticRonnie Sahlberg, May 14, 2014
  29. 28/42 refs.c: add transaction.status and track OPEN/CLOSED/ERRORRonnie Sahlberg, May 14, 2014
  30. 29/42 refs.c: remove the update_ref_lock functionRonnie Sahlberg, May 14, 2014
  31. 30/42 refs.c: remove the update_ref_write functionRonnie Sahlberg, May 14, 2014
  32. 31/42 refs.c: remove lock_ref_sha1Ronnie Sahlberg, May 14, 2014
  33. 32/42 refs.c: make prune_ref use a transaction to delete the refRonnie Sahlberg, May 14, 2014
  34. 33/42 refs.c: make delete_ref use a transactionRonnie Sahlberg, May 14, 2014
  35. 34/42 refs.c: pass the ref log message to _create/delete/update instead of _commitRonnie Sahlberg, May 14, 2014
  36. 35/42 refs.c: pass NULL as *flags to read_ref_fullRonnie Sahlberg, May 14, 2014
  37. 36/42 refs.c: pack all refs before we start to rename a refRonnie Sahlberg, May 14, 2014
  38. 37/42 refs.c: move the check for valid refname to lock_ref_sha1_basicRonnie Sahlberg, May 14, 2014
  39. 38/42 refs.c: call lock_ref_sha1_basic directly from commitRonnie Sahlberg, May 14, 2014
  40. 39/42 refs.c: add a new flag for transaction delete for refs we know are packed onlyRonnie Sahlberg, May 14, 2014
  41. 40/42 refs.c: pass a skip list to name_conflict_fnRonnie Sahlberg, May 14, 2014
  42. 41/42 refs.c: make rename_ref use a transactionRonnie Sahlberg, May 14, 2014
  43. 42/42 refs.c: remove forward declaration of write_ref_sha1Ronnie Sahlberg, May 14, 2014

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