[PATCH v2 26/33] lock_ref_for_update(): new function
- From
Michael Haggerty <mhagger@alum.mit.edu>
- Date
- May 6, 2016, 16:14 UTC
- Message-ID
- <bfba3b42460c75064ce0538cbd6ad820a7ddc537.1462550456.git.mhagger@alum.mit.edu>
- In-Reply-To
- <cover.1462550456.git.mhagger@alum.mit.edu>
Extract a new function, lock_ref_for_update(), from ref_transaction_commit().
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> --- refs/files-backend.c | 152 ++++++++++++++++++++++++++++----------------------- 1 file changed, 85 insertions(+), 67 deletions(-)
diff --git a/refs/files-backend.c b/refs/files-backend.c index f0eef9e..1c20af5 100644 --- a/refs/files-backend.c +++ b/refs/files-backend.c @@ -3051,6 +3051,88 @@ static int ref_update_reject_duplicates(struct string_list *refnames, return 0; } +/* + * Acquire all locks, verify old values if provided, check + * that new values are valid, and write new values to the + * lockfiles, ready to be activated. Only keep one lockfile + * open at a time to avoid running out of file descriptors. + */ +static int lock_ref_for_update(struct ref_update *update, + struct ref_transaction *transaction, + struct string_list *affected_refnames, + struct strbuf *err) +{ + int ret; + + if ((update->flags & REF_HAVE_NEW) && + is_null_sha1(update->new_sha1)) + update->flags |= REF_DELETING; + update->lock = lock_ref_sha1_basic( + update->refname, + ((update->flags & REF_HAVE_OLD) ? + update->old_sha1 : NULL), + affected_refnames, NULL, + update->flags, + &update->type, + err); + if (!update->lock) { + char *reason; + + ret = (errno == ENOTDIR) + ? TRANSACTION_NAME_CONFLICT + : TRANSACTION_GENERIC_ERROR; + reason = strbuf_detach(err, NULL); + strbuf_addf(err, "cannot lock ref '%s': %s", + update->refname, reason); + free(reason); + return ret; + } + if ((update->flags & REF_HAVE_NEW) && + !(update->flags & REF_DELETING) && + !(update->flags & REF_LOG_ONLY)) { + int overwriting_symref = ((update->type & REF_ISSYMREF) && + (update->flags & REF_NODEREF)); + + if (!overwriting_symref && + !hashcmp(update->lock->old_oid.hash, update->new_sha1)) { + /* + * The reference already has the desired + * value, so we don't need to write it. + */ + } else if (write_ref_to_lockfile(update->lock, + update->new_sha1, + err)) { + char *write_err = strbuf_detach(err, NULL); + + /* + * The lock was freed upon failure of + * write_ref_to_lockfile(): + */ + update->lock = NULL; + strbuf_addf(err, + "cannot update the ref '%s': %s", + update->refname, write_err); + free(write_err); + return TRANSACTION_GENERIC_ERROR; + } else { + update->flags |= REF_NEEDS_COMMIT; + } + } + if (!(update->flags & REF_NEEDS_COMMIT)) { + /* + * We didn't call write_ref_to_lockfile(), so + * the lockfile is still open. Close it to + * free up the file descriptor: + */ + if (close_ref(update->lock)) { + strbuf_addf(err, "couldn't close '%s.lock'", + update->refname); + return TRANSACTION_GENERIC_ERROR; + } + } + return 0; +} + int ref_transaction_commit(struct ref_transaction *transaction, struct strbuf *err) { @@ -3088,74 +3170,10 @@ int ref_transaction_commit(struct ref_transaction *transaction, for (i = 0; i < transaction->nr; i++) { struct ref_update *update = updates[i]; - if ((update->flags & REF_HAVE_NEW) && - is_null_sha1(update->new_sha1)) - update->flags |= REF_DELETING; - update->lock = lock_ref_sha1_basic( - update->refname, - ((update->flags & REF_HAVE_OLD) ? - update->old_sha1 : NULL), - &affected_refnames, NULL, - update->flags, - &update->type, - err); - if (!update->lock) { - char *reason; - - ret = (errno == ENOTDIR) - ? TRANSACTION_NAME_CONFLICT - : TRANSACTION_GENERIC_ERROR; - reason = strbuf_detach(err, NULL); - strbuf_addf(err, "cannot lock ref '%s': %s", - update->refname, reason); - free(reason); + ret = lock_ref_for_update(update, transaction, + &affected_refnames, err); + if (ret) goto cleanup; - } - if ((update->flags & REF_HAVE_NEW) && - !(update->flags & REF_DELETING) && - !(update->flags & REF_LOG_ONLY)) { - int overwriting_symref = ((update->type & REF_ISSYMREF) && - (update->flags & REF_NODEREF)); - - if (!overwriting_symref && - !hashcmp(update->lock->old_oid.hash, update->new_sha1)) { - /* - * The reference already has the desired - * value, so we don't need to write it. - */ - } else if (write_ref_to_lockfile(update->lock, - update->new_sha1, - err)) { - char *write_err = strbuf_detach(err, NULL); - - /* - * The lock was freed upon failure of - * write_ref_to_lockfile(): - */ - update->lock = NULL; - strbuf_addf(err, - "cannot update the ref '%s': %s", - update->refname, write_err); - free(write_err); - ret = TRANSACTION_GENERIC_ERROR; - goto cleanup; - } else { - update->flags |= REF_NEEDS_COMMIT; - } - } - if (!(update->flags & REF_NEEDS_COMMIT)) { - /* - * We didn't call write_ref_to_lockfile(), so - * the lockfile is still open. Close it to - * free up the file descriptor: - */ - if (close_ref(update->lock)) { - strbuf_addf(err, "couldn't close '%s.lock'", - update->refname); - ret = TRANSACTION_GENERIC_ERROR; - goto cleanup; - } - } } /* Perform updates first so live commits remain referenced */
-- 2.8.1