This patch series can also be found at https://github.com/rsahlberg/git/tree/ref-transactions This patch series is based on next and expands on the transaction API. It converts all ref updates, inside refs.c as well as external, to use the transaction API for updates. This makes most of the ref updates to become atomic when there are failures locking or writing to a ref. This version completes the work to convert all ref updates to use transactions. Now that all updates are through transactions I will start working on cleaning up the reading of refs and to create an api for managing reflogs but all that will go in a different patch series. Version 7: - Updated commit messages per JNs review comments. - Changed REF_ISPRUNING and REF_ISPACKONLY to be private flags and not exposed through refs.h Version 6: - Convert all updates in refs.c to use transactions too. Version 5: - Reword commit messages for having _create/_delete/_update returning success/failure. There are no conditions yet that return an error from these failures but there will be in the future. So we still check the return from these functions in the callers in preparation for this. - Don't leak memory by just passing a strbuf_detach() pointer to functions. Use <obj>.buf and explicitely strbuf_release the data afterwards. - Remove the function update_ref_lock. - Remove the function update_ref_write. - Track transaction status and die(BUG:) if we call _create/_delete/_update/ _commit for a transaction that is not OPEN. Version 4: - Rename patch series from "Use ref transactions from most callers" to "Use ref transactions for all ref updates". - Convert all external ref writes to use transactions and make write_ref_sha1 and lock_ref_sha1 static functions. - Change the ref commit and free handling so we no longer pass pointer to pointer to _commit. _commit no longer frees the transaction. The caller MUST call _free itself. - Change _commit to take a strbuf pointer instead of a char* for error reporting back to the caller. - Re-add the walker patch after fixing it. Version 3: - Remove the walker patch for now. Walker needs more complex solution so defer it until the basics are done. - Remove the onerr argument to ref_transaction_commit(). All callers that need to die() on error now have to do this explicitely. - Pass an error string from ref_transaction_commit() back to the callers so that they can craft a nice error message upon failures. - Make ref_transaction_rollback() accept NULL as argument. - Change ref_transaction_commit() to take a pointer to pointer argument for the transaction and have it clear the callers pointer to NULL when invoked. This allows for much nicer handling of transaction rollback on failure. Version 2: - Add a patch to ref_transaction_commit to make it honor onerr even if the error triggered in ref_Transaction_commit itself rather than in a call to other functions (that already honor onerr). - Add a patch to make the update_ref() helper function use transactions internally. - Change ref_transaction_update to die() instead of error() if we pass if a NULL old_sha1 but have have_old == true. - Change ref_transaction_create to die() instead of error() if new_sha1 is false but we pass it a null_sha1. - Change ref_transaction_delete die() instead of error() if we pass if a NULL old_sha1 but have have_old == true. - Change several places to do if(!transaction || ref_transaction_update() || ref_Transaction_commit()) die(generic-message) instead of checking each step separately and having a different message for each failure. Most users are likely not interested in what step of the transaction failed and only whether it failed or not. - Change commit.c to only pass a pointer to ref_transaction_update iff current_head is non-NULL. The previous patch used to compute a garbage pointer for current_head->object.sha1 and relied on the fact that ref_transaction_update would not try to dereference this pointer if !!current_head was 0. - Updated commit message for the walker_fetch change to try to justify why the change in locking semantics should not be harmful. Ronnie Sahlberg (42): refs.c: constify the sha arguments for ref_transaction_create|delete|update refs.c: allow passing NULL to ref_transaction_free refs.c: add a strbuf argument to ref_transaction_commit for error logging refs.c: make ref_update_reject_duplicates take a strbuf argument for errors update-ref.c: log transaction error from the update_ref refs.c: make update_ref_write update a strbuf on failure refs.c: remove the onerr argument to ref_transaction_commit refs.c: change ref_transaction_update() to do error checking and return status refs.c: change ref_transaction_create to do error checking and return status refs.c: ref_transaction_delete to check for error and return status tag.c: use ref transactions when doing updates replace.c: use the ref transaction functions for updates commit.c: use ref transactions for updates sequencer.c: use ref transactions for all ref updates fast-import.c: change update_branch to use ref transactions branch.c: use ref transaction for all ref updates refs.c: change update_ref to use a transaction refs.c: free the transaction before returning when number of updates is 0 refs.c: ref_transaction_commit should not free the transaction fetch.c: clear errno before calling functions that might set it fetch.c: change s_update_ref to use a ref transaction fetch.c: use a single ref transaction for all ref updates receive-pack.c: use a reference transaction for updating the refs fast-import.c: use a ref transaction when dumping tags walker.c: use ref transaction for ref updates refs.c: make write_ref_sha1 static refs.c: make lock_ref_sha1 static refs.c: add transaction.status and track OPEN/CLOSED/ERROR refs.c: remove the update_ref_lock function refs.c: remove the update_ref_write function refs.c: remove lock_ref_sha1 refs.c: make prune_ref use a transaction to delete the ref refs.c: make delete_ref use a transaction refs.c: pass the ref log message to _create/delete/update instead of _commit refs.c: pass NULL as *flags to read_ref_full refs.c: pack all refs before we start to rename a ref refs.c: move the check for valid refname to lock_ref_sha1_basic refs.c: call lock_ref_sha1_basic directly from commit refs.c: add a new flag for transaction delete for refs we know are packed only refs.c: pass a skip list to name_conflict_fn refs.c: make rename_ref use a transaction refs.c: remove forward declaration of write_ref_sha1 branch.c | 31 ++-- builtin/commit.c | 24 ++- builtin/fetch.c | 29 ++-- builtin/receive-pack.c | 20 +-- builtin/replace.c | 15 +- builtin/tag.c | 15 +- builtin/update-ref.c | 32 ++-- fast-import.c | 39 +++-- refs.c | 413 ++++++++++++++++++++++++++++--------------------- refs.h | 48 +++--- sequencer.c | 24 ++- t/t3200-branch.sh | 2 +- walker.c | 51 +++--- 13 files changed, 422 insertions(+), 321 deletions(-) -- 2.0.0.rc3.471.g2055d11.dirty -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
