From 58a646a3688ea3c15adaf481e440e9ca2d3bce06 Mon Sep 17 00:00:00 2001 From: Patrick Steinhardt Date: Tue, 12 Jan 2021 13:27:35 +0100 Subject: [PATCH 1/5] fetch: extract writing to FETCH_HEAD When performing a fetch with the default `--write-fetch-head` option, we write all updated references to FETCH_HEAD while the updates are performed. Given that updates are not performed atomically, it means that we we write to FETCH_HEAD even if some or all of the reference updates fail. Given that we simply update FETCH_HEAD ad-hoc with each reference, the logic is completely contained in `store_update_refs` and thus quite hard to extend. This can already be seen by the way we skip writing to the FETCH_HEAD: instead of having a conditional which simply skips writing, we instead open "/dev/null" and needlessly write all updates there. We are about to extend git-fetch(1) to accept an `--atomic` flag which will make the fetch an all-or-nothing operation with regards to the reference updates. This will also require us to make the updates to FETCH_HEAD an all-or-nothing operation, but as explained doing so is not easy with the current layout. This commit thus refactors the wa we write to FETCH_HEAD and pulls out the logic to open, append to, commit and close the file. While this may seem rather over-the top at first, pulling out this logic will make it a lot easier to update the code in a subsequent commit. It also allows us to easily skip writing completely in case `--no-write-fetch-head` was passed. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano --- builtin/fetch.c | 108 +++++++++++++++++++++++++++++++++++------------- remote.h | 2 +- 2 files changed, 80 insertions(+), 30 deletions(-) diff --git a/builtin/fetch.c b/builtin/fetch.c index ecf8537605..2dd5fcb652 100644 --- a/builtin/fetch.c +++ b/builtin/fetch.c @@ -897,6 +897,73 @@ static int iterate_ref_map(void *cb_data, struct object_id *oid) return 0; } +struct fetch_head { + FILE *fp; +}; + +static int open_fetch_head(struct fetch_head *fetch_head) +{ + const char *filename = git_path_fetch_head(the_repository); + + if (write_fetch_head) { + fetch_head->fp = fopen(filename, "a"); + if (!fetch_head->fp) + return error_errno(_("cannot open %s"), filename); + } else { + fetch_head->fp = NULL; + } + + return 0; +} + +static void append_fetch_head(struct fetch_head *fetch_head, + const struct object_id *old_oid, + enum fetch_head_status fetch_head_status, + const char *note, + const char *url, size_t url_len) +{ + char old_oid_hex[GIT_MAX_HEXSZ + 1]; + const char *merge_status_marker; + size_t i; + + if (!fetch_head->fp) + return; + + switch (fetch_head_status) { + case FETCH_HEAD_NOT_FOR_MERGE: + merge_status_marker = "not-for-merge"; + break; + case FETCH_HEAD_MERGE: + merge_status_marker = ""; + break; + default: + /* do not write anything to FETCH_HEAD */ + return; + } + + fprintf(fetch_head->fp, "%s\t%s\t%s", + oid_to_hex_r(old_oid_hex, old_oid), merge_status_marker, note); + for (i = 0; i < url_len; ++i) + if ('\n' == url[i]) + fputs("\\n", fetch_head->fp); + else + fputc(url[i], fetch_head->fp); + fputc('\n', fetch_head->fp); +} + +static void commit_fetch_head(struct fetch_head *fetch_head) +{ + /* Nothing to commit yet. */ +} + +static void close_fetch_head(struct fetch_head *fetch_head) +{ + if (!fetch_head->fp) + return; + + fclose(fetch_head->fp); +} + static const char warn_show_forced_updates[] = N_("Fetch normally indicates which branches had a forced update,\n" "but that check has been disabled. To re-enable, use '--show-forced-updates'\n" @@ -909,22 +976,19 @@ N_("It took %.2f seconds to check forced updates. You can use\n" static int store_updated_refs(const char *raw_url, const char *remote_name, int connectivity_checked, struct ref *ref_map) { - FILE *fp; + struct fetch_head fetch_head; struct commit *commit; int url_len, i, rc = 0; struct strbuf note = STRBUF_INIT; const char *what, *kind; struct ref *rm; char *url; - const char *filename = (!write_fetch_head - ? "/dev/null" - : git_path_fetch_head(the_repository)); int want_status; int summary_width = transport_summary_width(ref_map); - fp = fopen(filename, "a"); - if (!fp) - return error_errno(_("cannot open %s"), filename); + rc = open_fetch_head(&fetch_head); + if (rc) + return -1; if (raw_url) url = transport_anonymize_url(raw_url); @@ -953,7 +1017,6 @@ static int store_updated_refs(const char *raw_url, const char *remote_name, want_status++) { for (rm = ref_map; rm; rm = rm->next) { struct ref *ref = NULL; - const char *merge_status_marker = ""; if (rm->status == REF_STATUS_REJECT_SHALLOW) { if (want_status == FETCH_HEAD_MERGE) @@ -1011,26 +1074,10 @@ static int store_updated_refs(const char *raw_url, const char *remote_name, strbuf_addf(¬e, "%s ", kind); strbuf_addf(¬e, "'%s' of ", what); } - switch (rm->fetch_head_status) { - case FETCH_HEAD_NOT_FOR_MERGE: - merge_status_marker = "not-for-merge"; - /* fall-through */ - case FETCH_HEAD_MERGE: - fprintf(fp, "%s\t%s\t%s", - oid_to_hex(&rm->old_oid), - merge_status_marker, - note.buf); - for (i = 0; i < url_len; ++i) - if ('\n' == url[i]) - fputs("\\n", fp); - else - fputc(url[i], fp); - fputc('\n', fp); - break; - default: - /* do not write anything to FETCH_HEAD */ - break; - } + + append_fetch_head(&fetch_head, &rm->old_oid, + rm->fetch_head_status, + note.buf, url, url_len); strbuf_reset(¬e); if (ref) { @@ -1060,6 +1107,9 @@ static int store_updated_refs(const char *raw_url, const char *remote_name, } } + if (!rc) + commit_fetch_head(&fetch_head); + if (rc & STORE_REF_ERROR_DF_CONFLICT) error(_("some local refs could not be updated; try running\n" " 'git remote prune %s' to remove any old, conflicting " @@ -1077,7 +1127,7 @@ static int store_updated_refs(const char *raw_url, const char *remote_name, abort: strbuf_release(¬e); free(url); - fclose(fp); + close_fetch_head(&fetch_head); return rc; } diff --git a/remote.h b/remote.h index 3211abdf05..aad1a0f080 100644 --- a/remote.h +++ b/remote.h @@ -134,7 +134,7 @@ struct ref { * should be 0, so that xcalloc'd structures get it * by default. */ - enum { + enum fetch_head_status { FETCH_HEAD_MERGE = -1, FETCH_HEAD_NOT_FOR_MERGE = 0, FETCH_HEAD_IGNORE = 1 From 929d044575ed4f9657074f098e3a9be410d511ef Mon Sep 17 00:00:00 2001 From: Patrick Steinhardt Date: Tue, 12 Jan 2021 13:27:39 +0100 Subject: [PATCH 2/5] fetch: use strbuf to format FETCH_HEAD updates This commit refactors `append_fetch_head()` to use a `struct strbuf` for formatting the update which we're about to append to the FETCH_HEAD file. While the refactoring doesn't have much of a benefit right now, it serves as a preparatory step to implement atomic fetches where we need to buffer all updates to FETCH_HEAD and only flush them out if all reference updates succeeded. No change in behaviour is expected from this commit. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano --- builtin/fetch.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/builtin/fetch.c b/builtin/fetch.c index 2dd5fcb652..e317e828cd 100644 --- a/builtin/fetch.c +++ b/builtin/fetch.c @@ -899,6 +899,7 @@ static int iterate_ref_map(void *cb_data, struct object_id *oid) struct fetch_head { FILE *fp; + struct strbuf buf; }; static int open_fetch_head(struct fetch_head *fetch_head) @@ -909,6 +910,7 @@ static int open_fetch_head(struct fetch_head *fetch_head) fetch_head->fp = fopen(filename, "a"); if (!fetch_head->fp) return error_errno(_("cannot open %s"), filename); + strbuf_init(&fetch_head->buf, 0); } else { fetch_head->fp = NULL; } @@ -941,14 +943,17 @@ static void append_fetch_head(struct fetch_head *fetch_head, return; } - fprintf(fetch_head->fp, "%s\t%s\t%s", - oid_to_hex_r(old_oid_hex, old_oid), merge_status_marker, note); + strbuf_addf(&fetch_head->buf, "%s\t%s\t%s", + oid_to_hex_r(old_oid_hex, old_oid), merge_status_marker, note); for (i = 0; i < url_len; ++i) if ('\n' == url[i]) - fputs("\\n", fetch_head->fp); + strbuf_addstr(&fetch_head->buf, "\\n"); else - fputc(url[i], fetch_head->fp); - fputc('\n', fetch_head->fp); + strbuf_addch(&fetch_head->buf, url[i]); + strbuf_addch(&fetch_head->buf, '\n'); + + strbuf_write(&fetch_head->buf, fetch_head->fp); + strbuf_reset(&fetch_head->buf); } static void commit_fetch_head(struct fetch_head *fetch_head) @@ -962,6 +967,7 @@ static void close_fetch_head(struct fetch_head *fetch_head) return; fclose(fetch_head->fp); + strbuf_release(&fetch_head->buf); } static const char warn_show_forced_updates[] = From c45889f10453864130ccbfa45815e2f4e384ab5e Mon Sep 17 00:00:00 2001 From: Patrick Steinhardt Date: Tue, 12 Jan 2021 13:27:43 +0100 Subject: [PATCH 3/5] fetch: refactor `s_update_ref` to use common exit path The cleanup code in `s_update_ref()` is currently duplicated for both succesful and erroneous exit paths. This commit refactors the function to have a shared exit path for both cases to remove the duplication. Suggested-by: Christian Couder Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano --- builtin/fetch.c | 47 +++++++++++++++++++++++++++-------------------- 1 file changed, 27 insertions(+), 20 deletions(-) diff --git a/builtin/fetch.c b/builtin/fetch.c index e317e828cd..b24a9e09a4 100644 --- a/builtin/fetch.c +++ b/builtin/fetch.c @@ -589,7 +589,7 @@ static int s_update_ref(const char *action, char *rla = getenv("GIT_REFLOG_ACTION"); struct ref_transaction *transaction; struct strbuf err = STRBUF_INIT; - int ret, df_conflict = 0; + int ret; if (dry_run) return 0; @@ -598,30 +598,37 @@ static int s_update_ref(const char *action, msg = xstrfmt("%s: %s", rla, action); transaction = ref_transaction_begin(&err); - if (!transaction || - ref_transaction_update(transaction, ref->name, - &ref->new_oid, - check_old ? &ref->old_oid : NULL, - 0, msg, &err)) - goto fail; - - ret = ref_transaction_commit(transaction, &err); - if (ret) { - df_conflict = (ret == TRANSACTION_NAME_CONFLICT); - goto fail; + if (!transaction) { + ret = STORE_REF_ERROR_OTHER; + goto out; } + ret = ref_transaction_update(transaction, ref->name, &ref->new_oid, + check_old ? &ref->old_oid : NULL, + 0, msg, &err); + if (ret) { + ret = STORE_REF_ERROR_OTHER; + goto out; + } + + switch (ref_transaction_commit(transaction, &err)) { + case 0: + break; + case TRANSACTION_NAME_CONFLICT: + ret = STORE_REF_ERROR_DF_CONFLICT; + goto out; + default: + ret = STORE_REF_ERROR_OTHER; + goto out; + } + +out: ref_transaction_free(transaction); + if (ret) + error("%s", err.buf); strbuf_release(&err); free(msg); - return 0; -fail: - ref_transaction_free(transaction); - error("%s", err.buf); - strbuf_release(&err); - free(msg); - return df_conflict ? STORE_REF_ERROR_DF_CONFLICT - : STORE_REF_ERROR_OTHER; + return ret; } static int refcol_width = 10; From d4c8db8f1b43cb26efdd53d74afce60e6d9d195a Mon Sep 17 00:00:00 2001 From: Patrick Steinhardt Date: Tue, 12 Jan 2021 13:27:48 +0100 Subject: [PATCH 4/5] fetch: allow passing a transaction to `s_update_ref()` The handling of ref updates is completely handled by `s_update_ref()`, which will manage the complete lifecycle of the reference transaction. This is fine right now given that git-fetch(1) does not support atomic fetches, so each reference gets its own transaction. It is quite inflexible though, as `s_update_ref()` only knows about a single reference update at a time, so it doesn't allow us to alter the strategy. This commit prepares `s_update_ref()` and its only caller `update_local_ref()` to allow passing an external transaction. If none is given, then the existing behaviour is triggered which creates a new transaction and directly commits it. Otherwise, if the caller provides a transaction, then we only queue the update but don't commit it. This optionally allows the caller to manage when a transaction will be committed. Given that `update_local_ref()` is always called with a `NULL` transaction for now, no change in behaviour is expected from this change. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano --- builtin/fetch.c | 51 ++++++++++++++++++++++++++++++------------------- 1 file changed, 31 insertions(+), 20 deletions(-) diff --git a/builtin/fetch.c b/builtin/fetch.c index b24a9e09a4..cada732325 100644 --- a/builtin/fetch.c +++ b/builtin/fetch.c @@ -583,11 +583,12 @@ static struct ref *get_ref_map(struct remote *remote, static int s_update_ref(const char *action, struct ref *ref, + struct ref_transaction *transaction, int check_old) { char *msg; char *rla = getenv("GIT_REFLOG_ACTION"); - struct ref_transaction *transaction; + struct ref_transaction *our_transaction = NULL; struct strbuf err = STRBUF_INIT; int ret; @@ -597,10 +598,17 @@ static int s_update_ref(const char *action, rla = default_rla.buf; msg = xstrfmt("%s: %s", rla, action); - transaction = ref_transaction_begin(&err); + /* + * If no transaction was passed to us, we manage the transaction + * ourselves. Otherwise, we trust the caller to handle the transaction + * lifecycle. + */ if (!transaction) { - ret = STORE_REF_ERROR_OTHER; - goto out; + transaction = our_transaction = ref_transaction_begin(&err); + if (!transaction) { + ret = STORE_REF_ERROR_OTHER; + goto out; + } } ret = ref_transaction_update(transaction, ref->name, &ref->new_oid, @@ -611,19 +619,21 @@ static int s_update_ref(const char *action, goto out; } - switch (ref_transaction_commit(transaction, &err)) { - case 0: - break; - case TRANSACTION_NAME_CONFLICT: - ret = STORE_REF_ERROR_DF_CONFLICT; - goto out; - default: - ret = STORE_REF_ERROR_OTHER; - goto out; + if (our_transaction) { + switch (ref_transaction_commit(our_transaction, &err)) { + case 0: + break; + case TRANSACTION_NAME_CONFLICT: + ret = STORE_REF_ERROR_DF_CONFLICT; + goto out; + default: + ret = STORE_REF_ERROR_OTHER; + goto out; + } } out: - ref_transaction_free(transaction); + ref_transaction_free(our_transaction); if (ret) error("%s", err.buf); strbuf_release(&err); @@ -766,6 +776,7 @@ static void format_display(struct strbuf *display, char code, } static int update_local_ref(struct ref *ref, + struct ref_transaction *transaction, const char *remote, const struct ref *remote_ref, struct strbuf *display, @@ -806,7 +817,7 @@ static int update_local_ref(struct ref *ref, starts_with(ref->name, "refs/tags/")) { if (force || ref->force) { int r; - r = s_update_ref("updating tag", ref, 0); + r = s_update_ref("updating tag", ref, transaction, 0); format_display(display, r ? '!' : 't', _("[tag update]"), r ? _("unable to update local ref") : NULL, remote, pretty_ref, summary_width); @@ -843,7 +854,7 @@ static int update_local_ref(struct ref *ref, what = _("[new ref]"); } - r = s_update_ref(msg, ref, 0); + r = s_update_ref(msg, ref, transaction, 0); format_display(display, r ? '!' : '*', what, r ? _("unable to update local ref") : NULL, remote, pretty_ref, summary_width); @@ -865,7 +876,7 @@ static int update_local_ref(struct ref *ref, strbuf_add_unique_abbrev(&quickref, ¤t->object.oid, DEFAULT_ABBREV); strbuf_addstr(&quickref, ".."); strbuf_add_unique_abbrev(&quickref, &ref->new_oid, DEFAULT_ABBREV); - r = s_update_ref("fast-forward", ref, 1); + r = s_update_ref("fast-forward", ref, transaction, 1); format_display(display, r ? '!' : ' ', quickref.buf, r ? _("unable to update local ref") : NULL, remote, pretty_ref, summary_width); @@ -877,7 +888,7 @@ static int update_local_ref(struct ref *ref, strbuf_add_unique_abbrev(&quickref, ¤t->object.oid, DEFAULT_ABBREV); strbuf_addstr(&quickref, "..."); strbuf_add_unique_abbrev(&quickref, &ref->new_oid, DEFAULT_ABBREV); - r = s_update_ref("forced-update", ref, 1); + r = s_update_ref("forced-update", ref, transaction, 1); format_display(display, r ? '!' : '+', quickref.buf, r ? _("unable to update local ref") : _("forced update"), remote, pretty_ref, summary_width); @@ -1094,8 +1105,8 @@ static int store_updated_refs(const char *raw_url, const char *remote_name, strbuf_reset(¬e); if (ref) { - rc |= update_local_ref(ref, what, rm, ¬e, - summary_width); + rc |= update_local_ref(ref, NULL, what, + rm, ¬e, summary_width); free(ref); } else if (write_fetch_head || dry_run) { /* From c7b190dabdea16d5b1c29ae50430449a8547818f Mon Sep 17 00:00:00 2001 From: Patrick Steinhardt Date: Tue, 12 Jan 2021 13:27:52 +0100 Subject: [PATCH 5/5] fetch: implement support for atomic reference updates When executing a fetch, then git will currently allocate one reference transaction per reference update and directly commit it. This means that fetches are non-atomic: even if some of the reference updates fail, others may still succeed and modify local references. This is fine in many scenarios, but this strategy has its downsides. - The view of remote references may be inconsistent and may show a bastardized state of the remote repository. - Batching together updates may improve performance in certain scenarios. While the impact probably isn't as pronounced with loose references, the upcoming reftable backend may benefit as it needs to write less files in case the update is batched. - The reference-update hook is currently being executed twice per updated reference. While this doesn't matter when there is no such hook, we have seen severe performance regressions when doing a git-fetch(1) with reference-transaction hook when the remote repository has hundreds of thousands of references. Similar to `git push --atomic`, this commit thus introduces atomic fetches. Instead of allocating one reference transaction per updated reference, it causes us to only allocate a single transaction and commit it as soon as all updates were received. If locking of any reference fails, then we abort the complete transaction and don't update any reference, which gives us an all-or-nothing fetch. Note that this may not completely fix the first of above downsides, as the consistent view also depends on the server-side. If the server doesn't have a consistent view of its own references during the reference negotiation phase, then the client would get the same inconsistent view the server has. This is a separate problem though and, if it actually exists, can be fixed at a later point. This commit also changes the way we write FETCH_HEAD in case `--atomic` is passed. Instead of writing changes as we go, we need to accumulate all changes first and only commit them at the end when we know that all reference updates succeeded. Ideally, we'd just do so via a temporary file so that we don't need to carry all updates in-memory. This isn't trivially doable though considering the `--append` mode, where we do not truncate the file but simply append to it. And given that we support concurrent processes appending to FETCH_HEAD at the same time without any loss of data, seeding the temporary file with current contents of FETCH_HEAD initially and then doing a rename wouldn't work either. So this commit implements the simple strategy of buffering all changes and appending them to the file on commit. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano --- Documentation/fetch-options.txt | 4 + builtin/fetch.c | 46 ++++++++- t/t5510-fetch.sh | 168 ++++++++++++++++++++++++++++++++ 3 files changed, 213 insertions(+), 5 deletions(-) diff --git a/Documentation/fetch-options.txt b/Documentation/fetch-options.txt index 2bf77b46fd..07783deee3 100644 --- a/Documentation/fetch-options.txt +++ b/Documentation/fetch-options.txt @@ -7,6 +7,10 @@ existing contents of `.git/FETCH_HEAD`. Without this option old data in `.git/FETCH_HEAD` will be overwritten. +--atomic:: + Use an atomic transaction to update local refs. Either all refs are + updated, or on error, no refs are updated. + --depth=:: Limit fetching to the specified number of commits from the tip of each remote branch history. If fetching to a 'shallow' repository diff --git a/builtin/fetch.c b/builtin/fetch.c index cada732325..91f3d20696 100644 --- a/builtin/fetch.c +++ b/builtin/fetch.c @@ -63,6 +63,7 @@ static int enable_auto_gc = 1; static int tags = TAGS_DEFAULT, unshallow, update_shallow, deepen; static int max_jobs = -1, submodule_fetch_jobs_config = -1; static int fetch_parallel_config = 1; +static int atomic_fetch; static enum transport_family family; static const char *depth; static const char *deepen_since; @@ -144,6 +145,8 @@ static struct option builtin_fetch_options[] = { N_("set upstream for git pull/fetch")), OPT_BOOL('a', "append", &append, N_("append to .git/FETCH_HEAD instead of overwriting")), + OPT_BOOL(0, "atomic", &atomic_fetch, + N_("use atomic transaction to update references")), OPT_STRING(0, "upload-pack", &upload_pack, N_("path"), N_("path to upload pack on remote end")), OPT__FORCE(&force, N_("force overwrite of local reference"), 0), @@ -970,13 +973,23 @@ static void append_fetch_head(struct fetch_head *fetch_head, strbuf_addch(&fetch_head->buf, url[i]); strbuf_addch(&fetch_head->buf, '\n'); - strbuf_write(&fetch_head->buf, fetch_head->fp); - strbuf_reset(&fetch_head->buf); + /* + * When using an atomic fetch, we do not want to update FETCH_HEAD if + * any of the reference updates fails. We thus have to write all + * updates to a buffer first and only commit it as soon as all + * references have been successfully updated. + */ + if (!atomic_fetch) { + strbuf_write(&fetch_head->buf, fetch_head->fp); + strbuf_reset(&fetch_head->buf); + } } static void commit_fetch_head(struct fetch_head *fetch_head) { - /* Nothing to commit yet. */ + if (!fetch_head->fp || !atomic_fetch) + return; + strbuf_write(&fetch_head->buf, fetch_head->fp); } static void close_fetch_head(struct fetch_head *fetch_head) @@ -1003,7 +1016,8 @@ static int store_updated_refs(const char *raw_url, const char *remote_name, struct fetch_head fetch_head; struct commit *commit; int url_len, i, rc = 0; - struct strbuf note = STRBUF_INIT; + struct strbuf note = STRBUF_INIT, err = STRBUF_INIT; + struct ref_transaction *transaction = NULL; const char *what, *kind; struct ref *rm; char *url; @@ -1029,6 +1043,14 @@ static int store_updated_refs(const char *raw_url, const char *remote_name, } } + if (atomic_fetch) { + transaction = ref_transaction_begin(&err); + if (!transaction) { + error("%s", err.buf); + goto abort; + } + } + prepare_format_display(ref_map); /* @@ -1105,7 +1127,7 @@ static int store_updated_refs(const char *raw_url, const char *remote_name, strbuf_reset(¬e); if (ref) { - rc |= update_local_ref(ref, NULL, what, + rc |= update_local_ref(ref, transaction, what, rm, ¬e, summary_width); free(ref); } else if (write_fetch_head || dry_run) { @@ -1131,6 +1153,14 @@ static int store_updated_refs(const char *raw_url, const char *remote_name, } } + if (!rc && transaction) { + rc = ref_transaction_commit(transaction, &err); + if (rc) { + error("%s", err.buf); + goto abort; + } + } + if (!rc) commit_fetch_head(&fetch_head); @@ -1150,6 +1180,8 @@ static int store_updated_refs(const char *raw_url, const char *remote_name, abort: strbuf_release(¬e); + strbuf_release(&err); + ref_transaction_free(transaction); free(url); close_fetch_head(&fetch_head); return rc; @@ -1961,6 +1993,10 @@ int cmd_fetch(int argc, const char **argv, const char *prefix) die(_("--filter can only be used with the remote " "configured in extensions.partialclone")); + if (atomic_fetch) + die(_("--atomic can only be used when fetching " + "from one remote")); + if (stdin_refspecs) die(_("--stdin can only be used when fetching " "from one remote")); diff --git a/t/t5510-fetch.sh b/t/t5510-fetch.sh index 2013051a64..109d15be98 100755 --- a/t/t5510-fetch.sh +++ b/t/t5510-fetch.sh @@ -176,6 +176,174 @@ test_expect_success 'fetch --prune --tags with refspec prunes based on refspec' git rev-parse sometag ' +test_expect_success 'fetch --atomic works with a single branch' ' + test_when_finished "rm -rf \"$D\"/atomic" && + + cd "$D" && + git clone . atomic && + git branch atomic-branch && + oid=$(git rev-parse atomic-branch) && + echo "$oid" >expected && + + git -C atomic fetch --atomic origin && + git -C atomic rev-parse origin/atomic-branch >actual && + test_cmp expected actual && + test $oid = "$(git -C atomic rev-parse --verify FETCH_HEAD)" +' + +test_expect_success 'fetch --atomic works with multiple branches' ' + test_when_finished "rm -rf \"$D\"/atomic" && + + cd "$D" && + git clone . atomic && + git branch atomic-branch-1 && + git branch atomic-branch-2 && + git branch atomic-branch-3 && + git rev-parse refs/heads/atomic-branch-1 refs/heads/atomic-branch-2 refs/heads/atomic-branch-3 >actual && + + git -C atomic fetch --atomic origin && + git -C atomic rev-parse refs/remotes/origin/atomic-branch-1 refs/remotes/origin/atomic-branch-2 refs/remotes/origin/atomic-branch-3 >expected && + test_cmp expected actual +' + +test_expect_success 'fetch --atomic works with mixed branches and tags' ' + test_when_finished "rm -rf \"$D\"/atomic" && + + cd "$D" && + git clone . atomic && + git branch atomic-mixed-branch && + git tag atomic-mixed-tag && + git rev-parse refs/heads/atomic-mixed-branch refs/tags/atomic-mixed-tag >actual && + + git -C atomic fetch --tags --atomic origin && + git -C atomic rev-parse refs/remotes/origin/atomic-mixed-branch refs/tags/atomic-mixed-tag >expected && + test_cmp expected actual +' + +test_expect_success 'fetch --atomic prunes references' ' + test_when_finished "rm -rf \"$D\"/atomic" && + + cd "$D" && + git branch atomic-prune-delete && + git clone . atomic && + git branch --delete atomic-prune-delete && + git branch atomic-prune-create && + git rev-parse refs/heads/atomic-prune-create >actual && + + git -C atomic fetch --prune --atomic origin && + test_must_fail git -C atomic rev-parse refs/remotes/origin/atomic-prune-delete && + git -C atomic rev-parse refs/remotes/origin/atomic-prune-create >expected && + test_cmp expected actual +' + +test_expect_success 'fetch --atomic aborts with non-fast-forward update' ' + test_when_finished "rm -rf \"$D\"/atomic" && + + cd "$D" && + git branch atomic-non-ff && + git clone . atomic && + git rev-parse HEAD >actual && + + git branch atomic-new-branch && + parent_commit=$(git rev-parse atomic-non-ff~) && + git update-ref refs/heads/atomic-non-ff $parent_commit && + + test_must_fail git -C atomic fetch --atomic origin refs/heads/*:refs/remotes/origin/* && + test_must_fail git -C atomic rev-parse refs/remotes/origin/atomic-new-branch && + git -C atomic rev-parse refs/remotes/origin/atomic-non-ff >expected && + test_cmp expected actual && + test_must_be_empty atomic/.git/FETCH_HEAD +' + +test_expect_success 'fetch --atomic executes a single reference transaction only' ' + test_when_finished "rm -rf \"$D\"/atomic" && + + cd "$D" && + git clone . atomic && + git branch atomic-hooks-1 && + git branch atomic-hooks-2 && + head_oid=$(git rev-parse HEAD) && + + cat >expected <<-EOF && + prepared + $ZERO_OID $head_oid refs/remotes/origin/atomic-hooks-1 + $ZERO_OID $head_oid refs/remotes/origin/atomic-hooks-2 + committed + $ZERO_OID $head_oid refs/remotes/origin/atomic-hooks-1 + $ZERO_OID $head_oid refs/remotes/origin/atomic-hooks-2 + EOF + + rm -f atomic/actual && + write_script atomic/.git/hooks/reference-transaction <<-\EOF && + ( echo "$*" && cat ) >>actual + EOF + + git -C atomic fetch --atomic origin && + test_cmp expected atomic/actual +' + +test_expect_success 'fetch --atomic aborts all reference updates if hook aborts' ' + test_when_finished "rm -rf \"$D\"/atomic" && + + cd "$D" && + git clone . atomic && + git branch atomic-hooks-abort-1 && + git branch atomic-hooks-abort-2 && + git branch atomic-hooks-abort-3 && + git tag atomic-hooks-abort && + head_oid=$(git rev-parse HEAD) && + + cat >expected <<-EOF && + prepared + $ZERO_OID $head_oid refs/remotes/origin/atomic-hooks-abort-1 + $ZERO_OID $head_oid refs/remotes/origin/atomic-hooks-abort-2 + $ZERO_OID $head_oid refs/remotes/origin/atomic-hooks-abort-3 + $ZERO_OID $head_oid refs/tags/atomic-hooks-abort + aborted + $ZERO_OID $head_oid refs/remotes/origin/atomic-hooks-abort-1 + $ZERO_OID $head_oid refs/remotes/origin/atomic-hooks-abort-2 + $ZERO_OID $head_oid refs/remotes/origin/atomic-hooks-abort-3 + $ZERO_OID $head_oid refs/tags/atomic-hooks-abort + EOF + + rm -f atomic/actual && + write_script atomic/.git/hooks/reference-transaction <<-\EOF && + ( echo "$*" && cat ) >>actual + exit 1 + EOF + + git -C atomic for-each-ref >expected-refs && + test_must_fail git -C atomic fetch --tags --atomic origin && + git -C atomic for-each-ref >actual-refs && + test_cmp expected-refs actual-refs && + test_must_be_empty atomic/.git/FETCH_HEAD +' + +test_expect_success 'fetch --atomic --append appends to FETCH_HEAD' ' + test_when_finished "rm -rf \"$D\"/atomic" && + + cd "$D" && + git clone . atomic && + oid=$(git rev-parse HEAD) && + + git branch atomic-fetch-head-1 && + git -C atomic fetch --atomic origin atomic-fetch-head-1 && + test_line_count = 1 atomic/.git/FETCH_HEAD && + + git branch atomic-fetch-head-2 && + git -C atomic fetch --atomic --append origin atomic-fetch-head-2 && + test_line_count = 2 atomic/.git/FETCH_HEAD && + cp atomic/.git/FETCH_HEAD expected && + + write_script atomic/.git/hooks/reference-transaction <<-\EOF && + exit 1 + EOF + + git branch atomic-fetch-head-3 && + test_must_fail git -C atomic fetch --atomic --append origin atomic-fetch-head-3 && + test_cmp expected atomic/.git/FETCH_HEAD +' + test_expect_success '--refmap="" ignores configured refspec' ' cd "$TRASH_DIRECTORY" && git clone "$D" remote-refs &&