From 0a1bc12b6e401825f009ac8bb14fc438f77e2d9f Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?= Date: Thu, 5 Dec 2013 20:02:47 +0700 Subject: receive-pack: allow pushes that update .git/shallow MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The basic 8 steps to update .git/shallow does not fully apply here because the user may choose to accept just a few refs (while fetch always accepts all refs). The steps are modified a bit. 1-6. same as before. After calling assign_shallow_commits_to_refs at step 6, each shallow commit has a bitmap that marks all refs that require it. 7. mark all "ours" shallow commits that are reachable from any refs. We will need to do the original step 7 on them later. 8. go over all shallow commit bitmaps, mark refs that require new shallow commits. 9. setup a strict temporary shallow file to plug all the holes, even if it may cut some of our history short. This file is used by all hooks. The hooks could use --shallow-file=$GIT_DIR/shallow to overcome this and reach everything in current repo. 10. go over the new refs one by one. For each ref, do the reachability test if it needs a shallow commit on the list from step 7. Remove it if it's reachable from our refs. Gather all required shallow commits, run check_everything_connected() with the new ref, then install them to .git/shallow. This mode is disabled by default and can be turned on with receive.shallowupdate Signed-off-by: Nguyễn Thái Ngọc Duy Signed-off-by: Junio C Hamano diff --git a/Documentation/config.txt b/Documentation/config.txt index ab26963..1a0bd0d 100644 --- a/Documentation/config.txt +++ b/Documentation/config.txt @@ -2026,6 +2026,10 @@ receive.updateserverinfo:: If set to true, git-receive-pack will run git-update-server-info after receiving data from git-push and updating refs. +receive.shallowupdate:: + If set to true, .git/shallow can be updated when new refs + require new shallow roots. Otherwise those refs are rejected. + remote.pushdefault:: The remote to push to by default. Overrides `branch..remote` for all branches, and is overridden by diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c index b9de2e8..5c85bb4 100644 --- a/builtin/receive-pack.c +++ b/builtin/receive-pack.c @@ -44,6 +44,7 @@ static int fix_thin = 1; static const char *head_name; static void *head_name_to_free; static int sent_capabilities; +static int shallow_update; static const char *alt_shallow_file; static enum deny_action parse_deny_action(const char *var, const char *value) @@ -123,6 +124,11 @@ static int receive_pack_config(const char *var, const char *value, void *cb) return 0; } + if (strcmp(var, "receive.shallowupdate") == 0) { + shallow_update = git_config_bool(var, value); + return 0; + } + return git_default_config(var, value, cb); } @@ -423,7 +429,46 @@ static void refuse_unconfigured_deny_delete_current(void) rp_error("%s", refuse_unconfigured_deny_delete_current_msg[i]); } -static const char *update(struct command *cmd) +static int command_singleton_iterator(void *cb_data, unsigned char sha1[20]); +static int update_shallow_ref(struct command *cmd, struct shallow_info *si) +{ + static struct lock_file shallow_lock; + struct sha1_array extra = SHA1_ARRAY_INIT; + const char *alt_file; + uint32_t mask = 1 << (cmd->index % 32); + int i; + + trace_printf_key("GIT_TRACE_SHALLOW", + "shallow: update_shallow_ref %s\n", cmd->ref_name); + for (i = 0; i < si->shallow->nr; i++) + if (si->used_shallow[i] && + (si->used_shallow[i][cmd->index / 32] & mask) && + !delayed_reachability_test(si, i)) + sha1_array_append(&extra, si->shallow->sha1[i]); + + setup_alternate_shallow(&shallow_lock, &alt_file, &extra); + if (check_shallow_connected(command_singleton_iterator, + 0, cmd, alt_file)) { + rollback_lock_file(&shallow_lock); + sha1_array_clear(&extra); + return -1; + } + + commit_lock_file(&shallow_lock); + + /* + * Make sure setup_alternate_shallow() for the next ref does + * not lose these new roots.. + */ + for (i = 0; i < extra.nr; i++) + register_shallow(extra.sha1[i]); + + si->shallow_ref[cmd->index] = 0; + sha1_array_clear(&extra); + return 0; +} + +static const char *update(struct command *cmd, struct shallow_info *si) { const char *name = cmd->ref_name; struct strbuf namespaced_name_buf = STRBUF_INIT; @@ -531,6 +576,10 @@ static const char *update(struct command *cmd) return NULL; /* good */ } else { + if (shallow_update && si->shallow_ref[cmd->index] && + update_shallow_ref(cmd, si)) + return "shallow error"; + lock = lock_any_ref_for_update(namespaced_name, old_sha1, 0, NULL); if (!lock) { @@ -671,12 +720,16 @@ static int command_singleton_iterator(void *cb_data, unsigned char sha1[20]) return 0; } -static void set_connectivity_errors(struct command *commands) +static void set_connectivity_errors(struct command *commands, + struct shallow_info *si) { struct command *cmd; for (cmd = commands; cmd; cmd = cmd->next) { struct command *singleton = cmd; + if (shallow_update && si->shallow_ref[cmd->index]) + /* to be checked in update_shallow_ref() */ + continue; if (!check_everything_connected(command_singleton_iterator, 0, &singleton)) continue; @@ -684,18 +737,26 @@ static void set_connectivity_errors(struct command *commands) } } +struct iterate_data { + struct command *cmds; + struct shallow_info *si; +}; + static int iterate_receive_command_list(void *cb_data, unsigned char sha1[20]) { - struct command **cmd_list = cb_data; + struct iterate_data *data = cb_data; + struct command **cmd_list = &data->cmds; struct command *cmd = *cmd_list; - while (cmd) { + for (; cmd; cmd = cmd->next) { + if (shallow_update && data->si->shallow_ref[cmd->index]) + /* to be checked in update_shallow_ref() */ + continue; if (!is_null_sha1(cmd->new_sha1) && !cmd->skip_update) { hashcpy(sha1, cmd->new_sha1); *cmd_list = cmd->next; return 0; } - cmd = cmd->next; } *cmd_list = NULL; return -1; /* end of list */ @@ -715,10 +776,14 @@ static void reject_updates_to_hidden(struct command *commands) } } -static void execute_commands(struct command *commands, const char *unpacker_error) +static void execute_commands(struct command *commands, + const char *unpacker_error, + struct shallow_info *si) { + int checked_connectivity; struct command *cmd; unsigned char sha1[20]; + struct iterate_data data; if (unpacker_error) { for (cmd = commands; cmd; cmd = cmd->next) @@ -726,10 +791,10 @@ static void execute_commands(struct command *commands, const char *unpacker_erro return; } - cmd = commands; - if (check_everything_connected(iterate_receive_command_list, - 0, &cmd)) - set_connectivity_errors(commands); + data.cmds = commands; + data.si = si; + if (check_everything_connected(iterate_receive_command_list, 0, &data)) + set_connectivity_errors(commands, si); reject_updates_to_hidden(commands); @@ -746,6 +811,7 @@ static void execute_commands(struct command *commands, const char *unpacker_erro free(head_name_to_free); head_name = head_name_to_free = resolve_refdup("HEAD", sha1, 0, NULL); + checked_connectivity = 1; for (cmd = commands; cmd; cmd = cmd->next) { if (cmd->error_string) continue; @@ -753,7 +819,22 @@ static void execute_commands(struct command *commands, const char *unpacker_erro if (cmd->skip_update) continue; - cmd->error_string = update(cmd); + cmd->error_string = update(cmd, si); + if (shallow_update && !cmd->error_string && + si->shallow_ref[cmd->index]) { + error("BUG: connectivity check has not been run on ref %s", + cmd->ref_name); + checked_connectivity = 0; + } + } + + if (shallow_update) { + if (!checked_connectivity) + error("BUG: run 'git fsck' for safety.\n" + "If there are errors, try to remove " + "the reported refs above"); + if (alt_shallow_file && *alt_shallow_file) + unlink(alt_shallow_file); } } @@ -924,6 +1005,53 @@ static const char *unpack_with_sideband(struct shallow_info *si) return ret; } +static void prepare_shallow_update(struct command *commands, + struct shallow_info *si) +{ + int i, j, k, bitmap_size = (si->ref->nr + 31) / 32; + + si->used_shallow = xmalloc(sizeof(*si->used_shallow) * + si->shallow->nr); + assign_shallow_commits_to_refs(si, si->used_shallow, NULL); + + si->need_reachability_test = + xcalloc(si->shallow->nr, sizeof(*si->need_reachability_test)); + si->reachable = + xcalloc(si->shallow->nr, sizeof(*si->reachable)); + si->shallow_ref = xcalloc(si->ref->nr, sizeof(*si->shallow_ref)); + + for (i = 0; i < si->nr_ours; i++) + si->need_reachability_test[si->ours[i]] = 1; + + for (i = 0; i < si->shallow->nr; i++) { + if (!si->used_shallow[i]) + continue; + for (j = 0; j < bitmap_size; j++) { + if (!si->used_shallow[i][j]) + continue; + si->need_reachability_test[i]++; + for (k = 0; k < 32; k++) + if (si->used_shallow[i][j] & (1 << k)) + si->shallow_ref[j * 32 + k]++; + } + + /* + * true for those associated with some refs and belong + * in "ours" list aka "step 7 not done yet" + */ + si->need_reachability_test[i] = + si->need_reachability_test[i] > 1; + } + + /* + * keep hooks happy by forcing a temporary shallow file via + * env variable because we can't add --shallow-file to every + * command. check_everything_connected() will be done with + * true .git/shallow though. + */ + setenv(GIT_SHALLOW_FILE_ENVIRONMENT, alt_shallow_file, 1); +} + static void update_shallow_info(struct command *commands, struct shallow_info *si, struct sha1_array *ref) @@ -932,8 +1060,10 @@ static void update_shallow_info(struct command *commands, int *ref_status; remove_nonexistent_theirs_shallow(si); /* XXX remove_nonexistent_ours_in_pack() */ - if (!si->nr_ours && !si->nr_theirs) + if (!si->nr_ours && !si->nr_theirs) { + shallow_update = 0; return; + } for (cmd = commands; cmd; cmd = cmd->next) { if (is_null_sha1(cmd->new_sha1)) @@ -943,6 +1073,11 @@ static void update_shallow_info(struct command *commands, } si->ref = ref; + if (shallow_update) { + prepare_shallow_update(commands, si); + return; + } + ref_status = xmalloc(sizeof(*ref_status) * ref->nr); assign_shallow_commits_to_refs(si, NULL, ref_status); for (cmd = commands; cmd; cmd = cmd->next) { @@ -1064,11 +1199,13 @@ int cmd_receive_pack(int argc, const char **argv, const char *prefix) const char *unpack_status = NULL; prepare_shallow_info(&si, &shallow); + if (!si.nr_ours && !si.nr_theirs) + shallow_update = 0; if (!delete_only(commands)) { unpack_status = unpack_with_sideband(&si); update_shallow_info(commands, &si, &ref); } - execute_commands(commands, unpack_status); + execute_commands(commands, unpack_status, &si); if (pack_lockfile) unlink_or_warn(pack_lockfile); if (report_status) diff --git a/commit.h b/commit.h index 79649ef..a1f2d49 100644 --- a/commit.h +++ b/commit.h @@ -216,6 +216,14 @@ struct shallow_info { int *ours, nr_ours; int *theirs, nr_theirs; struct sha1_array *ref; + + /* for receive-pack */ + uint32_t **used_shallow; + int *need_reachability_test; + int *reachable; + int *shallow_ref; + struct commit **commits; + int nr_commits; }; extern void prepare_shallow_info(struct shallow_info *, struct sha1_array *); @@ -226,6 +234,7 @@ extern void remove_nonexistent_ours_in_pack(struct shallow_info *, extern void assign_shallow_commits_to_refs(struct shallow_info *info, uint32_t **used, int *ref_status); +extern int delayed_reachability_test(struct shallow_info *si, int c); int is_descendant_of(struct commit *, struct commit_list *); int in_merge_bases(struct commit *, struct commit *); diff --git a/shallow.c b/shallow.c index ec91794..3c36dd8 100644 --- a/shallow.c +++ b/shallow.c @@ -617,3 +617,26 @@ static void post_assign_shallow(struct shallow_info *info, free(ca.commits); } + +/* (Delayed) step 7, reachability test at commit level */ +int delayed_reachability_test(struct shallow_info *si, int c) +{ + if (si->need_reachability_test[c]) { + struct commit *commit = lookup_commit(si->shallow->sha1[c]); + + if (!si->commits) { + struct commit_array ca; + memset(&ca, 0, sizeof(ca)); + head_ref(add_ref, &ca); + for_each_ref(add_ref, &ca); + si->commits = ca.commits; + si->nr_commits = ca.nr; + } + + si->reachable[c] = in_merge_bases_many(commit, + si->nr_commits, + si->commits); + si->need_reachability_test[c] = 0; + } + return si->reachable[c]; +} diff --git a/t/t5538-push-shallow.sh b/t/t5538-push-shallow.sh index 650c31a..ff5eb5b 100755 --- a/t/t5538-push-shallow.sh +++ b/t/t5538-push-shallow.sh @@ -67,4 +67,19 @@ test_expect_success 'push from shallow clone, with grafted roots' ' git fsck ' +test_expect_success 'add new shallow root with receive.updateshallow on' ' + test_config receive.shallowupdate true && + ( + cd shallow2 && + git push ../.git +master:refs/remotes/shallow2/master + ) && + git log --format=%s shallow2/master >actual && + git fsck && + cat <expect && +c +b +EOF + test_cmp expect actual +' + test_done -- cgit v0.10.2-6-g49f6