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 <pclouds@xxxxxxxxx>
---
Documentation/config.txt | 4 ++
builtin/receive-pack.c | 163 +++++++++++++++++++++++++++++++++++++++++++----
commit.h | 9 +++
shallow.c | 23 +++++++
t/t5537-push-shallow.sh | 15 +++++
5 files changed, 201 insertions(+), 13 deletions(-)
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.<name>.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 5710690..e611639 100644
--- a/shallow.c
+++ b/shallow.c
@@ -618,3 +618,26 @@ 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/t5537-push-shallow.sh b/t/t5537-push-shallow.sh
index 650c31a..ff5eb5b 100755
--- a/t/t5537-push-shallow.sh
+++ b/t/t5537-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 <<EOF >expect &&
+c
+b
+EOF
+ test_cmp expect actual
+'
+
test_done
--
1.8.5.1.25.g8667982
--
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