diff mbox series

[v5,3/3] rev-list: add commit object support in `--missing` option

Message ID 20231026101109.43110-4-karthik.188@gmail.com (mailing list archive)
State New, archived
Headers show
Series rev-list: add support for commits in `--missing` | expand

Commit Message

Karthik Nayak Oct. 26, 2023, 10:11 a.m. UTC
The `--missing` object option in rev-list currently works only with
missing blobs/trees. For missing commits the revision walker fails with
a fatal error.

Let's extend the functionality of `--missing` option to also support
commit objects. This is done by adding a `missing_objects` field to
`rev_info`. This field is an `oidset` to which we'll add the missing
commits as we encounter them. The revision walker will now continue the
traversal and call `show_commit()` even for missing commits. In rev-list
we can then check if the commit is a missing commit and call the
existing code for parsing `--missing` objects.

A scenario where this option would be used is to find the boundary
objects between different object directories. Consider a repository with
a main object directory (GIT_OBJECT_DIRECTORY) and one or more alternate
object directories (GIT_ALTERNATE_OBJECT_DIRECTORIES). In such a
repository, using the `--missing=print` option while disabling the
alternate object directory allows us to find the boundary objects
between the main and alternate object directory.

Helped-by: Patrick Steinhardt <ps@pks.im>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
---
 builtin/rev-list.c          |  6 +++
 list-objects.c              |  3 ++
 revision.c                  | 17 ++++++++-
 revision.h                  |  4 ++
 t/t6022-rev-list-missing.sh | 74 +++++++++++++++++++++++++++++++++++++
 5 files changed, 102 insertions(+), 2 deletions(-)
 create mode 100755 t/t6022-rev-list-missing.sh

Comments

Patrick Steinhardt Oct. 27, 2023, 6:25 a.m. UTC | #1
On Thu, Oct 26, 2023 at 12:11:09PM +0200, Karthik Nayak wrote:
> The `--missing` object option in rev-list currently works only with
> missing blobs/trees. For missing commits the revision walker fails with
> a fatal error.
> 
> Let's extend the functionality of `--missing` option to also support
> commit objects. This is done by adding a `missing_objects` field to
> `rev_info`. This field is an `oidset` to which we'll add the missing
> commits as we encounter them. The revision walker will now continue the
> traversal and call `show_commit()` even for missing commits. In rev-list
> we can then check if the commit is a missing commit and call the
> existing code for parsing `--missing` objects.
> 
> A scenario where this option would be used is to find the boundary
> objects between different object directories. Consider a repository with
> a main object directory (GIT_OBJECT_DIRECTORY) and one or more alternate
> object directories (GIT_ALTERNATE_OBJECT_DIRECTORIES). In such a
> repository, using the `--missing=print` option while disabling the
> alternate object directory allows us to find the boundary objects
> between the main and alternate object directory.
> 
> Helped-by: Patrick Steinhardt <ps@pks.im>
> Helped-by: Junio C Hamano <gitster@pobox.com>
> Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
> ---
>  builtin/rev-list.c          |  6 +++
>  list-objects.c              |  3 ++
>  revision.c                  | 17 ++++++++-
>  revision.h                  |  4 ++
>  t/t6022-rev-list-missing.sh | 74 +++++++++++++++++++++++++++++++++++++
>  5 files changed, 102 insertions(+), 2 deletions(-)
>  create mode 100755 t/t6022-rev-list-missing.sh
> 
> diff --git a/builtin/rev-list.c b/builtin/rev-list.c
> index 98542e8b3c..181353dcf5 100644
> --- a/builtin/rev-list.c
> +++ b/builtin/rev-list.c
> @@ -149,6 +149,12 @@ static void show_commit(struct commit *commit, void *data)
>  
>  	display_progress(progress, ++progress_counter);
>  
> +	if (revs->do_not_die_on_missing_objects &&
> +	    oidset_contains(&revs->missing_commits, &commit->object.oid)) {
> +		finish_object__ma(&commit->object);
> +		return;
> +	}
> +
>  	if (show_disk_usage)
>  		total_disk_usage += get_object_disk_usage(&commit->object);
>  
> diff --git a/list-objects.c b/list-objects.c
> index 47296dff2f..f4e1104b56 100644
> --- a/list-objects.c
> +++ b/list-objects.c
> @@ -389,6 +389,9 @@ static void do_traverse(struct traversal_context *ctx)
>  		 */
>  		if (!ctx->revs->tree_objects)
>  			; /* do not bother loading tree */
> +		else if (ctx->revs->do_not_die_on_missing_objects &&
> +			 oidset_contains(&ctx->revs->missing_commits, &commit->object.oid))
> +			;
>  		else if (repo_get_commit_tree(the_repository, commit)) {
>  			struct tree *tree = repo_get_commit_tree(the_repository,
>  								 commit);
> diff --git a/revision.c b/revision.c
> index 219dc76716..738bacad08 100644
> --- a/revision.c
> +++ b/revision.c
> @@ -6,6 +6,7 @@
>  #include "object-name.h"
>  #include "object-file.h"
>  #include "object-store-ll.h"
> +#include "oidset.h"
>  #include "tag.h"
>  #include "blob.h"
>  #include "tree.h"
> @@ -1112,6 +1113,9 @@ static int process_parents(struct rev_info *revs, struct commit *commit,
>  
>  	if (commit->object.flags & ADDED)
>  		return 0;
> +	if (revs->do_not_die_on_missing_objects &&
> +	    oidset_contains(&revs->missing_commits, &commit->object.oid))
> +		return 0;
>  	commit->object.flags |= ADDED;
>  
>  	if (revs->include_check &&
> @@ -1168,7 +1172,8 @@ static int process_parents(struct rev_info *revs, struct commit *commit,
>  	for (parent = commit->parents; parent; parent = parent->next) {
>  		struct commit *p = parent->item;
>  		int gently = revs->ignore_missing_links ||
> -			     revs->exclude_promisor_objects;
> +			     revs->exclude_promisor_objects ||
> +			     revs->do_not_die_on_missing_objects;
>  		if (repo_parse_commit_gently(revs->repo, p, gently) < 0) {
>  			if (revs->exclude_promisor_objects &&
>  			    is_promisor_object(&p->object.oid)) {
> @@ -1176,7 +1181,11 @@ static int process_parents(struct rev_info *revs, struct commit *commit,
>  					break;
>  				continue;
>  			}
> -			return -1;
> +
> +			if (revs->do_not_die_on_missing_objects)
> +				oidset_insert(&revs->missing_commits, &p->object.oid);
> +			else
> +				return -1; /* corrupt repository */
>  		}
>  		if (revs->sources) {
>  			char **slot = revision_sources_at(revs->sources, p);
> @@ -3109,6 +3118,7 @@ void release_revisions(struct rev_info *revs)
>  	clear_decoration(&revs->merge_simplification, free);
>  	clear_decoration(&revs->treesame, free);
>  	line_log_free(revs);
> +	oidset_clear(&revs->missing_commits);
>  }
>  
>  static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
> @@ -3800,6 +3810,9 @@ int prepare_revision_walk(struct rev_info *revs)
>  				       FOR_EACH_OBJECT_PROMISOR_ONLY);
>  	}
>  
> +	if (revs->do_not_die_on_missing_objects)
> +		oidset_init(&revs->missing_commits, 0);
> +

We unconditionally clear the oidset now, so shouldn't we also
unconditionally initialize it?

Patrick

>  	if (!revs->reflog_info)
>  		prepare_to_use_bloom_filter(revs);
>  	if (!revs->unsorted_input)
> diff --git a/revision.h b/revision.h
> index c73c92ef40..94c43138bc 100644
> --- a/revision.h
> +++ b/revision.h
> @@ -4,6 +4,7 @@
>  #include "commit.h"
>  #include "grep.h"
>  #include "notes.h"
> +#include "oidset.h"
>  #include "pretty.h"
>  #include "diff.h"
>  #include "commit-slab-decl.h"
> @@ -373,6 +374,9 @@ struct rev_info {
>  
>  	/* Location where temporary objects for remerge-diff are written. */
>  	struct tmp_objdir *remerge_objdir;
> +
> +	/* Missing commits to be tracked without failing traversal. */
> +	struct oidset missing_commits;
>  };
>  
>  /**
> diff --git a/t/t6022-rev-list-missing.sh b/t/t6022-rev-list-missing.sh
> new file mode 100755
> index 0000000000..40265a4f66
> --- /dev/null
> +++ b/t/t6022-rev-list-missing.sh
> @@ -0,0 +1,74 @@
> +#!/bin/sh
> +
> +test_description='handling of missing objects in rev-list'
> +
> +TEST_PASSES_SANITIZE_LEAK=true
> +. ./test-lib.sh
> +
> +# We setup the repository with two commits, this way HEAD is always
> +# available and we can hide commit 1.
> +test_expect_success 'create repository and alternate directory' '
> +	test_commit 1 &&
> +	test_commit 2 &&
> +	test_commit 3
> +'
> +
> +for obj in "HEAD~1" "HEAD~1^{tree}" "HEAD:1.t"
> +do
> +	test_expect_success "rev-list --missing=error fails with missing object $obj" '
> +		oid="$(git rev-parse $obj)" &&
> +		path=".git/objects/$(test_oid_to_path $oid)" &&
> +
> +		mv "$path" "$path.hidden" &&
> +		test_when_finished "mv $path.hidden $path" &&
> +
> +		test_must_fail git rev-list --missing=error --objects \
> +			--no-object-names HEAD
> +	'
> +done
> +
> +for obj in "HEAD~1" "HEAD~1^{tree}" "HEAD:1.t"
> +do
> +	for action in "allow-any" "print"
> +	do
> +		test_expect_success "rev-list --missing=$action with missing $obj" '
> +			oid="$(git rev-parse $obj)" &&
> +			path=".git/objects/$(test_oid_to_path $oid)" &&
> +
> +			# Before the object is made missing, we use rev-list to
> +			# get the expected oids.
> +			git rev-list --objects --no-object-names \
> +				HEAD ^$obj >expect.raw &&
> +
> +			# Blobs are shared by all commits, so evethough a commit/tree
> +			# might be skipped, its blob must be accounted for.
> +			if [ $obj != "HEAD:1.t" ]; then
> +				echo $(git rev-parse HEAD:1.t) >>expect.raw &&
> +				echo $(git rev-parse HEAD:2.t) >>expect.raw
> +			fi &&
> +
> +			mv "$path" "$path.hidden" &&
> +			test_when_finished "mv $path.hidden $path" &&
> +
> +			git rev-list --missing=$action --objects --no-object-names \
> +				HEAD >actual.raw &&
> +
> +			# When the action is to print, we should also add the missing
> +			# oid to the expect list.
> +			case $action in
> +			allow-any)
> +				;;
> +			print)
> +				grep ?$oid actual.raw &&
> +				echo ?$oid >>expect.raw
> +				;;
> +			esac &&
> +
> +			sort actual.raw >actual &&
> +			sort expect.raw >expect &&
> +			test_cmp expect actual
> +		'
> +	done
> +done
> +
> +test_done
> -- 
> 2.42.0
>
Karthik Nayak Oct. 27, 2023, 7:54 a.m. UTC | #2
On Fri, Oct 27, 2023 at 8:25 AM Patrick Steinhardt <ps@pks.im> wrote:
>
> We unconditionally clear the oidset now, so shouldn't we also
> unconditionally initialize it?
>

You're right. I should have added that in.

Junio, I'm replying to this email with the amended commit for v5. If
you want me to reroll
v6, I could do that too. Thanks!
diff mbox series

Patch

diff --git a/builtin/rev-list.c b/builtin/rev-list.c
index 98542e8b3c..181353dcf5 100644
--- a/builtin/rev-list.c
+++ b/builtin/rev-list.c
@@ -149,6 +149,12 @@  static void show_commit(struct commit *commit, void *data)
 
 	display_progress(progress, ++progress_counter);
 
+	if (revs->do_not_die_on_missing_objects &&
+	    oidset_contains(&revs->missing_commits, &commit->object.oid)) {
+		finish_object__ma(&commit->object);
+		return;
+	}
+
 	if (show_disk_usage)
 		total_disk_usage += get_object_disk_usage(&commit->object);
 
diff --git a/list-objects.c b/list-objects.c
index 47296dff2f..f4e1104b56 100644
--- a/list-objects.c
+++ b/list-objects.c
@@ -389,6 +389,9 @@  static void do_traverse(struct traversal_context *ctx)
 		 */
 		if (!ctx->revs->tree_objects)
 			; /* do not bother loading tree */
+		else if (ctx->revs->do_not_die_on_missing_objects &&
+			 oidset_contains(&ctx->revs->missing_commits, &commit->object.oid))
+			;
 		else if (repo_get_commit_tree(the_repository, commit)) {
 			struct tree *tree = repo_get_commit_tree(the_repository,
 								 commit);
diff --git a/revision.c b/revision.c
index 219dc76716..738bacad08 100644
--- a/revision.c
+++ b/revision.c
@@ -6,6 +6,7 @@ 
 #include "object-name.h"
 #include "object-file.h"
 #include "object-store-ll.h"
+#include "oidset.h"
 #include "tag.h"
 #include "blob.h"
 #include "tree.h"
@@ -1112,6 +1113,9 @@  static int process_parents(struct rev_info *revs, struct commit *commit,
 
 	if (commit->object.flags & ADDED)
 		return 0;
+	if (revs->do_not_die_on_missing_objects &&
+	    oidset_contains(&revs->missing_commits, &commit->object.oid))
+		return 0;
 	commit->object.flags |= ADDED;
 
 	if (revs->include_check &&
@@ -1168,7 +1172,8 @@  static int process_parents(struct rev_info *revs, struct commit *commit,
 	for (parent = commit->parents; parent; parent = parent->next) {
 		struct commit *p = parent->item;
 		int gently = revs->ignore_missing_links ||
-			     revs->exclude_promisor_objects;
+			     revs->exclude_promisor_objects ||
+			     revs->do_not_die_on_missing_objects;
 		if (repo_parse_commit_gently(revs->repo, p, gently) < 0) {
 			if (revs->exclude_promisor_objects &&
 			    is_promisor_object(&p->object.oid)) {
@@ -1176,7 +1181,11 @@  static int process_parents(struct rev_info *revs, struct commit *commit,
 					break;
 				continue;
 			}
-			return -1;
+
+			if (revs->do_not_die_on_missing_objects)
+				oidset_insert(&revs->missing_commits, &p->object.oid);
+			else
+				return -1; /* corrupt repository */
 		}
 		if (revs->sources) {
 			char **slot = revision_sources_at(revs->sources, p);
@@ -3109,6 +3118,7 @@  void release_revisions(struct rev_info *revs)
 	clear_decoration(&revs->merge_simplification, free);
 	clear_decoration(&revs->treesame, free);
 	line_log_free(revs);
+	oidset_clear(&revs->missing_commits);
 }
 
 static void add_child(struct rev_info *revs, struct commit *parent, struct commit *child)
@@ -3800,6 +3810,9 @@  int prepare_revision_walk(struct rev_info *revs)
 				       FOR_EACH_OBJECT_PROMISOR_ONLY);
 	}
 
+	if (revs->do_not_die_on_missing_objects)
+		oidset_init(&revs->missing_commits, 0);
+
 	if (!revs->reflog_info)
 		prepare_to_use_bloom_filter(revs);
 	if (!revs->unsorted_input)
diff --git a/revision.h b/revision.h
index c73c92ef40..94c43138bc 100644
--- a/revision.h
+++ b/revision.h
@@ -4,6 +4,7 @@ 
 #include "commit.h"
 #include "grep.h"
 #include "notes.h"
+#include "oidset.h"
 #include "pretty.h"
 #include "diff.h"
 #include "commit-slab-decl.h"
@@ -373,6 +374,9 @@  struct rev_info {
 
 	/* Location where temporary objects for remerge-diff are written. */
 	struct tmp_objdir *remerge_objdir;
+
+	/* Missing commits to be tracked without failing traversal. */
+	struct oidset missing_commits;
 };
 
 /**
diff --git a/t/t6022-rev-list-missing.sh b/t/t6022-rev-list-missing.sh
new file mode 100755
index 0000000000..40265a4f66
--- /dev/null
+++ b/t/t6022-rev-list-missing.sh
@@ -0,0 +1,74 @@ 
+#!/bin/sh
+
+test_description='handling of missing objects in rev-list'
+
+TEST_PASSES_SANITIZE_LEAK=true
+. ./test-lib.sh
+
+# We setup the repository with two commits, this way HEAD is always
+# available and we can hide commit 1.
+test_expect_success 'create repository and alternate directory' '
+	test_commit 1 &&
+	test_commit 2 &&
+	test_commit 3
+'
+
+for obj in "HEAD~1" "HEAD~1^{tree}" "HEAD:1.t"
+do
+	test_expect_success "rev-list --missing=error fails with missing object $obj" '
+		oid="$(git rev-parse $obj)" &&
+		path=".git/objects/$(test_oid_to_path $oid)" &&
+
+		mv "$path" "$path.hidden" &&
+		test_when_finished "mv $path.hidden $path" &&
+
+		test_must_fail git rev-list --missing=error --objects \
+			--no-object-names HEAD
+	'
+done
+
+for obj in "HEAD~1" "HEAD~1^{tree}" "HEAD:1.t"
+do
+	for action in "allow-any" "print"
+	do
+		test_expect_success "rev-list --missing=$action with missing $obj" '
+			oid="$(git rev-parse $obj)" &&
+			path=".git/objects/$(test_oid_to_path $oid)" &&
+
+			# Before the object is made missing, we use rev-list to
+			# get the expected oids.
+			git rev-list --objects --no-object-names \
+				HEAD ^$obj >expect.raw &&
+
+			# Blobs are shared by all commits, so evethough a commit/tree
+			# might be skipped, its blob must be accounted for.
+			if [ $obj != "HEAD:1.t" ]; then
+				echo $(git rev-parse HEAD:1.t) >>expect.raw &&
+				echo $(git rev-parse HEAD:2.t) >>expect.raw
+			fi &&
+
+			mv "$path" "$path.hidden" &&
+			test_when_finished "mv $path.hidden $path" &&
+
+			git rev-list --missing=$action --objects --no-object-names \
+				HEAD >actual.raw &&
+
+			# When the action is to print, we should also add the missing
+			# oid to the expect list.
+			case $action in
+			allow-any)
+				;;
+			print)
+				grep ?$oid actual.raw &&
+				echo ?$oid >>expect.raw
+				;;
+			esac &&
+
+			sort actual.raw >actual &&
+			sort expect.raw >expect &&
+			test_cmp expect actual
+		'
+	done
+done
+
+test_done