[PATCH v4 00/10] Partial clone part 2: fsck and promisors

[PATCH v4 00/10] Partial clone part 2: fsck and promisors

[Jeff Hostetler]

From: Jeff Hostetler <jeffhost@microsoft.com>

This is part 2 of a 3 part sequence for partial clone.
Part 2 assumes part 1 is in place.

This patch series is labeled V4 to keep it in sync with the
V4 version of part 1.  (There was no V3 of this part.)

Part 2 is concerned with fsck, gc, initial support for dynamic
object fetching, and tracking promisor objects.  Jonathan Tan
originally developed this code.  I have moved it on top of
part 1 and updated it slightly.

Jonathan Tan (10):
  extension.partialclone: introduce partial clone extension
  fsck: introduce partialclone extension
  fsck: support refs pointing to promisor objects
  fsck: support referenced promisor objects
  fsck: support promisor objects as CLI argument
  index-pack: refactor writing of .keep files
  introduce fetch-object: fetch one promisor object
  sha1_file: support lazily fetching missing objects
  rev-list: support termination at promisor objects
  gc: do not repack promisor packfiles

 Documentation/git-pack-objects.txt             |  12 +-
 Documentation/gitremote-helpers.txt            |   6 +
 Documentation/rev-list-options.txt             |  12 +-
 Documentation/technical/repository-version.txt |  12 +
 Makefile                                       |   1 +
 builtin/cat-file.c                             |   2 +
 builtin/fetch-pack.c                           |  10 +
 builtin/fsck.c                                 |  26 +-
 builtin/gc.c                                   |   3 +
 builtin/index-pack.c                           | 113 ++++----
 builtin/pack-objects.c                         |  36 +++
 builtin/prune.c                                |   7 +
 builtin/repack.c                               |   8 +-
 builtin/rev-list.c                             |  74 +++++-
 cache.h                                        |  13 +-
 environment.c                                  |   1 +
 fetch-object.c                                 |  26 ++
 fetch-object.h                                 |   6 +
 fetch-pack.c                                   |   8 +-
 fetch-pack.h                                   |   2 +
 list-objects.c                                 |  29 ++-
 object.c                                       |   2 +-
 packfile.c                                     |  77 +++++-
 packfile.h                                     |  13 +
 remote-curl.c                                  |  14 +-
 revision.c                                     |  33 ++-
 revision.h                                     |   5 +-
 setup.c                                        |   7 +-
 sha1_file.c                                    |  38 ++-
 t/t0410-partial-clone.sh                       | 343 +++++++++++++++++++++++++
 transport.c                                    |   8 +
 transport.h                                    |   8 +
 32 files changed, 872 insertions(+), 83 deletions(-)
 create mode 100644 fetch-object.c
 create mode 100644 fetch-object.h
 create mode 100755 t/t0410-partial-clone.sh

-- 
2.9.3

[PATCH v4 01/10] extension.partialclone: introduce partial clone extension

[Jeff Hostetler]

From: Jonathan Tan <jonathantanmy@google.com>

Introduce new repository extension option:
    `extensions.partialclone`

See the update to Documentation/technical/repository-version.txt
in this patch for more information.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
---
 Documentation/technical/repository-version.txt | 12 ++++++++++++
 cache.h                                        |  2 ++
 environment.c                                  |  1 +
 setup.c                                        |  7 ++++++-
 4 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/Documentation/technical/repository-version.txt b/Documentation/technical/repository-version.txt
index 00ad379..e03eacc 100644
--- a/Documentation/technical/repository-version.txt
+++ b/Documentation/technical/repository-version.txt
@@ -86,3 +86,15 @@ for testing format-1 compatibility.
 When the config key `extensions.preciousObjects` is set to `true`,
 objects in the repository MUST NOT be deleted (e.g., by `git-prune` or
 `git repack -d`).
+
+`partialclone`
+~~~~~~~~~~~~~~
+
+When the config key `extensions.partialclone` is set, it indicates
+that the repo was created with a partial clone (or later performed
+a partial fetch) and that the remote may have omitted sending
+certain unwanted objects.  Such a remote is called a "promisor remote"
+and it promises that all such omitted objects can be fetched from it
+in the future.
+
+The value of this key is the name of the promisor remote.
diff --git a/cache.h b/cache.h
index 6440e2b..35e3f5e 100644
--- a/cache.h
+++ b/cache.h
@@ -860,10 +860,12 @@ extern int grafts_replace_parents;
 #define GIT_REPO_VERSION 0
 #define GIT_REPO_VERSION_READ 1
 extern int repository_format_precious_objects;
+extern char *repository_format_partial_clone;
 
 struct repository_format {
 	int version;
 	int precious_objects;
+	char *partial_clone; /* value of extensions.partialclone */
 	int is_bare;
 	char *work_tree;
 	struct string_list unknown_extensions;
diff --git a/environment.c b/environment.c
index 8289c25..e52aab3 100644
--- a/environment.c
+++ b/environment.c
@@ -27,6 +27,7 @@ int warn_ambiguous_refs = 1;
 int warn_on_object_refname_ambiguity = 1;
 int ref_paranoia = -1;
 int repository_format_precious_objects;
+char *repository_format_partial_clone;
 const char *git_commit_encoding;
 const char *git_log_output_encoding;
 const char *apply_default_whitespace;
diff --git a/setup.c b/setup.c
index 03f51e0..58536bd 100644
--- a/setup.c
+++ b/setup.c
@@ -420,7 +420,11 @@ static int check_repo_format(const char *var, const char *value, void *vdata)
 			;
 		else if (!strcmp(ext, "preciousobjects"))
 			data->precious_objects = git_config_bool(var, value);
-		else
+		else if (!strcmp(ext, "partialclone")) {
+			if (!value)
+				return config_error_nonbool(var);
+			data->partial_clone = xstrdup(value);
+		} else
 			string_list_append(&data->unknown_extensions, ext);
 	} else if (strcmp(var, "core.bare") == 0) {
 		data->is_bare = git_config_bool(var, value);
@@ -463,6 +467,7 @@ static int check_repository_format_gently(const char *gitdir, int *nongit_ok)
 	}
 
 	repository_format_precious_objects = candidate.precious_objects;
+	repository_format_partial_clone = candidate.partial_clone;
 	string_list_clear(&candidate.unknown_extensions, 0);
 	if (!has_common) {
 		if (candidate.is_bare != -1) {
-- 
2.9.3

[PATCH v4 02/10] fsck: introduce partialclone extension

[Jeff Hostetler]

From: Jonathan Tan <jonathantanmy@google.com>

Currently, Git does not support repos with very large numbers of objects
or repos that wish to minimize manipulation of certain blobs (for
example, because they are very large) very well, even if the user
operates mostly on part of the repo, because Git is designed on the
assumption that every referenced object is available somewhere in the
repo storage. In such an arrangement, the full set of objects is usually
available in remote storage, ready to be lazily downloaded.

Teach fsck about the new state of affairs. In this commit, teach fsck
that missing promisor objects referenced from the reflog are not an
error case; in future commits, fsck will be taught about other cases.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
---
 builtin/fsck.c           |  2 +-
 cache.h                  |  3 +-
 packfile.c               | 77 +++++++++++++++++++++++++++++++++++++++++++--
 packfile.h               | 13 ++++++++
 t/t0410-partial-clone.sh | 81 ++++++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 171 insertions(+), 5 deletions(-)
 create mode 100755 t/t0410-partial-clone.sh

diff --git a/builtin/fsck.c b/builtin/fsck.c
index 56afe40..2934299 100644
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -398,7 +398,7 @@ static void fsck_handle_reflog_oid(const char *refname, struct object_id *oid,
 					xstrfmt("%s@{%"PRItime"}", refname, timestamp));
 			obj->flags |= USED;
 			mark_object_reachable(obj);
-		} else {
+		} else if (!is_promisor_object(oid)) {
 			error("%s: invalid reflog entry %s", refname, oid_to_hex(oid));
 			errors_found |= ERROR_REACHABLE;
 		}
diff --git a/cache.h b/cache.h
index 35e3f5e..c76f2e9 100644
--- a/cache.h
+++ b/cache.h
@@ -1587,7 +1587,8 @@ extern struct packed_git {
 	unsigned pack_local:1,
 		 pack_keep:1,
 		 freshened:1,
-		 do_not_close:1;
+		 do_not_close:1,
+		 pack_promisor:1;
 	unsigned char sha1[20];
 	struct revindex_entry *revindex;
 	/* something like ".git/objects/pack/xxxxx.pack" */
diff --git a/packfile.c b/packfile.c
index 4a5fe7a..234797c 100644
--- a/packfile.c
+++ b/packfile.c
@@ -8,6 +8,11 @@
 #include "list.h"
 #include "streaming.h"
 #include "sha1-lookup.h"
+#include "commit.h"
+#include "object.h"
+#include "tag.h"
+#include "tree-walk.h"
+#include "tree.h"
 
 char *odb_pack_name(struct strbuf *buf,
 		    const unsigned char *sha1,
@@ -643,10 +648,10 @@ struct packed_git *add_packed_git(const char *path, size_t path_len, int local)
 		return NULL;
 
 	/*
-	 * ".pack" is long enough to hold any suffix we're adding (and
+	 * ".promisor" is long enough to hold any suffix we're adding (and
 	 * the use xsnprintf double-checks that)
 	 */
-	alloc = st_add3(path_len, strlen(".pack"), 1);
+	alloc = st_add3(path_len, strlen(".promisor"), 1);
 	p = alloc_packed_git(alloc);
 	memcpy(p->pack_name, path, path_len);
 
@@ -654,6 +659,10 @@ struct packed_git *add_packed_git(const char *path, size_t path_len, int local)
 	if (!access(p->pack_name, F_OK))
 		p->pack_keep = 1;
 
+	xsnprintf(p->pack_name + path_len, alloc - path_len, ".promisor");
+	if (!access(p->pack_name, F_OK))
+		p->pack_promisor = 1;
+
 	xsnprintf(p->pack_name + path_len, alloc - path_len, ".pack");
 	if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
 		free(p);
@@ -781,7 +790,8 @@ static void prepare_packed_git_one(char *objdir, int local)
 		if (ends_with(de->d_name, ".idx") ||
 		    ends_with(de->d_name, ".pack") ||
 		    ends_with(de->d_name, ".bitmap") ||
-		    ends_with(de->d_name, ".keep"))
+		    ends_with(de->d_name, ".keep") ||
+		    ends_with(de->d_name, ".promisor"))
 			string_list_append(&garbage, path.buf);
 		else
 			report_garbage(PACKDIR_FILE_GARBAGE, path.buf);
@@ -1889,6 +1899,9 @@ int for_each_packed_object(each_packed_object_fn cb, void *data, unsigned flags)
 	for (p = packed_git; p; p = p->next) {
 		if ((flags & FOR_EACH_OBJECT_LOCAL_ONLY) && !p->pack_local)
 			continue;
+		if ((flags & FOR_EACH_OBJECT_PROMISOR_ONLY) &&
+		    !p->pack_promisor)
+			continue;
 		if (open_pack_index(p)) {
 			pack_errors = 1;
 			continue;
@@ -1899,3 +1912,61 @@ int for_each_packed_object(each_packed_object_fn cb, void *data, unsigned flags)
 	}
 	return r ? r : pack_errors;
 }
+
+static int add_promisor_object(const struct object_id *oid,
+			       struct packed_git *pack,
+			       uint32_t pos,
+			       void *set_)
+{
+	struct oidset *set = set_;
+	struct object *obj = parse_object(oid);
+	if (!obj)
+		return 1;
+
+	oidset_insert(set, oid);
+
+	/*
+	 * If this is a tree, commit, or tag, the objects it refers
+	 * to are also promisor objects. (Blobs refer to no objects.)
+	 */
+	if (obj->type == OBJ_TREE) {
+		struct tree *tree = (struct tree *)obj;
+		struct tree_desc desc;
+		struct name_entry entry;
+		if (init_tree_desc_gently(&desc, tree->buffer, tree->size))
+			/*
+			 * Error messages are given when packs are
+			 * verified, so do not print any here.
+			 */
+			return 0;
+		while (tree_entry_gently(&desc, &entry))
+			oidset_insert(set, entry.oid);
+	} else if (obj->type == OBJ_COMMIT) {
+		struct commit *commit = (struct commit *) obj;
+		struct commit_list *parents = commit->parents;
+
+		oidset_insert(set, &commit->tree->object.oid);
+		for (; parents; parents = parents->next)
+			oidset_insert(set, &parents->item->object.oid);
+	} else if (obj->type == OBJ_TAG) {
+		struct tag *tag = (struct tag *) obj;
+		oidset_insert(set, &tag->tagged->oid);
+	}
+	return 0;
+}
+
+int is_promisor_object(const struct object_id *oid)
+{
+	static struct oidset promisor_objects;
+	static int promisor_objects_prepared;
+
+	if (!promisor_objects_prepared) {
+		if (repository_format_partial_clone) {
+			for_each_packed_object(add_promisor_object,
+					       &promisor_objects,
+					       FOR_EACH_OBJECT_PROMISOR_ONLY);
+		}
+		promisor_objects_prepared = 1;
+	}
+	return oidset_contains(&promisor_objects, oid);
+}
diff --git a/packfile.h b/packfile.h
index 0cdeb54..a7fca59 100644
--- a/packfile.h
+++ b/packfile.h
@@ -1,6 +1,8 @@
 #ifndef PACKFILE_H
 #define PACKFILE_H
 
+#include "oidset.h"
+
 /*
  * Generate the filename to be used for a pack file with checksum "sha1" and
  * extension "ext". The result is written into the strbuf "buf", overwriting
@@ -125,6 +127,11 @@ extern int has_sha1_pack(const unsigned char *sha1);
 extern int has_pack_index(const unsigned char *sha1);
 
 /*
+ * Only iterate over packs obtained from the promisor remote.
+ */
+#define FOR_EACH_OBJECT_PROMISOR_ONLY 2
+
+/*
  * Iterate over packed objects in both the local
  * repository and any alternates repositories (unless the
  * FOR_EACH_OBJECT_LOCAL_ONLY flag, defined in cache.h, is set).
@@ -135,4 +142,10 @@ typedef int each_packed_object_fn(const struct object_id *oid,
 				  void *data);
 extern int for_each_packed_object(each_packed_object_fn, void *, unsigned flags);
 
+/*
+ * Return 1 if an object in a promisor packfile is or refers to the given
+ * object, 0 otherwise.
+ */
+extern int is_promisor_object(const struct object_id *oid);
+
 #endif
diff --git a/t/t0410-partial-clone.sh b/t/t0410-partial-clone.sh
new file mode 100755
index 0000000..3ddb3b9
--- /dev/null
+++ b/t/t0410-partial-clone.sh
@@ -0,0 +1,81 @@
+#!/bin/sh
+
+test_description='partial clone'
+
+. ./test-lib.sh
+
+delete_object () {
+	rm $1/.git/objects/$(echo $2 | sed -e 's|^..|&/|')
+}
+
+pack_as_from_promisor () {
+	HASH=$(git -C repo pack-objects .git/objects/pack/pack) &&
+	>repo/.git/objects/pack/pack-$HASH.promisor
+}
+
+test_expect_success 'missing reflog object, but promised by a commit, passes fsck' '
+	test_create_repo repo &&
+	test_commit -C repo my_commit &&
+
+	A=$(git -C repo commit-tree -m a HEAD^{tree}) &&
+	C=$(git -C repo commit-tree -m c -p $A HEAD^{tree}) &&
+
+	# Reference $A only from reflog, and delete it
+	git -C repo branch my_branch "$A" &&
+	git -C repo branch -f my_branch my_commit &&
+	delete_object repo "$A" &&
+
+	# State that we got $C, which refers to $A, from promisor
+	printf "$C\n" | pack_as_from_promisor &&
+
+	# Normally, it fails
+	test_must_fail git -C repo fsck &&
+
+	# But with the extension, it succeeds
+	git -C repo config core.repositoryformatversion 1 &&
+	git -C repo config extensions.partialclone "arbitrary string" &&
+	git -C repo fsck
+'
+
+test_expect_success 'missing reflog object, but promised by a tag, passes fsck' '
+	rm -rf repo &&
+	test_create_repo repo &&
+	test_commit -C repo my_commit &&
+
+	A=$(git -C repo commit-tree -m a HEAD^{tree}) &&
+	git -C repo tag -a -m d my_tag_name $A &&
+	T=$(git -C repo rev-parse my_tag_name) &&
+	git -C repo tag -d my_tag_name &&
+
+	# Reference $A only from reflog, and delete it
+	git -C repo branch my_branch "$A" &&
+	git -C repo branch -f my_branch my_commit &&
+	delete_object repo "$A" &&
+
+	# State that we got $T, which refers to $A, from promisor
+	printf "$T\n" | pack_as_from_promisor &&
+
+	git -C repo config core.repositoryformatversion 1 &&
+	git -C repo config extensions.partialclone "arbitrary string" &&
+	git -C repo fsck
+'
+
+test_expect_success 'missing reflog object alone fails fsck, even with extension set' '
+	rm -rf repo &&
+	test_create_repo repo &&
+	test_commit -C repo my_commit &&
+
+	A=$(git -C repo commit-tree -m a HEAD^{tree}) &&
+	B=$(git -C repo commit-tree -m b HEAD^{tree}) &&
+
+	# Reference $A only from reflog, and delete it
+	git -C repo branch my_branch "$A" &&
+	git -C repo branch -f my_branch my_commit &&
+	delete_object repo "$A" &&
+
+	git -C repo config core.repositoryformatversion 1 &&
+	git -C repo config extensions.partialclone "arbitrary string" &&
+	test_must_fail git -C repo fsck
+'
+
+test_done
-- 
2.9.3

[PATCH v4 03/10] fsck: support refs pointing to promisor objects

[Jeff Hostetler]

From: Jonathan Tan <jonathantanmy@google.com>

Teach fsck to not treat refs referring to missing promisor objects as an
error when extensions.partialclone is set.

For the purposes of warning about no default refs, such refs are still
treated as legitimate refs.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
---
 builtin/fsck.c           |  8 ++++++++
 t/t0410-partial-clone.sh | 24 ++++++++++++++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/builtin/fsck.c b/builtin/fsck.c
index 2934299..ee937bb 100644
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -434,6 +434,14 @@ static int fsck_handle_ref(const char *refname, const struct object_id *oid,
 
 	obj = parse_object(oid);
 	if (!obj) {
+		if (is_promisor_object(oid)) {
+			/*
+			 * Increment default_refs anyway, because this is a
+			 * valid ref.
+			 */
+			 default_refs++;
+			 return 0;
+		}
 		error("%s: invalid sha1 pointer %s", refname, oid_to_hex(oid));
 		errors_found |= ERROR_REACHABLE;
 		/* We'll continue with the rest despite the error.. */
diff --git a/t/t0410-partial-clone.sh b/t/t0410-partial-clone.sh
index 3ddb3b9..bf75162 100755
--- a/t/t0410-partial-clone.sh
+++ b/t/t0410-partial-clone.sh
@@ -13,6 +13,14 @@ pack_as_from_promisor () {
 	>repo/.git/objects/pack/pack-$HASH.promisor
 }
 
+promise_and_delete () {
+	HASH=$(git -C repo rev-parse "$1") &&
+	git -C repo tag -a -m message my_annotated_tag "$HASH" &&
+	git -C repo rev-parse my_annotated_tag | pack_as_from_promisor &&
+	git -C repo tag -d my_annotated_tag &&
+	delete_object repo "$HASH"
+}
+
 test_expect_success 'missing reflog object, but promised by a commit, passes fsck' '
 	test_create_repo repo &&
 	test_commit -C repo my_commit &&
@@ -78,4 +86,20 @@ test_expect_success 'missing reflog object alone fails fsck, even with extension
 	test_must_fail git -C repo fsck
 '
 
+test_expect_success 'missing ref object, but promised, passes fsck' '
+	rm -rf repo &&
+	test_create_repo repo &&
+	test_commit -C repo my_commit &&
+
+	A=$(git -C repo commit-tree -m a HEAD^{tree}) &&
+
+	# Reference $A only from ref
+	git -C repo branch my_branch "$A" &&
+	promise_and_delete "$A" &&
+
+	git -C repo config core.repositoryformatversion 1 &&
+	git -C repo config extensions.partialclone "arbitrary string" &&
+	git -C repo fsck
+'
+
 test_done
-- 
2.9.3

[PATCH v4 04/10] fsck: support referenced promisor objects

[Jeff Hostetler]

From: Jonathan Tan <jonathantanmy@google.com>

Teach fsck to not treat missing promisor objects indirectly pointed to
by refs as an error when extensions.partialclone is set.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
---
 builtin/fsck.c           | 11 +++++++++++
 t/t0410-partial-clone.sh | 23 +++++++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/builtin/fsck.c b/builtin/fsck.c
index ee937bb..4c2a56d 100644
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -149,6 +149,15 @@ static int mark_object(struct object *obj, int type, void *data, struct fsck_opt
 	if (obj->flags & REACHABLE)
 		return 0;
 	obj->flags |= REACHABLE;
+
+	if (is_promisor_object(&obj->oid))
+		/*
+		 * Further recursion does not need to be performed on this
+		 * object since it is a promisor object (so it does not need to
+		 * be added to "pending").
+		 */
+		return 0;
+
 	if (!(obj->flags & HAS_OBJ)) {
 		if (parent && !has_object_file(&obj->oid)) {
 			printf("broken link from %7s %s\n",
@@ -208,6 +217,8 @@ static void check_reachable_object(struct object *obj)
 	 * do a full fsck
 	 */
 	if (!(obj->flags & HAS_OBJ)) {
+		if (is_promisor_object(&obj->oid))
+			return;
 		if (has_sha1_pack(obj->oid.hash))
 			return; /* it is in pack - forget about it */
 		printf("missing %s %s\n", printable_type(obj),
diff --git a/t/t0410-partial-clone.sh b/t/t0410-partial-clone.sh
index bf75162..4f9931f 100755
--- a/t/t0410-partial-clone.sh
+++ b/t/t0410-partial-clone.sh
@@ -102,4 +102,27 @@ test_expect_success 'missing ref object, but promised, passes fsck' '
 	git -C repo fsck
 '
 
+test_expect_success 'missing object, but promised, passes fsck' '
+	rm -rf repo &&
+	test_create_repo repo &&
+	test_commit -C repo 1 &&
+	test_commit -C repo 2 &&
+	test_commit -C repo 3 &&
+	git -C repo tag -a annotated_tag -m "annotated tag" &&
+
+	C=$(git -C repo rev-parse 1) &&
+	T=$(git -C repo rev-parse 2^{tree}) &&
+	B=$(git hash-object repo/3.t) &&
+	AT=$(git -C repo rev-parse annotated_tag) &&
+
+	promise_and_delete "$C" &&
+	promise_and_delete "$T" &&
+	promise_and_delete "$B" &&
+	promise_and_delete "$AT" &&
+
+	git -C repo config core.repositoryformatversion 1 &&
+	git -C repo config extensions.partialclone "arbitrary string" &&
+	git -C repo fsck
+'
+
 test_done
-- 
2.9.3

[PATCH v4 05/10] fsck: support promisor objects as CLI argument

[Jeff Hostetler]

From: Jonathan Tan <jonathantanmy@google.com>

Teach fsck to not treat missing promisor objects provided on the CLI as
an error when extensions.partialclone is set.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
---
 builtin/fsck.c           |  2 ++
 t/t0410-partial-clone.sh | 13 +++++++++++++
 2 files changed, 15 insertions(+)

diff --git a/builtin/fsck.c b/builtin/fsck.c
index 4c2a56d..578a7c8 100644
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -750,6 +750,8 @@ int cmd_fsck(int argc, const char **argv, const char *prefix)
 			struct object *obj = lookup_object(oid.hash);
 
 			if (!obj || !(obj->flags & HAS_OBJ)) {
+				if (is_promisor_object(&oid))
+					continue;
 				error("%s: object missing", oid_to_hex(&oid));
 				errors_found |= ERROR_OBJECT;
 				continue;
diff --git a/t/t0410-partial-clone.sh b/t/t0410-partial-clone.sh
index 4f9931f..e96f436 100755
--- a/t/t0410-partial-clone.sh
+++ b/t/t0410-partial-clone.sh
@@ -125,4 +125,17 @@ test_expect_success 'missing object, but promised, passes fsck' '
 	git -C repo fsck
 '
 
+test_expect_success 'missing CLI object, but promised, passes fsck' '
+	rm -rf repo &&
+	test_create_repo repo &&
+	test_commit -C repo my_commit &&
+
+	A=$(git -C repo commit-tree -m a HEAD^{tree}) &&
+	promise_and_delete "$A" &&
+
+	git -C repo config core.repositoryformatversion 1 &&
+	git -C repo config extensions.partialclone "arbitrary string" &&
+	git -C repo fsck "$A"
+'
+
 test_done
-- 
2.9.3

[PATCH v4 06/10] index-pack: refactor writing of .keep files

[Jeff Hostetler]

From: Jonathan Tan <jonathantanmy@google.com>

In a subsequent commit, index-pack will be taught to write ".promisor"
files which are similar to the ".keep" files it knows how to write.
Refactor the writing of ".keep" files, so that the implementation of
writing ".promisor" files becomes easier.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
---
 builtin/index-pack.c | 99 ++++++++++++++++++++++++++++------------------------
 1 file changed, 53 insertions(+), 46 deletions(-)

diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index 8ec459f..4f305a7 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -1389,15 +1389,58 @@ static void fix_unresolved_deltas(struct sha1file *f)
 	free(sorted_by_pos);
 }
 
+static const char *derive_filename(const char *pack_name, const char *suffix,
+				   struct strbuf *buf)
+{
+	size_t len;
+	if (!strip_suffix(pack_name, ".pack", &len))
+		die(_("packfile name '%s' does not end with '.pack'"),
+		    pack_name);
+	strbuf_add(buf, pack_name, len);
+	strbuf_addch(buf, '.');
+	strbuf_addstr(buf, suffix);
+	return buf->buf;
+}
+
+static void write_special_file(const char *suffix, const char *msg,
+			       const char *pack_name, const unsigned char *sha1,
+			       const char **report)
+{
+	struct strbuf name_buf = STRBUF_INIT;
+	const char *filename;
+	int fd;
+	int msg_len = strlen(msg);
+
+	if (pack_name)
+		filename = derive_filename(pack_name, suffix, &name_buf);
+	else
+		filename = odb_pack_name(&name_buf, sha1, suffix);
+
+	fd = odb_pack_keep(filename);
+	if (fd < 0) {
+		if (errno != EEXIST)
+			die_errno(_("cannot write %s file '%s'"),
+				  suffix, filename);
+	} else {
+		if (msg_len > 0) {
+			write_or_die(fd, msg, msg_len);
+			write_or_die(fd, "\n", 1);
+		}
+		if (close(fd) != 0)
+			die_errno(_("cannot close written %s file '%s'"),
+				  suffix, filename);
+		*report = suffix;
+	}
+	strbuf_release(&name_buf);
+}
+
 static void final(const char *final_pack_name, const char *curr_pack_name,
 		  const char *final_index_name, const char *curr_index_name,
-		  const char *keep_name, const char *keep_msg,
-		  unsigned char *sha1)
+		  const char *keep_msg, unsigned char *sha1)
 {
 	const char *report = "pack";
 	struct strbuf pack_name = STRBUF_INIT;
 	struct strbuf index_name = STRBUF_INIT;
-	struct strbuf keep_name_buf = STRBUF_INIT;
 	int err;
 
 	if (!from_stdin) {
@@ -1409,28 +1452,9 @@ static void final(const char *final_pack_name, const char *curr_pack_name,
 			die_errno(_("error while closing pack file"));
 	}
 
-	if (keep_msg) {
-		int keep_fd, keep_msg_len = strlen(keep_msg);
-
-		if (!keep_name)
-			keep_name = odb_pack_name(&keep_name_buf, sha1, "keep");
-
-		keep_fd = odb_pack_keep(keep_name);
-		if (keep_fd < 0) {
-			if (errno != EEXIST)
-				die_errno(_("cannot write keep file '%s'"),
-					  keep_name);
-		} else {
-			if (keep_msg_len > 0) {
-				write_or_die(keep_fd, keep_msg, keep_msg_len);
-				write_or_die(keep_fd, "\n", 1);
-			}
-			if (close(keep_fd) != 0)
-				die_errno(_("cannot close written keep file '%s'"),
-					  keep_name);
-			report = "keep";
-		}
-	}
+	if (keep_msg)
+		write_special_file("keep", keep_msg, final_pack_name, sha1,
+				   &report);
 
 	if (final_pack_name != curr_pack_name) {
 		if (!final_pack_name)
@@ -1472,7 +1496,6 @@ static void final(const char *final_pack_name, const char *curr_pack_name,
 
 	strbuf_release(&index_name);
 	strbuf_release(&pack_name);
-	strbuf_release(&keep_name_buf);
 }
 
 static int git_index_pack_config(const char *k, const char *v, void *cb)
@@ -1615,26 +1638,13 @@ static void show_pack_info(int stat_only)
 	}
 }
 
-static const char *derive_filename(const char *pack_name, const char *suffix,
-				   struct strbuf *buf)
-{
-	size_t len;
-	if (!strip_suffix(pack_name, ".pack", &len))
-		die(_("packfile name '%s' does not end with '.pack'"),
-		    pack_name);
-	strbuf_add(buf, pack_name, len);
-	strbuf_addstr(buf, suffix);
-	return buf->buf;
-}
-
 int cmd_index_pack(int argc, const char **argv, const char *prefix)
 {
 	int i, fix_thin_pack = 0, verify = 0, stat_only = 0;
 	const char *curr_index;
 	const char *index_name = NULL, *pack_name = NULL;
-	const char *keep_name = NULL, *keep_msg = NULL;
-	struct strbuf index_name_buf = STRBUF_INIT,
-		      keep_name_buf = STRBUF_INIT;
+	const char *keep_msg = NULL;
+	struct strbuf index_name_buf = STRBUF_INIT;
 	struct pack_idx_entry **idx_objects;
 	struct pack_idx_option opts;
 	unsigned char pack_sha1[20];
@@ -1745,9 +1755,7 @@ int cmd_index_pack(int argc, const char **argv, const char *prefix)
 	if (from_stdin && !startup_info->have_repository)
 		die(_("--stdin requires a git repository"));
 	if (!index_name && pack_name)
-		index_name = derive_filename(pack_name, ".idx", &index_name_buf);
-	if (keep_msg && !keep_name && pack_name)
-		keep_name = derive_filename(pack_name, ".keep", &keep_name_buf);
+		index_name = derive_filename(pack_name, "idx", &index_name_buf);
 
 	if (verify) {
 		if (!index_name)
@@ -1795,13 +1803,12 @@ int cmd_index_pack(int argc, const char **argv, const char *prefix)
 	if (!verify)
 		final(pack_name, curr_pack,
 		      index_name, curr_index,
-		      keep_name, keep_msg,
+		      keep_msg,
 		      pack_sha1);
 	else
 		close(input_fd);
 	free(objects);
 	strbuf_release(&index_name_buf);
-	strbuf_release(&keep_name_buf);
 	if (pack_name == NULL)
 		free((void *) curr_pack);
 	if (index_name == NULL)
-- 
2.9.3

[PATCH v4 07/10] introduce fetch-object: fetch one promisor object

[Jeff Hostetler]

From: Jonathan Tan <jonathantanmy@google.com>

Introduce fetch-object, providing the ability to fetch one object from a
promisor remote.

This uses fetch-pack. To do this, the transport mechanism has been
updated with 2 flags, "from-promisor" to indicate that the resulting
pack comes from a promisor remote (and thus should be annotated as such
by index-pack), and "no-haves" to suppress the sending of "have" lines.

This will be tested in a subsequent commit.

NEEDSWORK: update this when we have more information about protocol v2,
which should allow a way to suppress the ref advertisement and
officially allow any object type to be "want"-ed.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
---
 Documentation/gitremote-helpers.txt |  6 ++++++
 Makefile                            |  1 +
 builtin/fetch-pack.c                |  8 ++++++++
 builtin/index-pack.c                | 16 +++++++++++++---
 fetch-object.c                      | 23 +++++++++++++++++++++++
 fetch-object.h                      |  6 ++++++
 fetch-pack.c                        |  8 ++++++--
 fetch-pack.h                        |  2 ++
 remote-curl.c                       | 14 +++++++++++++-
 transport.c                         |  8 ++++++++
 transport.h                         |  8 ++++++++
 11 files changed, 94 insertions(+), 6 deletions(-)
 create mode 100644 fetch-object.c
 create mode 100644 fetch-object.h

diff --git a/Documentation/gitremote-helpers.txt b/Documentation/gitremote-helpers.txt
index 4a584f3..1ceab89 100644
--- a/Documentation/gitremote-helpers.txt
+++ b/Documentation/gitremote-helpers.txt
@@ -466,6 +466,12 @@ set by Git if the remote helper has the 'option' capability.
 	Transmit <string> as a push option. As the push option
 	must not contain LF or NUL characters, the string is not encoded.
 
+'option from-promisor' {'true'|'false'}::
+	Indicate that these objects are being fetch by a promisor.
+
+'option no-haves' {'true'|'false'}::
+	Do not send "have" lines.
+
 SEE ALSO
 --------
 linkgit:git-remote[1]
diff --git a/Makefile b/Makefile
index ca378a4..795e0c7 100644
--- a/Makefile
+++ b/Makefile
@@ -792,6 +792,7 @@ LIB_OBJS += ewah/ewah_bitmap.o
 LIB_OBJS += ewah/ewah_io.o
 LIB_OBJS += ewah/ewah_rlw.o
 LIB_OBJS += exec_cmd.o
+LIB_OBJS += fetch-object.o
 LIB_OBJS += fetch-pack.o
 LIB_OBJS += fsck.o
 LIB_OBJS += gettext.o
diff --git a/builtin/fetch-pack.c b/builtin/fetch-pack.c
index 366b9d1..9f303cf 100644
--- a/builtin/fetch-pack.c
+++ b/builtin/fetch-pack.c
@@ -143,6 +143,14 @@ int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 			args.update_shallow = 1;
 			continue;
 		}
+		if (!strcmp("--from-promisor", arg)) {
+			args.from_promisor = 1;
+			continue;
+		}
+		if (!strcmp("--no-haves", arg)) {
+			args.no_haves = 1;
+			continue;
+		}
 		usage(fetch_pack_usage);
 	}
 	if (deepen_not.nr)
diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index 4f305a7..24c2f05 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -1429,14 +1429,16 @@ static void write_special_file(const char *suffix, const char *msg,
 		if (close(fd) != 0)
 			die_errno(_("cannot close written %s file '%s'"),
 				  suffix, filename);
-		*report = suffix;
+		if (report)
+			*report = suffix;
 	}
 	strbuf_release(&name_buf);
 }
 
 static void final(const char *final_pack_name, const char *curr_pack_name,
 		  const char *final_index_name, const char *curr_index_name,
-		  const char *keep_msg, unsigned char *sha1)
+		  const char *keep_msg, const char *promisor_msg,
+		  unsigned char *sha1)
 {
 	const char *report = "pack";
 	struct strbuf pack_name = STRBUF_INIT;
@@ -1455,6 +1457,9 @@ static void final(const char *final_pack_name, const char *curr_pack_name,
 	if (keep_msg)
 		write_special_file("keep", keep_msg, final_pack_name, sha1,
 				   &report);
+	if (promisor_msg)
+		write_special_file("promisor", promisor_msg, final_pack_name,
+				   sha1, NULL);
 
 	if (final_pack_name != curr_pack_name) {
 		if (!final_pack_name)
@@ -1644,6 +1649,7 @@ int cmd_index_pack(int argc, const char **argv, const char *prefix)
 	const char *curr_index;
 	const char *index_name = NULL, *pack_name = NULL;
 	const char *keep_msg = NULL;
+	const char *promisor_msg = NULL;
 	struct strbuf index_name_buf = STRBUF_INIT;
 	struct pack_idx_entry **idx_objects;
 	struct pack_idx_option opts;
@@ -1693,6 +1699,10 @@ int cmd_index_pack(int argc, const char **argv, const char *prefix)
 				keep_msg = "";
 			} else if (starts_with(arg, "--keep=")) {
 				keep_msg = arg + 7;
+			} else if (!strcmp(arg, "--promisor")) {
+				promisor_msg = "";
+			} else if (starts_with(arg, "--promisor=")) {
+				promisor_msg = arg + strlen("--promisor=");
 			} else if (starts_with(arg, "--threads=")) {
 				char *end;
 				nr_threads = strtoul(arg+10, &end, 0);
@@ -1803,7 +1813,7 @@ int cmd_index_pack(int argc, const char **argv, const char *prefix)
 	if (!verify)
 		final(pack_name, curr_pack,
 		      index_name, curr_index,
-		      keep_msg,
+		      keep_msg, promisor_msg,
 		      pack_sha1);
 	else
 		close(input_fd);
diff --git a/fetch-object.c b/fetch-object.c
new file mode 100644
index 0000000..f89dbba
--- /dev/null
+++ b/fetch-object.c
@@ -0,0 +1,23 @@
+#include "cache.h"
+#include "packfile.h"
+#include "pkt-line.h"
+#include "strbuf.h"
+#include "transport.h"
+
+void fetch_object(const char *remote_name, const unsigned char *sha1)
+{
+	struct remote *remote;
+	struct transport *transport;
+	struct ref *ref;
+
+	remote = remote_get(remote_name);
+	if (!remote->url[0])
+		die(_("Remote with no URL"));
+	transport = transport_get(remote, remote->url[0]);
+
+	ref = alloc_ref(sha1_to_hex(sha1));
+	hashcpy(ref->old_oid.hash, sha1);
+	transport_set_option(transport, TRANS_OPT_FROM_PROMISOR, "1");
+	transport_set_option(transport, TRANS_OPT_NO_HAVES, "1");
+	transport_fetch_refs(transport, ref);
+}
diff --git a/fetch-object.h b/fetch-object.h
new file mode 100644
index 0000000..f371300
--- /dev/null
+++ b/fetch-object.h
@@ -0,0 +1,6 @@
+#ifndef FETCH_OBJECT_H
+#define FETCH_OBJECT_H
+
+extern void fetch_object(const char *remote_name, const unsigned char *sha1);
+
+#endif
diff --git a/fetch-pack.c b/fetch-pack.c
index 008b25d..4640b4e 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -450,6 +450,8 @@ static int find_common(struct fetch_pack_args *args,
 
 	flushes = 0;
 	retval = -1;
+	if (args->no_haves)
+		goto done;
 	while ((oid = get_rev())) {
 		packet_buf_write(&req_buf, "have %s\n", oid_to_hex(oid));
 		print_verbose(args, "have %s", oid_to_hex(oid));
@@ -832,7 +834,7 @@ static int get_pack(struct fetch_pack_args *args,
 		argv_array_push(&cmd.args, alternate_shallow_file);
 	}
 
-	if (do_keep) {
+	if (do_keep || args->from_promisor) {
 		if (pack_lockfile)
 			cmd.out = -1;
 		cmd_name = "index-pack";
@@ -842,7 +844,7 @@ static int get_pack(struct fetch_pack_args *args,
 			argv_array_push(&cmd.args, "-v");
 		if (args->use_thin_pack)
 			argv_array_push(&cmd.args, "--fix-thin");
-		if (args->lock_pack || unpack_limit) {
+		if (do_keep && (args->lock_pack || unpack_limit)) {
 			char hostname[HOST_NAME_MAX + 1];
 			if (xgethostname(hostname, sizeof(hostname)))
 				xsnprintf(hostname, sizeof(hostname), "localhost");
@@ -852,6 +854,8 @@ static int get_pack(struct fetch_pack_args *args,
 		}
 		if (args->check_self_contained_and_connected)
 			argv_array_push(&cmd.args, "--check-self-contained-and-connected");
+		if (args->from_promisor)
+			argv_array_push(&cmd.args, "--promisor");
 	}
 	else {
 		cmd_name = "unpack-objects";
diff --git a/fetch-pack.h b/fetch-pack.h
index b6aeb43..84904c3 100644
--- a/fetch-pack.h
+++ b/fetch-pack.h
@@ -29,6 +29,8 @@ struct fetch_pack_args {
 	unsigned cloning:1;
 	unsigned update_shallow:1;
 	unsigned deepen:1;
+	unsigned from_promisor:1;
+	unsigned no_haves:1;
 };
 
 /*
diff --git a/remote-curl.c b/remote-curl.c
index 0053b09..34a81b8 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -33,7 +33,9 @@ struct options {
 		thin : 1,
 		/* One of the SEND_PACK_PUSH_CERT_* constants. */
 		push_cert : 2,
-		deepen_relative : 1;
+		deepen_relative : 1,
+		from_promisor : 1,
+		no_haves : 1;
 };
 static struct options options;
 static struct string_list cas_options = STRING_LIST_INIT_DUP;
@@ -157,6 +159,12 @@ static int set_option(const char *name, const char *value)
 			return -1;
 		return 0;
 #endif /* LIBCURL_VERSION_NUM >= 0x070a08 */
+	} else if (!strcmp(name, "from-promisor")) {
+		options.from_promisor = 1;
+		return 0;
+	} else if (!strcmp(name, "no-haves")) {
+		options.no_haves = 1;
+		return 0;
 	} else {
 		return 1 /* unsupported */;
 	}
@@ -822,6 +830,10 @@ static int fetch_git(struct discovery *heads,
 				 options.deepen_not.items[i].string);
 	if (options.deepen_relative && options.depth)
 		argv_array_push(&args, "--deepen-relative");
+	if (options.from_promisor)
+		argv_array_push(&args, "--from-promisor");
+	if (options.no_haves)
+		argv_array_push(&args, "--no-haves");
 	argv_array_push(&args, url.buf);
 
 	for (i = 0; i < nr_heads; i++) {
diff --git a/transport.c b/transport.c
index f1e2f61..8211f82 100644
--- a/transport.c
+++ b/transport.c
@@ -160,6 +160,12 @@ static int set_git_option(struct git_transport_options *opts,
 	} else if (!strcmp(name, TRANS_OPT_DEEPEN_RELATIVE)) {
 		opts->deepen_relative = !!value;
 		return 0;
+	} else if (!strcmp(name, TRANS_OPT_FROM_PROMISOR)) {
+		opts->from_promisor = !!value;
+		return 0;
+	} else if (!strcmp(name, TRANS_OPT_NO_HAVES)) {
+		opts->no_haves = !!value;
+		return 0;
 	}
 	return 1;
 }
@@ -228,6 +234,8 @@ static int fetch_refs_via_pack(struct transport *transport,
 		data->options.check_self_contained_and_connected;
 	args.cloning = transport->cloning;
 	args.update_shallow = data->options.update_shallow;
+	args.from_promisor = data->options.from_promisor;
+	args.no_haves = data->options.no_haves;
 
 	if (!data->got_remote_heads) {
 		connect_setup(transport, 0);
diff --git a/transport.h b/transport.h
index bc55715..67428f6 100644
--- a/transport.h
+++ b/transport.h
@@ -15,6 +15,8 @@ struct git_transport_options {
 	unsigned self_contained_and_connected : 1;
 	unsigned update_shallow : 1;
 	unsigned deepen_relative : 1;
+	unsigned from_promisor : 1;
+	unsigned no_haves : 1;
 	int depth;
 	const char *deepen_since;
 	const struct string_list *deepen_not;
@@ -210,6 +212,12 @@ void transport_check_allowed(const char *type);
 /* Send push certificates */
 #define TRANS_OPT_PUSH_CERT "pushcert"
 
+/* Indicate that these objects are being fetched by a promisor */
+#define TRANS_OPT_FROM_PROMISOR "from-promisor"
+
+/* Do not send "have" lines */
+#define TRANS_OPT_NO_HAVES "no-haves"
+
 /**
  * Returns 0 if the option was used, non-zero otherwise. Prints a
  * message to stderr if the option is not used.
-- 
2.9.3

Re: [PATCH v4 07/10] introduce fetch-object: fetch one promisor object

[Ramsay Jones]

On 16/11/17 18:12, Jeff Hostetler wrote:
> From: Jonathan Tan <jonathantanmy@google.com>
> 
> Introduce fetch-object, providing the ability to fetch one object from a
> promisor remote.
> 
> This uses fetch-pack. To do this, the transport mechanism has been
> updated with 2 flags, "from-promisor" to indicate that the resulting
> pack comes from a promisor remote (and thus should be annotated as such
> by index-pack), and "no-haves" to suppress the sending of "have" lines.
> 
> This will be tested in a subsequent commit.
> 
> NEEDSWORK: update this when we have more information about protocol v2,
> which should allow a way to suppress the ref advertisement and
> officially allow any object type to be "want"-ed.
> 
> Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
> ---
>  Documentation/gitremote-helpers.txt |  6 ++++++
>  Makefile                            |  1 +
>  builtin/fetch-pack.c                |  8 ++++++++
>  builtin/index-pack.c                | 16 +++++++++++++---
>  fetch-object.c                      | 23 +++++++++++++++++++++++
>  fetch-object.h                      |  6 ++++++
>  fetch-pack.c                        |  8 ++++++--
>  fetch-pack.h                        |  2 ++
>  remote-curl.c                       | 14 +++++++++++++-
>  transport.c                         |  8 ++++++++
>  transport.h                         |  8 ++++++++
>  11 files changed, 94 insertions(+), 6 deletions(-)
>  create mode 100644 fetch-object.c
>  create mode 100644 fetch-object.h
> 
[snip]
> diff --git a/fetch-object.c b/fetch-object.c
> new file mode 100644
> index 0000000..f89dbba
> --- /dev/null
> +++ b/fetch-object.c
> @@ -0,0 +1,23 @@
> +#include "cache.h"
> +#include "packfile.h"
> +#include "pkt-line.h"
> +#include "strbuf.h"
> +#include "transport.h"

I note that this still does not #include "fetch_object.h".
[If you recall, this suppresses a sparse warning].

> +
> +void fetch_object(const char *remote_name, const unsigned char *sha1)
> +{
> +	struct remote *remote;
> +	struct transport *transport;
> +	struct ref *ref;
> +
> +	remote = remote_get(remote_name);
> +	if (!remote->url[0])
> +		die(_("Remote with no URL"));
> +	transport = transport_get(remote, remote->url[0]);
> +
> +	ref = alloc_ref(sha1_to_hex(sha1));
> +	hashcpy(ref->old_oid.hash, sha1);
> +	transport_set_option(transport, TRANS_OPT_FROM_PROMISOR, "1");
> +	transport_set_option(transport, TRANS_OPT_NO_HAVES, "1");
> +	transport_fetch_refs(transport, ref);
> +}
> diff --git a/fetch-object.h b/fetch-object.h
> new file mode 100644
> index 0000000..f371300
> --- /dev/null
> +++ b/fetch-object.h
> @@ -0,0 +1,6 @@
> +#ifndef FETCH_OBJECT_H
> +#define FETCH_OBJECT_H
> +
> +extern void fetch_object(const char *remote_name, const unsigned char *sha1);
> +
> +#endif

ATB,
Ramsay Jones

Re: [PATCH v4 07/10] introduce fetch-object: fetch one promisor object

[Jeff Hostetler]

On 11/16/2017 2:57 PM, Ramsay Jones wrote:
> 
> 
> On 16/11/17 18:12, Jeff Hostetler wrote:
>> From: Jonathan Tan <jonathantanmy@google.com>
>>
>> Introduce fetch-object, providing the ability to fetch one object from a
>> promisor remote.
[snip]
>> +#include "transport.h"
> 
> I note that this still does not #include "fetch_object.h".
> [If you recall, this suppresses a sparse warning].
> 

Sorry, I missed that.  I know I did a DEVELOPER=1 build and
I didn't see a warning, but I'll check again.

Thanks,
Jeff

Re: [PATCH v4 07/10] introduce fetch-object: fetch one promisor object

[Stefan Beller]

On Fri, Nov 17, 2017 at 11:49 AM, Jeff Hostetler <git@jeffhostetler.com> wrote:
>
>
> On 11/16/2017 2:57 PM, Ramsay Jones wrote:
>>
>>
>>
>> On 16/11/17 18:12, Jeff Hostetler wrote:
>>>
>>> From: Jonathan Tan <jonathantanmy@google.com>
>>>
>>> Introduce fetch-object, providing the ability to fetch one object from a
>>> promisor remote.
>
> [snip]
>>>
>>> +#include "transport.h"
>>
>>
>> I note that this still does not #include "fetch_object.h".
>> [If you recall, this suppresses a sparse warning].
>>
>
> Sorry, I missed that.  I know I did a DEVELOPER=1 build and
> I didn't see a warning, but I'll check again.

sparse is an extra tool, which you have to run/install;
it is not included in the developer build.

https://en.wikipedia.org/wiki/Sparse

Re: [PATCH v4 07/10] introduce fetch-object: fetch one promisor object

[Jeff Hostetler]

On 11/17/2017 3:17 PM, Stefan Beller wrote:
> On Fri, Nov 17, 2017 at 11:49 AM, Jeff Hostetler <git@jeffhostetler.com> wrote:
>>
>>
>> On 11/16/2017 2:57 PM, Ramsay Jones wrote:
>>>
>>>
>>>
>>> On 16/11/17 18:12, Jeff Hostetler wrote:
>>>>
>>>> From: Jonathan Tan <jonathantanmy@google.com>
>>>>
>>>> Introduce fetch-object, providing the ability to fetch one object from a
>>>> promisor remote.
>>
>> [snip]
>>>>
>>>> +#include "transport.h"
>>>
>>>
>>> I note that this still does not #include "fetch_object.h".
>>> [If you recall, this suppresses a sparse warning].
>>>
>>
>> Sorry, I missed that.  I know I did a DEVELOPER=1 build and
>> I didn't see a warning, but I'll check again.
> 
> sparse is an extra tool, which you have to run/install;
> it is not included in the developer build.
> 
> https://en.wikipedia.org/wiki/Sparse
> 

ah, thanks!
Jeff

Re: [PATCH v4 07/10] introduce fetch-object: fetch one promisor object

[Ramsay Jones]

On 17/11/17 19:49, Jeff Hostetler wrote:
> 
> 
> On 11/16/2017 2:57 PM, Ramsay Jones wrote:
>>
>>
>> On 16/11/17 18:12, Jeff Hostetler wrote:
>>> From: Jonathan Tan <jonathantanmy@google.com>
>>>
>>> Introduce fetch-object, providing the ability to fetch one object from a
>>> promisor remote.
> [snip]
>>> +#include "transport.h"
>>
>> I note that this still does not #include "fetch_object.h".
>> [If you recall, this suppresses a sparse warning].
>>
> 
> Sorry, I missed that.  I know I did a DEVELOPER=1 build and
> I didn't see a warning, but I'll check again.

Unless you have sparse installed and 'make sparse' as part of
your build, you won't see anything. ;-)

However, ignore sparse for the moment, if you don't #include
the header (interface) file in fetch-object.c, you can't
expect the compiler to tell you when there is a mismatch
between the interface and implementation.

There are some additional sparse warnings associated with
these series, ... (hopefully I can find some time tonight)

ATB,
Ramsay Jones

[PATCH v4 08/10] sha1_file: support lazily fetching missing objects

[Jeff Hostetler]

From: Jonathan Tan <jonathantanmy@google.com>

Teach sha1_file to fetch objects from the remote configured in
extensions.partialclone whenever an object is requested but missing.

The fetching of objects can be suppressed through a global variable.
This is used by fsck and index-pack.

However, by default, such fetching is not suppressed. This is meant as a
temporary measure to ensure that all Git commands work in such a
situation. Future patches will update some commands to either tolerate
missing objects (without fetching them) or be more efficient in fetching
them.

In order to determine the code changes in sha1_file.c necessary, I
investigated the following:
 (1) functions in sha1_file.c that take in a hash, without the user
     regarding how the object is stored (loose or packed)
 (2) functions in packfile.c (because I need to check callers that know
     about the loose/packed distinction and operate on both differently,
     and ensure that they can handle the concept of objects that are
     neither loose nor packed)

(1) is handled by the modification to sha1_object_info_extended().

For (2), I looked at for_each_packed_object and others.  For
for_each_packed_object, the callers either already work or are fixed in
this patch:
 - reachable - only to find recent objects
 - builtin/fsck - already knows about missing objects
 - builtin/cat-file - warning message added in this commit

Callers of the other functions do not need to be changed:
 - parse_pack_index
   - http - indirectly from http_get_info_packs
   - find_pack_entry_one
     - this searches a single pack that is provided as an argument; the
       caller already knows (through other means) that the sought object
       is in a specific pack
 - find_sha1_pack
   - fast-import - appears to be an optimization to not store a file if
     it is already in a pack
   - http-walker - to search through a struct alt_base
   - http-push - to search through remote packs
 - has_sha1_pack
   - builtin/fsck - already knows about promisor objects
   - builtin/count-objects - informational purposes only (check if loose
     object is also packed)
   - builtin/prune-packed - check if object to be pruned is packed (if
     not, don't prune it)
   - revision - used to exclude packed objects if requested by user
   - diff - just for optimization

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
---
 builtin/cat-file.c       |  2 ++
 builtin/fetch-pack.c     |  2 ++
 builtin/fsck.c           |  3 +++
 builtin/index-pack.c     |  6 ++++++
 cache.h                  |  8 ++++++++
 fetch-object.c           |  3 +++
 sha1_file.c              | 38 ++++++++++++++++++++++++------------
 t/t0410-partial-clone.sh | 51 ++++++++++++++++++++++++++++++++++++++++++++++++
 8 files changed, 100 insertions(+), 13 deletions(-)

diff --git a/builtin/cat-file.c b/builtin/cat-file.c
index f5fa4fd..cf9ea5c 100644
--- a/builtin/cat-file.c
+++ b/builtin/cat-file.c
@@ -475,6 +475,8 @@ static int batch_objects(struct batch_options *opt)
 
 		for_each_loose_object(batch_loose_object, &sa, 0);
 		for_each_packed_object(batch_packed_object, &sa, 0);
+		if (repository_format_partial_clone)
+			warning("This repository has extensions.partialClone set. Some objects may not be loaded.");
 
 		cb.opt = opt;
 		cb.expand = &data;
diff --git a/builtin/fetch-pack.c b/builtin/fetch-pack.c
index 9f303cf..9a7ebf6 100644
--- a/builtin/fetch-pack.c
+++ b/builtin/fetch-pack.c
@@ -53,6 +53,8 @@ int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 	struct oid_array shallow = OID_ARRAY_INIT;
 	struct string_list deepen_not = STRING_LIST_INIT_DUP;
 
+	fetch_if_missing = 0;
+
 	packet_trace_identity("fetch-pack");
 
 	memset(&args, 0, sizeof(args));
diff --git a/builtin/fsck.c b/builtin/fsck.c
index 578a7c8..3b76c0e 100644
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -678,6 +678,9 @@ int cmd_fsck(int argc, const char **argv, const char *prefix)
 	int i;
 	struct alternate_object_database *alt;
 
+	/* fsck knows how to handle missing promisor objects */
+	fetch_if_missing = 0;
+
 	errors_found = 0;
 	check_replace_refs = 0;
 
diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index 24c2f05..a0a35e6 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -1657,6 +1657,12 @@ int cmd_index_pack(int argc, const char **argv, const char *prefix)
 	unsigned foreign_nr = 1;	/* zero is a "good" value, assume bad */
 	int report_end_of_input = 0;
 
+	/*
+	 * index-pack never needs to fetch missing objects, since it only
+	 * accesses the repo to do hash collision checks
+	 */
+	fetch_if_missing = 0;
+
 	if (argc == 2 && !strcmp(argv[1], "-h"))
 		usage(index_pack_usage);
 
diff --git a/cache.h b/cache.h
index c76f2e9..6980072 100644
--- a/cache.h
+++ b/cache.h
@@ -1727,6 +1727,14 @@ struct object_info {
 #define OBJECT_INFO_QUICK 8
 extern int sha1_object_info_extended(const unsigned char *, struct object_info *, unsigned flags);
 
+/*
+ * Set this to 0 to prevent sha1_object_info_extended() from fetching missing
+ * blobs. This has a difference only if extensions.partialClone is set.
+ *
+ * Its default value is 1.
+ */
+extern int fetch_if_missing;
+
 /* Dumb servers support */
 extern int update_server_info(int);
 
diff --git a/fetch-object.c b/fetch-object.c
index f89dbba..369b61c 100644
--- a/fetch-object.c
+++ b/fetch-object.c
@@ -9,7 +9,9 @@ void fetch_object(const char *remote_name, const unsigned char *sha1)
 	struct remote *remote;
 	struct transport *transport;
 	struct ref *ref;
+	int original_fetch_if_missing = fetch_if_missing;
 
+	fetch_if_missing = 0;
 	remote = remote_get(remote_name);
 	if (!remote->url[0])
 		die(_("Remote with no URL"));
@@ -20,4 +22,5 @@ void fetch_object(const char *remote_name, const unsigned char *sha1)
 	transport_set_option(transport, TRANS_OPT_FROM_PROMISOR, "1");
 	transport_set_option(transport, TRANS_OPT_NO_HAVES, "1");
 	transport_fetch_refs(transport, ref);
+	fetch_if_missing = original_fetch_if_missing;
 }
diff --git a/sha1_file.c b/sha1_file.c
index 10c3a00..fc7718a 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -29,6 +29,7 @@
 #include "mergesort.h"
 #include "quote.h"
 #include "packfile.h"
+#include "fetch-object.h"
 
 const unsigned char null_sha1[GIT_MAX_RAWSZ];
 const struct object_id null_oid;
@@ -1144,6 +1145,8 @@ static int sha1_loose_object_info(const unsigned char *sha1,
 	return (status < 0) ? status : 0;
 }
 
+int fetch_if_missing = 1;
+
 int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi, unsigned flags)
 {
 	static struct object_info blank_oi = OBJECT_INFO_INIT;
@@ -1152,6 +1155,7 @@ int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi,
 	const unsigned char *real = (flags & OBJECT_INFO_LOOKUP_REPLACE) ?
 				    lookup_replace_object(sha1) :
 				    sha1;
+	int already_retried = 0;
 
 	if (!oi)
 		oi = &blank_oi;
@@ -1176,28 +1180,36 @@ int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi,
 		}
 	}
 
-	if (!find_pack_entry(real, &e)) {
-		/* Most likely it's a loose object. */
-		if (!sha1_loose_object_info(real, oi, flags))
-			return 0;
+retry:
+	if (find_pack_entry(real, &e))
+		goto found_packed;
 
-		/* Not a loose object; someone else may have just packed it. */
-		if (flags & OBJECT_INFO_QUICK) {
-			return -1;
-		} else {
-			reprepare_packed_git();
-			if (!find_pack_entry(real, &e))
-				return -1;
-		}
+	/* Most likely it's a loose object. */
+	if (!sha1_loose_object_info(real, oi, flags))
+		return 0;
+
+	/* Not a loose object; someone else may have just packed it. */
+	reprepare_packed_git();
+	if (find_pack_entry(real, &e))
+		goto found_packed;
+
+	/* Check if it is a missing object */
+	if (fetch_if_missing && repository_format_partial_clone &&
+	    !already_retried) {
+		fetch_object(repository_format_partial_clone, real);
+		already_retried = 1;
+		goto retry;
 	}
 
+	return -1;
+
+found_packed:
 	if (oi == &blank_oi)
 		/*
 		 * We know that the caller doesn't actually need the
 		 * information below, so return early.
 		 */
 		return 0;
-
 	rtype = packed_object_info(e.p, e.offset, oi);
 	if (rtype < 0) {
 		mark_bad_packed_object(e.p, real);
diff --git a/t/t0410-partial-clone.sh b/t/t0410-partial-clone.sh
index e96f436..8a90f6a 100755
--- a/t/t0410-partial-clone.sh
+++ b/t/t0410-partial-clone.sh
@@ -138,4 +138,55 @@ test_expect_success 'missing CLI object, but promised, passes fsck' '
 	git -C repo fsck "$A"
 '
 
+test_expect_success 'fetching of missing objects' '
+	rm -rf repo &&
+	test_create_repo server &&
+	test_commit -C server foo &&
+	git -C server repack -a -d --write-bitmap-index &&
+
+	git clone "file://$(pwd)/server" repo &&
+	HASH=$(git -C repo rev-parse foo) &&
+	rm -rf repo/.git/objects/* &&
+
+	git -C repo config core.repositoryformatversion 1 &&
+	git -C repo config extensions.partialclone "origin" &&
+	git -C repo cat-file -p "$HASH" &&
+
+	# Ensure that the .promisor file is written, and check that its
+	# associated packfile contains the object
+	ls repo/.git/objects/pack/pack-*.promisor >promisorlist &&
+	test_line_count = 1 promisorlist &&
+	IDX=$(cat promisorlist | sed "s/promisor$/idx/") &&
+	git verify-pack --verbose "$IDX" | grep "$HASH"
+'
+
+LIB_HTTPD_PORT=12345  # default port, 410, cannot be used as non-root
+. "$TEST_DIRECTORY"/lib-httpd.sh
+start_httpd
+
+test_expect_success 'fetching of missing objects from an HTTP server' '
+	rm -rf repo &&
+	SERVER="$HTTPD_DOCUMENT_ROOT_PATH/server" &&
+	test_create_repo "$SERVER" &&
+	test_commit -C "$SERVER" foo &&
+	git -C "$SERVER" repack -a -d --write-bitmap-index &&
+
+	git clone $HTTPD_URL/smart/server repo &&
+	HASH=$(git -C repo rev-parse foo) &&
+	rm -rf repo/.git/objects/* &&
+
+	git -C repo config core.repositoryformatversion 1 &&
+	git -C repo config extensions.partialclone "origin" &&
+	git -C repo cat-file -p "$HASH" &&
+
+	# Ensure that the .promisor file is written, and check that its
+	# associated packfile contains the object
+	ls repo/.git/objects/pack/pack-*.promisor >promisorlist &&
+	test_line_count = 1 promisorlist &&
+	IDX=$(cat promisorlist | sed "s/promisor$/idx/") &&
+	git verify-pack --verbose "$IDX" | grep "$HASH"
+'
+
+stop_httpd
+
 test_done
-- 
2.9.3

[PATCH v4 09/10] rev-list: support termination at promisor objects

[Jeff Hostetler]

From: Jonathan Tan <jonathantanmy@google.com>

Teach rev-list to support termination of an object traversal at any
object from a promisor remote (whether one that the local repo also has,
or one that the local repo knows about because it has another promisor
object that references it).

This will be used subsequently in gc and in the connectivity check used
by fetch.

For efficiency, if an object is referenced by a promisor object, and is
in the local repo only as a non-promisor object, object traversal will
not stop there. This is to avoid building the list of promisor object
references.

(In list-objects.c, the case where obj is NULL in process_blob() and
process_tree() do not need to be changed because those happen only when
there is a conflict between the expected type and the existing object.
If the object doesn't exist, an object will be synthesized, which is
fine.)

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 Documentation/rev-list-options.txt |  12 ++++-
 builtin/rev-list.c                 |  74 ++++++++++++++++++++++++---
 list-objects.c                     |  29 ++++++++++-
 object.c                           |   2 +-
 revision.c                         |  33 +++++++++++-
 revision.h                         |   5 +-
 t/t0410-partial-clone.sh           | 101 +++++++++++++++++++++++++++++++++++++
 7 files changed, 243 insertions(+), 13 deletions(-)

diff --git a/Documentation/rev-list-options.txt b/Documentation/rev-list-options.txt
index c84e465..2beffe3 100644
--- a/Documentation/rev-list-options.txt
+++ b/Documentation/rev-list-options.txt
@@ -730,7 +730,7 @@ specification contained in <path>.
 	Only useful with `--filter=`; prints a list of the omitted objects.
 	Object IDs are prefixed with a ``~'' character.
 
---missing=(error|allow-any|print)::
+--missing=(error|allow-any|allow-promisor|print)::
 	Specifies how missing objects are handled.  The repository may
 	have missing objects after a partial clone, for example.
 +
@@ -741,10 +741,20 @@ The value 'allow-any' will allow object traversal to continue if a
 missing object is encountered.  Missing objects will silently be omitted
 from the results.
 +
+The value 'allow-promisor' is like 'allow-any' in that it will allow
+object traversal to continue, but only for EXPECTED missing objects.
++
 The value 'print' is like 'allow-any', but will also print a list of the
 missing objects.  Object IDs are prefixed with a ``?'' character.
 endif::git-rev-list[]
 
+--exclude-promisor-objects::
+	(For internal use only.)  Prefilter object traversal at
+	promisor boundary.  This is used with partial clone.  This is
+	stronger than `--missing=allow-promisor` because it limits the
+	traversal, rather than just silencing errors about missing
+	objects.
+
 --no-walk[=(sorted|unsorted)]::
 	Only show the given commits, but do not traverse their ancestors.
 	This has no effect if a range is specified. If the argument
diff --git a/builtin/rev-list.c b/builtin/rev-list.c
index da4a39b..d144d66 100644
--- a/builtin/rev-list.c
+++ b/builtin/rev-list.c
@@ -15,6 +15,7 @@
 #include "progress.h"
 #include "reflog-walk.h"
 #include "oidset.h"
+#include "packfile.h"
 
 static const char rev_list_usage[] =
 "git rev-list [OPTION] <commit-id>... [ -- paths... ]\n"
@@ -67,6 +68,7 @@ enum missing_action {
 	MA_ERROR = 0,    /* fail if any missing objects are encountered */
 	MA_ALLOW_ANY,    /* silently allow ALL missing objects */
 	MA_PRINT,        /* print ALL missing objects in special section */
+	MA_ALLOW_PROMISOR, /* silently allow all missing PROMISOR objects */
 };
 static enum missing_action arg_missing_action;
 
@@ -197,6 +199,12 @@ static void finish_commit(struct commit *commit, void *data)
 
 static inline void finish_object__ma(struct object *obj)
 {
+	/*
+	 * Whether or not we try to dynamically fetch missing objects
+	 * from the server, we currently DO NOT have the object.  We
+	 * can either print, allow (ignore), or conditionally allow
+	 * (ignore) them.
+	 */
 	switch (arg_missing_action) {
 	case MA_ERROR:
 		die("missing blob object '%s'", oid_to_hex(&obj->oid));
@@ -209,25 +217,36 @@ static inline void finish_object__ma(struct object *obj)
 		oidset_insert(&missing_objects, &obj->oid);
 		return;
 
+	case MA_ALLOW_PROMISOR:
+		if (is_promisor_object(&obj->oid))
+			return;
+		die("unexpected missing blob object '%s'",
+		    oid_to_hex(&obj->oid));
+		return;
+
 	default:
 		BUG("unhandled missing_action");
 		return;
 	}
 }
 
-static void finish_object(struct object *obj, const char *name, void *cb_data)
+static int finish_object(struct object *obj, const char *name, void *cb_data)
 {
 	struct rev_list_info *info = cb_data;
-	if (obj->type == OBJ_BLOB && !has_object_file(&obj->oid))
+	if (obj->type == OBJ_BLOB && !has_object_file(&obj->oid)) {
 		finish_object__ma(obj);
+		return 1;
+	}
 	if (info->revs->verify_objects && !obj->parsed && obj->type != OBJ_COMMIT)
 		parse_object(&obj->oid);
+	return 0;
 }
 
 static void show_object(struct object *obj, const char *name, void *cb_data)
 {
 	struct rev_list_info *info = cb_data;
-	finish_object(obj, name, cb_data);
+	if (finish_object(obj, name, cb_data))
+		return;
 	display_progress(progress, ++progress_counter);
 	if (info->flags & REV_LIST_QUIET)
 		return;
@@ -315,11 +334,19 @@ static inline int parse_missing_action_value(const char *value)
 
 	if (!strcmp(value, "allow-any")) {
 		arg_missing_action = MA_ALLOW_ANY;
+		fetch_if_missing = 0;
 		return 1;
 	}
 
 	if (!strcmp(value, "print")) {
 		arg_missing_action = MA_PRINT;
+		fetch_if_missing = 0;
+		return 1;
+	}
+
+	if (!strcmp(value, "allow-promisor")) {
+		arg_missing_action = MA_ALLOW_PROMISOR;
+		fetch_if_missing = 0;
 		return 1;
 	}
 
@@ -344,6 +371,38 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix)
 	init_revisions(&revs, prefix);
 	revs.abbrev = DEFAULT_ABBREV;
 	revs.commit_format = CMIT_FMT_UNSPECIFIED;
+
+	/*
+	 * Scan the argument list before invoking setup_revisions(), so that we
+	 * know if fetch_if_missing needs to be set to 0.
+	 *
+	 * "--exclude-promisor-objects" acts as a pre-filter on missing objects
+	 * by not crossing the boundary from realized objects to promisor
+	 * objects.  This overrides any "--missing" value.  For consistency in
+	 * our variables, we force MA_ALLOW_PROMISOR knowning that list-objects
+	 * should not touch other missing objects unless there is an error.
+	 *
+	 * Otherwise, let "--missing" to conditionally set fetch_if_missing.
+	 */
+	for (i = 1; i < argc; i++) {
+		const char *arg = argv[i];
+		if (!strcmp(arg, "--exclude-promisor-objects")) {
+			fetch_if_missing = 0;
+			revs.exclude_promisor_objects = 1;
+			arg_missing_action = MA_ALLOW_PROMISOR;
+			break;
+		}
+	}
+	for (i = 1; i < argc; i++) {
+		const char *arg = argv[i];
+		if (skip_prefix(arg, "--missing=", &arg)) {
+			if (revs.exclude_promisor_objects)
+				die(_("cannot combine --exclude-promisor-objects and --missing"));
+			if (parse_missing_action_value(arg))
+				break;
+		}
+	}
+
 	argc = setup_revisions(argc, argv, &revs, NULL);
 
 	memset(&info, 0, sizeof(info));
@@ -408,10 +467,11 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix)
 			continue;
 		}
 
-		if (skip_prefix(arg, "--missing=", &arg) &&
-		    parse_missing_action_value(arg))
-			continue;
-		
+		if (!strcmp(arg, "--exclude-promisor-objects"))
+			continue; /* already handled above */
+		if (skip_prefix(arg, "--missing=", &arg))
+			continue; /* already handled above */
+
 		usage(rev_list_usage);
 
 	}
diff --git a/list-objects.c b/list-objects.c
index d9e83d0..58621fc 100644
--- a/list-objects.c
+++ b/list-objects.c
@@ -9,6 +9,7 @@
 #include "list-objects.h"
 #include "list-objects-filter.h"
 #include "list-objects-filter-options.h"
+#include "packfile.h"
 
 static void process_blob(struct rev_info *revs,
 			 struct blob *blob,
@@ -30,6 +31,20 @@ static void process_blob(struct rev_info *revs,
 	if (obj->flags & (UNINTERESTING | SEEN))
 		return;
 
+	/*
+	 * Pre-filter known-missing objects when explicitly requested.
+	 * Otherwise, a missing object error message may be reported
+	 * later (depending on other filtering criteria).
+	 *
+	 * Note that this "--exclude-promisor-objects" pre-filtering
+	 * may cause the actual filter to report an incomplete list
+	 * of missing objects.
+	 */
+	if (revs->exclude_promisor_objects &&
+	    !has_object_file(&obj->oid) &&
+	    is_promisor_object(&obj->oid))
+		return;
+
 	pathlen = path->len;
 	strbuf_addstr(path, name);
 	if (filter_fn)
@@ -91,6 +106,8 @@ static void process_tree(struct rev_info *revs,
 		all_entries_interesting: entry_not_interesting;
 	int baselen = base->len;
 	enum list_objects_filter_result r = LOFR_MARK_SEEN | LOFR_DO_SHOW;
+	int gently = revs->ignore_missing_links ||
+		     revs->exclude_promisor_objects;
 
 	if (!revs->tree_objects)
 		return;
@@ -98,9 +115,19 @@ static void process_tree(struct rev_info *revs,
 		die("bad tree object");
 	if (obj->flags & (UNINTERESTING | SEEN))
 		return;
-	if (parse_tree_gently(tree, revs->ignore_missing_links) < 0) {
+	if (parse_tree_gently(tree, gently) < 0) {
 		if (revs->ignore_missing_links)
 			return;
+
+		/*
+		 * Pre-filter known-missing tree objects when explicitly
+		 * requested.  This may cause the actual filter to report
+		 * an incomplete list of missing objects.
+		 */
+		if (revs->exclude_promisor_objects &&
+		    is_promisor_object(&obj->oid))
+			return;
+
 		die("bad tree object %s", oid_to_hex(&obj->oid));
 	}
 
diff --git a/object.c b/object.c
index b9a4a0e..4c222d6 100644
--- a/object.c
+++ b/object.c
@@ -252,7 +252,7 @@ struct object *parse_object(const struct object_id *oid)
 	if (obj && obj->parsed)
 		return obj;
 
-	if ((obj && obj->type == OBJ_BLOB) ||
+	if ((obj && obj->type == OBJ_BLOB && has_object_file(oid)) ||
 	    (!obj && has_object_file(oid) &&
 	     sha1_object_info(oid->hash, NULL) == OBJ_BLOB)) {
 		if (check_sha1_signature(repl, NULL, 0, NULL) < 0) {
diff --git a/revision.c b/revision.c
index d167223..05a7aac 100644
--- a/revision.c
+++ b/revision.c
@@ -198,6 +198,8 @@ static struct object *get_reference(struct rev_info *revs, const char *name,
 	if (!object) {
 		if (revs->ignore_missing)
 			return object;
+		if (revs->exclude_promisor_objects && is_promisor_object(oid))
+			return NULL;
 		die("bad object %s", name);
 	}
 	object->flags |= flags;
@@ -790,9 +792,17 @@ static int add_parents_to_list(struct rev_info *revs, struct commit *commit,
 
 	for (parent = commit->parents; parent; parent = parent->next) {
 		struct commit *p = parent->item;
-
-		if (parse_commit_gently(p, revs->ignore_missing_links) < 0)
+		int gently = revs->ignore_missing_links ||
+			     revs->exclude_promisor_objects;
+		if (parse_commit_gently(p, gently) < 0) {
+			if (revs->exclude_promisor_objects &&
+			    is_promisor_object(&p->object.oid)) {
+				if (revs->first_parent_only)
+					break;
+				continue;
+			}
 			return -1;
+		}
 		if (revs->show_source && !p->util)
 			p->util = commit->util;
 		p->object.flags |= left_flag;
@@ -2088,6 +2098,10 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
 		revs->limited = 1;
 	} else if (!strcmp(arg, "--ignore-missing")) {
 		revs->ignore_missing = 1;
+	} else if (!strcmp(arg, "--exclude-promisor-objects")) {
+		if (fetch_if_missing)
+			die("BUG: exclude_promisor_objects can only be used when fetch_if_missing is 0");
+		revs->exclude_promisor_objects = 1;
 	} else {
 		int opts = diff_opt_parse(&revs->diffopt, argv, argc, revs->prefix);
 		if (!opts)
@@ -2830,6 +2844,16 @@ void reset_revision_walk(void)
 	clear_object_flags(SEEN | ADDED | SHOWN);
 }
 
+static int mark_uninteresting(const struct object_id *oid,
+			      struct packed_git *pack,
+			      uint32_t pos,
+			      void *unused)
+{
+	struct object *o = parse_object(oid);
+	o->flags |= UNINTERESTING | SEEN;
+	return 0;
+}
+
 int prepare_revision_walk(struct rev_info *revs)
 {
 	int i;
@@ -2858,6 +2882,11 @@ int prepare_revision_walk(struct rev_info *revs)
 	    (revs->limited && limiting_can_increase_treesame(revs)))
 		revs->treesame.name = "treesame";
 
+	if (revs->exclude_promisor_objects) {
+		for_each_packed_object(mark_uninteresting, NULL,
+				       FOR_EACH_OBJECT_PROMISOR_ONLY);
+	}
+
 	if (revs->no_walk != REVISION_WALK_NO_WALK_UNSORTED)
 		commit_list_sort_by_date(&revs->commits);
 	if (revs->no_walk)
diff --git a/revision.h b/revision.h
index 5476120..5f9a49c 100644
--- a/revision.h
+++ b/revision.h
@@ -121,7 +121,10 @@ struct rev_info {
 			bisect:1,
 			ancestry_path:1,
 			first_parent_only:1,
-			line_level_traverse:1;
+			line_level_traverse:1,
+
+			/* for internal use only */
+			exclude_promisor_objects:1;
 
 	/* Diff flags */
 	unsigned int	diff:1,
diff --git a/t/t0410-partial-clone.sh b/t/t0410-partial-clone.sh
index 8a90f6a..3ca6af5 100755
--- a/t/t0410-partial-clone.sh
+++ b/t/t0410-partial-clone.sh
@@ -160,6 +160,107 @@ test_expect_success 'fetching of missing objects' '
 	git verify-pack --verbose "$IDX" | grep "$HASH"
 '
 
+test_expect_success 'rev-list stops traversal at missing and promised commit' '
+	rm -rf repo &&
+	test_create_repo repo &&
+	test_commit -C repo foo &&
+	test_commit -C repo bar &&
+
+	FOO=$(git -C repo rev-parse foo) &&
+	promise_and_delete "$FOO" &&
+
+	git -C repo config core.repositoryformatversion 1 &&
+	git -C repo config extensions.partialclone "arbitrary string" &&
+	git -C repo rev-list --exclude-promisor-objects --objects bar >out &&
+	grep $(git -C repo rev-parse bar) out &&
+	! grep $FOO out
+'
+
+test_expect_success 'rev-list stops traversal at missing and promised tree' '
+	rm -rf repo &&
+	test_create_repo repo &&
+	test_commit -C repo foo &&
+	mkdir repo/a_dir &&
+	echo something >repo/a_dir/something &&
+	git -C repo add a_dir/something &&
+	git -C repo commit -m bar &&
+
+	# foo^{tree} (tree referenced from commit)
+	TREE=$(git -C repo rev-parse foo^{tree}) &&
+
+	# a tree referenced by HEAD^{tree} (tree referenced from tree)
+	TREE2=$(git -C repo ls-tree HEAD^{tree} | grep " tree " | head -1 | cut -b13-52) &&
+
+	promise_and_delete "$TREE" &&
+	promise_and_delete "$TREE2" &&
+
+	git -C repo config core.repositoryformatversion 1 &&
+	git -C repo config extensions.partialclone "arbitrary string" &&
+	git -C repo rev-list --exclude-promisor-objects --objects HEAD >out &&
+	grep $(git -C repo rev-parse foo) out &&
+	! grep $TREE out &&
+	grep $(git -C repo rev-parse HEAD) out &&
+	! grep $TREE2 out
+'
+
+test_expect_success 'rev-list stops traversal at missing and promised blob' '
+	rm -rf repo &&
+	test_create_repo repo &&
+	echo something >repo/something &&
+	git -C repo add something &&
+	git -C repo commit -m foo &&
+
+	BLOB=$(git -C repo hash-object -w something) &&
+	promise_and_delete "$BLOB" &&
+
+	git -C repo config core.repositoryformatversion 1 &&
+	git -C repo config extensions.partialclone "arbitrary string" &&
+	git -C repo rev-list --exclude-promisor-objects --objects HEAD >out &&
+	grep $(git -C repo rev-parse HEAD) out &&
+	! grep $BLOB out
+'
+
+test_expect_success 'rev-list stops traversal at promisor commit, tree, and blob' '
+	rm -rf repo &&
+	test_create_repo repo &&
+	test_commit -C repo foo &&
+	test_commit -C repo bar &&
+	test_commit -C repo baz &&
+
+	COMMIT=$(git -C repo rev-parse foo) &&
+	TREE=$(git -C repo rev-parse bar^{tree}) &&
+	BLOB=$(git hash-object repo/baz.t) &&
+	printf "%s\n%s\n%s\n" $COMMIT $TREE $BLOB | pack_as_from_promisor &&
+
+	git -C repo config core.repositoryformatversion 1 &&
+	git -C repo config extensions.partialclone "arbitrary string" &&
+	git -C repo rev-list --exclude-promisor-objects --objects HEAD >out &&
+	! grep $COMMIT out &&
+	! grep $TREE out &&
+	! grep $BLOB out &&
+	grep $(git -C repo rev-parse bar) out  # sanity check that some walking was done
+'
+
+test_expect_success 'rev-list accepts missing and promised objects on command line' '
+	rm -rf repo &&
+	test_create_repo repo &&
+	test_commit -C repo foo &&
+	test_commit -C repo bar &&
+	test_commit -C repo baz &&
+
+	COMMIT=$(git -C repo rev-parse foo) &&
+	TREE=$(git -C repo rev-parse bar^{tree}) &&
+	BLOB=$(git hash-object repo/baz.t) &&
+
+	promise_and_delete $COMMIT &&
+	promise_and_delete $TREE &&
+	promise_and_delete $BLOB &&
+
+	git -C repo config core.repositoryformatversion 1 &&
+	git -C repo config extensions.partialclone "arbitrary string" &&
+	git -C repo rev-list --exclude-promisor-objects --objects "$COMMIT" "$TREE" "$BLOB"
+'
+
 LIB_HTTPD_PORT=12345  # default port, 410, cannot be used as non-root
 . "$TEST_DIRECTORY"/lib-httpd.sh
 start_httpd
-- 
2.9.3

[PATCH v4 10/10] gc: do not repack promisor packfiles

[Jeff Hostetler]

From: Jonathan Tan <jonathantanmy@google.com>

Teach gc to stop traversal at promisor objects, and to leave promisor
packfiles alone. This has the effect of only repacking non-promisor
packfiles, and preserves the distinction between promisor packfiles and
non-promisor packfiles.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
---
 Documentation/git-pack-objects.txt | 12 ++++++++-
 builtin/gc.c                       |  3 +++
 builtin/pack-objects.c             | 36 ++++++++++++++++++++++++++
 builtin/prune.c                    |  7 +++++
 builtin/repack.c                   |  8 ++++--
 t/t0410-partial-clone.sh           | 52 +++++++++++++++++++++++++++++++++++++-
 6 files changed, 114 insertions(+), 4 deletions(-)

diff --git a/Documentation/git-pack-objects.txt b/Documentation/git-pack-objects.txt
index 5fad696..33a824e 100644
--- a/Documentation/git-pack-objects.txt
+++ b/Documentation/git-pack-objects.txt
@@ -242,9 +242,19 @@ So does `git bundle` (see linkgit:git-bundle[1]) when it creates a bundle.
 	the resulting packfile.  See linkgit:git-rev-list[1] for valid
 	`<filter-spec>` forms.
 
---missing=(error|allow-any):
+--missing=(error|allow-any|allow-promisor):
 	Specifies how missing objects are handled.  This is useful, for
 	example, when there are missing objects from a prior partial clone.
+	This is stronger than `--missing=allow-promisor` because it limits
+	the traversal, rather than just silencing errors about missing
+	objects.
+
+--exclude-promisor-objects::
+	Omit objects that are known to be in the promisor remote". (This
+	option has the purpose of operating only on locally created objects,
+	so that when we repack, we still maintain a distinction between
+	locally created objects [without .promisor] and objects from the
+	promisor remote [with .promisor].)  This is used with partial clone.
 
 SEE ALSO
 --------
diff --git a/builtin/gc.c b/builtin/gc.c
index 3c5eae0..77fa720 100644
--- a/builtin/gc.c
+++ b/builtin/gc.c
@@ -458,6 +458,9 @@ int cmd_gc(int argc, const char **argv, const char *prefix)
 			argv_array_push(&prune, prune_expire);
 			if (quiet)
 				argv_array_push(&prune, "--no-progress");
+			if (repository_format_partial_clone)
+				argv_array_push(&prune,
+						"--exclude-promisor-objects");
 			if (run_command_v_opt(prune.argv, RUN_GIT_CMD))
 				return error(FAILED_RUN, prune.argv[0]);
 		}
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index 45ad35d..4534209 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -75,6 +75,8 @@ static int use_bitmap_index = -1;
 static int write_bitmap_index;
 static uint16_t write_bitmap_options;
 
+static int exclude_promisor_objects;
+
 static unsigned long delta_cache_size = 0;
 static unsigned long max_delta_cache_size = 256 * 1024 * 1024;
 static unsigned long cache_max_small_delta_size = 1000;
@@ -86,6 +88,7 @@ static struct list_objects_filter_options filter_options;
 enum missing_action {
 	MA_ERROR = 0,    /* fail if any missing objects are encountered */
 	MA_ALLOW_ANY,    /* silently allow ALL missing objects */
+	MA_ALLOW_PROMISOR, /* silently allow all missing PROMISOR objects */
 };
 static enum missing_action arg_missing_action;
 static show_object_fn fn_show_object;
@@ -2577,6 +2580,20 @@ static void show_object__ma_allow_any(struct object *obj, const char *name, void
 	show_object(obj, name, data);
 }
 
+static void show_object__ma_allow_promisor(struct object *obj, const char *name, void *data)
+{
+	assert(arg_missing_action == MA_ALLOW_PROMISOR);
+
+	/*
+	 * Quietly ignore EXPECTED missing objects.  This avoids problems with
+	 * staging them now and getting an odd error later.
+	 */
+	if (!has_object_file(&obj->oid) && is_promisor_object(&obj->oid))
+		return;
+
+	show_object(obj, name, data);
+}
+
 static int option_parse_missing_action(const struct option *opt,
 				       const char *arg, int unset)
 {
@@ -2591,10 +2608,18 @@ static int option_parse_missing_action(const struct option *opt,
 
 	if (!strcmp(arg, "allow-any")) {
 		arg_missing_action = MA_ALLOW_ANY;
+		fetch_if_missing = 0;
 		fn_show_object = show_object__ma_allow_any;
 		return 0;
 	}
 
+	if (!strcmp(arg, "allow-promisor")) {
+		arg_missing_action = MA_ALLOW_PROMISOR;
+		fetch_if_missing = 0;
+		fn_show_object = show_object__ma_allow_promisor;
+		return 0;
+	}
+
 	die(_("invalid value for --missing"));
 	return 0;
 }
@@ -3008,6 +3033,8 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 		{ OPTION_CALLBACK, 0, "missing", NULL, N_("action"),
 		  N_("handling for missing objects"), PARSE_OPT_NONEG,
 		  option_parse_missing_action },
+		OPT_BOOL(0, "exclude-promisor-objects", &exclude_promisor_objects,
+			 N_("do not pack objects in promisor packfiles")),
 		OPT_END(),
 	};
 
@@ -3053,6 +3080,15 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 		argv_array_push(&rp, "--unpacked");
 	}
 
+	if (exclude_promisor_objects) {
+		use_internal_rev_list = 1;
+		fetch_if_missing = 0;
+		argv_array_push(&rp, "--exclude-promisor-objects");
+		/* silently override any "--missing=" value */
+		arg_missing_action = MA_ALLOW_PROMISOR;
+		fn_show_object = show_object__ma_allow_promisor;
+	}
+
 	if (!reuse_object)
 		reuse_delta = 0;
 	if (pack_compression_level == -1)
diff --git a/builtin/prune.c b/builtin/prune.c
index cddabf2..be34645 100644
--- a/builtin/prune.c
+++ b/builtin/prune.c
@@ -101,12 +101,15 @@ int cmd_prune(int argc, const char **argv, const char *prefix)
 {
 	struct rev_info revs;
 	struct progress *progress = NULL;
+	int exclude_promisor_objects = 0;
 	const struct option options[] = {
 		OPT__DRY_RUN(&show_only, N_("do not remove, show only")),
 		OPT__VERBOSE(&verbose, N_("report pruned objects")),
 		OPT_BOOL(0, "progress", &show_progress, N_("show progress")),
 		OPT_EXPIRY_DATE(0, "expire", &expire,
 				N_("expire objects older than <time>")),
+		OPT_BOOL(0, "exclude-promisor-objects", &exclude_promisor_objects,
+			 N_("limit traversal to objects outside promisor packfiles")),
 		OPT_END()
 	};
 	char *s;
@@ -139,6 +142,10 @@ int cmd_prune(int argc, const char **argv, const char *prefix)
 		show_progress = isatty(2);
 	if (show_progress)
 		progress = start_delayed_progress(_("Checking connectivity"), 0);
+	if (exclude_promisor_objects) {
+		fetch_if_missing = 0;
+		revs.exclude_promisor_objects = 1;
+	}
 
 	mark_reachable_objects(&revs, 1, expire, progress);
 	stop_progress(&progress);
diff --git a/builtin/repack.c b/builtin/repack.c
index f17a68a..7bdb401 100644
--- a/builtin/repack.c
+++ b/builtin/repack.c
@@ -83,7 +83,8 @@ static void remove_pack_on_signal(int signo)
 
 /*
  * Adds all packs hex strings to the fname list, which do not
- * have a corresponding .keep file.
+ * have a corresponding .keep or .promisor file. These packs are not to
+ * be kept if we are going to pack everything into one file.
  */
 static void get_non_kept_pack_filenames(struct string_list *fname_list)
 {
@@ -101,7 +102,8 @@ static void get_non_kept_pack_filenames(struct string_list *fname_list)
 
 		fname = xmemdupz(e->d_name, len);
 
-		if (!file_exists(mkpath("%s/%s.keep", packdir, fname)))
+		if (!file_exists(mkpath("%s/%s.keep", packdir, fname)) &&
+		    !file_exists(mkpath("%s/%s.promisor", packdir, fname)))
 			string_list_append_nodup(fname_list, fname);
 		else
 			free(fname);
@@ -232,6 +234,8 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 	argv_array_push(&cmd.args, "--all");
 	argv_array_push(&cmd.args, "--reflog");
 	argv_array_push(&cmd.args, "--indexed-objects");
+	if (repository_format_partial_clone)
+		argv_array_push(&cmd.args, "--exclude-promisor-objects");
 	if (window)
 		argv_array_pushf(&cmd.args, "--window=%s", window);
 	if (window_memory)
diff --git a/t/t0410-partial-clone.sh b/t/t0410-partial-clone.sh
index 3ca6af5..071736c 100755
--- a/t/t0410-partial-clone.sh
+++ b/t/t0410-partial-clone.sh
@@ -11,13 +11,15 @@ delete_object () {
 pack_as_from_promisor () {
 	HASH=$(git -C repo pack-objects .git/objects/pack/pack) &&
 	>repo/.git/objects/pack/pack-$HASH.promisor
+	echo $HASH
 }
 
 promise_and_delete () {
 	HASH=$(git -C repo rev-parse "$1") &&
 	git -C repo tag -a -m message my_annotated_tag "$HASH" &&
 	git -C repo rev-parse my_annotated_tag | pack_as_from_promisor &&
-	git -C repo tag -d my_annotated_tag &&
+	# tag -d prints a message to stdout, so redirect it
+	git -C repo tag -d my_annotated_tag >/dev/null &&
 	delete_object repo "$HASH"
 }
 
@@ -261,6 +263,54 @@ test_expect_success 'rev-list accepts missing and promised objects on command li
 	git -C repo rev-list --exclude-promisor-objects --objects "$COMMIT" "$TREE" "$BLOB"
 '
 
+test_expect_success 'gc does not repack promisor objects' '
+	rm -rf repo &&
+	test_create_repo repo &&
+	test_commit -C repo my_commit &&
+
+	TREE_HASH=$(git -C repo rev-parse HEAD^{tree}) &&
+	HASH=$(printf "$TREE_HASH\n" | pack_as_from_promisor) &&
+
+	git -C repo config core.repositoryformatversion 1 &&
+	git -C repo config extensions.partialclone "arbitrary string" &&
+	git -C repo gc &&
+
+	# Ensure that the promisor packfile still exists, and remove it
+	test -e repo/.git/objects/pack/pack-$HASH.pack &&
+	rm repo/.git/objects/pack/pack-$HASH.* &&
+
+	# Ensure that the single other pack contains the commit, but not the tree
+	ls repo/.git/objects/pack/pack-*.pack >packlist &&
+	test_line_count = 1 packlist &&
+	git verify-pack repo/.git/objects/pack/pack-*.pack -v >out &&
+	grep "$(git -C repo rev-parse HEAD)" out &&
+	! grep "$TREE_HASH" out
+'
+
+test_expect_success 'gc stops traversal when a missing but promised object is reached' '
+	rm -rf repo &&
+	test_create_repo repo &&
+	test_commit -C repo my_commit &&
+
+	TREE_HASH=$(git -C repo rev-parse HEAD^{tree}) &&
+	HASH=$(promise_and_delete $TREE_HASH) &&
+
+	git -C repo config core.repositoryformatversion 1 &&
+	git -C repo config extensions.partialclone "arbitrary string" &&
+	git -C repo gc &&
+
+	# Ensure that the promisor packfile still exists, and remove it
+	test -e repo/.git/objects/pack/pack-$HASH.pack &&
+	rm repo/.git/objects/pack/pack-$HASH.* &&
+
+	# Ensure that the single other pack contains the commit, but not the tree
+	ls repo/.git/objects/pack/pack-*.pack >packlist &&
+	test_line_count = 1 packlist &&
+	git verify-pack repo/.git/objects/pack/pack-*.pack -v >out &&
+	grep "$(git -C repo rev-parse HEAD)" out &&
+	! grep "$TREE_HASH" out
+'
+
 LIB_HTTPD_PORT=12345  # default port, 410, cannot be used as non-root
 . "$TEST_DIRECTORY"/lib-httpd.sh
 start_httpd
-- 
2.9.3

Re: [PATCH v4 00/10] Partial clone part 2: fsck and promisors

[Jonathan Tan]

I patched both this series and the first 9 patches of mine [1] on part 1
of the entire partial clone implementation [2], and then
diffed them. I'll review just the differences between the two.

You can see the entire diff below (minus means in my patch set but not
in Jeff's, plus means the contrary) - I did not trim it.

[1] https://public-inbox.org/git/cover.1506714999.git.jonathantanmy@google.com/
[2] https://public-inbox.org/git/20171116180743.61353-1-git@jeffhostetler.com/T/#t

> diff --git a/Documentation/git-pack-objects.txt b/Documentation/git-pack-objects.txt
> index 5fad696c5..33a824eed 100644
> --- a/Documentation/git-pack-objects.txt
> +++ b/Documentation/git-pack-objects.txt
> @@ -242,9 +242,19 @@ So does `git bundle` (see linkgit:git-bundle[1]) when it creates a bundle.
>  	the resulting packfile.  See linkgit:git-rev-list[1] for valid
>  	`<filter-spec>` forms.
>  
> ---missing=(error|allow-any):
> +--missing=(error|allow-any|allow-promisor):
>  	Specifies how missing objects are handled.  This is useful, for
>  	example, when there are missing objects from a prior partial clone.
> +	This is stronger than `--missing=allow-promisor` because it limits
> +	the traversal, rather than just silencing errors about missing
> +	objects.

What is stronger than `--missing=allow-promisor`?

> +
> +--exclude-promisor-objects::
> +	Omit objects that are known to be in the promisor remote". (This

Stray quote.

> +	option has the purpose of operating only on locally created objects,
> +	so that when we repack, we still maintain a distinction between
> +	locally created objects [without .promisor] and objects from the
> +	promisor remote [with .promisor].)  This is used with partial clone.
>  
>  SEE ALSO
>  --------
> diff --git a/Documentation/gitremote-helpers.txt b/Documentation/gitremote-helpers.txt
> index 4a584f3c5..1ceab8944 100644
> --- a/Documentation/gitremote-helpers.txt
> +++ b/Documentation/gitremote-helpers.txt
> @@ -466,6 +466,12 @@ set by Git if the remote helper has the 'option' capability.
>  	Transmit <string> as a push option. As the push option
>  	must not contain LF or NUL characters, the string is not encoded.
>  
> +'option from-promisor' {'true'|'false'}::
> +	Indicate that these objects are being fetch by a promisor.

Should be: ...are being fetched from a promisor.

> +
> +'option no-haves' {'true'|'false'}::
> +	Do not send "have" lines.
> +
>  SEE ALSO
>  --------
>  linkgit:git-remote[1]
> diff --git a/Documentation/rev-list-options.txt b/Documentation/rev-list-options.txt
> index c84e46522..2beffe320 100644
> --- a/Documentation/rev-list-options.txt
> +++ b/Documentation/rev-list-options.txt
> @@ -730,7 +730,7 @@ specification contained in <path>.
>  	Only useful with `--filter=`; prints a list of the omitted objects.
>  	Object IDs are prefixed with a ``~'' character.
>  
> ---missing=(error|allow-any|print)::
> +--missing=(error|allow-any|allow-promisor|print)::
>  	Specifies how missing objects are handled.  The repository may
>  	have missing objects after a partial clone, for example.
>  +
> @@ -741,10 +741,20 @@ The value 'allow-any' will allow object traversal to continue if a
>  missing object is encountered.  Missing objects will silently be omitted
>  from the results.
>  +
> +The value 'allow-promisor' is like 'allow-any' in that it will allow
> +object traversal to continue, but only for EXPECTED missing objects.
> ++
>  The value 'print' is like 'allow-any', but will also print a list of the
>  missing objects.  Object IDs are prefixed with a ``?'' character.
>  endif::git-rev-list[]
>  
> +--exclude-promisor-objects::
> +	(For internal use only.)  Prefilter object traversal at
> +	promisor boundary.  This is used with partial clone.  This is
> +	stronger than `--missing=allow-promisor` because it limits the
> +	traversal, rather than just silencing errors about missing
> +	objects.
> +
>  --no-walk[=(sorted|unsorted)]::
>  	Only show the given commits, but do not traverse their ancestors.
>  	This has no effect if a range is specified. If the argument
> diff --git a/Documentation/technical/repository-version.txt b/Documentation/technical/repository-version.txt
> index 074ccb9e0..e03eacceb 100644
> --- a/Documentation/technical/repository-version.txt
> +++ b/Documentation/technical/repository-version.txt
> @@ -87,14 +87,14 @@ When the config key `extensions.preciousObjects` is set to `true`,
>  objects in the repository MUST NOT be deleted (e.g., by `git-prune` or
>  `git repack -d`).
>  
> -`partialClone`
> +`partialclone`
>  ~~~~~~~~~~~~~~
>  
> -When the config key `extensions.partialClone` is set, a remote is
> -designated as a "promisor remote". Objects referenced by packed objects
> -obtained from that promisor remote do not need to be in the local repo.
> -Instead, the promisor remote promises that all such objects can be
> -fetched from it in the future, and Git will fetch those objects when
> -needed.
> +When the config key `extensions.partialclone` is set, it indicates
> +that the repo was created with a partial clone (or later performed
> +a partial fetch) and that the remote may have omitted sending
> +certain unwanted objects.  Such a remote is called a "promisor remote"
> +and it promises that all such omitted objects can be fetched from it
> +in the future.
>  
> -The value of this key is the name of the aforementioned promisor remote.
> +The value of this key is the name of the promisor remote.
> diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
> index f31f92a8e..32e92dbeb 100644
> --- a/builtin/pack-objects.c
> +++ b/builtin/pack-objects.c
> @@ -88,6 +88,7 @@ static struct list_objects_filter_options filter_options;
>  enum missing_action {
>  	MA_ERROR = 0,    /* fail if any missing objects are encountered */
>  	MA_ALLOW_ANY,    /* silently allow ALL missing objects */
> +	MA_ALLOW_PROMISOR, /* silently allow all missing PROMISOR objects */
>  };
>  static enum missing_action arg_missing_action;
>  static show_object_fn fn_show_object;
> @@ -2580,6 +2581,20 @@ static void show_object__ma_allow_any(struct object *obj, const char *name, void
>  	show_object(obj, name, data);
>  }
>  
> +static void show_object__ma_allow_promisor(struct object *obj, const char *name, void *data)
> +{
> +	assert(arg_missing_action == MA_ALLOW_PROMISOR);
> +
> +	/*
> +	 * Quietly ignore EXPECTED missing objects.  This avoids problems with
> +	 * staging them now and getting an odd error later.
> +	 */
> +	if (!has_object_file(&obj->oid) && is_promisor_object(&obj->oid))
> +		return;
> +
> +	show_object(obj, name, data);
> +}
> +
>  static int option_parse_missing_action(const struct option *opt,
>  				       const char *arg, int unset)
>  {
> @@ -2594,10 +2609,18 @@ static int option_parse_missing_action(const struct option *opt,
>  
>  	if (!strcmp(arg, "allow-any")) {
>  		arg_missing_action = MA_ALLOW_ANY;
> +		fetch_if_missing = 0;
>  		fn_show_object = show_object__ma_allow_any;
>  		return 0;
>  	}
>  
> +	if (!strcmp(arg, "allow-promisor")) {
> +		arg_missing_action = MA_ALLOW_PROMISOR;
> +		fetch_if_missing = 0;
> +		fn_show_object = show_object__ma_allow_promisor;
> +		return 0;
> +	}
> +
>  	die(_("invalid value for --missing"));
>  	return 0;
>  }
> @@ -3062,6 +3085,9 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
>  		use_internal_rev_list = 1;
>  		fetch_if_missing = 0;
>  		argv_array_push(&rp, "--exclude-promisor-objects");
> +		/* silently override any "--missing=" value */
> +		arg_missing_action = MA_ALLOW_PROMISOR;
> +		fn_show_object = show_object__ma_allow_promisor;

--exclude-promisor-objects should be orthogonal to handling of missing
objects (and the tests pass when I remove these lines, showing that to
be true in practice).

If mixing the two is problematic from a UI standpoint, maybe it's better
to warn or die about them. But probably the best thing to do is to
document --exclude-promisor-objects as "internal use only".

>  	}
>  
>  	if (!reuse_object)
> diff --git a/builtin/repack.c b/builtin/repack.c
> index f43317bb5..7bdb40142 100644
> --- a/builtin/repack.c
> +++ b/builtin/repack.c
> @@ -234,7 +234,8 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
>  	argv_array_push(&cmd.args, "--all");
>  	argv_array_push(&cmd.args, "--reflog");
>  	argv_array_push(&cmd.args, "--indexed-objects");
> -	argv_array_push(&cmd.args, "--exclude-promisor-objects");
> +	if (repository_format_partial_clone)
> +		argv_array_push(&cmd.args, "--exclude-promisor-objects");
>  	if (window)
>  		argv_array_pushf(&cmd.args, "--window=%s", window);
>  	if (window_memory)
> diff --git a/builtin/rev-list.c b/builtin/rev-list.c
> index e17ab2b0f..5c5acd3d6 100644
> --- a/builtin/rev-list.c
> +++ b/builtin/rev-list.c
> @@ -68,6 +68,7 @@ enum missing_action {
>  	MA_ERROR = 0,    /* fail if any missing objects are encountered */
>  	MA_ALLOW_ANY,    /* silently allow ALL missing objects */
>  	MA_PRINT,        /* print ALL missing objects in special section */
> +	MA_ALLOW_PROMISOR, /* silently allow all missing PROMISOR objects */
>  };
>  static enum missing_action arg_missing_action;
>  
> @@ -198,6 +199,12 @@ static void finish_commit(struct commit *commit, void *data)
>  
>  static inline void finish_object__ma(struct object *obj)
>  {
> +	/*
> +	 * Whether or not we try to dynamically fetch missing objects
> +	 * from the server, we currently DO NOT have the object.  We
> +	 * can either print, allow (ignore), or conditionally allow
> +	 * (ignore) them.
> +	 */
>  	switch (arg_missing_action) {
>  	case MA_ERROR:
>  		die("missing blob object '%s'", oid_to_hex(&obj->oid));
> @@ -210,25 +217,36 @@ static inline void finish_object__ma(struct object *obj)
>  		oidset_insert(&missing_objects, &obj->oid);
>  		return;
>  
> +	case MA_ALLOW_PROMISOR:
> +		if (is_promisor_object(&obj->oid))
> +			return;
> +		die("unexpected missing blob object '%s'",
> +		    oid_to_hex(&obj->oid));
> +		return;
> +
>  	default:
>  		BUG("unhandled missing_action");
>  		return;
>  	}
>  }
>  
> -static void finish_object(struct object *obj, const char *name, void *cb_data)
> +static int finish_object(struct object *obj, const char *name, void *cb_data)
>  {
>  	struct rev_list_info *info = cb_data;
> -	if (obj->type == OBJ_BLOB && !has_object_file(&obj->oid))
> +	if (obj->type == OBJ_BLOB && !has_object_file(&obj->oid)) {
>  		finish_object__ma(obj);
> +		return 1;
> +	}
>  	if (info->revs->verify_objects && !obj->parsed && obj->type != OBJ_COMMIT)
>  		parse_object(&obj->oid);
> +	return 0;
>  }

As I said in [3], making finish_object() return int makes sense, because
we might want to suppress the object from being shown. (My version of
the code was not designed with the --missing parameter in mind.)

[3] https://public-inbox.org/git/20171108135116.f96c58500caa302583bb2810@google.com/

>  
>  static void show_object(struct object *obj, const char *name, void *cb_data)
>  {
>  	struct rev_list_info *info = cb_data;
> -	finish_object(obj, name, cb_data);
> +	if (finish_object(obj, name, cb_data))
> +		return;
>  	display_progress(progress, ++progress_counter);
>  	if (info->flags & REV_LIST_QUIET)
>  		return;
> @@ -316,11 +334,19 @@ static inline int parse_missing_action_value(const char *value)
>  
>  	if (!strcmp(value, "allow-any")) {
>  		arg_missing_action = MA_ALLOW_ANY;
> +		fetch_if_missing = 0;
>  		return 1;
>  	}
>  
>  	if (!strcmp(value, "print")) {
>  		arg_missing_action = MA_PRINT;
> +		fetch_if_missing = 0;
> +		return 1;
> +	}
> +
> +	if (!strcmp(value, "allow-promisor")) {
> +		arg_missing_action = MA_ALLOW_PROMISOR;
> +		fetch_if_missing = 0;
>  		return 1;
>  	}
>  
> @@ -349,13 +375,33 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix)
>  	/*
>  	 * Scan the argument list before invoking setup_revisions(), so that we
>  	 * know if fetch_if_missing needs to be set to 0.
> +	 *
> +	 * "--exclude-promisor-objects" acts as a pre-filter on missing objects
> +	 * by not crossing the boundary from realized objects to promisor
> +	 * objects.  This overrides any "--missing" value.  For consistency in
> +	 * our variables, we force MA_ALLOW_PROMISOR knowning that list-objects
> +	 * should not touch other missing objects unless there is an error.
> +	 *
> +	 * Otherwise, let "--missing" to conditionally set fetch_if_missing.
>  	 */
>  	for (i = 1; i < argc; i++) {
> -		if (!strcmp(argv[i], "--exclude-promisor-objects")) {
> +		const char *arg = argv[i];
> +		if (!strcmp(arg, "--exclude-promisor-objects")) {
>  			fetch_if_missing = 0;
> +			revs.exclude_promisor_objects = 1;
> +			arg_missing_action = MA_ALLOW_PROMISOR;
>  			break;
>  		}
>  	}
> +	for (i = 1; i < argc; i++) {
> +		const char *arg = argv[i];
> +		if (skip_prefix(arg, "--missing=", &arg)) {
> +			if (revs.exclude_promisor_objects)
> +				die(_("cannot combine --exclude-promisor-objects and --missing"));
> +			if (parse_missing_action_value(arg))
> +				break;
> +		}
> +	}

Same comment as above about the orthogonality of
--exclude-promisor-objects and --missing.

>  
>  	argc = setup_revisions(argc, argv, &revs, NULL);
>  
> @@ -421,10 +467,11 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix)
>  			continue;
>  		}
>  
> -		if (skip_prefix(arg, "--missing=", &arg) &&
> -		    parse_missing_action_value(arg))
> -			continue;
> -		
> +		if (!strcmp(arg, "--exclude-promisor-objects"))
> +			continue; /* already handled above */
> +		if (skip_prefix(arg, "--missing=", &arg))
> +			continue; /* already handled above */
> +
>  		usage(rev_list_usage);
>  
>  	}
> diff --git a/cache.h b/cache.h
> index 38ea41efc..05e979d4d 100644
> --- a/cache.h
> +++ b/cache.h
> @@ -889,7 +889,7 @@ extern char *repository_format_partial_clone;
>  struct repository_format {
>  	int version;
>  	int precious_objects;
> -	char *partial_clone;
> +	char *partial_clone; /* value of extensions.partialclone */
>  	int is_bare;
>  	char *work_tree;
>  	struct string_list unknown_extensions;
> diff --git a/list-objects.c b/list-objects.c
> index bdf12c500..58621fc6e 100644
> --- a/list-objects.c
> +++ b/list-objects.c
> @@ -30,13 +30,20 @@ static void process_blob(struct rev_info *revs,
>  		die("bad blob object");
>  	if (obj->flags & (UNINTERESTING | SEEN))
>  		return;
> -	if (!has_object_file(&obj->oid)) {
> -		if (revs->exclude_promisor_objects &&
> -		    is_promisor_object(&obj->oid)) {
> -			return;
> -		}
> -		/* error message will be reported later */
> -	}
> +
> +	/*
> +	 * Pre-filter known-missing objects when explicitly requested.
> +	 * Otherwise, a missing object error message may be reported
> +	 * later (depending on other filtering criteria).
> +	 *
> +	 * Note that this "--exclude-promisor-objects" pre-filtering
> +	 * may cause the actual filter to report an incomplete list
> +	 * of missing objects.
> +	 */
> +	if (revs->exclude_promisor_objects &&
> +	    !has_object_file(&obj->oid) &&
> +	    is_promisor_object(&obj->oid))
> +		return;
>  
>  	pathlen = path->len;
>  	strbuf_addstr(path, name);
> @@ -111,10 +118,16 @@ static void process_tree(struct rev_info *revs,
>  	if (parse_tree_gently(tree, gently) < 0) {
>  		if (revs->ignore_missing_links)
>  			return;
> +
> +		/*
> +		 * Pre-filter known-missing tree objects when explicitly
> +		 * requested.  This may cause the actual filter to report
> +		 * an incomplete list of missing objects.
> +		 */
>  		if (revs->exclude_promisor_objects &&
> -		    is_promisor_object(&obj->oid)) {
> +		    is_promisor_object(&obj->oid))
>  			return;
> -		}
> +

The {} here are unnecessary for a one-line block.

>  		die("bad tree object %s", oid_to_hex(&obj->oid));
>  	}