[PATCH v2 5/7] multi-pack-index: implement 'expire' verb

From

Derrick Stolee via GitGitGadget <gitgitgadget@gmail.com>

Date

Dec 21, 2018, 16:28 UTC

Message-ID

<1c4af93f5e9833d74a7cf7fc6d38df7fd93c1acc.1545409716.git.gitgitgadget@gmail.com>

In-Reply-To

<pull.92.v2.git.gitgitgadget@gmail.com>

From: Derrick Stolee <dstolee@microsoft.com>

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
---
 midx.c                      | 82 +++++++++++++++++++++++++++++++++++--
 t/t5319-multi-pack-index.sh | 15 +++++++
 2 files changed, 93 insertions(+), 4 deletions(-)

diff --git a/midx.c b/midx.c
index 3bd7183a53..043cd1fd97 100644
--- a/midx.c
+++ b/midx.c
@@ -751,7 +751,8 @@ static size_t write_midx_large_offsets(struct hashfile *f, uint32_t nr_large_off
 	return written;
 }
 
-int write_midx_file(const char *object_dir)
+static int write_midx_internal(const char *object_dir, struct multi_pack_index *m,
+			       struct string_list *packs_to_drop)
 {
 	unsigned char cur_chunk, num_chunks = 0;
 	char *midx_name;
@@ -765,6 +766,7 @@ int write_midx_file(const char *object_dir)
 	uint32_t nr_entries, num_large_offsets = 0;
 	struct pack_midx_entry *entries = NULL;
 	int large_offsets_needed = 0;
+	int result = 0;
 
 	midx_name = get_midx_filename(object_dir);
 	if (safe_create_leading_directories(midx_name)) {
@@ -773,7 +775,10 @@ int write_midx_file(const char *object_dir)
 			  midx_name);
 	}
 
-	packs.m = load_multi_pack_index(object_dir, 1);
+	if (m)
+		packs.m = m;
+	else
+		packs.m = load_multi_pack_index(object_dir, 1);
 
 	packs.nr = 0;
 	packs.alloc_list = packs.m ? packs.m->num_packs : 16;
@@ -787,7 +792,25 @@ int write_midx_file(const char *object_dir)
 	ALLOC_ARRAY(packs.perm, packs.alloc_perm);
 
 	if (packs.m) {
+		int drop_index = 0, missing_drops = 0;
 		for (i = 0; i < packs.m->num_packs; i++) {
+			if (packs_to_drop && drop_index < packs_to_drop->nr) {
+				int cmp = strcmp(packs.m->pack_names[i],
+						 packs_to_drop->items[drop_index].string);
+
+				if (!cmp) {
+					drop_index++;
+					continue;
+				} else if (cmp > 0) {
+					error(_("did not see pack-file %s to drop"),
+					      packs_to_drop->items[drop_index].string);
+					drop_index++;
+					i--;
+					missing_drops++;
+					continue;
+				}
+			}
+
 			ALLOC_GROW(packs.list, packs.nr + 1, packs.alloc_list);
 			ALLOC_GROW(packs.names, packs.nr + 1, packs.alloc_names);
 			ALLOC_GROW(packs.perm, packs.nr + 1, packs.alloc_perm);
@@ -798,6 +821,12 @@ int write_midx_file(const char *object_dir)
 			packs.pack_name_concat_len += strlen(packs.names[packs.nr]) + 1;
 			packs.nr++;
 		}
+
+		if (packs_to_drop && (drop_index < packs_to_drop->nr || missing_drops)) {
+			error(_("did not see all pack-files to drop"));
+			result = 1;
+			goto cleanup;
+		}
 	}
 
 	for_each_file_in_pack_dir(object_dir, add_pack_to_midx, &packs);
@@ -932,7 +961,12 @@ int write_midx_file(const char *object_dir)
 	free(packs.perm);
 	free(entries);
 	free(midx_name);
-	return 0;
+	return result;
+}
+
+int write_midx_file(const char *object_dir)
+{
+	return write_midx_internal(object_dir, NULL, NULL);
 }
 
 void clear_midx_file(struct repository *r)
@@ -1034,5 +1068,45 @@ int verify_midx_file(const char *object_dir)
 
 int expire_midx_packs(const char *object_dir)
 {
-	return 0;
+	uint32_t i, *count, result = 0;
+	struct string_list packs_to_drop = STRING_LIST_INIT_DUP;
+	struct multi_pack_index *m = load_multi_pack_index(object_dir, 1);
+
+	if (!m)
+		return 0;
+
+	count = xcalloc(m->num_packs, sizeof(uint32_t));
+	for (i = 0; i < m->num_objects; i++) {
+		int pack_int_id = nth_midxed_pack_int_id(m, i);
+		count[pack_int_id]++;
+	}
+
+	for (i = 0; i < m->num_packs; i++) {
+		char *pack_name;
+
+		if (count[i])
+			continue;
+
+		if (prepare_midx_pack(m, i))
+			continue;
+
+		if (m->packs[i]->pack_keep)
+			continue;
+
+		pack_name = xstrdup(m->packs[i]->pack_name);
+		close_pack(m->packs[i]);
+		FREE_AND_NULL(m->packs[i]);
+
+		string_list_insert(&packs_to_drop, m->pack_names[i]);
+		unlink_pack_path(pack_name, 0);
+		free(pack_name);
+	}
+
+	free(count);
+
+	if (packs_to_drop.nr)
+		result = write_midx_internal(object_dir, m, &packs_to_drop);
+
+	string_list_clear(&packs_to_drop, 0);
+	return result;
 }
diff --git a/t/t5319-multi-pack-index.sh b/t/t5319-multi-pack-index.sh
index 948effc1ee..210279a3cf 100755
--- a/t/t5319-multi-pack-index.sh
+++ b/t/t5319-multi-pack-index.sh
@@ -395,4 +395,19 @@ test_expect_success 'expire does not remove any packs' '
 	)
 '
 
+test_expect_success 'expire removes unreferenced packs' '
+	(
+		cd dup &&
+		git pack-objects --revs .git/objects/pack/pack-combined <<-EOF &&
+		refs/heads/A
+		^refs/heads/C
+		EOF
+		git multi-pack-index write &&
+		ls .git/objects/pack | grep -v -e pack-[AB] >expect &&
+		git multi-pack-index expire &&
+		ls .git/objects/pack >actual &&
+		test_cmp expect actual
+	)
+'
+
 test_done

-- 
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