[PATCH v2] repack: Add option to preserve and prune old pack files

From

JMJames Melvin <jmelvin@codeaurora.org>

Date

Mar 10, 2017, 22:00 UTC

Message-ID

<20170310220020.2666-1-jmelvin@codeaurora.org>

Signed-off-by: James Melvin <jmelvin@codeaurora.org>
---
 Documentation/git-repack.txt |  4 +++
 builtin/repack.c             | 66 +++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 69 insertions(+), 1 deletion(-)

diff --git a/Documentation/git-repack.txt b/Documentation/git-repack.txt
index 26afe6ed5..effd98a43 100644
--- a/Documentation/git-repack.txt
+++ b/Documentation/git-repack.txt
@@ -143,6 +143,10 @@ other objects in that pack they already have locally.
 	being removed. In addition, any unreachable loose objects will
 	be packed (and their loose counterparts removed).
 
+--preserve-and-prune::
+	 Preserve old pack files by renaming them instead of deleting. Prune any
+	 previously preserved pack files before preserving new ones.
+
 Configuration
 -------------
 
diff --git a/builtin/repack.c b/builtin/repack.c
index 677bc7c81..78fad8f1a 100644
--- a/builtin/repack.c
+++ b/builtin/repack.c
@@ -10,6 +10,7 @@
 
 static int delta_base_offset = 1;
 static int pack_kept_objects = -1;
+static int preserve_and_prune;
 static int write_bitmaps;
 static char *packdir, *packtmp;
 
@@ -108,6 +109,60 @@ static void get_non_kept_pack_filenames(struct string_list *fname_list)
 	closedir(dir);
 }
 
+/*
+ * Adds all preserved packs hex strings to the fname list
+ */
+static void get_preserved_pack_filenames(struct string_list *fname_list)
+{
+	DIR *dir;
+	struct dirent *e;
+	char *fname;
+
+	if (!(dir = opendir(packdir)))
+		return;
+
+	while ((e = readdir(dir)) != NULL) {
+		size_t len;
+		if (!strip_suffix(e->d_name, ".old-pack", &len))
+			continue;
+
+		fname = xmemdupz(e->d_name, len);
+		string_list_append_nodup(fname_list, fname);
+	}
+	closedir(dir);
+}
+
+static void remove_preserved_packs(void) {
+	const char *exts[] = {"pack", "idx", "keep", "bitmap"};
+	int i;
+	struct string_list names = STRING_LIST_INIT_DUP;
+	struct string_list_item *item;
+
+	get_preserved_pack_filenames(&names);
+
+	for_each_string_list_item(item, &names) {
+		for (i = 0; i < ARRAY_SIZE(exts); i++) {
+			char *fname;
+			fname = mkpathdup("%s/%s.old-%s",
+					  packdir,
+					  item->string,
+					  exts[i]);
+			if (remove_path(fname))
+				warning(_("failed to remove '%s'"), fname);
+			free(fname);
+		}
+	}
+}
+
+static void preserve_pack(const char *file_path, const char *file_name,  const char *file_ext)
+{
+	char *fname_old;
+
+	fname_old = mkpathdup("%s/%s.old-%s", packdir, file_name, ++file_ext);
+	rename(file_path, fname_old);
+	free(fname_old);
+}
+
 static void remove_redundant_pack(const char *dir_name, const char *base_name)
 {
 	const char *exts[] = {".pack", ".idx", ".keep", ".bitmap"};
@@ -121,7 +176,10 @@ static void remove_redundant_pack(const char *dir_name, const char *base_name)
 	for (i = 0; i < ARRAY_SIZE(exts); i++) {
 		strbuf_setlen(&buf, plen);
 		strbuf_addstr(&buf, exts[i]);
-		unlink(buf.buf);
+		if (preserve_and_prune)
+			preserve_pack(buf.buf, base_name, exts[i]);
+		else
+			unlink(buf.buf);
 	}
 	strbuf_release(&buf);
 }
@@ -194,6 +252,9 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 				N_("maximum size of each packfile")),
 		OPT_BOOL(0, "pack-kept-objects", &pack_kept_objects,
 				N_("repack objects in packs marked with .keep")),
+		OPT_BOOL(0, "preserve-and-prune", &preserve_and_prune,
+				N_("preserve old pack files by renaming them instead of deleting, prune any "
+						"previously preserved pack files before preserving new ones")),
 		OPT_END()
 	};
 
@@ -404,6 +465,9 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 
 	/* End of pack replacement. */
 
+	if (preserve_and_prune)
+		remove_preserved_packs();
+
 	if (delete_redundant) {
 		int opts = 0;
 		string_list_sort(&names);

-- 
2.12.0.191.ga15447d9f