1 files changed, 98 insertions, 0 deletions
diff --git a/repack-cruft.c b/repack-cruft.c
new file mode 100644
index 0000000000..0653e88792
--- /dev/null
+++ b/repack-cruft.c
@@ -0,0 +1,98 @@
+#include "git-compat-util.h"
+#include "repack.h"
+#include "packfile.h"
+#include "repository.h"
+#include "run-command.h"
+
+static void combine_small_cruft_packs(FILE *in, off_t combine_cruft_below_size,
+				      struct existing_packs *existing)
+{
+	struct packed_git *p;
+	struct strbuf buf = STRBUF_INIT;
+	size_t i;
+
+	repo_for_each_pack(existing->repo, p) {
+		if (!(p->is_cruft && p->pack_local))
+			continue;
+
+		strbuf_reset(&buf);
+		strbuf_addstr(&buf, pack_basename(p));
+		strbuf_strip_suffix(&buf, ".pack");
+
+		if (!string_list_has_string(&existing->cruft_packs, buf.buf))
+			continue;
+
+		if (p->pack_size < combine_cruft_below_size) {
+			fprintf(in, "-%s\n", pack_basename(p));
+		} else {
+			existing_packs_retain_cruft(existing, p);
+			fprintf(in, "%s\n", pack_basename(p));
+		}
+	}
+
+	for (i = 0; i < existing->non_kept_packs.nr; i++)
+		fprintf(in, "-%s.pack\n",
+			existing->non_kept_packs.items[i].string);
+
+	strbuf_release(&buf);
+}
+
+int write_cruft_pack(const struct write_pack_opts *opts,
+		     const char *cruft_expiration,
+		     unsigned long combine_cruft_below_size,
+		     struct string_list *names,
+		     struct existing_packs *existing)
+{
+	struct child_process cmd = CHILD_PROCESS_INIT;
+	struct string_list_item *item;
+	FILE *in;
+	int ret;
+	const char *pack_prefix = write_pack_opts_pack_prefix(opts);
+
+	prepare_pack_objects(&cmd, opts->po_args, opts->destination);
+
+	strvec_push(&cmd.args, "--cruft");
+	if (cruft_expiration)
+		strvec_pushf(&cmd.args, "--cruft-expiration=%s",
+			     cruft_expiration);
+
+	strvec_push(&cmd.args, "--non-empty");
+
+	cmd.in = -1;
+
+	ret = start_command(&cmd);
+	if (ret)
+		return ret;
+
+	/*
+	 * names has a confusing double use: it both provides the list
+	 * of just-written new packs, and accepts the name of the cruft
+	 * pack we are writing.
+	 *
+	 * By the time it is read here, it contains only the pack(s)
+	 * that were just written, which is exactly the set of packs we
+	 * want to consider kept.
+	 *
+	 * If `--expire-to` is given, the double-use served by `names`
+	 * ensures that the pack written to `--expire-to` excludes any
+	 * objects contained in the cruft pack.
+	 */
+	in = xfdopen(cmd.in, "w");
+	for_each_string_list_item(item, names)
+		fprintf(in, "%s-%s.pack\n", pack_prefix, item->string);
+	if (combine_cruft_below_size && !cruft_expiration) {
+		combine_small_cruft_packs(in, combine_cruft_below_size,
+					  existing);
+	} else {
+		for_each_string_list_item(item, &existing->non_kept_packs)
+			fprintf(in, "-%s.pack\n", item->string);
+		for_each_string_list_item(item, &existing->cruft_packs)
+			fprintf(in, "-%s.pack\n", item->string);
+	}
+	for_each_string_list_item(item, &existing->kept_packs)
+		fprintf(in, "%s.pack\n", item->string);
+	fclose(in);
+
+	return finish_pack_objects_cmd(existing->repo->hash_algo, opts, &cmd,
+				       names);
+}