[GSoC PATCH v5 1/6] builtin/repack: add --drop-filtered and --dry-run options
From: Siddharth Shrimali <hidden>
Date: 2026-08-13 20:08:55
Subsystem:
the rest · Maintainer:
Linus Torvalds
Add two new command-line options to 'git-repack':
--drop-filtered: intended to eventually delete objects that match
the filter specification. Requires --filter and -a,
and is incompatible with --filter-to.
--dry-run: show which objects would be dropped without making any
changes. Only meaningful with --drop-filtered.
Keep --dry-run as a separate option rather than folding it into
--drop-filtered (e.g. --drop-filtered=dry-run), to stay consistent with
the --dry-run option other Git commands already provide and to leave
room for it to describe other repack behavior later. A
--drop-filtered=<mode> form can still be added later if more
drop-specific modes are needed.
--drop-filtered also requires a promisor remote to be configured, since
dropping objects without a remote to fetch them back from would be
permanent data loss.
--drop-filtered is incompatible with bitmap writing: filtering breaks
the "all objects in one pack" closure that bitmaps require. Detect an
explicit -b/--write-bitmap-index on the command line with a dedicated
option callback that sets a "write_bitmaps_given" flag, so it can be
distinguished from a repack.writeBitmaps configuration value even when
config already enables bitmaps. An explicit -b is reported as a conflict,
while a config-provided default is silently disabled for the duration
of the command.
These options currently only perform validation. The actual enumeration
and deletion will be added in follow-up commits.
Mentored-by: Christian Couder [off-list ref]
Mentored-by: Siddharth Asthana [off-list ref]
Signed-off-by: Siddharth Shrimali <redacted>
---
builtin/repack.c | 74 +++++++++++++++++++++++++++++++--
t/meson.build | 1 +
t/t7706-repack-drop-filtered.sh | 55 ++++++++++++++++++++++++
3 files changed, 127 insertions(+), 3 deletions(-)
create mode 100755 t/t7706-repack-drop-filtered.sh
diff --git a/builtin/repack.c b/builtin/repack.c
index db504d673f..ed79c04e13 100644
--- a/builtin/repack.c
+++ b/builtin/repack.c@@ -14,6 +14,7 @@ #include "promisor-remote.h" #include "repack.h" #include "shallow.h" +#include "list-objects-filter-options.h" #define ALL_INTO_ONE 1 #define LOOSEN_UNREACHABLE 2
@@ -28,11 +29,15 @@ static int use_delta_islands; static int run_update_server_info = 1; static char *packdir, *packtmp_name, *packtmp; static int midx_must_contain_cruft = 1; +static int drop_filtered; +static int dry_run; +static int write_bitmaps_given; static const char *const git_repack_usage[] = { N_("git repack [-a] [-A] [-d] [-f] [-F] [-l] [-n] [-q] [-b] [-m]\n" "[--window=<n>] [--depth=<n>] [--threads=<n>] [--keep-pack=<pack-name>]\n" - "[--write-midx[=<mode>]] [--name-hash-version=<n>] [--path-walk]"), + "[--write-midx[=<mode>]] [--name-hash-version=<n>] [--path-walk]\n" + "[--filter=<filter-spec>] [--drop-filtered [--dry-run]]"), NULL };
@@ -111,6 +116,21 @@ static int repack_config(const char *var, const char *value, return git_default_config(var, value, ctx, cb); } +static int option_parse_write_bitmaps(const struct option *opt, const char *arg, + int unset) +{ + int *value = opt->value; + + BUG_ON_OPT_ARG(arg); + if (unset) + *value = 0; + else + *value = 1; + + write_bitmaps_given = 1; + return 0; +} + static int option_parse_write_midx(const struct option *opt, const char *arg, int unset) {
@@ -194,8 +214,9 @@ int cmd_repack(int argc, OPT__QUIET(&po_args.quiet, N_("be quiet")), OPT_BOOL('l', "local", &po_args.local, N_("pass --local to git-pack-objects")), - OPT_BOOL('b', "write-bitmap-index", &write_bitmaps, - N_("write bitmap index")), + OPT_CALLBACK_F('b', "write-bitmap-index", &write_bitmaps, NULL, + N_("write bitmap index"), + PARSE_OPT_NOARG, option_parse_write_bitmaps), OPT_BOOL('i', "delta-islands", &use_delta_islands, N_("pass --delta-islands to git-pack-objects")), OPT_STRING(0, "unpack-unreachable", &unpack_unreachable, N_("approxidate"),
@@ -231,6 +252,10 @@ int cmd_repack(int argc, N_("pack prefix to store a pack containing pruned objects")), OPT_STRING(0, "filter-to", &filter_to, N_("dir"), N_("pack prefix to store a pack containing filtered out objects")), + OPT_BOOL(0, "drop-filtered", &drop_filtered, + N_("delete filtered out objects (requires --filter)")), + OPT_BOOL(0, "dry-run", &dry_run, + N_("only show which objects would be dropped")), OPT_END() };
@@ -252,6 +277,49 @@ int cmd_repack(int argc, po_args.depth = xstrdup_or_null(opt_depth); po_args.threads = xstrdup_or_null(opt_threads); + die_for_incompatible_opt2(drop_filtered, "--drop-filtered", + !!filter_to, "--filter-to"); + + if (dry_run && !drop_filtered) + die(_("--dry-run only takes effect with --drop-filtered")); + + if (drop_filtered) { + if (!dry_run) + die(_("--drop-filtered does not work without --dry-run yet")); + + if (!po_args.filter_options.choice) + die(_("--drop-filtered requires --filter")); + + if (!(pack_everything & ALL_INTO_ONE)) + die(_("--drop-filtered requires -a")); + + /* + * Only blob:limit=<n> is supported for now. Reject other + * filter choices early, before walking the object database. + */ + if (po_args.filter_options.choice != LOFC_BLOB_LIMIT) + die(_("--drop-filtered only supports --filter=blob:limit=<n> for now")); + + /* + * An explicit -b on the command line is a conflict we have to + * report; a bitmap setting from config is silently overridden + * for the duration of the command. + */ + if (write_bitmaps_given && write_bitmaps > 0) + die(_("options '%s' and '%s' cannot be used together"), + "--drop-filtered", "--write-bitmap-index"); + + /* + * Without a promisor remote there is nowhere to re-fetch the + * dropped objects from, so dropping them would be permanent + * data loss. + */ + if (!repo_has_promisor_remote(repo)) + die(_("--drop-filtered requires a promisor remote")); + + write_bitmaps = 0; + } + if (delete_redundant && repo->repository_format_precious_objects) die(_("cannot delete packs in a precious-objects repo"));
diff --git a/t/meson.build b/t/meson.build
index a25f37d2f5..92352e43c4 100644
--- a/t/meson.build
+++ b/t/meson.build@@ -964,6 +964,7 @@ integration_tests = [ 't7703-repack-geometric.sh', 't7704-repack-cruft.sh', 't7705-repack-incremental-midx.sh', + 't7706-repack-drop-filtered.sh', 't7800-difftool.sh', 't7810-grep.sh', 't7811-grep-open.sh',
diff --git a/t/t7706-repack-drop-filtered.sh b/t/t7706-repack-drop-filtered.sh
new file mode 100755
index 0000000000..07a976874a
--- /dev/null
+++ b/t/t7706-repack-drop-filtered.sh@@ -0,0 +1,55 @@ +#!/bin/sh + +test_description='git repack --drop-filtered option validation' + +. ./test-lib.sh + +# Check option validation before any promisor walk +test_expect_success 'setup plain repo for validation' ' + git init plain && + test_commit -C plain initial && + git clone --bare plain plain.git && + git -C plain.git repack -a -d +' + +test_expect_success '--drop-filtered requires --filter' ' + test_must_fail git -C plain.git repack --drop-filtered --dry-run -a 2>err && + test_grep "drop-filtered requires --filter" err +' + +test_expect_success '--drop-filtered cannot be used with --filter-to' ' + test_must_fail git -C plain.git repack --drop-filtered \ + --filter=blob:limit=1k --filter-to=./filter-out 2>err && + test_grep "options .--drop-filtered. and .--filter-to. cannot be used together" err +' + +test_expect_success '--dry-run only takes effect with --drop-filtered' ' + test_must_fail git -C plain.git repack --dry-run 2>err && + test_grep "dry-run only takes effect with --drop-filtered" err +' + +test_expect_success '--drop-filtered requires -a' ' + test_must_fail git -C plain.git repack --drop-filtered \ + --filter=blob:limit=1k --dry-run 2>err && + test_grep "drop-filtered requires -a" err +' + +test_expect_success '--drop-filtered fails with --write-bitmap-index' ' + test_must_fail git -C plain.git repack --drop-filtered \ + --filter=blob:limit=1k --dry-run -a -b 2>err && + test_grep "options .--drop-filtered. and .--write-bitmap-index. cannot be used together" err +' + +test_expect_success '--drop-filtered rejects explicit -b even when repack.writeBitmaps=true' ' + test_must_fail git -C plain.git -c repack.writeBitmaps=true \ + repack --drop-filtered --filter=blob:limit=1k --dry-run -a -b 2>err && + test_grep "options .--drop-filtered. and .--write-bitmap-index. cannot be used together" err +' + +test_expect_success '--drop-filtered fails without a promisor remote' ' + test_must_fail git -C plain.git repack --drop-filtered \ + --filter=blob:limit=1k --dry-run -a 2>err && + test_grep "drop-filtered requires a promisor remote" err +' + +test_done
--
2.54.0