/src/git/builtin/repack.c

Source (jump to first uncovered line)
#include "builtin.h"
#include "config.h"
#include "dir.h"
#include "environment.h"
#include "gettext.h"
#include "hex.h"
#include "parse-options.h"
#include "path.h"
#include "run-command.h"
#include "server-info.h"
#include "strbuf.h"
#include "string-list.h"
#include "strvec.h"
#include "midx.h"
#include "packfile.h"
#include "prune-packed.h"
#include "object-store-ll.h"
#include "promisor-remote.h"
#include "shallow.h"
#include "pack.h"
#include "pack-bitmap.h"
#include "refs.h"
#include "list-objects-filter-options.h"

#define ALL_INTO_ONE 1
#define LOOSEN_UNREACHABLE 2
#define PACK_CRUFT 4

#define DELETE_PACK 1
#define RETAIN_PACK 2

static int pack_everything;
static int delta_base_offset = 1;
static int pack_kept_objects = -1;
static int write_bitmaps = -1;
static int use_delta_islands;
static int run_update_server_info = 1;
static char *packdir, *packtmp_name, *packtmp;

static const char *const git_repack_usage[] = {
  N_("git repack [<options>]"),
  NULL
};

static const char incremental_bitmap_conflict_error[] = N_(
"Incremental repacks are incompatible with bitmap indexes.  Use\n"
"--no-write-bitmap-index or disable the pack.writeBitmaps configuration."
);

struct pack_objects_args {
  char *window;
  char *window_memory;
  char *depth;
  char *threads;
  unsigned long max_pack_size;
  int no_reuse_delta;
  int no_reuse_object;
  int quiet;
  int local;
  struct list_objects_filter_options filter_options;
};

static int repack_config(const char *var, const char *value,
       const struct config_context *ctx, void *cb)
{
  struct pack_objects_args *cruft_po_args = cb;
  if (!strcmp(var, "repack.usedeltabaseoffset")) {
    delta_base_offset = git_config_bool(var, value);
    return 0;
  }
  if (!strcmp(var, "repack.packkeptobjects")) {
    pack_kept_objects = git_config_bool(var, value);
    return 0;
  }
  if (!strcmp(var, "repack.writebitmaps") ||
      !strcmp(var, "pack.writebitmaps")) {
    write_bitmaps = git_config_bool(var, value);
    return 0;
  }
  if (!strcmp(var, "repack.usedeltaislands")) {
    use_delta_islands = git_config_bool(var, value);
    return 0;
  }
  if (strcmp(var, "repack.updateserverinfo") == 0) {
    run_update_server_info = git_config_bool(var, value);
    return 0;
  }
  if (!strcmp(var, "repack.cruftwindow"))
    return git_config_string(&cruft_po_args->window, var, value);
  if (!strcmp(var, "repack.cruftwindowmemory"))
    return git_config_string(&cruft_po_args->window_memory, var, value);
  if (!strcmp(var, "repack.cruftdepth"))
    return git_config_string(&cruft_po_args->depth, var, value);
  if (!strcmp(var, "repack.cruftthreads"))
    return git_config_string(&cruft_po_args->threads, var, value);
  return git_default_config(var, value, ctx, cb);
}

struct existing_packs {
  struct string_list kept_packs;
  struct string_list non_kept_packs;
  struct string_list cruft_packs;
};

#define EXISTING_PACKS_INIT { \
  .kept_packs = STRING_LIST_INIT_DUP, \
  .non_kept_packs = STRING_LIST_INIT_DUP, \
  .cruft_packs = STRING_LIST_INIT_DUP, \
}

static int has_existing_non_kept_packs(const struct existing_packs *existing)
{
  return existing->non_kept_packs.nr || existing->cruft_packs.nr;
}

static void pack_mark_for_deletion(struct string_list_item *item)
{
  item->util = (void*)((uintptr_t)item->util | DELETE_PACK);
}

static void pack_unmark_for_deletion(struct string_list_item *item)
{
  item->util = (void*)((uintptr_t)item->util & ~DELETE_PACK);
}

static int pack_is_marked_for_deletion(struct string_list_item *item)
{
  return (uintptr_t)item->util & DELETE_PACK;
}

static void pack_mark_retained(struct string_list_item *item)
{
  item->util = (void*)((uintptr_t)item->util | RETAIN_PACK);
}

static int pack_is_retained(struct string_list_item *item)
{
  return (uintptr_t)item->util & RETAIN_PACK;
}

static void mark_packs_for_deletion_1(struct string_list *names,
              struct string_list *list)
{
  struct string_list_item *item;
  const int hexsz = the_hash_algo->hexsz;

  for_each_string_list_item(item, list) {
    char *sha1;
    size_t len = strlen(item->string);
    if (len < hexsz)
      continue;
    sha1 = item->string + len - hexsz;

    if (pack_is_retained(item)) {
      pack_unmark_for_deletion(item);
    } else if (!string_list_has_string(names, sha1)) {
      /*
       * Mark this pack for deletion, which ensures
       * that this pack won't be included in a MIDX
       * (if `--write-midx` was given) and that we
       * will actually delete this pack (if `-d` was
       * given).
       */
      pack_mark_for_deletion(item);
    }
  }
}

static void retain_cruft_pack(struct existing_packs *existing,
            struct packed_git *cruft)
{
  struct strbuf buf = STRBUF_INIT;
  struct string_list_item *item;

  strbuf_addstr(&buf, pack_basename(cruft));
  strbuf_strip_suffix(&buf, ".pack");

  item = string_list_lookup(&existing->cruft_packs, buf.buf);
  if (!item)
    BUG("could not find cruft pack '%s'", pack_basename(cruft));

  pack_mark_retained(item);
  strbuf_release(&buf);
}

static void mark_packs_for_deletion(struct existing_packs *existing,
            struct string_list *names)

{
  mark_packs_for_deletion_1(names, &existing->non_kept_packs);
  mark_packs_for_deletion_1(names, &existing->cruft_packs);
}

static void remove_redundant_pack(const char *dir_name, const char *base_name)
{
  struct strbuf buf = STRBUF_INIT;
  struct multi_pack_index *m = get_local_multi_pack_index(the_repository);
  strbuf_addf(&buf, "%s.pack", base_name);
  if (m && midx_contains_pack(m, buf.buf))
    clear_midx_file(the_repository);
  strbuf_insertf(&buf, 0, "%s/", dir_name);
  unlink_pack_path(buf.buf, 1);
  strbuf_release(&buf);
}

static void remove_redundant_packs_1(struct string_list *packs)
{
  struct string_list_item *item;
  for_each_string_list_item(item, packs) {
    if (!pack_is_marked_for_deletion(item))
      continue;
    remove_redundant_pack(packdir, item->string);
  }
}

static void remove_redundant_existing_packs(struct existing_packs *existing)
{
  remove_redundant_packs_1(&existing->non_kept_packs);
  remove_redundant_packs_1(&existing->cruft_packs);
}

static void existing_packs_release(struct existing_packs *existing)
{
  string_list_clear(&existing->kept_packs, 0);
  string_list_clear(&existing->non_kept_packs, 0);
  string_list_clear(&existing->cruft_packs, 0);
}

/*
 * Adds all packs hex strings (pack-$HASH) to either packs->non_kept
 * or packs->kept based on whether each pack has a corresponding
 * .keep file or not.  Packs without a .keep file are not to be kept
 * if we are going to pack everything into one file.
 */
static void collect_pack_filenames(struct existing_packs *existing,
           const struct string_list *extra_keep)
{
  struct packed_git *p;
  struct strbuf buf = STRBUF_INIT;

  for (p = get_all_packs(the_repository); p; p = p->next) {
    int i;
    const char *base;

    if (!p->pack_local)
      continue;

    base = pack_basename(p);

    for (i = 0; i < extra_keep->nr; i++)
      if (!fspathcmp(base, extra_keep->items[i].string))
        break;

    strbuf_reset(&buf);
    strbuf_addstr(&buf, base);
    strbuf_strip_suffix(&buf, ".pack");

    if ((extra_keep->nr > 0 && i < extra_keep->nr) || p->pack_keep)
      string_list_append(&existing->kept_packs, buf.buf);
    else if (p->is_cruft)
      string_list_append(&existing->cruft_packs, buf.buf);
    else
      string_list_append(&existing->non_kept_packs, buf.buf);
  }

  string_list_sort(&existing->kept_packs);
  string_list_sort(&existing->non_kept_packs);
  string_list_sort(&existing->cruft_packs);
  strbuf_release(&buf);
}

static void prepare_pack_objects(struct child_process *cmd,
         const struct pack_objects_args *args,
         const char *out)
{
  strvec_push(&cmd->args, "pack-objects");
  if (args->window)
    strvec_pushf(&cmd->args, "--window=%s", args->window);
  if (args->window_memory)
    strvec_pushf(&cmd->args, "--window-memory=%s", args->window_memory);
  if (args->depth)
    strvec_pushf(&cmd->args, "--depth=%s", args->depth);
  if (args->threads)
    strvec_pushf(&cmd->args, "--threads=%s", args->threads);
  if (args->max_pack_size)
    strvec_pushf(&cmd->args, "--max-pack-size=%lu", args->max_pack_size);
  if (args->no_reuse_delta)
    strvec_pushf(&cmd->args, "--no-reuse-delta");
  if (args->no_reuse_object)
    strvec_pushf(&cmd->args, "--no-reuse-object");
  if (args->local)
    strvec_push(&cmd->args,  "--local");
  if (args->quiet)
    strvec_push(&cmd->args,  "--quiet");
  if (delta_base_offset)
    strvec_push(&cmd->args,  "--delta-base-offset");
  strvec_push(&cmd->args, out);
  cmd->git_cmd = 1;
  cmd->out = -1;
}

/*
 * Write oid to the given struct child_process's stdin, starting it first if
 * necessary.
 */
static int write_oid(const struct object_id *oid,
         struct packed_git *pack UNUSED,
         uint32_t pos UNUSED, void *data)
{
  struct child_process *cmd = data;

  if (cmd->in == -1) {
    if (start_command(cmd))
      die(_("could not start pack-objects to repack promisor objects"));
  }

  if (write_in_full(cmd->in, oid_to_hex(oid), the_hash_algo->hexsz) < 0 ||
      write_in_full(cmd->in, "\n", 1) < 0)
    die(_("failed to feed promisor objects to pack-objects"));
  return 0;
}

static struct {
  const char *name;
  unsigned optional:1;
} exts[] = {
  {".pack"},
  {".rev", 1},
  {".mtimes", 1},
  {".bitmap", 1},
  {".promisor", 1},
  {".idx"},
};

struct generated_pack_data {
  struct tempfile *tempfiles[ARRAY_SIZE(exts)];
};

static struct generated_pack_data *populate_pack_exts(const char *name)
{
  struct stat statbuf;
  struct strbuf path = STRBUF_INIT;
  struct generated_pack_data *data = xcalloc(1, sizeof(*data));
  int i;

  for (i = 0; i < ARRAY_SIZE(exts); i++) {
    strbuf_reset(&path);
    strbuf_addf(&path, "%s-%s%s", packtmp, name, exts[i].name);

    if (stat(path.buf, &statbuf))
      continue;

    data->tempfiles[i] = register_tempfile(path.buf);
  }

  strbuf_release(&path);
  return data;
}

static int has_pack_ext(const struct generated_pack_data *data,
      const char *ext)
{
  int i;
  for (i = 0; i < ARRAY_SIZE(exts); i++) {
    if (strcmp(exts[i].name, ext))
      continue;
    return !!data->tempfiles[i];
  }
  BUG("unknown pack extension: '%s'", ext);
}

static void repack_promisor_objects(const struct pack_objects_args *args,
            struct string_list *names)
{
  struct child_process cmd = CHILD_PROCESS_INIT;
  FILE *out;
  struct strbuf line = STRBUF_INIT;

  prepare_pack_objects(&cmd, args, packtmp);
  cmd.in = -1;

  /*
   * NEEDSWORK: Giving pack-objects only the OIDs without any ordering
   * hints may result in suboptimal deltas in the resulting pack. See if
   * the OIDs can be sent with fake paths such that pack-objects can use a
   * {type -> existing pack order} ordering when computing deltas instead
   * of a {type -> size} ordering, which may produce better deltas.
   */
  for_each_packed_object(write_oid, &cmd,
             FOR_EACH_OBJECT_PROMISOR_ONLY);

  if (cmd.in == -1) {
    /* No packed objects; cmd was never started */
    child_process_clear(&cmd);
    return;
  }

  close(cmd.in);

  out = xfdopen(cmd.out, "r");
  while (strbuf_getline_lf(&line, out) != EOF) {
    struct string_list_item *item;
    char *promisor_name;

    if (line.len != the_hash_algo->hexsz)
      die(_("repack: Expecting full hex object ID lines only from pack-objects."));
    item = string_list_append(names, line.buf);

    /*
     * pack-objects creates the .pack and .idx files, but not the
     * .promisor file. Create the .promisor file, which is empty.
     *
     * NEEDSWORK: fetch-pack sometimes generates non-empty
     * .promisor files containing the ref names and associated
     * hashes at the point of generation of the corresponding
     * packfile, but this would not preserve their contents. Maybe
     * concatenate the contents of all .promisor files instead of
     * just creating a new empty file.
     */
    promisor_name = mkpathdup("%s-%s.promisor", packtmp,
            line.buf);
    write_promisor_file(promisor_name, NULL, 0);

    item->util = populate_pack_exts(item->string);

    free(promisor_name);
  }
  fclose(out);
  if (finish_command(&cmd))
    die(_("could not finish pack-objects to repack promisor objects"));
}

struct pack_geometry {
  struct packed_git **pack;
  uint32_t pack_nr, pack_alloc;
  uint32_t split;

  int split_factor;
};

static uint32_t geometry_pack_weight(struct packed_git *p)
{
  if (open_pack_index(p))
    die(_("cannot open index for %s"), p->pack_name);
  return p->num_objects;
}

static int geometry_cmp(const void *va, const void *vb)
{
  uint32_t aw = geometry_pack_weight(*(struct packed_git **)va),
     bw = geometry_pack_weight(*(struct packed_git **)vb);

  if (aw < bw)
    return -1;
  if (aw > bw)
    return 1;
  return 0;
}

static void init_pack_geometry(struct pack_geometry *geometry,
             struct existing_packs *existing,
             const struct pack_objects_args *args)
{
  struct packed_git *p;
  struct strbuf buf = STRBUF_INIT;

  for (p = get_all_packs(the_repository); p; p = p->next) {
    if (args->local && !p->pack_local)
      /*
       * When asked to only repack local packfiles we skip
       * over any packfiles that are borrowed from alternate
       * object directories.
       */
      continue;

    if (!pack_kept_objects) {
      /*
       * Any pack that has its pack_keep bit set will
       * appear in existing->kept_packs below, but
       * this saves us from doing a more expensive
       * check.
       */
      if (p->pack_keep)
        continue;

      /*
       * The pack may be kept via the --keep-pack
       * option; check 'existing->kept_packs' to
       * determine whether to ignore it.
       */
      strbuf_reset(&buf);
      strbuf_addstr(&buf, pack_basename(p));
      strbuf_strip_suffix(&buf, ".pack");

      if (string_list_has_string(&existing->kept_packs, buf.buf))
        continue;
    }
    if (p->is_cruft)
      continue;

    ALLOC_GROW(geometry->pack,
         geometry->pack_nr + 1,
         geometry->pack_alloc);

    geometry->pack[geometry->pack_nr] = p;
    geometry->pack_nr++;
  }

  QSORT(geometry->pack, geometry->pack_nr, geometry_cmp);
  strbuf_release(&buf);
}

static void split_pack_geometry(struct pack_geometry *geometry)
{
  uint32_t i;
  uint32_t split;
  off_t total_size = 0;

  if (!geometry->pack_nr) {
    geometry->split = geometry->pack_nr;
    return;
  }

  /*
   * First, count the number of packs (in descending order of size) which
   * already form a geometric progression.
   */
  for (i = geometry->pack_nr - 1; i > 0; i--) {
    struct packed_git *ours = geometry->pack[i];
    struct packed_git *prev = geometry->pack[i - 1];

    if (unsigned_mult_overflows(geometry->split_factor,
              geometry_pack_weight(prev)))
      die(_("pack %s too large to consider in geometric "
            "progression"),
          prev->pack_name);

    if (geometry_pack_weight(ours) <
        geometry->split_factor * geometry_pack_weight(prev))
      break;
  }

  split = i;

  if (split) {
    /*
     * Move the split one to the right, since the top element in the
     * last-compared pair can't be in the progression. Only do this
     * when we split in the middle of the array (otherwise if we got
     * to the end, then the split is in the right place).
     */
    split++;
  }

  /*
   * Then, anything to the left of 'split' must be in a new pack. But,
   * creating that new pack may cause packs in the heavy half to no longer
   * form a geometric progression.
   *
   * Compute an expected size of the new pack, and then determine how many
   * packs in the heavy half need to be joined into it (if any) to restore
   * the geometric progression.
   */
  for (i = 0; i < split; i++) {
    struct packed_git *p = geometry->pack[i];

    if (unsigned_add_overflows(total_size, geometry_pack_weight(p)))
      die(_("pack %s too large to roll up"), p->pack_name);
    total_size += geometry_pack_weight(p);
  }
  for (i = split; i < geometry->pack_nr; i++) {
    struct packed_git *ours = geometry->pack[i];

    if (unsigned_mult_overflows(geometry->split_factor,
              total_size))
      die(_("pack %s too large to roll up"), ours->pack_name);

    if (geometry_pack_weight(ours) <
        geometry->split_factor * total_size) {
      if (unsigned_add_overflows(total_size,
               geometry_pack_weight(ours)))
        die(_("pack %s too large to roll up"),
            ours->pack_name);

      split++;
      total_size += geometry_pack_weight(ours);
    } else
      break;
  }

  geometry->split = split;
}

static struct packed_git *get_preferred_pack(struct pack_geometry *geometry)
{
  uint32_t i;

  if (!geometry) {
    /*
     * No geometry means either an all-into-one repack (in which
     * case there is only one pack left and it is the largest) or an
     * incremental one.
     *
     * If repacking incrementally, then we could check the size of
     * all packs to determine which should be preferred, but leave
     * this for later.
     */
    return NULL;
  }
  if (geometry->split == geometry->pack_nr)
    return NULL;

  /*
   * The preferred pack is the largest pack above the split line. In
   * other words, it is the largest pack that does not get rolled up in
   * the geometric repack.
   */
  for (i = geometry->pack_nr; i > geometry->split; i--)
    /*
     * A pack that is not local would never be included in a
     * multi-pack index. We thus skip over any non-local packs.
     */
    if (geometry->pack[i - 1]->pack_local)
      return geometry->pack[i - 1];

  return NULL;
}

static void geometry_remove_redundant_packs(struct pack_geometry *geometry,
              struct string_list *names,
              struct existing_packs *existing)
{
  struct strbuf buf = STRBUF_INIT;
  uint32_t i;

  for (i = 0; i < geometry->split; i++) {
    struct packed_git *p = geometry->pack[i];
    if (string_list_has_string(names, hash_to_hex(p->hash)))
      continue;

    strbuf_reset(&buf);
    strbuf_addstr(&buf, pack_basename(p));
    strbuf_strip_suffix(&buf, ".pack");

    if ((p->pack_keep) ||
        (string_list_has_string(&existing->kept_packs, buf.buf)))
      continue;

    remove_redundant_pack(packdir, buf.buf);
  }

  strbuf_release(&buf);
}

static void free_pack_geometry(struct pack_geometry *geometry)
{
  if (!geometry)
    return;

  free(geometry->pack);
}

struct midx_snapshot_ref_data {
  struct tempfile *f;
  struct oidset seen;
  int preferred;
};

static int midx_snapshot_ref_one(const char *refname UNUSED,
         const char *referent UNUSED,
         const struct object_id *oid,
         int flag UNUSED, void *_data)
{
  struct midx_snapshot_ref_data *data = _data;
  struct object_id peeled;

  if (!peel_iterated_oid(the_repository, oid, &peeled))
    oid = &peeled;

  if (oidset_insert(&data->seen, oid))
    return 0; /* already seen */

  if (oid_object_info(the_repository, oid, NULL) != OBJ_COMMIT)
    return 0;

  fprintf(data->f->fp, "%s%s\n", data->preferred ? "+" : "",
    oid_to_hex(oid));

  return 0;
}

static void midx_snapshot_refs(struct tempfile *f)
{
  struct midx_snapshot_ref_data data;
  const struct string_list *preferred = bitmap_preferred_tips(the_repository);

  data.f = f;
  data.preferred = 0;
  oidset_init(&data.seen, 0);

  if (!fdopen_tempfile(f, "w"))
     die(_("could not open tempfile %s for writing"),
         get_tempfile_path(f));

  if (preferred) {
    struct string_list_item *item;

    data.preferred = 1;
    for_each_string_list_item(item, preferred)
      refs_for_each_ref_in(get_main_ref_store(the_repository),
               item->string,
               midx_snapshot_ref_one, &data);
    data.preferred = 0;
  }

  refs_for_each_ref(get_main_ref_store(the_repository),
        midx_snapshot_ref_one, &data);

  if (close_tempfile_gently(f)) {
    int save_errno = errno;
    delete_tempfile(&f);
    errno = save_errno;
    die_errno(_("could not close refs snapshot tempfile"));
  }

  oidset_clear(&data.seen);
}

static void midx_included_packs(struct string_list *include,
        struct existing_packs *existing,
        struct string_list *names,
        struct pack_geometry *geometry)
{
  struct string_list_item *item;
  struct strbuf buf = STRBUF_INIT;

  for_each_string_list_item(item, &existing->kept_packs) {
    strbuf_reset(&buf);
    strbuf_addf(&buf, "%s.idx", item->string);
    string_list_insert(include, buf.buf);
  }

  for_each_string_list_item(item, names) {
    strbuf_reset(&buf);
    strbuf_addf(&buf, "pack-%s.idx", item->string);
    string_list_insert(include, buf.buf);
  }

  if (geometry->split_factor) {
    uint32_t i;

    for (i = geometry->split; i < geometry->pack_nr; i++) {
      struct packed_git *p = geometry->pack[i];

      /*
       * The multi-pack index never refers to packfiles part
       * of an alternate object database, so we skip these.
       * While git-multi-pack-index(1) would silently ignore
       * them anyway, this allows us to skip executing the
       * command completely when we have only non-local
       * packfiles.
       */
      if (!p->pack_local)
        continue;

      strbuf_reset(&buf);
      strbuf_addstr(&buf, pack_basename(p));
      strbuf_strip_suffix(&buf, ".pack");
      strbuf_addstr(&buf, ".idx");

      string_list_insert(include, buf.buf);
    }
  } else {
    for_each_string_list_item(item, &existing->non_kept_packs) {
      if (pack_is_marked_for_deletion(item))
        continue;

      strbuf_reset(&buf);
      strbuf_addf(&buf, "%s.idx", item->string);
      string_list_insert(include, buf.buf);
    }
  }

  for_each_string_list_item(item, &existing->cruft_packs) {
    /*
     * When doing a --geometric repack, there is no need to check
     * for deleted packs, since we're by definition not doing an
     * ALL_INTO_ONE repack (hence no packs will be deleted).
     * Otherwise we must check for and exclude any packs which are
     * enqueued for deletion.
     *
     * So we could omit the conditional below in the --geometric
     * case, but doing so is unnecessary since no packs are marked
     * as pending deletion (since we only call
     * `mark_packs_for_deletion()` when doing an all-into-one
     * repack).
     */
    if (pack_is_marked_for_deletion(item))
      continue;

    strbuf_reset(&buf);
    strbuf_addf(&buf, "%s.idx", item->string);
    string_list_insert(include, buf.buf);
  }

  strbuf_release(&buf);
}

static int write_midx_included_packs(struct string_list *include,
             struct pack_geometry *geometry,
             struct string_list *names,
             const char *refs_snapshot,
             int show_progress, int write_bitmaps)
{
  struct child_process cmd = CHILD_PROCESS_INIT;
  struct string_list_item *item;
  struct packed_git *preferred = get_preferred_pack(geometry);
  FILE *in;
  int ret;

  if (!include->nr)
    return 0;

  cmd.in = -1;
  cmd.git_cmd = 1;

  strvec_push(&cmd.args, "multi-pack-index");
  strvec_pushl(&cmd.args, "write", "--stdin-packs", NULL);

  if (show_progress)
    strvec_push(&cmd.args, "--progress");
  else
    strvec_push(&cmd.args, "--no-progress");

  if (write_bitmaps)
    strvec_push(&cmd.args, "--bitmap");

  if (preferred)
    strvec_pushf(&cmd.args, "--preferred-pack=%s",
           pack_basename(preferred));
  else if (names->nr) {
    /* The largest pack was repacked, meaning that either
     * one or two packs exist depending on whether the
     * repository has a cruft pack or not.
     *
     * Select the non-cruft one as preferred to encourage
     * pack-reuse among packs containing reachable objects
     * over unreachable ones.
     *
     * (Note we could write multiple packs here if
     * `--max-pack-size` was given, but any one of them
     * will suffice, so pick the first one.)
     */
    for_each_string_list_item(item, names) {
      struct generated_pack_data *data = item->util;
      if (has_pack_ext(data, ".mtimes"))
        continue;

      strvec_pushf(&cmd.args, "--preferred-pack=pack-%s.pack",
             item->string);
      break;
    }
  } else {
    /*
     * No packs were kept, and no packs were written. The
     * only thing remaining are .keep packs (unless
     * --pack-kept-objects was given).
     *
     * Set the `--preferred-pack` arbitrarily here.
     */
    ;
  }

  if (refs_snapshot)
    strvec_pushf(&cmd.args, "--refs-snapshot=%s", refs_snapshot);

  ret = start_command(&cmd);
  if (ret)
    return ret;

  in = xfdopen(cmd.in, "w");
  for_each_string_list_item(item, include)
    fprintf(in, "%s\n", item->string);
  fclose(in);

  return finish_command(&cmd);
}

static void remove_redundant_bitmaps(struct string_list *include,
             const char *packdir)
{
  struct strbuf path = STRBUF_INIT;
  struct string_list_item *item;
  size_t packdir_len;

  strbuf_addstr(&path, packdir);
  strbuf_addch(&path, '/');
  packdir_len = path.len;

  /*
   * Remove any pack bitmaps corresponding to packs which are now
   * included in the MIDX.
   */
  for_each_string_list_item(item, include) {
    strbuf_addstr(&path, item->string);
    strbuf_strip_suffix(&path, ".idx");
    strbuf_addstr(&path, ".bitmap");

    if (unlink(path.buf) && errno != ENOENT)
      warning_errno(_("could not remove stale bitmap: %s"),
              path.buf);

    strbuf_setlen(&path, packdir_len);
  }
  strbuf_release(&path);
}

static int finish_pack_objects_cmd(struct child_process *cmd,
           struct string_list *names,
           int local)
{
  FILE *out;
  struct strbuf line = STRBUF_INIT;

  out = xfdopen(cmd->out, "r");
  while (strbuf_getline_lf(&line, out) != EOF) {
    struct string_list_item *item;

    if (line.len != the_hash_algo->hexsz)
      die(_("repack: Expecting full hex object ID lines only "
            "from pack-objects."));
    /*
     * Avoid putting packs written outside of the repository in the
     * list of names.
     */
    if (local) {
      item = string_list_append(names, line.buf);
      item->util = populate_pack_exts(line.buf);
    }
  }
  fclose(out);

  strbuf_release(&line);

  return finish_command(cmd);
}

static int write_filtered_pack(const struct pack_objects_args *args,
             const char *destination,
             const char *pack_prefix,
             struct existing_packs *existing,
             struct string_list *names)
{
  struct child_process cmd = CHILD_PROCESS_INIT;
  struct string_list_item *item;
  FILE *in;
  int ret;
  const char *caret;
  const char *scratch;
  int local = skip_prefix(destination, packdir, &scratch);

  prepare_pack_objects(&cmd, args, destination);

  strvec_push(&cmd.args, "--stdin-packs");

  if (!pack_kept_objects)
    strvec_push(&cmd.args, "--honor-pack-keep");
  for_each_string_list_item(item, &existing->kept_packs)
    strvec_pushf(&cmd.args, "--keep-pack=%s", item->string);

  cmd.in = -1;

  ret = start_command(&cmd);
  if (ret)
    return ret;

  /*
   * Here 'names' contains only the pack(s) that were just
   * written, which is exactly the packs we want to keep. Also
   * 'existing_kept_packs' already contains the packs in
   * 'keep_pack_list'.
   */
  in = xfdopen(cmd.in, "w");
  for_each_string_list_item(item, names)
    fprintf(in, "^%s-%s.pack\n", pack_prefix, item->string);
  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);
  caret = pack_kept_objects ? "" : "^";
  for_each_string_list_item(item, &existing->kept_packs)
    fprintf(in, "%s%s.pack\n", caret, item->string);
  fclose(in);

  return finish_pack_objects_cmd(&cmd, names, local);
}

static int existing_cruft_pack_cmp(const void *va, const void *vb)
{
  struct packed_git *a = *(struct packed_git **)va;
  struct packed_git *b = *(struct packed_git **)vb;

  if (a->pack_size < b->pack_size)
    return -1;
  if (a->pack_size > b->pack_size)
    return 1;
  return 0;
}

static void collapse_small_cruft_packs(FILE *in, size_t max_size,
               struct existing_packs *existing)
{
  struct packed_git **existing_cruft, *p;
  struct strbuf buf = STRBUF_INIT;
  size_t total_size = 0;
  size_t existing_cruft_nr = 0;
  size_t i;

  ALLOC_ARRAY(existing_cruft, existing->cruft_packs.nr);

  for (p = get_all_packs(the_repository); p; p = p->next) {
    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 (existing_cruft_nr >= existing->cruft_packs.nr)
      BUG("too many cruft packs (found %"PRIuMAX", but knew "
          "of %"PRIuMAX")",
          (uintmax_t)existing_cruft_nr + 1,
          (uintmax_t)existing->cruft_packs.nr);
    existing_cruft[existing_cruft_nr++] = p;
  }

  QSORT(existing_cruft, existing_cruft_nr, existing_cruft_pack_cmp);

  for (i = 0; i < existing_cruft_nr; i++) {
    size_t proposed;

    p = existing_cruft[i];
    proposed = st_add(total_size, p->pack_size);

    if (proposed <= max_size) {
      total_size = proposed;
      fprintf(in, "-%s\n", pack_basename(p));
    } else {
      retain_cruft_pack(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);
  free(existing_cruft);
}

static int write_cruft_pack(const struct pack_objects_args *args,
          const char *destination,
          const char *pack_prefix,
          const char *cruft_expiration,
          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 *scratch;
  int local = skip_prefix(destination, packdir, &scratch);

  prepare_pack_objects(&cmd, args, destination);

  strvec_push(&cmd.args, "--cruft");
  if (cruft_expiration)
    strvec_pushf(&cmd.args, "--cruft-expiration=%s",
           cruft_expiration);

  strvec_push(&cmd.args, "--honor-pack-keep");
  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 (args->max_pack_size && !cruft_expiration) {
    collapse_small_cruft_packs(in, args->max_pack_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(&cmd, names, local);
}

static const char *find_pack_prefix(const char *packdir, const char *packtmp)
{
  const char *pack_prefix;
  if (!skip_prefix(packtmp, packdir, &pack_prefix))
    die(_("pack prefix %s does not begin with objdir %s"),
        packtmp, packdir);
  if (*pack_prefix == '/')
    pack_prefix++;
  return pack_prefix;
}

int cmd_repack(int argc, const char **argv, const char *prefix)
{
  struct child_process cmd = CHILD_PROCESS_INIT;
  struct string_list_item *item;
  struct string_list names = STRING_LIST_INIT_DUP;
  struct existing_packs existing = EXISTING_PACKS_INIT;
  struct pack_geometry geometry = { 0 };
  struct tempfile *refs_snapshot = NULL;
  int i, ext, ret;
  int show_progress;

  /* variables to be filled by option parsing */
  int delete_redundant = 0;
  const char *unpack_unreachable = NULL;
  int keep_unreachable = 0;
  struct string_list keep_pack_list = STRING_LIST_INIT_NODUP;
  struct pack_objects_args po_args = {NULL};
  struct pack_objects_args cruft_po_args = {NULL};
  int write_midx = 0;
  const char *cruft_expiration = NULL;
  const char *expire_to = NULL;
  const char *filter_to = NULL;

  struct option builtin_repack_options[] = {
    OPT_BIT('a', NULL, &pack_everything,
        N_("pack everything in a single pack"), ALL_INTO_ONE),
    OPT_BIT('A', NULL, &pack_everything,
        N_("same as -a, and turn unreachable objects loose"),
           LOOSEN_UNREACHABLE | ALL_INTO_ONE),
    OPT_BIT(0, "cruft", &pack_everything,
        N_("same as -a, pack unreachable cruft objects separately"),
           PACK_CRUFT),
    OPT_STRING(0, "cruft-expiration", &cruft_expiration, N_("approxidate"),
        N_("with --cruft, expire objects older than this")),
    OPT_MAGNITUDE(0, "max-cruft-size", &cruft_po_args.max_pack_size,
        N_("with --cruft, limit the size of new cruft packs")),
    OPT_BOOL('d', NULL, &delete_redundant,
        N_("remove redundant packs, and run git-prune-packed")),
    OPT_BOOL('f', NULL, &po_args.no_reuse_delta,
        N_("pass --no-reuse-delta to git-pack-objects")),
    OPT_BOOL('F', NULL, &po_args.no_reuse_object,
        N_("pass --no-reuse-object to git-pack-objects")),
    OPT_NEGBIT('n', NULL, &run_update_server_info,
        N_("do not run git-update-server-info"), 1),
    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_BOOL('i', "delta-islands", &use_delta_islands,
        N_("pass --delta-islands to git-pack-objects")),
    OPT_STRING(0, "unpack-unreachable", &unpack_unreachable, N_("approxidate"),
        N_("with -A, do not loosen objects older than this")),
    OPT_BOOL('k', "keep-unreachable", &keep_unreachable,
        N_("with -a, repack unreachable objects")),
    OPT_STRING(0, "window", &po_args.window, N_("n"),
        N_("size of the window used for delta compression")),
    OPT_STRING(0, "window-memory", &po_args.window_memory, N_("bytes"),
        N_("same as the above, but limit memory size instead of entries count")),
    OPT_STRING(0, "depth", &po_args.depth, N_("n"),
        N_("limits the maximum delta depth")),
    OPT_STRING(0, "threads", &po_args.threads, N_("n"),
        N_("limits the maximum number of threads")),
    OPT_MAGNITUDE(0, "max-pack-size", &po_args.max_pack_size,
        N_("maximum size of each packfile")),
    OPT_PARSE_LIST_OBJECTS_FILTER(&po_args.filter_options),
    OPT_BOOL(0, "pack-kept-objects", &pack_kept_objects,
        N_("repack objects in packs marked with .keep")),
    OPT_STRING_LIST(0, "keep-pack", &keep_pack_list, N_("name"),
        N_("do not repack this pack")),
    OPT_INTEGER('g', "geometric", &geometry.split_factor,
          N_("find a geometric progression with factor <N>")),
    OPT_BOOL('m', "write-midx", &write_midx,
         N_("write a multi-pack index of the resulting packs")),
    OPT_STRING(0, "expire-to", &expire_to, N_("dir"),
         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_END()
  };

  list_objects_filter_init(&po_args.filter_options);

  git_config(repack_config, &cruft_po_args);

  argc = parse_options(argc, argv, prefix, builtin_repack_options,
        git_repack_usage, 0);

  if (delete_redundant && repository_format_precious_objects)
    die(_("cannot delete packs in a precious-objects repo"));

  die_for_incompatible_opt3(unpack_unreachable || (pack_everything & LOOSEN_UNREACHABLE), "-A",
          keep_unreachable, "-k/--keep-unreachable",
          pack_everything & PACK_CRUFT, "--cruft");

  if (pack_everything & PACK_CRUFT)
    pack_everything |= ALL_INTO_ONE;

  if (write_bitmaps < 0) {
    if (!write_midx &&
        (!(pack_everything & ALL_INTO_ONE) || !is_bare_repository()))
      write_bitmaps = 0;
  }
  if (pack_kept_objects < 0)
    pack_kept_objects = write_bitmaps > 0 && !write_midx;

  if (write_bitmaps && !(pack_everything & ALL_INTO_ONE) && !write_midx)
    die(_(incremental_bitmap_conflict_error));

  if (write_bitmaps && po_args.local && has_alt_odb(the_repository)) {
    /*
     * When asked to do a local repack, but we have
     * packfiles that are inherited from an alternate, then
     * we cannot guarantee that the multi-pack-index would
     * have full coverage of all objects. We thus disable
     * writing bitmaps in that case.
     */
    warning(_("disabling bitmap writing, as some objects are not being packed"));
    write_bitmaps = 0;
  }

  if (write_midx && write_bitmaps) {
    struct strbuf path = STRBUF_INIT;

    strbuf_addf(&path, "%s/%s_XXXXXX", get_object_directory(),
          "bitmap-ref-tips");

    refs_snapshot = xmks_tempfile(path.buf);
    midx_snapshot_refs(refs_snapshot);

    strbuf_release(&path);
  }

  packdir = mkpathdup("%s/pack", get_object_directory());
  packtmp_name = xstrfmt(".tmp-%d-pack", (int)getpid());
  packtmp = mkpathdup("%s/%s", packdir, packtmp_name);

  collect_pack_filenames(&existing, &keep_pack_list);

  if (geometry.split_factor) {
    if (pack_everything)
      die(_("options '%s' and '%s' cannot be used together"), "--geometric", "-A/-a");
    init_pack_geometry(&geometry, &existing, &po_args);
    split_pack_geometry(&geometry);
  }

  prepare_pack_objects(&cmd, &po_args, packtmp);

  show_progress = !po_args.quiet && isatty(2);

  strvec_push(&cmd.args, "--keep-true-parents");
  if (!pack_kept_objects)
    strvec_push(&cmd.args, "--honor-pack-keep");
  for (i = 0; i < keep_pack_list.nr; i++)
    strvec_pushf(&cmd.args, "--keep-pack=%s",
           keep_pack_list.items[i].string);
  strvec_push(&cmd.args, "--non-empty");
  if (!geometry.split_factor) {
    /*
     * We need to grab all reachable objects, including those that
     * are reachable from reflogs and the index.
     *
     * When repacking into a geometric progression of packs,
     * however, we ask 'git pack-objects --stdin-packs', and it is
     * not about packing objects based on reachability but about
     * repacking all the objects in specified packs and loose ones
     * (indeed, --stdin-packs is incompatible with these options).
     */
    strvec_push(&cmd.args, "--all");
    strvec_push(&cmd.args, "--reflog");
    strvec_push(&cmd.args, "--indexed-objects");
  }
  if (repo_has_promisor_remote(the_repository))
    strvec_push(&cmd.args, "--exclude-promisor-objects");
  if (!write_midx) {
    if (write_bitmaps > 0)
      strvec_push(&cmd.args, "--write-bitmap-index");
    else if (write_bitmaps < 0)
      strvec_push(&cmd.args, "--write-bitmap-index-quiet");
  }
  if (use_delta_islands)
    strvec_push(&cmd.args, "--delta-islands");

  if (pack_everything & ALL_INTO_ONE) {
    repack_promisor_objects(&po_args, &names);

    if (has_existing_non_kept_packs(&existing) &&
        delete_redundant &&
        !(pack_everything & PACK_CRUFT)) {
      for_each_string_list_item(item, &names) {
        strvec_pushf(&cmd.args, "--keep-pack=%s-%s.pack",
               packtmp_name, item->string);
      }
      if (unpack_unreachable) {
        strvec_pushf(&cmd.args,
               "--unpack-unreachable=%s",
               unpack_unreachable);
      } else if (pack_everything & LOOSEN_UNREACHABLE) {
        strvec_push(&cmd.args,
              "--unpack-unreachable");
      } else if (keep_unreachable) {
        strvec_push(&cmd.args, "--keep-unreachable");
        strvec_push(&cmd.args, "--pack-loose-unreachable");
      }
    }
  } else if (geometry.split_factor) {
    strvec_push(&cmd.args, "--stdin-packs");
    strvec_push(&cmd.args, "--unpacked");
  } else {
    strvec_push(&cmd.args, "--unpacked");
    strvec_push(&cmd.args, "--incremental");
  }

  if (po_args.filter_options.choice)
    strvec_pushf(&cmd.args, "--filter=%s",
           expand_list_objects_filter_spec(&po_args.filter_options));
  else if (filter_to)
    die(_("option '%s' can only be used along with '%s'"), "--filter-to", "--filter");

  if (geometry.split_factor)
    cmd.in = -1;
  else
    cmd.no_stdin = 1;

  ret = start_command(&cmd);
  if (ret)
    goto cleanup;

  if (geometry.split_factor) {
    FILE *in = xfdopen(cmd.in, "w");
    /*
     * The resulting pack should contain all objects in packs that
     * are going to be rolled up, but exclude objects in packs which
     * are being left alone.
     */
    for (i = 0; i < geometry.split; i++)
      fprintf(in, "%s\n", pack_basename(geometry.pack[i]));
    for (i = geometry.split; i < geometry.pack_nr; i++)
      fprintf(in, "^%s\n", pack_basename(geometry.pack[i]));
    fclose(in);
  }

  ret = finish_pack_objects_cmd(&cmd, &names, 1);
  if (ret)
    goto cleanup;

  if (!names.nr && !po_args.quiet)
    printf_ln(_("Nothing new to pack."));

  if (pack_everything & PACK_CRUFT) {
    const char *pack_prefix = find_pack_prefix(packdir, packtmp);

    if (!cruft_po_args.window)
      cruft_po_args.window = po_args.window;
    if (!cruft_po_args.window_memory)
      cruft_po_args.window_memory = po_args.window_memory;
    if (!cruft_po_args.depth)
      cruft_po_args.depth = po_args.depth;
    if (!cruft_po_args.threads)
      cruft_po_args.threads = po_args.threads;
    if (!cruft_po_args.max_pack_size)
      cruft_po_args.max_pack_size = po_args.max_pack_size;

    cruft_po_args.local = po_args.local;
    cruft_po_args.quiet = po_args.quiet;

    ret = write_cruft_pack(&cruft_po_args, packtmp, pack_prefix,
               cruft_expiration, &names,
               &existing);
    if (ret)
      goto cleanup;

    if (delete_redundant && expire_to) {
      /*
       * If `--expire-to` is given with `-d`, it's possible
       * that we're about to prune some objects. With cruft
       * packs, pruning is implicit: any objects from existing
       * packs that weren't picked up by new packs are removed
       * when their packs are deleted.
       *
       * Generate an additional cruft pack, with one twist:
       * `names` now includes the name of the cruft pack
       * written in the previous step. So the contents of
       * _this_ cruft pack exclude everything contained in the
       * existing cruft pack (that is, all of the unreachable
       * objects which are no older than
       * `--cruft-expiration`).
       *
       * To make this work, cruft_expiration must become NULL
       * so that this cruft pack doesn't actually prune any
       * objects. If it were non-NULL, this call would always
       * generate an empty pack (since every object not in the
       * cruft pack generated above will have an mtime older
       * than the expiration).
       */
      ret = write_cruft_pack(&cruft_po_args, expire_to,
                 pack_prefix,
                 NULL,
                 &names,
                 &existing);
      if (ret)
        goto cleanup;
    }
  }

  if (po_args.filter_options.choice) {
    if (!filter_to)
      filter_to = packtmp;

    ret = write_filtered_pack(&po_args,
            filter_to,
            find_pack_prefix(packdir, packtmp),
            &existing,
            &names);
    if (ret)
      goto cleanup;
  }

  string_list_sort(&names);

  close_object_store(the_repository->objects);

  /*
   * Ok we have prepared all new packfiles.
   */
  for_each_string_list_item(item, &names) {
    struct generated_pack_data *data = item->util;

    for (ext = 0; ext < ARRAY_SIZE(exts); ext++) {
      char *fname;

      fname = mkpathdup("%s/pack-%s%s",
          packdir, item->string, exts[ext].name);

      if (data->tempfiles[ext]) {
        const char *fname_old = get_tempfile_path(data->tempfiles[ext]);
        struct stat statbuffer;

        if (!stat(fname_old, &statbuffer)) {
          statbuffer.st_mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
          chmod(fname_old, statbuffer.st_mode);
        }

        if (rename_tempfile(&data->tempfiles[ext], fname))
          die_errno(_("renaming pack to '%s' failed"), fname);
      } else if (!exts[ext].optional)
        die(_("pack-objects did not write a '%s' file for pack %s-%s"),
            exts[ext].name, packtmp, item->string);
      else if (unlink(fname) < 0 && errno != ENOENT)
        die_errno(_("could not unlink: %s"), fname);

      free(fname);
    }
  }
  /* End of pack replacement. */

  if (delete_redundant && pack_everything & ALL_INTO_ONE)
    mark_packs_for_deletion(&existing, &names);

  if (write_midx) {
    struct string_list include = STRING_LIST_INIT_DUP;
    midx_included_packs(&include, &existing, &names, &geometry);

    ret = write_midx_included_packs(&include, &geometry, &names,
            refs_snapshot ? get_tempfile_path(refs_snapshot) : NULL,
            show_progress, write_bitmaps > 0);

    if (!ret && write_bitmaps)
      remove_redundant_bitmaps(&include, packdir);

    string_list_clear(&include, 0);

    if (ret)
      goto cleanup;
  }

  reprepare_packed_git(the_repository);

  if (delete_redundant) {
    int opts = 0;
    remove_redundant_existing_packs(&existing);

    if (geometry.split_factor)
      geometry_remove_redundant_packs(&geometry, &names,
              &existing);
    if (show_progress)
      opts |= PRUNE_PACKED_VERBOSE;
    prune_packed_objects(opts);

    if (!keep_unreachable &&
        (!(pack_everything & LOOSEN_UNREACHABLE) ||
         unpack_unreachable) &&
        is_repository_shallow(the_repository))
      prune_shallow(PRUNE_QUICK);
  }

  if (run_update_server_info)
    update_server_info(0);

  if (git_env_bool(GIT_TEST_MULTI_PACK_INDEX, 0)) {
    unsigned flags = 0;
    if (git_env_bool(GIT_TEST_MULTI_PACK_INDEX_WRITE_INCREMENTAL, 0))
      flags |= MIDX_WRITE_INCREMENTAL;
    write_midx_file(get_object_directory(), NULL, NULL, flags);
  }

cleanup:
  string_list_clear(&names, 1);
  existing_packs_release(&existing);
  free_pack_geometry(&geometry);
  list_objects_filter_release(&po_args.filter_options);

  return ret;
}

Coverage Report

Created: 2024-09-08 06:24