git-commit-vandalism/builtin/repack.c
Junio C Hamano a1af533323 Merge branch 'tb/pack-finalize-ordering'
The order in which various files that make up a single (conceptual)
packfile has been reevaluated and straightened up.  This matters in
correctness, as an incomplete set of files must not be shown to a
running Git.

* tb/pack-finalize-ordering:
  pack-objects: rename .idx files into place after .bitmap files
  pack-write: split up finish_tmp_packfile() function
  builtin/index-pack.c: move `.idx` files into place last
  index-pack: refactor renaming in final()
  builtin/repack.c: move `.idx` files into place last
  pack-write.c: rename `.idx` files after `*.rev`
  pack-write: refactor renaming in finish_tmp_packfile()
  bulk-checkin.c: store checksum directly
  pack.h: line-wrap the definition of finish_tmp_packfile()
2021-09-20 15:20:42 -07:00

747 lines
21 KiB
C

#include "builtin.h"
#include "cache.h"
#include "config.h"
#include "dir.h"
#include "parse-options.h"
#include "run-command.h"
#include "sigchain.h"
#include "strbuf.h"
#include "string-list.h"
#include "strvec.h"
#include "midx.h"
#include "packfile.h"
#include "prune-packed.h"
#include "object-store.h"
#include "promisor-remote.h"
#include "shallow.h"
#include "pack.h"
static int delta_base_offset = 1;
static int pack_kept_objects = -1;
static int write_bitmaps = -1;
static int use_delta_islands;
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."
);
static int repack_config(const char *var, const char *value, void *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;
}
return git_default_config(var, value, cb);
}
/*
* Remove temporary $GIT_OBJECT_DIRECTORY/pack/.tmp-$$-pack-* files.
*/
static void remove_temporary_files(void)
{
struct strbuf buf = STRBUF_INIT;
size_t dirlen, prefixlen;
DIR *dir;
struct dirent *e;
dir = opendir(packdir);
if (!dir)
return;
/* Point at the slash at the end of ".../objects/pack/" */
dirlen = strlen(packdir) + 1;
strbuf_addstr(&buf, packtmp);
/* Hold the length of ".tmp-%d-pack-" */
prefixlen = buf.len - dirlen;
while ((e = readdir(dir))) {
if (strncmp(e->d_name, buf.buf + dirlen, prefixlen))
continue;
strbuf_setlen(&buf, dirlen);
strbuf_addstr(&buf, e->d_name);
unlink(buf.buf);
}
closedir(dir);
strbuf_release(&buf);
}
static void remove_pack_on_signal(int signo)
{
remove_temporary_files();
sigchain_pop(signo);
raise(signo);
}
/*
* Adds all packs hex strings to the fname list, which do not
* have a corresponding .keep file. These packs are not to
* be kept if we are going to pack everything into one file.
*/
static void get_non_kept_pack_filenames(struct string_list *fname_list,
const struct string_list *extra_keep)
{
DIR *dir;
struct dirent *e;
char *fname;
if (!(dir = opendir(packdir)))
return;
while ((e = readdir(dir)) != NULL) {
size_t len;
int i;
for (i = 0; i < extra_keep->nr; i++)
if (!fspathcmp(e->d_name, extra_keep->items[i].string))
break;
if (extra_keep->nr > 0 && i < extra_keep->nr)
continue;
if (!strip_suffix(e->d_name, ".pack", &len))
continue;
fname = xmemdupz(e->d_name, len);
if (!file_exists(mkpath("%s/%s.keep", packdir, fname)))
string_list_append_nodup(fname_list, fname);
else
free(fname);
}
closedir(dir);
}
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);
}
struct pack_objects_args {
const char *window;
const char *window_memory;
const char *depth;
const char *threads;
const char *max_pack_size;
int no_reuse_delta;
int no_reuse_object;
int quiet;
int local;
};
static void prepare_pack_objects(struct child_process *cmd,
const struct pack_objects_args *args)
{
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=%s", 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, packtmp);
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,
uint32_t pos, 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"));
}
xwrite(cmd->in, oid_to_hex(oid), the_hash_algo->hexsz);
xwrite(cmd->in, "\n", 1);
return 0;
}
static struct {
const char *name;
unsigned optional:1;
} exts[] = {
{".pack"},
{".rev", 1},
{".bitmap", 1},
{".promisor", 1},
{".idx"},
};
static unsigned populate_pack_exts(char *name)
{
struct stat statbuf;
struct strbuf path = STRBUF_INIT;
unsigned ret = 0;
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;
ret |= (1 << i);
}
strbuf_release(&path);
return ret;
}
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);
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 */
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 = (void *)(uintptr_t)populate_pack_exts(item->string);
free(promisor_name);
}
fclose(out);
if (finish_command(&cmd))
die(_("could not finish pack-objects to repack promisor objects"));
}
#define ALL_INTO_ONE 1
#define LOOSEN_UNREACHABLE 2
struct pack_geometry {
struct packed_git **pack;
uint32_t pack_nr, pack_alloc;
uint32_t split;
};
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_p)
{
struct packed_git *p;
struct pack_geometry *geometry;
*geometry_p = xcalloc(1, sizeof(struct pack_geometry));
geometry = *geometry_p;
for (p = get_all_packs(the_repository); p; p = p->next) {
if (!pack_kept_objects && p->pack_keep)
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);
}
static void split_pack_geometry(struct pack_geometry *geometry, int factor)
{
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(factor, geometry_pack_weight(prev)))
die(_("pack %s too large to consider in geometric "
"progression"),
prev->pack_name);
if (geometry_pack_weight(ours) < 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(factor, total_size))
die(_("pack %s too large to roll up"), ours->pack_name);
if (geometry_pack_weight(ours) < 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 void clear_pack_geometry(struct pack_geometry *geometry)
{
if (!geometry)
return;
free(geometry->pack);
geometry->pack_nr = 0;
geometry->pack_alloc = 0;
geometry->split = 0;
}
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 string_list rollback = STRING_LIST_INIT_NODUP;
struct string_list existing_packs = STRING_LIST_INIT_DUP;
struct pack_geometry *geometry = NULL;
struct strbuf line = STRBUF_INIT;
int i, ext, ret;
FILE *out;
/* variables to be filled by option parsing */
int pack_everything = 0;
int delete_redundant = 0;
const char *unpack_unreachable = NULL;
int keep_unreachable = 0;
struct string_list keep_pack_list = STRING_LIST_INIT_NODUP;
int no_update_server_info = 0;
struct pack_objects_args po_args = {NULL};
int geometric_factor = 0;
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_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_BOOL('n', NULL, &no_update_server_info,
N_("do not run git-update-server-info")),
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_STRING(0, "max-pack-size", &po_args.max_pack_size, N_("bytes"),
N_("maximum size of each packfile")),
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", &geometric_factor,
N_("find a geometric progression with factor <N>")),
OPT_END()
};
git_config(repack_config, NULL);
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"));
if (keep_unreachable &&
(unpack_unreachable || (pack_everything & LOOSEN_UNREACHABLE)))
die(_("--keep-unreachable and -A are incompatible"));
if (write_bitmaps < 0) {
if (!(pack_everything & ALL_INTO_ONE) ||
!is_bare_repository())
write_bitmaps = 0;
} else if (write_bitmaps &&
git_env_bool(GIT_TEST_MULTI_PACK_INDEX, 0) &&
git_env_bool(GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP, 0)) {
write_bitmaps = 0;
}
if (pack_kept_objects < 0)
pack_kept_objects = write_bitmaps > 0;
if (write_bitmaps && !(pack_everything & ALL_INTO_ONE))
die(_(incremental_bitmap_conflict_error));
if (geometric_factor) {
if (pack_everything)
die(_("--geometric is incompatible with -A, -a"));
init_pack_geometry(&geometry);
split_pack_geometry(geometry, geometric_factor);
}
packdir = mkpathdup("%s/pack", get_object_directory());
packtmp_name = xstrfmt(".tmp-%d-pack", (int)getpid());
packtmp = mkpathdup("%s/%s", packdir, packtmp_name);
sigchain_push_common(remove_pack_on_signal);
prepare_pack_objects(&cmd, &po_args);
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) {
/*
* 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 (has_promisor_remote())
strvec_push(&cmd.args, "--exclude-promisor-objects");
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) {
get_non_kept_pack_filenames(&existing_packs, &keep_pack_list);
repack_promisor_objects(&po_args, &names);
if (existing_packs.nr && delete_redundant) {
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);
strvec_push(&cmd.env_array, "GIT_REF_PARANOIA=1");
} 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 {
strvec_push(&cmd.env_array, "GIT_REF_PARANOIA=1");
}
}
} else if (geometry) {
strvec_push(&cmd.args, "--stdin-packs");
strvec_push(&cmd.args, "--unpacked");
} else {
strvec_push(&cmd.args, "--unpacked");
strvec_push(&cmd.args, "--incremental");
}
if (geometry)
cmd.in = -1;
else
cmd.no_stdin = 1;
ret = start_command(&cmd);
if (ret)
return ret;
if (geometry) {
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);
}
out = xfdopen(cmd.out, "r");
while (strbuf_getline_lf(&line, out) != EOF) {
if (line.len != the_hash_algo->hexsz)
die(_("repack: Expecting full hex object ID lines only from pack-objects."));
string_list_append(&names, line.buf);
}
fclose(out);
ret = finish_command(&cmd);
if (ret)
return ret;
if (!names.nr && !po_args.quiet)
printf_ln(_("Nothing new to pack."));
for_each_string_list_item(item, &names) {
item->util = (void *)(uintptr_t)populate_pack_exts(item->string);
}
close_object_store(the_repository->objects);
/*
* Ok we have prepared all new packfiles.
*/
for_each_string_list_item(item, &names) {
for (ext = 0; ext < ARRAY_SIZE(exts); ext++) {
char *fname, *fname_old;
fname = mkpathdup("%s/pack-%s%s",
packdir, item->string, exts[ext].name);
fname_old = mkpathdup("%s-%s%s",
packtmp, item->string, exts[ext].name);
if (((uintptr_t)item->util) & (1 << 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(fname_old, fname))
die_errno(_("renaming '%s' failed"), fname_old);
} else if (!exts[ext].optional)
die(_("missing required file: %s"), fname_old);
else if (unlink(fname) < 0 && errno != ENOENT)
die_errno(_("could not unlink: %s"), fname);
free(fname);
free(fname_old);
}
}
/* End of pack replacement. */
reprepare_packed_git(the_repository);
if (delete_redundant) {
const int hexsz = the_hash_algo->hexsz;
int opts = 0;
string_list_sort(&names);
for_each_string_list_item(item, &existing_packs) {
char *sha1;
size_t len = strlen(item->string);
if (len < hexsz)
continue;
sha1 = item->string + len - hexsz;
if (!string_list_has_string(&names, sha1))
remove_redundant_pack(packdir, item->string);
}
if (geometry) {
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");
remove_redundant_pack(packdir, buf.buf);
}
strbuf_release(&buf);
}
if (!po_args.quiet && isatty(2))
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 (!no_update_server_info)
update_server_info(0);
remove_temporary_files();
if (git_env_bool(GIT_TEST_MULTI_PACK_INDEX, 0)) {
unsigned flags = 0;
if (git_env_bool(GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP, 0))
flags |= MIDX_WRITE_BITMAP | MIDX_WRITE_REV_INDEX;
write_midx_file(get_object_directory(), NULL, flags);
}
string_list_clear(&names, 0);
string_list_clear(&rollback, 0);
string_list_clear(&existing_packs, 0);
clear_pack_geometry(geometry);
strbuf_release(&line);
return 0;
}