git/builtin/multi-pack-index.c
Taylor Blau fcb2205b77 midx: implement support for writing incremental MIDX chains
Now that the rest of the MIDX subsystem and relevant callers have been
updated to learn about how to read and process incremental MIDX chains,
let's finally update the implementation in `write_midx_internal()` to be
able to write incremental MIDX chains.

This new feature is available behind the `--incremental` option for the
`multi-pack-index` builtin, like so:

    $ git multi-pack-index write --incremental

The implementation for doing so is relatively straightforward, and boils
down to a handful of different kinds of changes implemented in this
patch:

  - The `compute_sorted_entries()` function is taught to reject objects
    which appear in any existing MIDX layer.

  - Functions like `write_midx_revindex()` are adjusted to write
    pack_order values which are offset by the number of objects in the
    base MIDX layer.

  - The end of `write_midx_internal()` is adjusted to move
    non-incremental MIDX files when necessary (i.e. when creating an
    incremental chain with an existing non-incremental MIDX in the
    repository).

There are a handful of other changes that are introduced, like new
functions to clear incremental MIDX files that are unrelated to the
current chain (using the same "keep_hash" mechanism as in the
non-incremental case).

The tests explicitly exercising the new incremental MIDX feature are
relatively limited for two reasons:

  1. Most of the "interesting" behavior is already thoroughly covered in
     t5319-multi-pack-index.sh, which handles the core logic of reading
     objects through a MIDX.

     The new tests in t5334-incremental-multi-pack-index.sh are mostly
     focused on creating and destroying incremental MIDXs, as well as
     stitching their results together across layers.

  2. A new GIT_TEST environment variable is added called
     "GIT_TEST_MULTI_PACK_INDEX_WRITE_INCREMENTAL", which modifies the
     entire test suite to write incremental MIDXs after repacking when
     combined with the "GIT_TEST_MULTI_PACK_INDEX" variable.

     This exercises the long tail of other interesting behavior that is
     defined implicitly throughout the rest of the CI suite. It is
     likewise added to the linux-TEST-vars job.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-08-06 12:01:39 -07:00

302 lines
8 KiB
C

#include "builtin.h"
#include "abspath.h"
#include "config.h"
#include "environment.h"
#include "gettext.h"
#include "parse-options.h"
#include "midx.h"
#include "strbuf.h"
#include "trace2.h"
#include "object-store-ll.h"
#include "replace-object.h"
#define BUILTIN_MIDX_WRITE_USAGE \
N_("git multi-pack-index [<options>] write [--preferred-pack=<pack>]" \
"[--refs-snapshot=<path>]")
#define BUILTIN_MIDX_VERIFY_USAGE \
N_("git multi-pack-index [<options>] verify")
#define BUILTIN_MIDX_EXPIRE_USAGE \
N_("git multi-pack-index [<options>] expire")
#define BUILTIN_MIDX_REPACK_USAGE \
N_("git multi-pack-index [<options>] repack [--batch-size=<size>]")
static char const * const builtin_multi_pack_index_write_usage[] = {
BUILTIN_MIDX_WRITE_USAGE,
NULL
};
static char const * const builtin_multi_pack_index_verify_usage[] = {
BUILTIN_MIDX_VERIFY_USAGE,
NULL
};
static char const * const builtin_multi_pack_index_expire_usage[] = {
BUILTIN_MIDX_EXPIRE_USAGE,
NULL
};
static char const * const builtin_multi_pack_index_repack_usage[] = {
BUILTIN_MIDX_REPACK_USAGE,
NULL
};
static char const * const builtin_multi_pack_index_usage[] = {
BUILTIN_MIDX_WRITE_USAGE,
BUILTIN_MIDX_VERIFY_USAGE,
BUILTIN_MIDX_EXPIRE_USAGE,
BUILTIN_MIDX_REPACK_USAGE,
NULL
};
static struct opts_multi_pack_index {
char *object_dir;
const char *preferred_pack;
char *refs_snapshot;
unsigned long batch_size;
unsigned flags;
int stdin_packs;
} opts;
static int parse_object_dir(const struct option *opt, const char *arg,
int unset)
{
char **value = opt->value;
free(*value);
if (unset)
*value = xstrdup(get_object_directory());
else
*value = real_pathdup(arg, 1);
return 0;
}
static struct option common_opts[] = {
OPT_CALLBACK(0, "object-dir", &opts.object_dir,
N_("directory"),
N_("object directory containing set of packfile and pack-index pairs"),
parse_object_dir),
OPT_END(),
};
static struct option *add_common_options(struct option *prev)
{
return parse_options_concat(common_opts, prev);
}
static int git_multi_pack_index_write_config(const char *var, const char *value,
const struct config_context *ctx UNUSED,
void *cb UNUSED)
{
if (!strcmp(var, "pack.writebitmaphashcache")) {
if (git_config_bool(var, value))
opts.flags |= MIDX_WRITE_BITMAP_HASH_CACHE;
else
opts.flags &= ~MIDX_WRITE_BITMAP_HASH_CACHE;
}
if (!strcmp(var, "pack.writebitmaplookuptable")) {
if (git_config_bool(var, value))
opts.flags |= MIDX_WRITE_BITMAP_LOOKUP_TABLE;
else
opts.flags &= ~MIDX_WRITE_BITMAP_LOOKUP_TABLE;
}
/*
* We should never make a fall-back call to 'git_default_config', since
* this was already called in 'cmd_multi_pack_index()'.
*/
return 0;
}
static void read_packs_from_stdin(struct string_list *to)
{
struct strbuf buf = STRBUF_INIT;
while (strbuf_getline(&buf, stdin) != EOF)
string_list_append(to, buf.buf);
string_list_sort(to);
strbuf_release(&buf);
}
static int cmd_multi_pack_index_write(int argc, const char **argv,
const char *prefix)
{
struct option *options;
static struct option builtin_multi_pack_index_write_options[] = {
OPT_STRING(0, "preferred-pack", &opts.preferred_pack,
N_("preferred-pack"),
N_("pack for reuse when computing a multi-pack bitmap")),
OPT_BIT(0, "bitmap", &opts.flags, N_("write multi-pack bitmap"),
MIDX_WRITE_BITMAP | MIDX_WRITE_REV_INDEX),
OPT_BIT(0, "progress", &opts.flags,
N_("force progress reporting"), MIDX_PROGRESS),
OPT_BIT(0, "incremental", &opts.flags,
N_("write a new incremental MIDX"), MIDX_WRITE_INCREMENTAL),
OPT_BOOL(0, "stdin-packs", &opts.stdin_packs,
N_("write multi-pack index containing only given indexes")),
OPT_FILENAME(0, "refs-snapshot", &opts.refs_snapshot,
N_("refs snapshot for selecting bitmap commits")),
OPT_END(),
};
int ret;
opts.flags |= MIDX_WRITE_BITMAP_HASH_CACHE;
git_config(git_multi_pack_index_write_config, NULL);
options = add_common_options(builtin_multi_pack_index_write_options);
trace2_cmd_mode(argv[0]);
if (isatty(2))
opts.flags |= MIDX_PROGRESS;
argc = parse_options(argc, argv, prefix,
options, builtin_multi_pack_index_write_usage,
0);
if (argc)
usage_with_options(builtin_multi_pack_index_write_usage,
options);
FREE_AND_NULL(options);
if (opts.stdin_packs) {
struct string_list packs = STRING_LIST_INIT_DUP;
read_packs_from_stdin(&packs);
ret = write_midx_file_only(opts.object_dir, &packs,
opts.preferred_pack,
opts.refs_snapshot, opts.flags);
string_list_clear(&packs, 0);
free(opts.refs_snapshot);
return ret;
}
ret = write_midx_file(opts.object_dir, opts.preferred_pack,
opts.refs_snapshot, opts.flags);
free(opts.refs_snapshot);
return ret;
}
static int cmd_multi_pack_index_verify(int argc, const char **argv,
const char *prefix)
{
struct option *options;
static struct option builtin_multi_pack_index_verify_options[] = {
OPT_BIT(0, "progress", &opts.flags,
N_("force progress reporting"), MIDX_PROGRESS),
OPT_END(),
};
options = add_common_options(builtin_multi_pack_index_verify_options);
trace2_cmd_mode(argv[0]);
if (isatty(2))
opts.flags |= MIDX_PROGRESS;
argc = parse_options(argc, argv, prefix,
options, builtin_multi_pack_index_verify_usage,
0);
if (argc)
usage_with_options(builtin_multi_pack_index_verify_usage,
options);
FREE_AND_NULL(options);
return verify_midx_file(the_repository, opts.object_dir, opts.flags);
}
static int cmd_multi_pack_index_expire(int argc, const char **argv,
const char *prefix)
{
struct option *options;
static struct option builtin_multi_pack_index_expire_options[] = {
OPT_BIT(0, "progress", &opts.flags,
N_("force progress reporting"), MIDX_PROGRESS),
OPT_END(),
};
options = add_common_options(builtin_multi_pack_index_expire_options);
trace2_cmd_mode(argv[0]);
if (isatty(2))
opts.flags |= MIDX_PROGRESS;
argc = parse_options(argc, argv, prefix,
options, builtin_multi_pack_index_expire_usage,
0);
if (argc)
usage_with_options(builtin_multi_pack_index_expire_usage,
options);
FREE_AND_NULL(options);
return expire_midx_packs(the_repository, opts.object_dir, opts.flags);
}
static int cmd_multi_pack_index_repack(int argc, const char **argv,
const char *prefix)
{
struct option *options;
static struct option builtin_multi_pack_index_repack_options[] = {
OPT_MAGNITUDE(0, "batch-size", &opts.batch_size,
N_("during repack, collect pack-files of smaller size into a batch that is larger than this size")),
OPT_BIT(0, "progress", &opts.flags,
N_("force progress reporting"), MIDX_PROGRESS),
OPT_END(),
};
options = add_common_options(builtin_multi_pack_index_repack_options);
trace2_cmd_mode(argv[0]);
if (isatty(2))
opts.flags |= MIDX_PROGRESS;
argc = parse_options(argc, argv, prefix,
options,
builtin_multi_pack_index_repack_usage,
0);
if (argc)
usage_with_options(builtin_multi_pack_index_repack_usage,
options);
FREE_AND_NULL(options);
return midx_repack(the_repository, opts.object_dir,
(size_t)opts.batch_size, opts.flags);
}
int cmd_multi_pack_index(int argc, const char **argv,
const char *prefix)
{
int res;
parse_opt_subcommand_fn *fn = NULL;
struct option builtin_multi_pack_index_options[] = {
OPT_SUBCOMMAND("repack", &fn, cmd_multi_pack_index_repack),
OPT_SUBCOMMAND("write", &fn, cmd_multi_pack_index_write),
OPT_SUBCOMMAND("verify", &fn, cmd_multi_pack_index_verify),
OPT_SUBCOMMAND("expire", &fn, cmd_multi_pack_index_expire),
OPT_END(),
};
struct option *options = parse_options_concat(builtin_multi_pack_index_options, common_opts);
disable_replace_refs();
git_config(git_default_config, NULL);
if (the_repository &&
the_repository->objects &&
the_repository->objects->odb)
opts.object_dir = xstrdup(the_repository->objects->odb->path);
argc = parse_options(argc, argv, prefix, options,
builtin_multi_pack_index_usage, 0);
FREE_AND_NULL(options);
res = fn(argc, argv, prefix);
free(opts.object_dir);
return res;
}