Files
git/builtin/commit-graph.c
T
Patrick Steinhardt 623d2c7125 commit-graph: stop depending on struct odb_source
To read or write a commit graph we require access to the repository that
the graph should be read from or written for as well as the object
directory to derive its location. Instead of passing in these two bits
of information explicitly though, we pass in a `struct odb_source`,
which carries with it both of these pieces of information.

But ultimately, this is somewhat flawed as we now assume that the source
even has an on-disk representation, and furthermore we assume that the
commit graphs would live in ".git/objects/info". This is true for the
"files" backend, but it's not necessarily true for any other backend
that we may eventually want to introduce. So eventually, we'll want to
evolve the commit-graph subsystem to become agnostic of the backend's
layout and let the backend itself decide where to read a commit graph
from or where to write it to.

We're not there yet to do that switch, but the current design is already
causing issues for the intent of this patch series where we want to move
alternates into the "files" backend.

Convert the subsystem to take a repository plus an object directory path
instead. This unblocks moving around alternates, and it's also a step
in the right direction for moving commit graphs into the source in a
later series.

Note that we previously compared the `struct odb_source` pointers of two
commit graphs to figure out whether they were located in the same object
directory, whereas we now have to compare their paths. Callers may pass
in those paths in different forms though, for example relative to the
current working directory or as absolute paths. Convert the object
directory into an absolute path both when loading and when writing
commit graphs so that the comparisons become more robust.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-10-08 07:31:18 -07:00

376 lines
11 KiB
C

#define USE_THE_REPOSITORY_VARIABLE
#include "builtin.h"
#include "commit.h"
#include "config.h"
#include "environment.h"
#include "gettext.h"
#include "hex.h"
#include "parse-options.h"
#include "commit-graph.h"
#include "odb.h"
#include "odb/source.h"
#include "progress.h"
#include "replace-object.h"
#include "strbuf.h"
#include "tag.h"
#include "trace2.h"
#define BUILTIN_COMMIT_GRAPH_VERIFY_USAGE \
N_("git commit-graph verify [--object-dir <dir>] [--shallow] [--[no-]progress]")
#define BUILTIN_COMMIT_GRAPH_WRITE_USAGE \
N_("git commit-graph write [--object-dir <dir>] [--append]\n" \
" [--split[=<strategy>]] [--reachable | --stdin-packs | --stdin-commits]\n" \
" [--changed-paths] [--[no-]max-new-filters <n>] [--[no-]progress]\n" \
" <split-options>")
static const char * const builtin_commit_graph_verify_usage[] = {
BUILTIN_COMMIT_GRAPH_VERIFY_USAGE,
NULL
};
static const char * const builtin_commit_graph_write_usage[] = {
BUILTIN_COMMIT_GRAPH_WRITE_USAGE,
NULL
};
static char const * const builtin_commit_graph_usage[] = {
BUILTIN_COMMIT_GRAPH_VERIFY_USAGE,
BUILTIN_COMMIT_GRAPH_WRITE_USAGE,
NULL,
};
static struct opts_commit_graph {
const char *obj_dir;
int reachable;
int stdin_packs;
int stdin_commits;
int append;
int split;
int shallow;
int progress;
int enable_changed_paths;
} opts;
static struct option common_opts[] = {
OPT_STRING(0, "object-dir", &opts.obj_dir,
N_("dir"),
N_("the object directory to store the graph")),
OPT_END()
};
static struct option *add_common_options(struct option *to)
{
return parse_options_concat(common_opts, to);
}
static int graph_verify(int argc, const char **argv, const char *prefix,
struct repository *repo UNUSED)
{
struct commit_graph *graph = NULL;
struct odb_source *source = NULL;
char *graph_name;
char *chain_name;
enum { OPENED_NONE, OPENED_GRAPH, OPENED_CHAIN } opened = OPENED_NONE;
int fd;
struct stat st;
int flags = 0;
int incomplete_chain = 0;
int ret;
static struct option builtin_commit_graph_verify_options[] = {
OPT_BOOL(0, "shallow", &opts.shallow,
N_("if the commit-graph is split, only verify the tip file")),
OPT_BOOL(0, "progress", &opts.progress,
N_("force progress reporting")),
OPT_END(),
};
struct option *options = add_common_options(builtin_commit_graph_verify_options);
trace2_cmd_mode("verify");
opts.progress = isatty(2);
argc = parse_options(argc, argv, prefix,
options,
builtin_commit_graph_verify_usage, 0);
if (argc)
usage_with_options(builtin_commit_graph_verify_usage, options);
if (!opts.obj_dir)
opts.obj_dir = repo_get_object_directory(the_repository);
if (opts.shallow)
flags |= COMMIT_GRAPH_VERIFY_SHALLOW;
if (opts.progress)
flags |= COMMIT_GRAPH_WRITE_PROGRESS;
source = odb_find_source_or_die(the_repository->objects, opts.obj_dir);
graph_name = get_commit_graph_filename(source->path);
chain_name = get_commit_graph_chain_filename(source->path);
if (open_commit_graph(graph_name, &fd, &st))
opened = OPENED_GRAPH;
else if (errno != ENOENT)
die_errno(_("Could not open commit-graph '%s'"), graph_name);
else if (open_commit_graph_chain(chain_name, &fd, &st,
the_repository->hash_algo))
opened = OPENED_CHAIN;
else if (errno != ENOENT)
die_errno(_("could not open commit-graph chain '%s'"), chain_name);
FREE_AND_NULL(graph_name);
FREE_AND_NULL(chain_name);
FREE_AND_NULL(options);
if (opened == OPENED_NONE)
return 0;
else if (opened == OPENED_GRAPH)
graph = load_commit_graph_one_fd_st(the_repository, source->path, fd, &st);
else
graph = load_commit_graph_chain_fd_st(the_repository->objects, fd, &st,
&incomplete_chain);
if (!graph)
return 1;
ret = verify_commit_graph(graph, flags);
free_commit_graph(graph);
if (incomplete_chain) {
error("one or more commit-graph chain files could not be loaded");
ret |= 1;
}
return ret;
}
extern int read_replace_refs;
static struct commit_graph_opts write_opts;
static int write_option_parse_split(const struct option *opt, const char *arg,
int unset)
{
enum commit_graph_split_flags *flags = opt->value;
BUG_ON_OPT_NEG(unset);
opts.split = 1;
if (!arg)
return 0;
if (!strcmp(arg, "no-merge"))
*flags = COMMIT_GRAPH_SPLIT_MERGE_PROHIBITED;
else if (!strcmp(arg, "replace"))
*flags = COMMIT_GRAPH_SPLIT_REPLACE;
else
die(_("unrecognized --split argument, %s"), arg);
return 0;
}
static int read_one_commit(struct oidset *commits, struct progress *progress,
const char *hash)
{
struct object *result;
struct object_id oid;
const char *end;
if (parse_oid_hex(hash, &oid, &end))
return error(_("unexpected non-hex object ID: %s"), hash);
result = deref_tag(the_repository, parse_object(the_repository, &oid),
NULL, 0);
if (!result)
return error(_("invalid object: %s"), hash);
else if (object_as_type(result, OBJ_COMMIT, 1))
oidset_insert(commits, &result->oid);
display_progress(progress, oidset_size(commits));
return 0;
}
static int write_option_max_new_filters(const struct option *opt,
const char *arg,
int unset)
{
int *to = opt->value;
if (unset)
*to = -1;
else {
const char *s;
*to = strtol(arg, (char **)&s, 10);
if (*s)
return error(_("option `%s' expects a numerical value"),
"max-new-filters");
}
return 0;
}
static int git_commit_graph_write_config(const char *var, const char *value,
const struct config_context *ctx,
void *cb UNUSED)
{
if (!strcmp(var, "commitgraph.maxnewfilters"))
write_opts.max_new_filters = git_config_int(var, value, ctx->kvi);
else if (!strcmp(var, "commitgraph.changedpaths"))
opts.enable_changed_paths = git_config_bool(var, value) ? 1 : -1;
/*
* No need to fall-back to 'git_default_config', since this was already
* called in 'cmd_commit_graph()'.
*/
return 0;
}
static int graph_write(int argc, const char **argv, const char *prefix,
struct repository *repo UNUSED)
{
struct string_list pack_indexes = STRING_LIST_INIT_DUP;
struct strbuf buf = STRBUF_INIT;
struct oidset commits = OIDSET_INIT;
struct odb_source *source = NULL;
int result = 0;
enum commit_graph_write_flags flags = 0;
struct progress *progress = NULL;
static struct option builtin_commit_graph_write_options[] = {
OPT_BOOL(0, "reachable", &opts.reachable,
N_("start walk at all refs")),
OPT_BOOL(0, "stdin-packs", &opts.stdin_packs,
N_("scan pack-indexes listed by stdin for commits")),
OPT_BOOL(0, "stdin-commits", &opts.stdin_commits,
N_("start walk at commits listed by stdin")),
OPT_BOOL(0, "append", &opts.append,
N_("include all commits already in the commit-graph file")),
OPT_BOOL(0, "changed-paths", &opts.enable_changed_paths,
N_("enable computation for changed paths")),
OPT_CALLBACK_F(0, "split", &write_opts.split_flags, NULL,
N_("allow writing an incremental commit-graph file"),
PARSE_OPT_OPTARG | PARSE_OPT_NONEG,
write_option_parse_split),
OPT_INTEGER(0, "max-commits", &write_opts.max_commits,
N_("maximum number of commits in a non-base split commit-graph")),
OPT_INTEGER(0, "size-multiple", &write_opts.size_multiple,
N_("maximum ratio between two levels of a split commit-graph")),
OPT_EXPIRY_DATE(0, "expire-time", &write_opts.expire_time,
N_("only expire files older than a given date-time")),
OPT_CALLBACK_F(0, "max-new-filters", &write_opts.max_new_filters,
NULL, N_("maximum number of changed-path Bloom filters to compute"),
0, write_option_max_new_filters),
OPT_BOOL(0, "progress", &opts.progress,
N_("force progress reporting")),
OPT_END(),
};
struct option *options = add_common_options(builtin_commit_graph_write_options);
opts.progress = isatty(2);
opts.enable_changed_paths = -1;
write_opts.size_multiple = 2;
write_opts.max_commits = 0;
write_opts.expire_time = 0;
write_opts.max_new_filters = -1;
trace2_cmd_mode("write");
repo_config(the_repository, git_commit_graph_write_config, &opts);
argc = parse_options(argc, argv, prefix,
options,
builtin_commit_graph_write_usage, 0);
if (argc)
usage_with_options(builtin_commit_graph_write_usage, options);
if (opts.reachable + opts.stdin_packs + opts.stdin_commits > 1)
die(_("use at most one of --reachable, --stdin-commits, or --stdin-packs"));
if (!opts.obj_dir)
opts.obj_dir = repo_get_object_directory(the_repository);
if (opts.append)
flags |= COMMIT_GRAPH_WRITE_APPEND;
if (opts.split)
flags |= COMMIT_GRAPH_WRITE_SPLIT;
if (opts.progress)
flags |= COMMIT_GRAPH_WRITE_PROGRESS;
if (!opts.enable_changed_paths)
flags |= COMMIT_GRAPH_NO_WRITE_BLOOM_FILTERS;
if (opts.enable_changed_paths == 1 ||
git_env_bool(GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS, 0))
flags |= COMMIT_GRAPH_WRITE_BLOOM_FILTERS;
source = odb_find_source_or_die(the_repository->objects, opts.obj_dir);
if (opts.reachable) {
if (write_commit_graph_reachable(the_repository, source->path, flags, &write_opts))
result = 1;
goto cleanup;
}
if (opts.stdin_packs) {
struct strbuf packname = STRBUF_INIT;
size_t dirlen;
strbuf_addf(&packname, "%s/pack/", source->path);
dirlen = packname.len;
while (strbuf_getline(&buf, stdin) != EOF) {
strbuf_setlen(&packname, dirlen);
strbuf_addbuf(&packname, &buf);
string_list_append(&pack_indexes, packname.buf);
}
strbuf_release(&packname);
} else if (opts.stdin_commits) {
oidset_init(&commits, 0);
if (opts.progress)
progress = start_delayed_progress(
the_repository,
_("Collecting commits from input"), 0);
while (strbuf_getline(&buf, stdin) != EOF) {
if (read_one_commit(&commits, progress, buf.buf)) {
result = 1;
stop_progress(&progress);
goto cleanup;
}
}
stop_progress(&progress);
}
if (write_commit_graph(the_repository, source->path,
opts.stdin_packs ? &pack_indexes : NULL,
opts.stdin_commits ? &commits : NULL,
flags,
&write_opts))
result = 1;
cleanup:
FREE_AND_NULL(options);
string_list_clear(&pack_indexes, 0);
strbuf_release(&buf);
oidset_clear(&commits);
return result;
}
int cmd_commit_graph(int argc,
const char **argv,
const char *prefix,
struct repository *repo)
{
parse_opt_subcommand_fn *fn = NULL;
struct option builtin_commit_graph_options[] = {
OPT_SUBCOMMAND("verify", &fn, graph_verify),
OPT_SUBCOMMAND("write", &fn, graph_write),
OPT_END(),
};
struct option *options = parse_options_concat(builtin_commit_graph_options, common_opts);
repo_config(the_repository, git_default_config, NULL);
disable_replace_refs();
save_commit_buffer = 0;
argc = parse_options(argc, argv, prefix, options,
builtin_commit_graph_usage, 0);
FREE_AND_NULL(options);
return fn(argc, argv, prefix, repo);
}