git/builtin/commit-graph.c
Taylor Blau fdbde82fe5 builtin/commit-graph.c: introduce split strategy 'no-merge'
In the previous commit, we laid the groundwork for supporting different
splitting strategies. In this commit, we introduce the first splitting
strategy: 'no-merge'.

Passing '--split=no-merge' is useful for callers which wish to write a
new incremental commit-graph, but do not want to spend effort condensing
the incremental chain [1]. Previously, this was possible by passing
'--size-multiple=0', but this no longer the case following 63020f175f
(commit-graph: prefer default size_mult when given zero, 2020-01-02).

When '--split=no-merge' is given, the commit-graph machinery will never
condense an existing chain, and it will always write a new incremental.

[1]: This might occur when, for example, a server administrator running
some program after each push may want to ensure that each job runs
proportional in time to the size of the push, and does not "jump" when
the commit-graph machinery decides to trigger a merge.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-15 09:20:27 -07:00

260 lines
7.0 KiB
C

#include "builtin.h"
#include "config.h"
#include "dir.h"
#include "lockfile.h"
#include "parse-options.h"
#include "repository.h"
#include "commit-graph.h"
#include "object-store.h"
static char const * const builtin_commit_graph_usage[] = {
N_("git commit-graph verify [--object-dir <objdir>] [--shallow] [--[no-]progress]"),
N_("git commit-graph write [--object-dir <objdir>] [--append] "
"[--split[=<strategy>]] [--reachable|--stdin-packs|--stdin-commits] "
"[--[no-]progress] <split options>"),
NULL
};
static const char * const builtin_commit_graph_verify_usage[] = {
N_("git commit-graph verify [--object-dir <objdir>] [--shallow] [--[no-]progress]"),
NULL
};
static const char * const builtin_commit_graph_write_usage[] = {
N_("git commit-graph write [--object-dir <objdir>] [--append] "
"[--split[=<strategy>]] [--reachable|--stdin-packs|--stdin-commits] "
"[--[no-]progress] <split options>"),
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;
} opts;
static struct object_directory *find_odb(struct repository *r,
const char *obj_dir)
{
struct object_directory *odb;
char *obj_dir_real = real_pathdup(obj_dir, 1);
prepare_alt_odb(r);
for (odb = r->objects->odb; odb; odb = odb->next) {
if (!strcmp(obj_dir_real, real_path(odb->path)))
break;
}
free(obj_dir_real);
if (!odb)
die(_("could not find object directory matching %s"), obj_dir);
return odb;
}
static int graph_verify(int argc, const char **argv)
{
struct commit_graph *graph = NULL;
struct object_directory *odb = NULL;
char *graph_name;
int open_ok;
int fd;
struct stat st;
int flags = 0;
static struct option builtin_commit_graph_verify_options[] = {
OPT_STRING(0, "object-dir", &opts.obj_dir,
N_("dir"),
N_("The object directory to store the graph")),
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(),
};
trace2_cmd_mode("verify");
opts.progress = isatty(2);
argc = parse_options(argc, argv, NULL,
builtin_commit_graph_verify_options,
builtin_commit_graph_verify_usage, 0);
if (!opts.obj_dir)
opts.obj_dir = get_object_directory();
if (opts.shallow)
flags |= COMMIT_GRAPH_VERIFY_SHALLOW;
if (opts.progress)
flags |= COMMIT_GRAPH_WRITE_PROGRESS;
odb = find_odb(the_repository, opts.obj_dir);
graph_name = get_commit_graph_filename(odb);
open_ok = open_commit_graph(graph_name, &fd, &st);
if (!open_ok && errno != ENOENT)
die_errno(_("Could not open commit-graph '%s'"), graph_name);
FREE_AND_NULL(graph_name);
if (open_ok)
graph = load_commit_graph_one_fd_st(fd, &st, odb);
else
graph = read_commit_graph_one(the_repository, odb);
/* Return failure if open_ok predicted success */
if (!graph)
return !!open_ok;
UNLEAK(graph);
return verify_commit_graph(the_repository, graph, flags);
}
extern int read_replace_refs;
static struct split_commit_graph_opts split_opts;
static int write_option_parse_split(const struct option *opt, const char *arg,
int unset)
{
enum commit_graph_split_flags *flags = opt->value;
opts.split = 1;
if (!arg)
return 0;
if (!strcmp(arg, "no-merge"))
*flags = COMMIT_GRAPH_SPLIT_MERGE_PROHIBITED;
else
die(_("unrecognized --split argument, %s"), arg);
return 0;
}
static int graph_write(int argc, const char **argv)
{
struct string_list *pack_indexes = NULL;
struct string_list *commit_hex = NULL;
struct object_directory *odb = NULL;
struct string_list lines;
int result = 0;
enum commit_graph_write_flags flags = 0;
static struct option builtin_commit_graph_write_options[] = {
OPT_STRING(0, "object-dir", &opts.obj_dir,
N_("dir"),
N_("The object directory to store the graph")),
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, "progress", &opts.progress, N_("force progress reporting")),
OPT_CALLBACK_F(0, "split", &split_opts.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", &split_opts.max_commits,
N_("maximum number of commits in a non-base split commit-graph")),
OPT_INTEGER(0, "size-multiple", &split_opts.size_multiple,
N_("maximum ratio between two levels of a split commit-graph")),
OPT_EXPIRY_DATE(0, "expire-time", &split_opts.expire_time,
N_("maximum number of commits in a non-base split commit-graph")),
OPT_END(),
};
opts.progress = isatty(2);
split_opts.size_multiple = 2;
split_opts.max_commits = 0;
split_opts.expire_time = 0;
trace2_cmd_mode("write");
argc = parse_options(argc, argv, NULL,
builtin_commit_graph_write_options,
builtin_commit_graph_write_usage, 0);
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 = get_object_directory();
if (opts.append)
flags |= COMMIT_GRAPH_WRITE_APPEND;
if (opts.split)
flags |= COMMIT_GRAPH_WRITE_SPLIT;
if (opts.progress)
flags |= COMMIT_GRAPH_WRITE_PROGRESS;
read_replace_refs = 0;
odb = find_odb(the_repository, opts.obj_dir);
if (opts.reachable) {
if (write_commit_graph_reachable(odb, flags, &split_opts))
return 1;
return 0;
}
string_list_init(&lines, 0);
if (opts.stdin_packs || opts.stdin_commits) {
struct strbuf buf = STRBUF_INIT;
while (strbuf_getline(&buf, stdin) != EOF)
string_list_append(&lines, strbuf_detach(&buf, NULL));
if (opts.stdin_packs)
pack_indexes = &lines;
if (opts.stdin_commits) {
commit_hex = &lines;
flags |= COMMIT_GRAPH_WRITE_CHECK_OIDS;
}
UNLEAK(buf);
}
if (write_commit_graph(odb,
pack_indexes,
commit_hex,
flags,
&split_opts))
result = 1;
UNLEAK(lines);
return result;
}
int cmd_commit_graph(int argc, const char **argv, const char *prefix)
{
static struct option builtin_commit_graph_options[] = {
OPT_STRING(0, "object-dir", &opts.obj_dir,
N_("dir"),
N_("The object directory to store the graph")),
OPT_END(),
};
if (argc == 2 && !strcmp(argv[1], "-h"))
usage_with_options(builtin_commit_graph_usage,
builtin_commit_graph_options);
git_config(git_default_config, NULL);
argc = parse_options(argc, argv, prefix,
builtin_commit_graph_options,
builtin_commit_graph_usage,
PARSE_OPT_STOP_AT_NON_OPTION);
save_commit_buffer = 0;
if (argc > 0) {
if (!strcmp(argv[0], "verify"))
return graph_verify(argc, argv);
if (!strcmp(argv[0], "write"))
return graph_write(argc, argv);
}
usage_with_options(builtin_commit_graph_usage,
builtin_commit_graph_options);
}