git/list-objects-filter-options.c
Ævar Arnfjörð Bjarmason 5cb28270a1 pack-objects: lazily set up "struct rev_info", don't leak
In the preceding [1] (pack-objects: move revs out of
get_object_list(), 2022-03-22) the "repo_init_revisions()" was moved
to cmd_pack_objects() so that it unconditionally took place for all
invocations of "git pack-objects".

We'd thus start leaking memory, which is easily reproduced in
e.g. git.git by feeding e83c516331 (Initial revision of "git", the
information manager from hell, 2005-04-07) to "git pack-objects";

    $ echo e83c516331 | ./git pack-objects initial
    [...]
	==19130==ERROR: LeakSanitizer: detected memory leaks

	Direct leak of 7120 byte(s) in 1 object(s) allocated from:
	    #0 0x455308 in __interceptor_malloc (/home/avar/g/git/git+0x455308)
	    #1 0x75b399 in do_xmalloc /home/avar/g/git/wrapper.c:41:8
	    #2 0x75b356 in xmalloc /home/avar/g/git/wrapper.c:62:9
	    #3 0x5d7609 in prep_parse_options /home/avar/g/git/diff.c:5647:2
	    #4 0x5d415a in repo_diff_setup /home/avar/g/git/diff.c:4621:2
	    #5 0x6dffbb in repo_init_revisions /home/avar/g/git/revision.c:1853:2
	    #6 0x4f599d in cmd_pack_objects /home/avar/g/git/builtin/pack-objects.c:3980:2
	    #7 0x4592ca in run_builtin /home/avar/g/git/git.c:465:11
	    #8 0x457d81 in handle_builtin /home/avar/g/git/git.c:718:3
	    #9 0x458ca5 in run_argv /home/avar/g/git/git.c:785:4
	    #10 0x457b40 in cmd_main /home/avar/g/git/git.c:916:19
	    #11 0x562259 in main /home/avar/g/git/common-main.c:56:11
	    #12 0x7fce792ac7ec in __libc_start_main csu/../csu/libc-start.c:332:16
	    #13 0x4300f9 in _start (/home/avar/g/git/git+0x4300f9)

	SUMMARY: LeakSanitizer: 7120 byte(s) leaked in 1 allocation(s).
	Aborted

Narrowly fixing that commit would have been easy, just add call
repo_init_revisions() right before get_object_list(), which is
effectively what was done before that commit.

But an unstated constraint when setting it up early is that it was
needed for the subsequent [2] (pack-objects: parse --filter directly
into revs.filter, 2022-03-22), i.e. we might have a --filter
command-line option, and need to either have the "struct rev_info"
setup when we encounter that option, or later.

Let's just change the control flow so that we'll instead set up the
"struct rev_info" only when we need it. Doing so leads to a bit more
verbosity, but it's a lot clearer what we're doing and why.

An earlier version of this commit[3] went behind
opt_parse_list_objects_filter()'s back by faking up a "struct option"
before calling it. Let's avoid that and instead create a blessed API
for this pattern.

We could furthermore combine the two get_object_list() invocations
here by having repo_init_revisions() invoked on &pfd.revs, but I think
clearly separating the two makes the flow clearer. Likewise
redundantly but explicitly (i.e. redundant v.s. a "{ 0 }") "0" to
"have_revs" early in cmd_pack_objects().

While we're at it add parentheses around the arguments to the OPT_*
macros in in list-objects-filter-options.h, as we need to change those
lines anyway. It doesn't matter in this case, but is good general
practice.

1. https://lore.kernel.org/git/619b757d98465dbc4995bdc11a5282fbfcbd3daa.1647970119.git.gitgitgadget@gmail.com
2. https://lore.kernel.org/git/97de926904988b89b5663bd4c59c011a1723a8f5.1647970119.git.gitgitgadget@gmail.com
3. https://lore.kernel.org/git/patch-1.1-193534b0f07-20220325T121715Z-avarab@gmail.com/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-28 09:57:21 -07:00

425 lines
11 KiB
C

#include "cache.h"
#include "commit.h"
#include "config.h"
#include "revision.h"
#include "strvec.h"
#include "list-objects.h"
#include "list-objects-filter.h"
#include "list-objects-filter-options.h"
#include "promisor-remote.h"
#include "trace.h"
#include "url.h"
static int parse_combine_filter(
struct list_objects_filter_options *filter_options,
const char *arg,
struct strbuf *errbuf);
const char *list_object_filter_config_name(enum list_objects_filter_choice c)
{
switch (c) {
case LOFC_DISABLED:
/* we have no name for "no filter at all" */
break;
case LOFC_BLOB_NONE:
return "blob:none";
case LOFC_BLOB_LIMIT:
return "blob:limit";
case LOFC_TREE_DEPTH:
return "tree";
case LOFC_SPARSE_OID:
return "sparse:oid";
case LOFC_OBJECT_TYPE:
return "object:type";
case LOFC_COMBINE:
return "combine";
case LOFC__COUNT:
/* not a real filter type; just the count of all filters */
break;
}
BUG("list_object_filter_config_name: invalid argument '%d'", c);
}
int gently_parse_list_objects_filter(
struct list_objects_filter_options *filter_options,
const char *arg,
struct strbuf *errbuf)
{
const char *v0;
if (!arg)
return 0;
if (filter_options->choice)
BUG("filter_options already populated");
if (!strcmp(arg, "blob:none")) {
filter_options->choice = LOFC_BLOB_NONE;
return 0;
} else if (skip_prefix(arg, "blob:limit=", &v0)) {
if (git_parse_ulong(v0, &filter_options->blob_limit_value)) {
filter_options->choice = LOFC_BLOB_LIMIT;
return 0;
}
} else if (skip_prefix(arg, "tree:", &v0)) {
if (!git_parse_ulong(v0, &filter_options->tree_exclude_depth)) {
strbuf_addstr(errbuf, _("expected 'tree:<depth>'"));
return 1;
}
filter_options->choice = LOFC_TREE_DEPTH;
return 0;
} else if (skip_prefix(arg, "sparse:oid=", &v0)) {
filter_options->sparse_oid_name = xstrdup(v0);
filter_options->choice = LOFC_SPARSE_OID;
return 0;
} else if (skip_prefix(arg, "sparse:path=", &v0)) {
if (errbuf) {
strbuf_addstr(
errbuf,
_("sparse:path filters support has been dropped"));
}
return 1;
} else if (skip_prefix(arg, "object:type=", &v0)) {
int type = type_from_string_gently(v0, strlen(v0), 1);
if (type < 0) {
strbuf_addf(errbuf, _("'%s' for 'object:type=<type>' is "
"not a valid object type"), v0);
return 1;
}
filter_options->object_type = type;
filter_options->choice = LOFC_OBJECT_TYPE;
return 0;
} else if (skip_prefix(arg, "combine:", &v0)) {
return parse_combine_filter(filter_options, v0, errbuf);
}
/*
* Please update _git_fetch() in git-completion.bash when you
* add new filters
*/
strbuf_addf(errbuf, _("invalid filter-spec '%s'"), arg);
memset(filter_options, 0, sizeof(*filter_options));
return 1;
}
static const char *RESERVED_NON_WS = "~`!@#$^&*()[]{}\\;'\",<>?";
static int has_reserved_character(
struct strbuf *sub_spec, struct strbuf *errbuf)
{
const char *c = sub_spec->buf;
while (*c) {
if (*c <= ' ' || strchr(RESERVED_NON_WS, *c)) {
strbuf_addf(
errbuf,
_("must escape char in sub-filter-spec: '%c'"),
*c);
return 1;
}
c++;
}
return 0;
}
static int parse_combine_subfilter(
struct list_objects_filter_options *filter_options,
struct strbuf *subspec,
struct strbuf *errbuf)
{
size_t new_index = filter_options->sub_nr;
char *decoded;
int result;
ALLOC_GROW_BY(filter_options->sub, filter_options->sub_nr, 1,
filter_options->sub_alloc);
decoded = url_percent_decode(subspec->buf);
result = has_reserved_character(subspec, errbuf) ||
gently_parse_list_objects_filter(
&filter_options->sub[new_index], decoded, errbuf);
free(decoded);
return result;
}
static int parse_combine_filter(
struct list_objects_filter_options *filter_options,
const char *arg,
struct strbuf *errbuf)
{
struct strbuf **subspecs = strbuf_split_str(arg, '+', 0);
size_t sub;
int result = 0;
if (!subspecs[0]) {
strbuf_addstr(errbuf, _("expected something after combine:"));
result = 1;
goto cleanup;
}
for (sub = 0; subspecs[sub] && !result; sub++) {
if (subspecs[sub + 1]) {
/*
* This is not the last subspec. Remove trailing "+" so
* we can parse it.
*/
size_t last = subspecs[sub]->len - 1;
assert(subspecs[sub]->buf[last] == '+');
strbuf_remove(subspecs[sub], last, 1);
}
result = parse_combine_subfilter(
filter_options, subspecs[sub], errbuf);
}
filter_options->choice = LOFC_COMBINE;
cleanup:
strbuf_list_free(subspecs);
if (result) {
list_objects_filter_release(filter_options);
memset(filter_options, 0, sizeof(*filter_options));
}
return result;
}
static int allow_unencoded(char ch)
{
if (ch <= ' ' || ch == '%' || ch == '+')
return 0;
return !strchr(RESERVED_NON_WS, ch);
}
static void filter_spec_append_urlencode(
struct list_objects_filter_options *filter, const char *raw)
{
struct strbuf buf = STRBUF_INIT;
strbuf_addstr_urlencode(&buf, raw, allow_unencoded);
trace_printf("Add to combine filter-spec: %s\n", buf.buf);
string_list_append(&filter->filter_spec, strbuf_detach(&buf, NULL));
}
/*
* Changes filter_options into an equivalent LOFC_COMBINE filter options
* instance. Does not do anything if filter_options is already LOFC_COMBINE.
*/
static void transform_to_combine_type(
struct list_objects_filter_options *filter_options)
{
assert(filter_options->choice);
if (filter_options->choice == LOFC_COMBINE)
return;
{
const int initial_sub_alloc = 2;
struct list_objects_filter_options *sub_array =
xcalloc(initial_sub_alloc, sizeof(*sub_array));
sub_array[0] = *filter_options;
memset(filter_options, 0, sizeof(*filter_options));
filter_options->sub = sub_array;
filter_options->sub_alloc = initial_sub_alloc;
}
filter_options->sub_nr = 1;
filter_options->choice = LOFC_COMBINE;
string_list_append(&filter_options->filter_spec, xstrdup("combine:"));
filter_spec_append_urlencode(
filter_options,
list_objects_filter_spec(&filter_options->sub[0]));
/*
* We don't need the filter_spec strings for subfilter specs, only the
* top level.
*/
string_list_clear(&filter_options->sub[0].filter_spec, /*free_util=*/0);
}
void list_objects_filter_die_if_populated(
struct list_objects_filter_options *filter_options)
{
if (filter_options->choice)
die(_("multiple filter-specs cannot be combined"));
}
void parse_list_objects_filter(
struct list_objects_filter_options *filter_options,
const char *arg)
{
struct strbuf errbuf = STRBUF_INIT;
int parse_error;
if (!filter_options->choice) {
string_list_append(&filter_options->filter_spec, xstrdup(arg));
parse_error = gently_parse_list_objects_filter(
filter_options, arg, &errbuf);
} else {
/*
* Make filter_options an LOFC_COMBINE spec so we can trivially
* add subspecs to it.
*/
transform_to_combine_type(filter_options);
string_list_append(&filter_options->filter_spec, xstrdup("+"));
filter_spec_append_urlencode(filter_options, arg);
ALLOC_GROW_BY(filter_options->sub, filter_options->sub_nr, 1,
filter_options->sub_alloc);
parse_error = gently_parse_list_objects_filter(
&filter_options->sub[filter_options->sub_nr - 1], arg,
&errbuf);
}
if (parse_error)
die("%s", errbuf.buf);
}
int opt_parse_list_objects_filter(const struct option *opt,
const char *arg, int unset)
{
struct list_objects_filter_options *filter_options = opt->value;
opt_lof_init init = (opt_lof_init)opt->defval;
if (init)
filter_options = init(opt->value);
if (unset || !arg)
list_objects_filter_set_no_filter(filter_options);
else
parse_list_objects_filter(filter_options, arg);
return 0;
}
const char *list_objects_filter_spec(struct list_objects_filter_options *filter)
{
if (!filter->filter_spec.nr)
BUG("no filter_spec available for this filter");
if (filter->filter_spec.nr != 1) {
struct strbuf concatted = STRBUF_INIT;
strbuf_add_separated_string_list(
&concatted, "", &filter->filter_spec);
string_list_clear(&filter->filter_spec, /*free_util=*/0);
string_list_append(
&filter->filter_spec, strbuf_detach(&concatted, NULL));
}
return filter->filter_spec.items[0].string;
}
const char *expand_list_objects_filter_spec(
struct list_objects_filter_options *filter)
{
if (filter->choice == LOFC_BLOB_LIMIT) {
struct strbuf expanded_spec = STRBUF_INIT;
strbuf_addf(&expanded_spec, "blob:limit=%lu",
filter->blob_limit_value);
string_list_clear(&filter->filter_spec, /*free_util=*/0);
string_list_append(
&filter->filter_spec,
strbuf_detach(&expanded_spec, NULL));
}
return list_objects_filter_spec(filter);
}
void list_objects_filter_release(
struct list_objects_filter_options *filter_options)
{
size_t sub;
if (!filter_options)
return;
string_list_clear(&filter_options->filter_spec, /*free_util=*/0);
free(filter_options->sparse_oid_name);
for (sub = 0; sub < filter_options->sub_nr; sub++)
list_objects_filter_release(&filter_options->sub[sub]);
free(filter_options->sub);
memset(filter_options, 0, sizeof(*filter_options));
}
void partial_clone_register(
const char *remote,
struct list_objects_filter_options *filter_options)
{
struct promisor_remote *promisor_remote;
char *cfg_name;
char *filter_name;
/* Check if it is already registered */
if ((promisor_remote = promisor_remote_find(remote))) {
if (promisor_remote->partial_clone_filter)
/*
* Remote is already registered and a filter is already
* set, so we don't need to do anything here.
*/
return;
} else {
if (upgrade_repository_format(1) < 0)
die(_("unable to upgrade repository format to support partial clone"));
/* Add promisor config for the remote */
cfg_name = xstrfmt("remote.%s.promisor", remote);
git_config_set(cfg_name, "true");
free(cfg_name);
}
/*
* Record the initial filter-spec in the config as
* the default for subsequent fetches from this remote.
*/
filter_name = xstrfmt("remote.%s.partialclonefilter", remote);
/* NEEDSWORK: 'expand' result leaking??? */
git_config_set(filter_name,
expand_list_objects_filter_spec(filter_options));
free(filter_name);
/* Make sure the config info are reset */
promisor_remote_reinit();
}
void partial_clone_get_default_filter_spec(
struct list_objects_filter_options *filter_options,
const char *remote)
{
struct promisor_remote *promisor = promisor_remote_find(remote);
struct strbuf errbuf = STRBUF_INIT;
/*
* Parse default value, but silently ignore it if it is invalid.
*/
if (!promisor)
return;
string_list_append(&filter_options->filter_spec,
promisor->partial_clone_filter);
gently_parse_list_objects_filter(filter_options,
promisor->partial_clone_filter,
&errbuf);
strbuf_release(&errbuf);
}
void list_objects_filter_copy(
struct list_objects_filter_options *dest,
const struct list_objects_filter_options *src)
{
int i;
struct string_list_item *item;
/* Copy everything. We will overwrite the pointers shortly. */
memcpy(dest, src, sizeof(struct list_objects_filter_options));
string_list_init_dup(&dest->filter_spec);
for_each_string_list_item(item, &src->filter_spec)
string_list_append(&dest->filter_spec, item->string);
ALLOC_ARRAY(dest->sub, dest->sub_alloc);
for (i = 0; i < src->sub_nr; i++)
list_objects_filter_copy(&dest->sub[i], &src->sub[i]);
}