git/ls-refs.c
Junio C Hamano 39fe402d67 Merge branch 'tb/refs-exclusion-and-packed-refs'
Enumerating refs in the packed-refs file, while excluding refs that
match certain patterns, has been optimized.

* tb/refs-exclusion-and-packed-refs:
  ls-refs.c: avoid enumerating hidden refs where possible
  upload-pack.c: avoid enumerating hidden refs where possible
  builtin/receive-pack.c: avoid enumerating hidden references
  refs.h: implement `hidden_refs_to_excludes()`
  refs.h: let `for_each_namespaced_ref()` take excluded patterns
  revision.h: store hidden refs in a `strvec`
  refs/packed-backend.c: add trace2 counters for jump list
  refs/packed-backend.c: implement jump lists to avoid excluded pattern(s)
  refs/packed-backend.c: refactor `find_reference_location()`
  refs: plumb `exclude_patterns` argument throughout
  builtin/for-each-ref.c: add `--exclude` option
  ref-filter.c: parameterize match functions over patterns
  ref-filter: add `ref_filter_clear()`
  ref-filter: clear reachable list pointers after freeing
  ref-filter.h: provide `REF_FILTER_INIT`
  refs.c: rename `ref_filter`
2023-07-21 13:47:26 -07:00

213 lines
5.2 KiB
C

#include "git-compat-util.h"
#include "environment.h"
#include "gettext.h"
#include "hash.h"
#include "hex.h"
#include "repository.h"
#include "refs.h"
#include "remote.h"
#include "strvec.h"
#include "ls-refs.h"
#include "pkt-line.h"
#include "config.h"
#include "string-list.h"
static enum {
UNBORN_IGNORE = 0,
UNBORN_ALLOW,
UNBORN_ADVERTISE /* implies ALLOW */
} unborn_config(struct repository *r)
{
const char *str = NULL;
if (repo_config_get_string_tmp(r, "lsrefs.unborn", &str)) {
/*
* If there is no such config, advertise and allow it by
* default.
*/
return UNBORN_ADVERTISE;
} else {
if (!strcmp(str, "advertise")) {
return UNBORN_ADVERTISE;
} else if (!strcmp(str, "allow")) {
return UNBORN_ALLOW;
} else if (!strcmp(str, "ignore")) {
return UNBORN_IGNORE;
} else {
die(_("invalid value for '%s': '%s'"),
"lsrefs.unborn", str);
}
}
}
/*
* If we see this many or more "ref-prefix" lines from the client, we consider
* it "too many" and will avoid using the prefix feature entirely.
*/
#define TOO_MANY_PREFIXES 65536
/*
* Check if one of the prefixes is a prefix of the ref.
* If no prefixes were provided, all refs match.
*/
static int ref_match(const struct strvec *prefixes, const char *refname)
{
int i;
if (!prefixes->nr)
return 1; /* no restriction */
for (i = 0; i < prefixes->nr; i++) {
const char *prefix = prefixes->v[i];
if (starts_with(refname, prefix))
return 1;
}
return 0;
}
struct ls_refs_data {
unsigned peel;
unsigned symrefs;
struct strvec prefixes;
struct strbuf buf;
struct strvec hidden_refs;
unsigned unborn : 1;
};
static int send_ref(const char *refname, const struct object_id *oid,
int flag, void *cb_data)
{
struct ls_refs_data *data = cb_data;
const char *refname_nons = strip_namespace(refname);
strbuf_reset(&data->buf);
if (ref_is_hidden(refname_nons, refname, &data->hidden_refs))
return 0;
if (!ref_match(&data->prefixes, refname_nons))
return 0;
if (oid)
strbuf_addf(&data->buf, "%s %s", oid_to_hex(oid), refname_nons);
else
strbuf_addf(&data->buf, "unborn %s", refname_nons);
if (data->symrefs && flag & REF_ISSYMREF) {
struct object_id unused;
const char *symref_target = resolve_ref_unsafe(refname, 0,
&unused,
&flag);
if (!symref_target)
die("'%s' is a symref but it is not?", refname);
strbuf_addf(&data->buf, " symref-target:%s",
strip_namespace(symref_target));
}
if (data->peel && oid) {
struct object_id peeled;
if (!peel_iterated_oid(oid, &peeled))
strbuf_addf(&data->buf, " peeled:%s", oid_to_hex(&peeled));
}
strbuf_addch(&data->buf, '\n');
packet_fwrite(stdout, data->buf.buf, data->buf.len);
return 0;
}
static void send_possibly_unborn_head(struct ls_refs_data *data)
{
struct strbuf namespaced = STRBUF_INIT;
struct object_id oid;
int flag;
int oid_is_null;
strbuf_addf(&namespaced, "%sHEAD", get_git_namespace());
if (!resolve_ref_unsafe(namespaced.buf, 0, &oid, &flag))
return; /* bad ref */
oid_is_null = is_null_oid(&oid);
if (!oid_is_null ||
(data->unborn && data->symrefs && (flag & REF_ISSYMREF)))
send_ref(namespaced.buf, oid_is_null ? NULL : &oid, flag, data);
strbuf_release(&namespaced);
}
static int ls_refs_config(const char *var, const char *value,
const struct config_context *ctx UNUSED,
void *cb_data)
{
struct ls_refs_data *data = cb_data;
/*
* We only serve fetches over v2 for now, so respect only "uploadpack"
* config. This may need to eventually be expanded to "receive", but we
* don't yet know how that information will be passed to ls-refs.
*/
return parse_hide_refs_config(var, value, "uploadpack", &data->hidden_refs);
}
int ls_refs(struct repository *r, struct packet_reader *request)
{
struct ls_refs_data data;
memset(&data, 0, sizeof(data));
strvec_init(&data.prefixes);
strbuf_init(&data.buf, 0);
strvec_init(&data.hidden_refs);
git_config(ls_refs_config, &data);
while (packet_reader_read(request) == PACKET_READ_NORMAL) {
const char *arg = request->line;
const char *out;
if (!strcmp("peel", arg))
data.peel = 1;
else if (!strcmp("symrefs", arg))
data.symrefs = 1;
else if (skip_prefix(arg, "ref-prefix ", &out)) {
if (data.prefixes.nr < TOO_MANY_PREFIXES)
strvec_push(&data.prefixes, out);
}
else if (!strcmp("unborn", arg))
data.unborn = !!unborn_config(r);
else
die(_("unexpected line: '%s'"), arg);
}
if (request->status != PACKET_READ_FLUSH)
die(_("expected flush after ls-refs arguments"));
/*
* If we saw too many prefixes, we must avoid using them at all; as
* soon as we have any prefix, they are meant to form a comprehensive
* list.
*/
if (data.prefixes.nr >= TOO_MANY_PREFIXES)
strvec_clear(&data.prefixes);
send_possibly_unborn_head(&data);
if (!data.prefixes.nr)
strvec_push(&data.prefixes, "");
refs_for_each_fullref_in_prefixes(get_main_ref_store(r),
get_git_namespace(), data.prefixes.v,
hidden_refs_to_excludes(&data.hidden_refs),
send_ref, &data);
packet_fflush(stdout);
strvec_clear(&data.prefixes);
strbuf_release(&data.buf);
strvec_clear(&data.hidden_refs);
return 0;
}
int ls_refs_advertise(struct repository *r, struct strbuf *value)
{
if (value && unborn_config(r) == UNBORN_ADVERTISE)
strbuf_addstr(value, "unborn");
return 1;
}