[thirdparty/git.git] / server-info.c

#include "cache.h"
#include "repository.h"
#include "refs.h"
#include "object.h"
#include "commit.h"
#include "tag.h"
#include "packfile.h"
#include "object-store.h"
#include "strbuf.h"

struct update_info_ctx {
	FILE *cur_fp;
	FILE *old_fp; /* becomes NULL if it differs from cur_fp */
	struct strbuf cur_sb;
	struct strbuf old_sb;
};

static void uic_mark_stale(struct update_info_ctx *uic)
{
	fclose(uic->old_fp);
	uic->old_fp = NULL;
}

static int uic_is_stale(const struct update_info_ctx *uic)
{
	return uic->old_fp == NULL;
}

static int uic_printf(struct update_info_ctx *uic, const char *fmt, ...)
{
	va_list ap;
	int ret = -1;

	va_start(ap, fmt);

	if (uic_is_stale(uic)) {
		ret = vfprintf(uic->cur_fp, fmt, ap);
	} else {
		ssize_t r;
		struct strbuf *cur = &uic->cur_sb;
		struct strbuf *old = &uic->old_sb;

		strbuf_reset(cur);
		strbuf_vinsertf(cur, 0, fmt, ap);

		strbuf_reset(old);
		strbuf_grow(old, cur->len);
		r = fread(old->buf, 1, cur->len, uic->old_fp);
		if (r != cur->len || memcmp(old->buf, cur->buf, r))
			uic_mark_stale(uic);

		if (fwrite(cur->buf, 1, cur->len, uic->cur_fp) == cur->len)
			ret = 0;
	}

	va_end(ap);

	return ret;
}

/*
 * Create the file "path" by writing to a temporary file and renaming
 * it into place. The contents of the file come from "generate", which
 * should return non-zero if it encounters an error.
 */
static int update_info_file(char *path,
			int (*generate)(struct update_info_ctx *),
			int force)
{
	char *tmp = mkpathdup("%s_XXXXXX", path);
	int ret = -1;
	int fd = -1;
	FILE *to_close;
	struct update_info_ctx uic = {
		.cur_fp = NULL,
		.old_fp = NULL,
		.cur_sb = STRBUF_INIT,
		.old_sb = STRBUF_INIT
	};

	safe_create_leading_directories(path);
	fd = git_mkstemp_mode(tmp, 0666);
	if (fd < 0)
		goto out;
	to_close = uic.cur_fp = fdopen(fd, "w");
	if (!uic.cur_fp)
		goto out;
	fd = -1;

	/* no problem on ENOENT and old_fp == NULL, it's stale, now */
	if (!force)
		uic.old_fp = fopen_or_warn(path, "r");

	/*
	 * uic_printf will compare incremental comparison aginst old_fp
	 * and mark uic as stale if needed
	 */
	ret = generate(&uic);
	if (ret)
		goto out;

	/* new file may be shorter than the old one, check here */
	if (!uic_is_stale(&uic)) {
		struct stat st;
		long new_len = ftell(uic.cur_fp);
		int old_fd = fileno(uic.old_fp);

		if (new_len < 0) {
			ret = -1;
			goto out;
		}
		if (fstat(old_fd, &st) || (st.st_size != (size_t)new_len))
			uic_mark_stale(&uic);
	}

	uic.cur_fp = NULL;
	if (fclose(to_close))
		goto out;

	if (uic_is_stale(&uic)) {
		if (adjust_shared_perm(tmp) < 0)
			goto out;
		if (rename(tmp, path) < 0)
			goto out;
	} else {
		unlink(tmp);
	}
	ret = 0;

out:
	if (ret) {
		error_errno("unable to update %s", path);
		if (uic.cur_fp)
			fclose(uic.cur_fp);
		else if (fd >= 0)
			close(fd);
		unlink(tmp);
	}
	free(tmp);
	if (uic.old_fp)
		fclose(uic.old_fp);
	strbuf_release(&uic.old_sb);
	strbuf_release(&uic.cur_sb);
	return ret;
}

static int add_info_ref(const char *path, const struct object_id *oid,
			int flag, void *cb_data)
{
	struct update_info_ctx *uic = cb_data;
	struct object *o = parse_object(the_repository, oid);
	if (!o)
		return -1;

	if (uic_printf(uic, "%s	%s\n", oid_to_hex(oid), path) < 0)
		return -1;

	if (o->type == OBJ_TAG) {
		o = deref_tag(the_repository, o, path, 0);
		if (o)
			if (uic_printf(uic, "%s	%s^{}\n",
				oid_to_hex(&o->oid), path) < 0)
				return -1;
	}
	return 0;
}

static int generate_info_refs(struct update_info_ctx *uic)
{
	return for_each_ref(add_info_ref, uic);
}

static int update_info_refs(int force)
{
	char *path = git_pathdup("info/refs");
	int ret = update_info_file(path, generate_info_refs, force);
	free(path);
	return ret;
}

/* packs */
static struct pack_info {
	struct packed_git *p;
	int old_num;
	int new_num;
} **info;
static int num_pack;

static struct pack_info *find_pack_by_name(const char *name)
{
	int i;
	for (i = 0; i < num_pack; i++) {
		struct packed_git *p = info[i]->p;
		if (!strcmp(pack_basename(p), name))
			return info[i];
	}
	return NULL;
}

/* Returns non-zero when we detect that the info in the
 * old file is useless.
 */
static int parse_pack_def(const char *packname, int old_cnt)
{
	struct pack_info *i = find_pack_by_name(packname);
	if (i) {
		i->old_num = old_cnt;
		return 0;
	}
	else {
		/* The file describes a pack that is no longer here */
		return 1;
	}
}

/* Returns non-zero when we detect that the info in the
 * old file is useless.
 */
static int read_pack_info_file(const char *infofile)
{
	FILE *fp;
	struct strbuf line = STRBUF_INIT;
	int old_cnt = 0;
	int stale = 1;

	fp = fopen_or_warn(infofile, "r");
	if (!fp)
		return 1; /* nonexistent is not an error. */

	while (strbuf_getline(&line, fp) != EOF) {
		const char *arg;

		if (!line.len)
			continue;

		if (skip_prefix(line.buf, "P ", &arg)) {
			/* P name */
			if (parse_pack_def(arg, old_cnt++))
				goto out_stale;
		} else if (line.buf[0] == 'D') {
			/* we used to emit D but that was misguided. */
			goto out_stale;
		} else if (line.buf[0] == 'T') {
			/* we used to emit T but nobody uses it. */
			goto out_stale;
		} else {
			error("unrecognized: %s", line.buf);
		}
	}
	stale = 0;

 out_stale:
	strbuf_release(&line);
	fclose(fp);
	return stale;
}

static int compare_info(const void *a_, const void *b_)
{
	struct pack_info *const *a = a_;
	struct pack_info *const *b = b_;

	if (0 <= (*a)->old_num && 0 <= (*b)->old_num)
		/* Keep the order in the original */
		return (*a)->old_num - (*b)->old_num;
	else if (0 <= (*a)->old_num)
		/* Only A existed in the original so B is obviously newer */
		return -1;
	else if (0 <= (*b)->old_num)
		/* The other way around. */
		return 1;

	/* then it does not matter but at least keep the comparison stable */
	if ((*a)->p == (*b)->p)
		return 0;
	else if ((*a)->p < (*b)->p)
		return -1;
	else
		return 1;
}

static void init_pack_info(const char *infofile, int force)
{
	struct packed_git *p;
	int stale;
	int i = 0;

	for (p = get_all_packs(the_repository); p; p = p->next) {
		/* we ignore things on alternate path since they are
		 * not available to the pullers in general.
		 */
		if (!p->pack_local)
			continue;
		i++;
	}
	num_pack = i;
	info = xcalloc(num_pack, sizeof(struct pack_info *));
	for (i = 0, p = get_all_packs(the_repository); p; p = p->next) {
		if (!p->pack_local)
			continue;
		assert(i < num_pack);
		info[i] = xcalloc(1, sizeof(struct pack_info));
		info[i]->p = p;
		info[i]->old_num = -1;
		i++;
	}

	if (infofile && !force)
		stale = read_pack_info_file(infofile);
	else
		stale = 1;

	for (i = 0; i < num_pack; i++)
		if (stale)
			info[i]->old_num = -1;

	/* renumber them */
	QSORT(info, num_pack, compare_info);
	for (i = 0; i < num_pack; i++)
		info[i]->new_num = i;
}

static void free_pack_info(void)
{
	int i;
	for (i = 0; i < num_pack; i++)
		free(info[i]);
	free(info);
}

static int write_pack_info_file(struct update_info_ctx *uic)
{
	int i;
	for (i = 0; i < num_pack; i++) {
		if (uic_printf(uic, "P %s\n", pack_basename(info[i]->p)) < 0)
			return -1;
	}
	if (uic_printf(uic, "\n") < 0)
		return -1;
	return 0;
}

static int update_info_packs(int force)
{
	char *infofile = mkpathdup("%s/info/packs", get_object_directory());
	int ret;

	init_pack_info(infofile, force);
	ret = update_info_file(infofile, write_pack_info_file, force);
	free_pack_info();
	free(infofile);
	return ret;
}

/* public */
int update_server_info(int force)
{
	/* We would add more dumb-server support files later,
	 * including index of available pack files and their
	 * intended audiences.
	 */
	int errs = 0;

	errs = errs | update_info_refs(force);
	errs = errs | update_info_packs(force);

	/* remove leftover rev-cache file if there is any */
	unlink_or_warn(git_path("info/rev-cache"));

	return errs;
}
Commit	Line	Data
8f3f9b09	1	#include "cache.h"
a80d72db	2	#include "repository.h"
8f3f9b09 JH	3	#include "refs.h"
	4	#include "object.h"
	5	#include "commit.h"
b614e3d7	6	#include "tag.h"
0abe14f6	7	#include "packfile.h"
a80d72db	8	#include "object-store.h"
f4f476b6 EW	9	#include "strbuf.h"
	10
	11	struct update_info_ctx {
	12	FILE *cur_fp;
	13	FILE old_fp; / becomes NULL if it differs from cur_fp */
	14	struct strbuf cur_sb;
	15	struct strbuf old_sb;
	16	};
	17
	18	static void uic_mark_stale(struct update_info_ctx *uic)
	19	{
	20	fclose(uic->old_fp);
	21	uic->old_fp = NULL;
	22	}
	23
	24	static int uic_is_stale(const struct update_info_ctx *uic)
	25	{
	26	return uic->old_fp == NULL;
	27	}
	28
	29	static int uic_printf(struct update_info_ctx uic, const char fmt, ...)
	30	{
	31	va_list ap;
	32	int ret = -1;
	33
	34	va_start(ap, fmt);
	35
	36	if (uic_is_stale(uic)) {
	37	ret = vfprintf(uic->cur_fp, fmt, ap);
	38	} else {
	39	ssize_t r;
	40	struct strbuf *cur = &uic->cur_sb;
	41	struct strbuf *old = &uic->old_sb;
	42
	43	strbuf_reset(cur);
	44	strbuf_vinsertf(cur, 0, fmt, ap);
	45
	46	strbuf_reset(old);
	47	strbuf_grow(old, cur->len);
	48	r = fread(old->buf, 1, cur->len, uic->old_fp);
	49	if (r != cur->len \|\| memcmp(old->buf, cur->buf, r))
	50	uic_mark_stale(uic);
	51
	52	if (fwrite(cur->buf, 1, cur->len, uic->cur_fp) == cur->len)
	53	ret = 0;
	54	}
	55
	56	va_end(ap);
	57
	58	return ret;
	59	}
8f3f9b09	60
d38379ec JK	61	/*
	62	* Create the file "path" by writing to a temporary file and renaming
	63	* it into place. The contents of the file come from "generate", which
	64	* should return non-zero if it encounters an error.
	65	*/
f4f476b6 EW	66	static int update_info_file(char *path,
	67	int (generate)(struct update_info_ctx ),
	68	int force)
d38379ec JK	69	{
	70	char *tmp = mkpathdup("%s_XXXXXX", path);
	71	int ret = -1;
	72	int fd = -1;
f4f476b6 EW	73	FILE *to_close;
	74	struct update_info_ctx uic = {
	75	.cur_fp = NULL,
	76	.old_fp = NULL,
	77	.cur_sb = STRBUF_INIT,
	78	.old_sb = STRBUF_INIT
	79	};
d38379ec JK	80
d38379ec JK	81	safe_create_leading_directories(path);
d91175b2	82	fd = git_mkstemp_mode(tmp, 0666);
d38379ec JK	83	if (fd < 0)
d38379ec JK	84	goto out;
f4f476b6 EW	85	to_close = uic.cur_fp = fdopen(fd, "w");
f4f476b6 EW	86	if (!uic.cur_fp)
d38379ec	87	goto out;
fa1912c8	88	fd = -1;
f4f476b6 EW	89
	90	/* no problem on ENOENT and old_fp == NULL, it's stale, now */
	91	if (!force)
	92	uic.old_fp = fopen_or_warn(path, "r");
	93
	94	/*
	95	* uic_printf will compare incremental comparison aginst old_fp
	96	* and mark uic as stale if needed
	97	*/
	98	ret = generate(&uic);
d38379ec JK	99	if (ret)
d38379ec JK	100	goto out;
f4f476b6 EW	101
	102	/* new file may be shorter than the old one, check here */
	103	if (!uic_is_stale(&uic)) {
	104	struct stat st;
	105	long new_len = ftell(uic.cur_fp);
	106	int old_fd = fileno(uic.old_fp);
	107
	108	if (new_len < 0) {
	109	ret = -1;
	110	goto out;
	111	}
	112	if (fstat(old_fd, &st) \|\| (st.st_size != (size_t)new_len))
	113	uic_mark_stale(&uic);
	114	}
	115
	116	uic.cur_fp = NULL;
fa1912c8	117	if (fclose(to_close))
d38379ec	118	goto out;
f4f476b6 EW	119
	120	if (uic_is_stale(&uic)) {
	121	if (adjust_shared_perm(tmp) < 0)
	122	goto out;
	123	if (rename(tmp, path) < 0)
	124	goto out;
	125	} else {
	126	unlink(tmp);
	127	}
d38379ec JK	128	ret = 0;
	129
	130	out:
	131	if (ret) {
02382f51	132	error_errno("unable to update %s", path);
f4f476b6 EW	133	if (uic.cur_fp)
f4f476b6 EW	134	fclose(uic.cur_fp);
d38379ec JK	135	else if (fd >= 0)
	136	close(fd);
	137	unlink(tmp);
	138	}
	139	free(tmp);
f4f476b6 EW	140	if (uic.old_fp)
	141	fclose(uic.old_fp);
	142	strbuf_release(&uic.old_sb);
	143	strbuf_release(&uic.cur_sb);
d38379ec JK	144	return ret;
d38379ec JK	145	}
8f3f9b09	146
e2b0bcdf MH	147	static int add_info_ref(const char path, const struct object_id oid,
e2b0bcdf MH	148	int flag, void *cb_data)
8f3f9b09	149	{
f4f476b6	150	struct update_info_ctx *uic = cb_data;
109cd76d	151	struct object *o = parse_object(the_repository, oid);
76f8a302 SP	152	if (!o)
76f8a302 SP	153	return -1;
f6b42a81	154
f4f476b6	155	if (uic_printf(uic, "%s %s\n", oid_to_hex(oid), path) < 0)
d38379ec JK	156	return -1;
d38379ec JK	157
1974632c	158	if (o->type == OBJ_TAG) {
a74093da	159	o = deref_tag(the_repository, o, path, 0);
9534f40b	160	if (o)
f4f476b6	161	if (uic_printf(uic, "%s %s^{}\n",
f2fd0760	162	oid_to_hex(&o->oid), path) < 0)
d38379ec	163	return -1;
f6b42a81	164	}
8f3f9b09 JH	165	return 0;
	166	}
	167
f4f476b6	168	static int generate_info_refs(struct update_info_ctx *uic)
d38379ec	169	{
f4f476b6	170	return for_each_ref(add_info_ref, uic);
d38379ec JK	171	}
d38379ec JK	172
f4f476b6	173	static int update_info_refs(int force)
8f3f9b09	174	{
d38379ec	175	char *path = git_pathdup("info/refs");
f4f476b6	176	int ret = update_info_file(path, generate_info_refs, force);
d38379ec JK	177	free(path);
d38379ec JK	178	return ret;
8f3f9b09 JH	179	}
	180
	181	/* packs */
4d8fa916	182	static struct pack_info {
8f3f9b09 JH	183	struct packed_git *p;
	184	int old_num;
	185	int new_num;
8f3f9b09 JH	186	} **info;
8f3f9b09 JH	187	static int num_pack;
8f3f9b09	188
8f3f9b09 JH	189	static struct pack_info find_pack_by_name(const char name)
	190	{
	191	int i;
	192	for (i = 0; i < num_pack; i++) {
	193	struct packed_git *p = info[i]->p;
b9fb142e	194	if (!strcmp(pack_basename(p), name))
8f3f9b09 JH	195	return info[i];
	196	}
	197	return NULL;
	198	}
	199
8f3f9b09 JH	200	/* Returns non-zero when we detect that the info in the
	201	* old file is useless.
	202	*/
b83a3089	203	static int parse_pack_def(const char *packname, int old_cnt)
8f3f9b09	204	{
b83a3089	205	struct pack_info *i = find_pack_by_name(packname);
8f3f9b09 JH	206	if (i) {
	207	i->old_num = old_cnt;
	208	return 0;
	209	}
	210	else {
6f42f89c	211	/* The file describes a pack that is no longer here */
8f3f9b09 JH	212	return 1;
	213	}
	214	}
	215
8f3f9b09 JH	216	/* Returns non-zero when we detect that the info in the
	217	* old file is useless.
	218	*/
	219	static int read_pack_info_file(const char *infofile)
	220	{
	221	FILE *fp;
4ecbd649	222	struct strbuf line = STRBUF_INIT;
8f3f9b09	223	int old_cnt = 0;
965cc517	224	int stale = 1;
8f3f9b09	225
e9d983f1	226	fp = fopen_or_warn(infofile, "r");
8f3f9b09	227	if (!fp)
addf88e4	228	return 1; /* nonexistent is not an error. */
8f3f9b09	229
4ecbd649	230	while (strbuf_getline(&line, fp) != EOF) {
b83a3089	231	const char *arg;
8ac4838a	232
4ecbd649	233	if (!line.len)
8ac4838a	234	continue;
8f3f9b09	235
4ecbd649	236	if (skip_prefix(line.buf, "P ", &arg)) {
b83a3089 JK	237	/* P name */
b83a3089 JK	238	if (parse_pack_def(arg, old_cnt++))
8f3f9b09	239	goto out_stale;
4ecbd649	240	} else if (line.buf[0] == 'D') {
b83a3089	241	/* we used to emit D but that was misguided. */
3e15c67c	242	goto out_stale;
4ecbd649	243	} else if (line.buf[0] == 'T') {
b83a3089 JK	244	/* we used to emit T but nobody uses it. */
	245	goto out_stale;
	246	} else {
4ecbd649	247	error("unrecognized: %s", line.buf);
8f3f9b09 JH	248	}
8f3f9b09 JH	249	}
965cc517 JK	250	stale = 0;
965cc517 JK	251
8f3f9b09	252	out_stale:
4ecbd649	253	strbuf_release(&line);
8f3f9b09	254	fclose(fp);
965cc517	255	return stale;
8f3f9b09 JH	256	}
8f3f9b09 JH	257
8f3f9b09 JH	258	static int compare_info(const void a_, const void b_)
8f3f9b09 JH	259	{
4b25d091 FC	260	struct pack_info const a = a_;
4b25d091 FC	261	struct pack_info const b = b_;
8f3f9b09 JH	262
	263	if (0 <= (a)->old_num && 0 <= (b)->old_num)
	264	/* Keep the order in the original */
	265	return (a)->old_num - (b)->old_num;
	266	else if (0 <= (*a)->old_num)
	267	/* Only A existed in the original so B is obviously newer */
	268	return -1;
	269	else if (0 <= (*b)->old_num)
	270	/* The other way around. */
	271	return 1;
	272
d5eac498	273	/* then it does not matter but at least keep the comparison stable */
2dee5816 JH	274	if ((a)->p == (b)->p)
	275	return 0;
	276	else if ((a)->p < (b)->p)
	277	return -1;
	278	else
	279	return 1;
8f3f9b09 JH	280	}
	281
	282	static void init_pack_info(const char *infofile, int force)
	283	{
	284	struct packed_git *p;
	285	int stale;
	286	int i = 0;
8f3f9b09	287
454ea2e4	288	for (p = get_all_packs(the_repository); p; p = p->next) {
8f3f9b09 JH	289	/* we ignore things on alternate path since they are
	290	* not available to the pullers in general.
	291	*/
f13d7db4	292	if (!p->pack_local)
8f3f9b09 JH	293	continue;
	294	i++;
	295	}
	296	num_pack = i;
	297	info = xcalloc(num_pack, sizeof(struct pack_info *));
454ea2e4	298	for (i = 0, p = get_all_packs(the_repository); p; p = p->next) {
f13d7db4	299	if (!p->pack_local)
8f3f9b09	300	continue;
79bb8b3c	301	assert(i < num_pack);
6f42f89c	302	info[i] = xcalloc(1, sizeof(struct pack_info));
8f3f9b09 JH	303	info[i]->p = p;
	304	info[i]->old_num = -1;
	305	i++;
	306	}
	307
	308	if (infofile && !force)
	309	stale = read_pack_info_file(infofile);
	310	else
	311	stale = 1;
	312
910710bb	313	for (i = 0; i < num_pack; i++)
910710bb	314	if (stale)
8f3f9b09	315	info[i]->old_num = -1;
8f3f9b09	316
6f42f89c	317	/* renumber them */
9ed0d8d6	318	QSORT(info, num_pack, compare_info);
8f3f9b09 JH	319	for (i = 0; i < num_pack; i++)
8f3f9b09 JH	320	info[i]->new_num = i;
8f3f9b09 JH	321	}
8f3f9b09 JH	322
3907a407 JK	323	static void free_pack_info(void)
	324	{
	325	int i;
	326	for (i = 0; i < num_pack; i++)
	327	free(info[i]);
	328	free(info);
	329	}
	330
f4f476b6	331	static int write_pack_info_file(struct update_info_ctx *uic)
8f3f9b09	332	{
3e15c67c	333	int i;
d38379ec	334	for (i = 0; i < num_pack; i++) {
f4f476b6	335	if (uic_printf(uic, "P %s\n", pack_basename(info[i]->p)) < 0)
d38379ec JK	336	return -1;
d38379ec JK	337	}
f4f476b6	338	if (uic_printf(uic, "\n") < 0)
d38379ec JK	339	return -1;
d38379ec JK	340	return 0;
8f3f9b09 JH	341	}
	342
	343	static int update_info_packs(int force)
	344	{
d38379ec JK	345	char *infofile = mkpathdup("%s/info/packs", get_object_directory());
d38379ec JK	346	int ret;
8f3f9b09 JH	347
8f3f9b09 JH	348	init_pack_info(infofile, force);
f4f476b6	349	ret = update_info_file(infofile, write_pack_info_file, force);
3907a407	350	free_pack_info();
d38379ec JK	351	free(infofile);
d38379ec JK	352	return ret;
8f3f9b09 JH	353	}
8f3f9b09 JH	354
8f3f9b09 JH	355	/* public */
	356	int update_server_info(int force)
	357	{
	358	/* We would add more dumb-server support files later,
	359	* including index of available pack files and their
	360	* intended audiences.
	361	*/
	362	int errs = 0;
	363
f4f476b6	364	errs = errs \| update_info_refs(force);
8f3f9b09	365	errs = errs \| update_info_packs(force);
8f3f9b09	366
6f42f89c	367	/* remove leftover rev-cache file if there is any */
691f1a28	368	unlink_or_warn(git_path("info/rev-cache"));
6f42f89c	369
8f3f9b09 JH	370	return errs;
8f3f9b09 JH	371	}