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

#include "cache.h"
#include "dir.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;
	size_t alloc = 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 || !file_exists(p->pack_name))
			continue;

		i = num_pack++;
		ALLOC_GROW(info, num_pack, alloc);
		info[i] = xcalloc(1, sizeof(struct pack_info));
		info[i]->p = p;
		info[i]->old_num = -1;
	}

	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"
e941c48d	2	#include "dir.h"
a80d72db	3	#include "repository.h"
8f3f9b09 JH	4	#include "refs.h"
	5	#include "object.h"
	6	#include "commit.h"
b614e3d7	7	#include "tag.h"
0abe14f6	8	#include "packfile.h"
a80d72db	9	#include "object-store.h"
f4f476b6 EW	10	#include "strbuf.h"
	11
	12	struct update_info_ctx {
	13	FILE *cur_fp;
	14	FILE old_fp; / becomes NULL if it differs from cur_fp */
	15	struct strbuf cur_sb;
	16	struct strbuf old_sb;
	17	};
	18
	19	static void uic_mark_stale(struct update_info_ctx *uic)
	20	{
	21	fclose(uic->old_fp);
	22	uic->old_fp = NULL;
	23	}
	24
	25	static int uic_is_stale(const struct update_info_ctx *uic)
	26	{
	27	return uic->old_fp == NULL;
	28	}
	29
	30	static int uic_printf(struct update_info_ctx uic, const char fmt, ...)
	31	{
	32	va_list ap;
	33	int ret = -1;
	34
	35	va_start(ap, fmt);
	36
	37	if (uic_is_stale(uic)) {
	38	ret = vfprintf(uic->cur_fp, fmt, ap);
	39	} else {
	40	ssize_t r;
	41	struct strbuf *cur = &uic->cur_sb;
	42	struct strbuf *old = &uic->old_sb;
	43
	44	strbuf_reset(cur);
	45	strbuf_vinsertf(cur, 0, fmt, ap);
	46
	47	strbuf_reset(old);
	48	strbuf_grow(old, cur->len);
	49	r = fread(old->buf, 1, cur->len, uic->old_fp);
	50	if (r != cur->len \|\| memcmp(old->buf, cur->buf, r))
	51	uic_mark_stale(uic);
	52
	53	if (fwrite(cur->buf, 1, cur->len, uic->cur_fp) == cur->len)
	54	ret = 0;
	55	}
	56
	57	va_end(ap);
	58
	59	return ret;
	60	}
8f3f9b09	61
d38379ec JK	62	/*
	63	* Create the file "path" by writing to a temporary file and renaming
	64	* it into place. The contents of the file come from "generate", which
	65	* should return non-zero if it encounters an error.
	66	*/
f4f476b6 EW	67	static int update_info_file(char *path,
	68	int (generate)(struct update_info_ctx ),
	69	int force)
d38379ec JK	70	{
	71	char *tmp = mkpathdup("%s_XXXXXX", path);
	72	int ret = -1;
	73	int fd = -1;
f4f476b6 EW	74	FILE *to_close;
	75	struct update_info_ctx uic = {
	76	.cur_fp = NULL,
	77	.old_fp = NULL,
	78	.cur_sb = STRBUF_INIT,
	79	.old_sb = STRBUF_INIT
	80	};
d38379ec JK	81
d38379ec JK	82	safe_create_leading_directories(path);
d91175b2	83	fd = git_mkstemp_mode(tmp, 0666);
d38379ec JK	84	if (fd < 0)
d38379ec JK	85	goto out;
f4f476b6 EW	86	to_close = uic.cur_fp = fdopen(fd, "w");
f4f476b6 EW	87	if (!uic.cur_fp)
d38379ec	88	goto out;
fa1912c8	89	fd = -1;
f4f476b6 EW	90
	91	/* no problem on ENOENT and old_fp == NULL, it's stale, now */
	92	if (!force)
	93	uic.old_fp = fopen_or_warn(path, "r");
	94
	95	/*
	96	* uic_printf will compare incremental comparison aginst old_fp
	97	* and mark uic as stale if needed
	98	*/
	99	ret = generate(&uic);
d38379ec JK	100	if (ret)
d38379ec JK	101	goto out;
f4f476b6 EW	102
	103	/* new file may be shorter than the old one, check here */
	104	if (!uic_is_stale(&uic)) {
	105	struct stat st;
	106	long new_len = ftell(uic.cur_fp);
	107	int old_fd = fileno(uic.old_fp);
	108
	109	if (new_len < 0) {
	110	ret = -1;
	111	goto out;
	112	}
	113	if (fstat(old_fd, &st) \|\| (st.st_size != (size_t)new_len))
	114	uic_mark_stale(&uic);
	115	}
	116
	117	uic.cur_fp = NULL;
fa1912c8	118	if (fclose(to_close))
d38379ec	119	goto out;
f4f476b6 EW	120
	121	if (uic_is_stale(&uic)) {
	122	if (adjust_shared_perm(tmp) < 0)
	123	goto out;
	124	if (rename(tmp, path) < 0)
	125	goto out;
	126	} else {
	127	unlink(tmp);
	128	}
d38379ec JK	129	ret = 0;
	130
	131	out:
	132	if (ret) {
02382f51	133	error_errno("unable to update %s", path);
f4f476b6 EW	134	if (uic.cur_fp)
f4f476b6 EW	135	fclose(uic.cur_fp);
d38379ec JK	136	else if (fd >= 0)
	137	close(fd);
	138	unlink(tmp);
	139	}
	140	free(tmp);
f4f476b6 EW	141	if (uic.old_fp)
	142	fclose(uic.old_fp);
	143	strbuf_release(&uic.old_sb);
	144	strbuf_release(&uic.cur_sb);
d38379ec JK	145	return ret;
d38379ec JK	146	}
8f3f9b09	147
e2b0bcdf MH	148	static int add_info_ref(const char path, const struct object_id oid,
e2b0bcdf MH	149	int flag, void *cb_data)
8f3f9b09	150	{
f4f476b6	151	struct update_info_ctx *uic = cb_data;
109cd76d	152	struct object *o = parse_object(the_repository, oid);
76f8a302 SP	153	if (!o)
76f8a302 SP	154	return -1;
f6b42a81	155
f4f476b6	156	if (uic_printf(uic, "%s %s\n", oid_to_hex(oid), path) < 0)
d38379ec JK	157	return -1;
d38379ec JK	158
1974632c	159	if (o->type == OBJ_TAG) {
a74093da	160	o = deref_tag(the_repository, o, path, 0);
9534f40b	161	if (o)
f4f476b6	162	if (uic_printf(uic, "%s %s^{}\n",
f2fd0760	163	oid_to_hex(&o->oid), path) < 0)
d38379ec	164	return -1;
f6b42a81	165	}
8f3f9b09 JH	166	return 0;
	167	}
	168
f4f476b6	169	static int generate_info_refs(struct update_info_ctx *uic)
d38379ec	170	{
f4f476b6	171	return for_each_ref(add_info_ref, uic);
d38379ec JK	172	}
d38379ec JK	173
f4f476b6	174	static int update_info_refs(int force)
8f3f9b09	175	{
d38379ec	176	char *path = git_pathdup("info/refs");
f4f476b6	177	int ret = update_info_file(path, generate_info_refs, force);
d38379ec JK	178	free(path);
d38379ec JK	179	return ret;
8f3f9b09 JH	180	}
	181
	182	/* packs */
4d8fa916	183	static struct pack_info {
8f3f9b09 JH	184	struct packed_git *p;
	185	int old_num;
	186	int new_num;
8f3f9b09 JH	187	} **info;
8f3f9b09 JH	188	static int num_pack;
8f3f9b09	189
8f3f9b09 JH	190	static struct pack_info find_pack_by_name(const char name)
	191	{
	192	int i;
	193	for (i = 0; i < num_pack; i++) {
	194	struct packed_git *p = info[i]->p;
b9fb142e	195	if (!strcmp(pack_basename(p), name))
8f3f9b09 JH	196	return info[i];
	197	}
	198	return NULL;
	199	}
	200
8f3f9b09 JH	201	/* Returns non-zero when we detect that the info in the
	202	* old file is useless.
	203	*/
b83a3089	204	static int parse_pack_def(const char *packname, int old_cnt)
8f3f9b09	205	{
b83a3089	206	struct pack_info *i = find_pack_by_name(packname);
8f3f9b09 JH	207	if (i) {
	208	i->old_num = old_cnt;
	209	return 0;
	210	}
	211	else {
6f42f89c	212	/* The file describes a pack that is no longer here */
8f3f9b09 JH	213	return 1;
	214	}
	215	}
	216
8f3f9b09 JH	217	/* Returns non-zero when we detect that the info in the
	218	* old file is useless.
	219	*/
	220	static int read_pack_info_file(const char *infofile)
	221	{
	222	FILE *fp;
4ecbd649	223	struct strbuf line = STRBUF_INIT;
8f3f9b09	224	int old_cnt = 0;
965cc517	225	int stale = 1;
8f3f9b09	226
e9d983f1	227	fp = fopen_or_warn(infofile, "r");
8f3f9b09	228	if (!fp)
addf88e4	229	return 1; /* nonexistent is not an error. */
8f3f9b09	230
4ecbd649	231	while (strbuf_getline(&line, fp) != EOF) {
b83a3089	232	const char *arg;
8ac4838a	233
4ecbd649	234	if (!line.len)
8ac4838a	235	continue;
8f3f9b09	236
4ecbd649	237	if (skip_prefix(line.buf, "P ", &arg)) {
b83a3089 JK	238	/* P name */
b83a3089 JK	239	if (parse_pack_def(arg, old_cnt++))
8f3f9b09	240	goto out_stale;
4ecbd649	241	} else if (line.buf[0] == 'D') {
b83a3089	242	/* we used to emit D but that was misguided. */
3e15c67c	243	goto out_stale;
4ecbd649	244	} else if (line.buf[0] == 'T') {
b83a3089 JK	245	/* we used to emit T but nobody uses it. */
	246	goto out_stale;
	247	} else {
4ecbd649	248	error("unrecognized: %s", line.buf);
8f3f9b09 JH	249	}
8f3f9b09 JH	250	}
965cc517 JK	251	stale = 0;
965cc517 JK	252
8f3f9b09	253	out_stale:
4ecbd649	254	strbuf_release(&line);
8f3f9b09	255	fclose(fp);
965cc517	256	return stale;
8f3f9b09 JH	257	}
8f3f9b09 JH	258
8f3f9b09 JH	259	static int compare_info(const void a_, const void b_)
8f3f9b09 JH	260	{
4b25d091 FC	261	struct pack_info const a = a_;
4b25d091 FC	262	struct pack_info const b = b_;
8f3f9b09 JH	263
	264	if (0 <= (a)->old_num && 0 <= (b)->old_num)
	265	/* Keep the order in the original */
	266	return (a)->old_num - (b)->old_num;
	267	else if (0 <= (*a)->old_num)
	268	/* Only A existed in the original so B is obviously newer */
	269	return -1;
	270	else if (0 <= (*b)->old_num)
	271	/* The other way around. */
	272	return 1;
	273
d5eac498	274	/* then it does not matter but at least keep the comparison stable */
2dee5816 JH	275	if ((a)->p == (b)->p)
	276	return 0;
	277	else if ((a)->p < (b)->p)
	278	return -1;
	279	else
	280	return 1;
8f3f9b09 JH	281	}
	282
	283	static void init_pack_info(const char *infofile, int force)
	284	{
	285	struct packed_git *p;
	286	int stale;
e941c48d EW	287	int i;
e941c48d EW	288	size_t alloc = 0;
8f3f9b09	289
454ea2e4	290	for (p = get_all_packs(the_repository); p; p = p->next) {
8f3f9b09 JH	291	/* we ignore things on alternate path since they are
	292	* not available to the pullers in general.
	293	*/
e941c48d	294	if (!p->pack_local \|\| !file_exists(p->pack_name))
8f3f9b09	295	continue;
e941c48d EW	296
	297	i = num_pack++;
	298	ALLOC_GROW(info, num_pack, alloc);
6f42f89c	299	info[i] = xcalloc(1, sizeof(struct pack_info));
8f3f9b09 JH	300	info[i]->p = p;
8f3f9b09 JH	301	info[i]->old_num = -1;
8f3f9b09 JH	302	}
	303
	304	if (infofile && !force)
	305	stale = read_pack_info_file(infofile);
	306	else
	307	stale = 1;
	308
910710bb	309	for (i = 0; i < num_pack; i++)
910710bb	310	if (stale)
8f3f9b09	311	info[i]->old_num = -1;
8f3f9b09	312
6f42f89c	313	/* renumber them */
9ed0d8d6	314	QSORT(info, num_pack, compare_info);
8f3f9b09 JH	315	for (i = 0; i < num_pack; i++)
8f3f9b09 JH	316	info[i]->new_num = i;
8f3f9b09 JH	317	}
8f3f9b09 JH	318
3907a407 JK	319	static void free_pack_info(void)
	320	{
	321	int i;
	322	for (i = 0; i < num_pack; i++)
	323	free(info[i]);
	324	free(info);
	325	}
	326
f4f476b6	327	static int write_pack_info_file(struct update_info_ctx *uic)
8f3f9b09	328	{
3e15c67c	329	int i;
d38379ec	330	for (i = 0; i < num_pack; i++) {
f4f476b6	331	if (uic_printf(uic, "P %s\n", pack_basename(info[i]->p)) < 0)
d38379ec JK	332	return -1;
d38379ec JK	333	}
f4f476b6	334	if (uic_printf(uic, "\n") < 0)
d38379ec JK	335	return -1;
d38379ec JK	336	return 0;
8f3f9b09 JH	337	}
	338
	339	static int update_info_packs(int force)
	340	{
d38379ec JK	341	char *infofile = mkpathdup("%s/info/packs", get_object_directory());
d38379ec JK	342	int ret;
8f3f9b09 JH	343
8f3f9b09 JH	344	init_pack_info(infofile, force);
f4f476b6	345	ret = update_info_file(infofile, write_pack_info_file, force);
3907a407	346	free_pack_info();
d38379ec JK	347	free(infofile);
d38379ec JK	348	return ret;
8f3f9b09 JH	349	}
8f3f9b09 JH	350
8f3f9b09 JH	351	/* public */
	352	int update_server_info(int force)
	353	{
	354	/* We would add more dumb-server support files later,
	355	* including index of available pack files and their
	356	* intended audiences.
	357	*/
	358	int errs = 0;
	359
f4f476b6	360	errs = errs \| update_info_refs(force);
8f3f9b09	361	errs = errs \| update_info_packs(force);
8f3f9b09	362
6f42f89c	363	/* remove leftover rev-cache file if there is any */
691f1a28	364	unlink_or_warn(git_path("info/rev-cache"));
6f42f89c	365
8f3f9b09 JH	366	return errs;
8f3f9b09 JH	367	}