[thirdparty/git.git] / sha1_file.c

/*
 * GIT - The information manager from hell
 *
 * Copyright (C) Linus Torvalds, 2005
 *
 * This handles basic git sha1 object files - packing, unpacking,
 * creation etc.
 */
#include <stdarg.h>
#include "cache.h"

const char *sha1_file_directory = NULL;

#ifndef O_NOATIME
#if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
#define O_NOATIME 01000000
#else
#define O_NOATIME 0
#endif
#endif

static unsigned int sha1_file_open_flag = O_NOATIME;

static unsigned hexval(char c)
{
	if (c >= '0' && c <= '9')
		return c - '0';
	if (c >= 'a' && c <= 'f')
		return c - 'a' + 10;
	if (c >= 'A' && c <= 'F')
		return c - 'A' + 10;
	return ~0;
}

int get_sha1_hex(const char *hex, unsigned char *sha1)
{
	int i;
	for (i = 0; i < 20; i++) {
		unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
		if (val & ~0xff)
			return -1;
		*sha1++ = val;
		hex += 2;
	}
	return 0;
}

char * sha1_to_hex(const unsigned char *sha1)
{
	static char buffer[50];
	static const char hex[] = "0123456789abcdef";
	char *buf = buffer;
	int i;

	for (i = 0; i < 20; i++) {
		unsigned int val = *sha1++;
		*buf++ = hex[val >> 4];
		*buf++ = hex[val & 0xf];
	}
	return buffer;
}

/*
 * NOTE! This returns a statically allocated buffer, so you have to be
 * careful about using it. Do a "strdup()" if you need to save the
 * filename.
 */
char *sha1_file_name(const unsigned char *sha1)
{
	int i;
	static char *name, *base;

	if (!base) {
		char *sha1_file_directory = getenv(DB_ENVIRONMENT) ? : DEFAULT_DB_ENVIRONMENT;
		int len = strlen(sha1_file_directory);
		base = xmalloc(len + 60);
		memcpy(base, sha1_file_directory, len);
		memset(base+len, 0, 60);
		base[len] = '/';
		base[len+3] = '/';
		name = base + len + 1;
	}
	for (i = 0; i < 20; i++) {
		static char hex[] = "0123456789abcdef";
		unsigned int val = sha1[i];
		char *pos = name + i*2 + (i > 0);
		*pos++ = hex[val >> 4];
		*pos = hex[val & 0xf];
	}
	return base;
}

int check_sha1_signature(unsigned char *sha1, void *map, unsigned long size, const char *type)
{
	char header[100];
	unsigned char real_sha1[20];
	SHA_CTX c;

	SHA1_Init(&c);
	SHA1_Update(&c, header, 1+sprintf(header, "%s %lu", type, size));
	SHA1_Update(&c, map, size);
	SHA1_Final(real_sha1, &c);
	return memcmp(sha1, real_sha1, 20) ? -1 : 0;
}

void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
{
	char *filename = sha1_file_name(sha1);
	struct stat st;
	void *map;
	int fd;

	fd = open(filename, O_RDONLY | sha1_file_open_flag);
	if (fd < 0) {
		/* See if it works without O_NOATIME */
		switch (sha1_file_open_flag) {
		default:
			fd = open(filename, O_RDONLY);
			if (fd >= 0)
				break;
		/* Fallthrough */
		case 0:
			perror(filename);
			return NULL;
		}

		/* If it failed once, it will probably fail again. Stop using O_NOATIME */
		sha1_file_open_flag = 0;
	}
	if (fstat(fd, &st) < 0) {
		close(fd);
		return NULL;
	}
	map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
	close(fd);
	if (-1 == (int)(long)map)
		return NULL;
	*size = st.st_size;
	return map;
}

void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size)
{
	int ret, bytes;
	z_stream stream;
	char buffer[8192];
	char *buf;

	/* Get the data stream */
	memset(&stream, 0, sizeof(stream));
	stream.next_in = map;
	stream.avail_in = mapsize;
	stream.next_out = buffer;
	stream.avail_out = sizeof(buffer);

	inflateInit(&stream);
	ret = inflate(&stream, 0);
	if (ret < Z_OK)
		return NULL;
	if (sscanf(buffer, "%10s %lu", type, size) != 2)
		return NULL;

	bytes = strlen(buffer) + 1;
	buf = xmalloc(*size);

	memcpy(buf, buffer + bytes, stream.total_out - bytes);
	bytes = stream.total_out - bytes;
	if (bytes < *size && ret == Z_OK) {
		stream.next_out = buf + bytes;
		stream.avail_out = *size - bytes;
		while (inflate(&stream, Z_FINISH) == Z_OK)
			/* nothing */;
	}
	inflateEnd(&stream);
	return buf;
}

void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
{
	unsigned long mapsize;
	void *map, *buf;

	map = map_sha1_file(sha1, &mapsize);
	if (map) {
		buf = unpack_sha1_file(map, mapsize, type, size);
		munmap(map, mapsize);
		return buf;
	}
	return NULL;
}

void *read_tree_with_tree_or_commit_sha1(const unsigned char *sha1,
					 unsigned long *size,
					 unsigned char *tree_sha1_return)
{
	char type[20];
	void *buffer;
	unsigned long isize;
	int was_commit = 0;
	unsigned char tree_sha1[20];

	buffer = read_sha1_file(sha1, type, &isize);

	/* 
	 * We might have read a commit instead of a tree, in which case
	 * we parse out the tree_sha1 and attempt to read from there.
	 * (buffer + 5) is because the tree sha1 is always at offset 5
	 * in a commit record ("tree ").
	 */
	if (buffer &&
	    !strcmp(type, "commit") &&
	    !get_sha1_hex(buffer + 5, tree_sha1)) {
		free(buffer);
		buffer = read_sha1_file(tree_sha1, type, &isize);
		was_commit = 1;
	}

	/*
	 * Now do we have something and if so is it a tree?
	 */
	if (!buffer || strcmp(type, "tree")) {
		free(buffer);
		return NULL;
	}

	*size = isize;
	if (tree_sha1_return)
		memcpy(tree_sha1_return, was_commit ? tree_sha1 : sha1, 20);
	return buffer;
}

int write_sha1_file(char *buf, unsigned long len, const char *type, unsigned char *returnsha1)
{
	int size;
	char *compressed;
	z_stream stream;
	unsigned char sha1[20];
	SHA_CTX c;
	char *filename;
	char hdr[50];
	int fd, hdrlen;

	/* Generate the header */
	hdrlen = sprintf(hdr, "%s %lu", type, len)+1;

	/* Sha1.. */
	SHA1_Init(&c);
	SHA1_Update(&c, hdr, hdrlen);
	SHA1_Update(&c, buf, len);
	SHA1_Final(sha1, &c);

	if (returnsha1)
		memcpy(returnsha1, sha1, 20);

	filename = sha1_file_name(sha1);
	fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
	if (fd < 0) {
		if (errno != EEXIST)
			return -1;

		/*
		 * We might do collision checking here, but we'd need to
		 * uncompress the old file and check it. Later.
		 */
		return 0;
	}

	/* Set it up */
	memset(&stream, 0, sizeof(stream));
	deflateInit(&stream, Z_BEST_COMPRESSION);
	size = deflateBound(&stream, len+hdrlen);
	compressed = xmalloc(size);

	/* Compress it */
	stream.next_out = compressed;
	stream.avail_out = size;

	/* First header.. */
	stream.next_in = hdr;
	stream.avail_in = hdrlen;
	while (deflate(&stream, 0) == Z_OK)
		/* nothing */

	/* Then the data itself.. */
	stream.next_in = buf;
	stream.avail_in = len;
	while (deflate(&stream, Z_FINISH) == Z_OK)
		/* nothing */;
	deflateEnd(&stream);
	size = stream.total_out;

	if (write(fd, compressed, size) != size)
		die("unable to write file");
	close(fd);
		
	return 0;
}

static inline int collision_check(char *filename, void *buf, unsigned int size)
{
#ifdef COLLISION_CHECK
	void *map;
	int fd = open(filename, O_RDONLY);
	struct stat st;
	int cmp;

	/* Unreadable object, or object went away? Strange. */
	if (fd < 0)
		return -1;

	if (fstat(fd, &st) < 0 || size != st.st_size)
		return -1;

	map = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
	close(fd);
	if (map == MAP_FAILED)
		return -1;
	cmp = memcmp(buf, map, size);
	munmap(map, size);
	if (cmp)
		return -1;
#endif
	return 0;
}

int write_sha1_buffer(const unsigned char *sha1, void *buf, unsigned int size)
{
	char *filename = sha1_file_name(sha1);
	int fd;

	fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
	if (fd < 0) {
		if (errno != EEXIST)
			return -1;
		if (collision_check(filename, buf, size))
			return error("SHA1 collision detected!"
					" This is bad, bad, BAD!\a\n");
		return 0;
	}
	write(fd, buf, size);
	close(fd);
	return 0;
}

int write_sha1_from_fd(const unsigned char *sha1, int fd)
{
	char *filename = sha1_file_name(sha1);

	int local;
	z_stream stream;
	unsigned char real_sha1[20];
	char buf[4096];
	char discard[4096];
	int ret;
	SHA_CTX c;

	local = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666);

	if (local < 0)
		return error("Couldn't open %s\n", filename);

	memset(&stream, 0, sizeof(stream));

	inflateInit(&stream);

	SHA1_Init(&c);

	do {
		ssize_t size;
		size = read(fd, buf, 4096);
		if (size <= 0) {
			close(local);
			unlink(filename);
			if (!size)
				return error("Connection closed?");
			perror("Reading from connection");
			return -1;
		}
		write(local, buf, size);
		stream.avail_in = size;
		stream.next_in = buf;
		do {
			stream.next_out = discard;
			stream.avail_out = sizeof(discard);
			ret = inflate(&stream, Z_SYNC_FLUSH);
			SHA1_Update(&c, discard, sizeof(discard) -
				    stream.avail_out);
		} while (stream.avail_in && ret == Z_OK);
		
	} while (ret == Z_OK);
	inflateEnd(&stream);

	close(local);
	SHA1_Final(real_sha1, &c);
	if (ret != Z_STREAM_END) {
		unlink(filename);
		return error("File %s corrupted", sha1_to_hex(sha1));
	}
	if (memcmp(sha1, real_sha1, 20)) {
		unlink(filename);
		return error("File %s has bad hash\n", sha1_to_hex(sha1));
	}
	
	return 0;
}

int has_sha1_file(const unsigned char *sha1)
{
	char *filename = sha1_file_name(sha1);
	struct stat st;

	if (!stat(filename, &st))
		return 1;
	return 0;
}
Commit	Line	Data
0fcfd160 LT	1	/*
	2	* GIT - The information manager from hell
	3	*
	4	* Copyright (C) Linus Torvalds, 2005
	5	*
	6	* This handles basic git sha1 object files - packing, unpacking,
	7	* creation etc.
	8	*/
	9	#include <stdarg.h>
	10	#include "cache.h"
	11
	12	const char *sha1_file_directory = NULL;
	13
144bde78 LT	14	#ifndef O_NOATIME
	15	#if defined(__linux__) && (defined(__i386__) \|\| defined(__PPC__))
	16	#define O_NOATIME 01000000
	17	#else
	18	#define O_NOATIME 0
	19	#endif
	20	#endif
	21
	22	static unsigned int sha1_file_open_flag = O_NOATIME;
	23
0fcfd160 LT	24	static unsigned hexval(char c)
	25	{
	26	if (c >= '0' && c <= '9')
	27	return c - '0';
	28	if (c >= 'a' && c <= 'f')
	29	return c - 'a' + 10;
	30	if (c >= 'A' && c <= 'F')
	31	return c - 'A' + 10;
	32	return ~0;
	33	}
	34
	35	int get_sha1_hex(const char hex, unsigned char sha1)
	36	{
	37	int i;
	38	for (i = 0; i < 20; i++) {
	39	unsigned int val = (hexval(hex[0]) << 4) \| hexval(hex[1]);
	40	if (val & ~0xff)
	41	return -1;
	42	*sha1++ = val;
	43	hex += 2;
	44	}
	45	return 0;
	46	}
	47
	48	char * sha1_to_hex(const unsigned char *sha1)
	49	{
	50	static char buffer[50];
	51	static const char hex[] = "0123456789abcdef";
	52	char *buf = buffer;
	53	int i;
	54
	55	for (i = 0; i < 20; i++) {
	56	unsigned int val = *sha1++;
	57	*buf++ = hex[val >> 4];
	58	*buf++ = hex[val & 0xf];
	59	}
	60	return buffer;
	61	}
	62
	63	/*
	64	* NOTE! This returns a statically allocated buffer, so you have to be
	65	* careful about using it. Do a "strdup()" if you need to save the
	66	* filename.
	67	*/
	68	char sha1_file_name(const unsigned char sha1)
	69	{
	70	int i;
	71	static char name, base;
	72
	73	if (!base) {
	74	char *sha1_file_directory = getenv(DB_ENVIRONMENT) ? : DEFAULT_DB_ENVIRONMENT;
	75	int len = strlen(sha1_file_directory);
812666c8	76	base = xmalloc(len + 60);
0fcfd160 LT	77	memcpy(base, sha1_file_directory, len);
	78	memset(base+len, 0, 60);
	79	base[len] = '/';
	80	base[len+3] = '/';
	81	name = base + len + 1;
	82	}
	83	for (i = 0; i < 20; i++) {
	84	static char hex[] = "0123456789abcdef";
	85	unsigned int val = sha1[i];
	86	char pos = name + i2 + (i > 0);
	87	*pos++ = hex[val >> 4];
	88	*pos = hex[val & 0xf];
	89	}
	90	return base;
	91	}
	92
d98b46f8	93	int check_sha1_signature(unsigned char sha1, void map, unsigned long size, const char *type)
0fcfd160	94	{
d98b46f8	95	char header[100];
0fcfd160 LT	96	unsigned char real_sha1[20];
	97	SHA_CTX c;
	98
	99	SHA1_Init(&c);
d98b46f8	100	SHA1_Update(&c, header, 1+sprintf(header, "%s %lu", type, size));
0fcfd160 LT	101	SHA1_Update(&c, map, size);
	102	SHA1_Final(real_sha1, &c);
	103	return memcmp(sha1, real_sha1, 20) ? -1 : 0;
	104	}
	105
	106	void map_sha1_file(const unsigned char sha1, unsigned long *size)
	107	{
	108	char *filename = sha1_file_name(sha1);
0fcfd160 LT	109	struct stat st;
0fcfd160 LT	110	void *map;
144bde78	111	int fd;
0fcfd160	112
144bde78	113	fd = open(filename, O_RDONLY \| sha1_file_open_flag);
0fcfd160	114	if (fd < 0) {
144bde78 LT	115	/* See if it works without O_NOATIME */
	116	switch (sha1_file_open_flag) {
	117	default:
	118	fd = open(filename, O_RDONLY);
	119	if (fd >= 0)
	120	break;
	121	/* Fallthrough */
	122	case 0:
	123	perror(filename);
	124	return NULL;
	125	}
	126
	127	/* If it failed once, it will probably fail again. Stop using O_NOATIME */
	128	sha1_file_open_flag = 0;
0fcfd160 LT	129	}
	130	if (fstat(fd, &st) < 0) {
	131	close(fd);
	132	return NULL;
	133	}
	134	map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
	135	close(fd);
	136	if (-1 == (int)(long)map)
	137	return NULL;
	138	*size = st.st_size;
	139	return map;
	140	}
	141
	142	void * unpack_sha1_file(void map, unsigned long mapsize, char type, unsigned long *size)
	143	{
	144	int ret, bytes;
	145	z_stream stream;
	146	char buffer[8192];
	147	char *buf;
	148
	149	/* Get the data stream */
	150	memset(&stream, 0, sizeof(stream));
	151	stream.next_in = map;
	152	stream.avail_in = mapsize;
	153	stream.next_out = buffer;
	154	stream.avail_out = sizeof(buffer);
	155
	156	inflateInit(&stream);
	157	ret = inflate(&stream, 0);
a44c9a5e LT	158	if (ret < Z_OK)
a44c9a5e LT	159	return NULL;
0fcfd160 LT	160	if (sscanf(buffer, "%10s %lu", type, size) != 2)
	161	return NULL;
	162
	163	bytes = strlen(buffer) + 1;
812666c8	164	buf = xmalloc(*size);
0fcfd160 LT	165
	166	memcpy(buf, buffer + bytes, stream.total_out - bytes);
	167	bytes = stream.total_out - bytes;
	168	if (bytes < *size && ret == Z_OK) {
	169	stream.next_out = buf + bytes;
	170	stream.avail_out = *size - bytes;
	171	while (inflate(&stream, Z_FINISH) == Z_OK)
	172	/* nothing */;
	173	}
	174	inflateEnd(&stream);
	175	return buf;
	176	}
	177
	178	void * read_sha1_file(const unsigned char sha1, char type, unsigned long *size)
	179	{
	180	unsigned long mapsize;
	181	void map, buf;
	182
	183	map = map_sha1_file(sha1, &mapsize);
	184	if (map) {
	185	buf = unpack_sha1_file(map, mapsize, type, size);
	186	munmap(map, mapsize);
	187	return buf;
	188	}
	189	return NULL;
	190	}
	191
f4913f91 JH	192	void read_tree_with_tree_or_commit_sha1(const unsigned char sha1,
	193	unsigned long *size,
	194	unsigned char *tree_sha1_return)
	195	{
	196	char type[20];
	197	void *buffer;
	198	unsigned long isize;
	199	int was_commit = 0;
860edf7a	200	unsigned char tree_sha1[20];
f4913f91 JH	201
	202	buffer = read_sha1_file(sha1, type, &isize);
	203
	204	/*
	205	* We might have read a commit instead of a tree, in which case
	206	* we parse out the tree_sha1 and attempt to read from there.
	207	* (buffer + 5) is because the tree sha1 is always at offset 5
	208	* in a commit record ("tree ").
	209	*/
	210	if (buffer &&
	211	!strcmp(type, "commit") &&
	212	!get_sha1_hex(buffer + 5, tree_sha1)) {
	213	free(buffer);
	214	buffer = read_sha1_file(tree_sha1, type, &isize);
	215	was_commit = 1;
	216	}
	217
	218	/*
	219	* Now do we have something and if so is it a tree?
	220	*/
	221	if (!buffer \|\| strcmp(type, "tree")) {
	222	free(buffer);
860edf7a	223	return NULL;
f4913f91 JH	224	}
	225
	226	*size = isize;
	227	if (tree_sha1_return)
	228	memcpy(tree_sha1_return, was_commit ? tree_sha1 : sha1, 20);
	229	return buffer;
	230	}
	231
f5b913c9	232	int write_sha1_file(char buf, unsigned long len, const char type, unsigned char *returnsha1)
0fcfd160 LT	233	{
	234	int size;
	235	char *compressed;
	236	z_stream stream;
	237	unsigned char sha1[20];
	238	SHA_CTX c;
706bc531	239	char *filename;
a44c9a5e LT	240	char hdr[50];
	241	int fd, hdrlen;
	242
	243	/* Generate the header */
f5b913c9	244	hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
0fcfd160	245
d98b46f8 LT	246	/* Sha1.. */
d98b46f8 LT	247	SHA1_Init(&c);
a44c9a5e	248	SHA1_Update(&c, hdr, hdrlen);
d98b46f8 LT	249	SHA1_Update(&c, buf, len);
	250	SHA1_Final(sha1, &c);
	251
706bc531 LT	252	if (returnsha1)
	253	memcpy(returnsha1, sha1, 20);
	254
	255	filename = sha1_file_name(sha1);
	256	fd = open(filename, O_WRONLY \| O_CREAT \| O_EXCL, 0666);
	257	if (fd < 0) {
	258	if (errno != EEXIST)
	259	return -1;
	260
	261	/*
	262	* We might do collision checking here, but we'd need to
	263	* uncompress the old file and check it. Later.
	264	*/
	265	return 0;
	266	}
	267
0fcfd160 LT	268	/* Set it up */
	269	memset(&stream, 0, sizeof(stream));
	270	deflateInit(&stream, Z_BEST_COMPRESSION);
a44c9a5e	271	size = deflateBound(&stream, len+hdrlen);
812666c8	272	compressed = xmalloc(size);
0fcfd160 LT	273
0fcfd160 LT	274	/* Compress it */
0fcfd160 LT	275	stream.next_out = compressed;
0fcfd160 LT	276	stream.avail_out = size;
a44c9a5e LT	277
	278	/* First header.. */
	279	stream.next_in = hdr;
	280	stream.avail_in = hdrlen;
	281	while (deflate(&stream, 0) == Z_OK)
	282	/* nothing */
	283
	284	/* Then the data itself.. */
	285	stream.next_in = buf;
	286	stream.avail_in = len;
0fcfd160 LT	287	while (deflate(&stream, Z_FINISH) == Z_OK)
	288	/* nothing */;
	289	deflateEnd(&stream);
	290	size = stream.total_out;
	291
706bc531 LT	292	if (write(fd, compressed, size) != size)
	293	die("unable to write file");
	294	close(fd);
	295
0fcfd160 LT	296	return 0;
	297	}
	298
	299	static inline int collision_check(char filename, void buf, unsigned int size)
	300	{
	301	#ifdef COLLISION_CHECK
	302	void *map;
	303	int fd = open(filename, O_RDONLY);
	304	struct stat st;
	305	int cmp;
	306
	307	/* Unreadable object, or object went away? Strange. */
	308	if (fd < 0)
	309	return -1;
	310
	311	if (fstat(fd, &st) < 0 \|\| size != st.st_size)
	312	return -1;
	313
	314	map = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
	315	close(fd);
	316	if (map == MAP_FAILED)
	317	return -1;
	318	cmp = memcmp(buf, map, size);
	319	munmap(map, size);
	320	if (cmp)
	321	return -1;
	322	#endif
	323	return 0;
	324	}
	325
	326	int write_sha1_buffer(const unsigned char sha1, void buf, unsigned int size)
	327	{
	328	char *filename = sha1_file_name(sha1);
	329	int fd;
	330
	331	fd = open(filename, O_WRONLY \| O_CREAT \| O_EXCL, 0666);
	332	if (fd < 0) {
	333	if (errno != EEXIST)
	334	return -1;
	335	if (collision_check(filename, buf, size))
	336	return error("SHA1 collision detected!"
	337	" This is bad, bad, BAD!\a\n");
	338	return 0;
	339	}
	340	write(fd, buf, size);
	341	close(fd);
	342	return 0;
	343	}
8237b185 DB	344
	345	int write_sha1_from_fd(const unsigned char *sha1, int fd)
	346	{
	347	char *filename = sha1_file_name(sha1);
	348
	349	int local;
	350	z_stream stream;
	351	unsigned char real_sha1[20];
	352	char buf[4096];
	353	char discard[4096];
	354	int ret;
	355	SHA_CTX c;
	356
	357	local = open(filename, O_WRONLY \| O_CREAT \| O_EXCL, 0666);
	358
	359	if (local < 0)
	360	return error("Couldn't open %s\n", filename);
	361
	362	memset(&stream, 0, sizeof(stream));
	363
	364	inflateInit(&stream);
	365
	366	SHA1_Init(&c);
	367
	368	do {
	369	ssize_t size;
	370	size = read(fd, buf, 4096);
	371	if (size <= 0) {
	372	close(local);
	373	unlink(filename);
	374	if (!size)
	375	return error("Connection closed?");
	376	perror("Reading from connection");
	377	return -1;
	378	}
	379	write(local, buf, size);
	380	stream.avail_in = size;
	381	stream.next_in = buf;
	382	do {
	383	stream.next_out = discard;
	384	stream.avail_out = sizeof(discard);
	385	ret = inflate(&stream, Z_SYNC_FLUSH);
	386	SHA1_Update(&c, discard, sizeof(discard) -
	387	stream.avail_out);
	388	} while (stream.avail_in && ret == Z_OK);
	389
	390	} while (ret == Z_OK);
	391	inflateEnd(&stream);
	392
	393	close(local);
	394	SHA1_Final(real_sha1, &c);
	395	if (ret != Z_STREAM_END) {
	396	unlink(filename);
	397	return error("File %s corrupted", sha1_to_hex(sha1));
	398	}
	399	if (memcmp(sha1, real_sha1, 20)) {
	400	unlink(filename);
	401	return error("File %s has bad hash\n", sha1_to_hex(sha1));
	402	}
	403
	404	return 0;
	405	}
	406
	407	int has_sha1_file(const unsigned char *sha1)
408	{
409	char *filename = sha1_file_name(sha1);
410	struct stat st;
411
412	if (!stat(filename, &st))
413	return 1;
414	return 0;
415	}