[thirdparty/git.git] / streaming.c

/*
 * Copyright (c) 2011, Google Inc.
 */
#include "cache.h"
#include "streaming.h"

enum input_source {
	stream_error = -1,
	incore = 0,
	loose = 1,
	pack_non_delta = 2
};

typedef int (*open_istream_fn)(struct git_istream *,
			       struct object_info *,
			       const unsigned char *,
			       enum object_type *);
typedef int (*close_istream_fn)(struct git_istream *);
typedef ssize_t (*read_istream_fn)(struct git_istream *, char *, size_t);

struct stream_vtbl {
	close_istream_fn close;
	read_istream_fn read;
};

#define open_method_decl(name) \
	int open_istream_ ##name \
	(struct git_istream *st, struct object_info *oi, \
	 const unsigned char *sha1, \
	 enum object_type *type)

#define close_method_decl(name) \
	int close_istream_ ##name \
	(struct git_istream *st)

#define read_method_decl(name) \
	ssize_t read_istream_ ##name \
	(struct git_istream *st, char *buf, size_t sz)

/* forward declaration */
static open_method_decl(incore);
static open_method_decl(loose);
static open_method_decl(pack_non_delta);
static struct git_istream *attach_stream_filter(struct git_istream *st,
						struct stream_filter *filter);


static open_istream_fn open_istream_tbl[] = {
	open_istream_incore,
	open_istream_loose,
	open_istream_pack_non_delta,
};

#define FILTER_BUFFER (1024*16)

struct filtered_istream {
	struct git_istream *upstream;
	struct stream_filter *filter;
	char ibuf[FILTER_BUFFER];
	char obuf[FILTER_BUFFER];
	int i_end, i_ptr;
	int o_end, o_ptr;
	int input_finished;
};

struct git_istream {
	const struct stream_vtbl *vtbl;
	unsigned long size; /* inflated size of full object */
	z_stream z;
	enum { z_unused, z_used, z_done, z_error } z_state;

	union {
		struct {
			char *buf; /* from read_object() */
			unsigned long read_ptr;
		} incore;

		struct {
			void *mapped;
			unsigned long mapsize;
			char hdr[32];
			int hdr_avail;
			int hdr_used;
		} loose;

		struct {
			struct packed_git *pack;
			off_t pos;
		} in_pack;

		struct filtered_istream filtered;
	} u;
};

int close_istream(struct git_istream *st)
{
	return st->vtbl->close(st);
}

ssize_t read_istream(struct git_istream *st, char *buf, size_t sz)
{
	return st->vtbl->read(st, buf, sz);
}

static enum input_source istream_source(const unsigned char *sha1,
					enum object_type *type,
					struct object_info *oi)
{
	unsigned long size;
	int status;

	oi->sizep = &size;
	status = sha1_object_info_extended(sha1, oi);
	if (status < 0)
		return stream_error;
	*type = status;

	switch (oi->whence) {
	case OI_LOOSE:
		return loose;
	case OI_PACKED:
		if (!oi->u.packed.is_delta && big_file_threshold <= size)
			return pack_non_delta;
		/* fallthru */
	default:
		return incore;
	}
}

struct git_istream *open_istream(const unsigned char *sha1,
				 enum object_type *type,
				 unsigned long *size,
				 struct stream_filter *filter)
{
	struct git_istream *st;
	struct object_info oi;
	const unsigned char *real = lookup_replace_object(sha1);
	enum input_source src = istream_source(real, type, &oi);

	if (src < 0)
		return NULL;

	st = xmalloc(sizeof(*st));
	if (open_istream_tbl[src](st, &oi, real, type)) {
		if (open_istream_incore(st, &oi, real, type)) {
			free(st);
			return NULL;
		}
	}
	if (st && filter) {
		/* Add "&& !is_null_stream_filter(filter)" for performance */
		struct git_istream *nst = attach_stream_filter(st, filter);
		if (!nst)
			close_istream(st);
		st = nst;
	}

	*size = st->size;
	return st;
}


/*****************************************************************
 *
 * Common helpers
 *
 *****************************************************************/

static void close_deflated_stream(struct git_istream *st)
{
	if (st->z_state == z_used)
		git_inflate_end(&st->z);
}


/*****************************************************************
 *
 * Filtered stream
 *
 *****************************************************************/

static close_method_decl(filtered)
{
	free_stream_filter(st->u.filtered.filter);
	return close_istream(st->u.filtered.upstream);
}

static read_method_decl(filtered)
{
	struct filtered_istream *fs = &(st->u.filtered);
	size_t filled = 0;

	while (sz) {
		/* do we already have filtered output? */
		if (fs->o_ptr < fs->o_end) {
			size_t to_move = fs->o_end - fs->o_ptr;
			if (sz < to_move)
				to_move = sz;
			memcpy(buf + filled, fs->obuf + fs->o_ptr, to_move);
			fs->o_ptr += to_move;
			sz -= to_move;
			filled += to_move;
			continue;
		}
		fs->o_end = fs->o_ptr = 0;

		/* do we have anything to feed the filter with? */
		if (fs->i_ptr < fs->i_end) {
			size_t to_feed = fs->i_end - fs->i_ptr;
			size_t to_receive = FILTER_BUFFER;
			if (stream_filter(fs->filter,
					  fs->ibuf + fs->i_ptr, &to_feed,
					  fs->obuf, &to_receive))
				return -1;
			fs->i_ptr = fs->i_end - to_feed;
			fs->o_end = FILTER_BUFFER - to_receive;
			continue;
		}

		/* tell the filter to drain upon no more input */
		if (fs->input_finished) {
			size_t to_receive = FILTER_BUFFER;
			if (stream_filter(fs->filter,
					  NULL, NULL,
					  fs->obuf, &to_receive))
				return -1;
			fs->o_end = FILTER_BUFFER - to_receive;
			if (!fs->o_end)
				break;
			continue;
		}
		fs->i_end = fs->i_ptr = 0;

		/* refill the input from the upstream */
		if (!fs->input_finished) {
			fs->i_end = read_istream(fs->upstream, fs->ibuf, FILTER_BUFFER);
			if (fs->i_end < 0)
				break;
			if (fs->i_end)
				continue;
		}
		fs->input_finished = 1;
	}
	return filled;
}

static struct stream_vtbl filtered_vtbl = {
	close_istream_filtered,
	read_istream_filtered,
};

static struct git_istream *attach_stream_filter(struct git_istream *st,
						struct stream_filter *filter)
{
	struct git_istream *ifs = xmalloc(sizeof(*ifs));
	struct filtered_istream *fs = &(ifs->u.filtered);

	ifs->vtbl = &filtered_vtbl;
	fs->upstream = st;
	fs->filter = filter;
	fs->i_end = fs->i_ptr = 0;
	fs->o_end = fs->o_ptr = 0;
	fs->input_finished = 0;
	ifs->size = -1; /* unknown */
	return ifs;
}

/*****************************************************************
 *
 * Loose object stream
 *
 *****************************************************************/

static read_method_decl(loose)
{
	size_t total_read = 0;

	switch (st->z_state) {
	case z_done:
		return 0;
	case z_error:
		return -1;
	default:
		break;
	}

	if (st->u.loose.hdr_used < st->u.loose.hdr_avail) {
		size_t to_copy = st->u.loose.hdr_avail - st->u.loose.hdr_used;
		if (sz < to_copy)
			to_copy = sz;
		memcpy(buf, st->u.loose.hdr + st->u.loose.hdr_used, to_copy);
		st->u.loose.hdr_used += to_copy;
		total_read += to_copy;
	}

	while (total_read < sz) {
		int status;

		st->z.next_out = (unsigned char *)buf + total_read;
		st->z.avail_out = sz - total_read;
		status = git_inflate(&st->z, Z_FINISH);

		total_read = st->z.next_out - (unsigned char *)buf;

		if (status == Z_STREAM_END) {
			git_inflate_end(&st->z);
			st->z_state = z_done;
			break;
		}
		if (status != Z_OK && status != Z_BUF_ERROR) {
			git_inflate_end(&st->z);
			st->z_state = z_error;
			return -1;
		}
	}
	return total_read;
}

static close_method_decl(loose)
{
	close_deflated_stream(st);
	munmap(st->u.loose.mapped, st->u.loose.mapsize);
	return 0;
}

static struct stream_vtbl loose_vtbl = {
	close_istream_loose,
	read_istream_loose,
};

static open_method_decl(loose)
{
	st->u.loose.mapped = map_sha1_file(sha1, &st->u.loose.mapsize);
	if (!st->u.loose.mapped)
		return -1;
	if (unpack_sha1_header(&st->z,
			       st->u.loose.mapped,
			       st->u.loose.mapsize,
			       st->u.loose.hdr,
			       sizeof(st->u.loose.hdr)) < 0) {
		git_inflate_end(&st->z);
		munmap(st->u.loose.mapped, st->u.loose.mapsize);
		return -1;
	}

	parse_sha1_header(st->u.loose.hdr, &st->size);
	st->u.loose.hdr_used = strlen(st->u.loose.hdr) + 1;
	st->u.loose.hdr_avail = st->z.total_out;
	st->z_state = z_used;

	st->vtbl = &loose_vtbl;
	return 0;
}


/*****************************************************************
 *
 * Non-delta packed object stream
 *
 *****************************************************************/

static read_method_decl(pack_non_delta)
{
	size_t total_read = 0;

	switch (st->z_state) {
	case z_unused:
		memset(&st->z, 0, sizeof(st->z));
		git_inflate_init(&st->z);
		st->z_state = z_used;
		break;
	case z_done:
		return 0;
	case z_error:
		return -1;
	case z_used:
		break;
	}

	while (total_read < sz) {
		int status;
		struct pack_window *window = NULL;
		unsigned char *mapped;

		mapped = use_pack(st->u.in_pack.pack, &window,
				  st->u.in_pack.pos, &st->z.avail_in);

		st->z.next_out = (unsigned char *)buf + total_read;
		st->z.avail_out = sz - total_read;
		st->z.next_in = mapped;
		status = git_inflate(&st->z, Z_FINISH);

		st->u.in_pack.pos += st->z.next_in - mapped;
		total_read = st->z.next_out - (unsigned char *)buf;
		unuse_pack(&window);

		if (status == Z_STREAM_END) {
			git_inflate_end(&st->z);
			st->z_state = z_done;
			break;
		}
		if (status != Z_OK && status != Z_BUF_ERROR) {
			git_inflate_end(&st->z);
			st->z_state = z_error;
			return -1;
		}
	}
	return total_read;
}

static close_method_decl(pack_non_delta)
{
	close_deflated_stream(st);
	return 0;
}

static struct stream_vtbl pack_non_delta_vtbl = {
	close_istream_pack_non_delta,
	read_istream_pack_non_delta,
};

static open_method_decl(pack_non_delta)
{
	struct pack_window *window;
	enum object_type in_pack_type;

	st->u.in_pack.pack = oi->u.packed.pack;
	st->u.in_pack.pos = oi->u.packed.offset;
	window = NULL;

	in_pack_type = unpack_object_header(st->u.in_pack.pack,
					    &window,
					    &st->u.in_pack.pos,
					    &st->size);
	unuse_pack(&window);
	switch (in_pack_type) {
	default:
		return -1; /* we do not do deltas for now */
	case OBJ_COMMIT:
	case OBJ_TREE:
	case OBJ_BLOB:
	case OBJ_TAG:
		break;
	}
	st->z_state = z_unused;
	st->vtbl = &pack_non_delta_vtbl;
	return 0;
}


/*****************************************************************
 *
 * In-core stream
 *
 *****************************************************************/

static close_method_decl(incore)
{
	free(st->u.incore.buf);
	return 0;
}

static read_method_decl(incore)
{
	size_t read_size = sz;
	size_t remainder = st->size - st->u.incore.read_ptr;

	if (remainder <= read_size)
		read_size = remainder;
	if (read_size) {
		memcpy(buf, st->u.incore.buf + st->u.incore.read_ptr, read_size);
		st->u.incore.read_ptr += read_size;
	}
	return read_size;
}

static struct stream_vtbl incore_vtbl = {
	close_istream_incore,
	read_istream_incore,
};

static open_method_decl(incore)
{
	st->u.incore.buf = read_sha1_file_extended(sha1, type, &st->size, 0);
	st->u.incore.read_ptr = 0;
	st->vtbl = &incore_vtbl;

	return st->u.incore.buf ? 0 : -1;
}
Commit	Line	Data
46bf0438 JH	1	/*
	2	* Copyright (c) 2011, Google Inc.
	3	*/
	4	#include "cache.h"
	5	#include "streaming.h"
	6
	7	enum input_source {
	8	stream_error = -1,
	9	incore = 0,
	10	loose = 1,
	11	pack_non_delta = 2
	12	};
	13
	14	typedef int (open_istream_fn)(struct git_istream ,
	15	struct object_info *,
	16	const unsigned char *,
	17	enum object_type *);
	18	typedef int (close_istream_fn)(struct git_istream );
	19	typedef ssize_t (read_istream_fn)(struct git_istream , char *, size_t);
	20
	21	struct stream_vtbl {
	22	close_istream_fn close;
	23	read_istream_fn read;
	24	};
	25
	26	#define open_method_decl(name) \
	27	int open_istream_ ##name \
	28	(struct git_istream st, struct object_info oi, \
	29	const unsigned char *sha1, \
	30	enum object_type *type)
	31
	32	#define close_method_decl(name) \
	33	int close_istream_ ##name \
	34	(struct git_istream *st)
	35
	36	#define read_method_decl(name) \
	37	ssize_t read_istream_ ##name \
	38	(struct git_istream st, char buf, size_t sz)
	39
	40	/* forward declaration */
	41	static open_method_decl(incore);
	42	static open_method_decl(loose);
	43	static open_method_decl(pack_non_delta);
b6691092 JH	44	static struct git_istream attach_stream_filter(struct git_istream st,
	45	struct stream_filter *filter);
	46
46bf0438 JH	47
	48	static open_istream_fn open_istream_tbl[] = {
	49	open_istream_incore,
	50	open_istream_loose,
	51	open_istream_pack_non_delta,
	52	};
	53
b6691092 JH	54	#define FILTER_BUFFER (1024*16)
	55
	56	struct filtered_istream {
	57	struct git_istream *upstream;
	58	struct stream_filter *filter;
	59	char ibuf[FILTER_BUFFER];
	60	char obuf[FILTER_BUFFER];
	61	int i_end, i_ptr;
	62	int o_end, o_ptr;
4ae66704	63	int input_finished;
b6691092 JH	64	};
b6691092 JH	65
46bf0438 JH	66	struct git_istream {
	67	const struct stream_vtbl *vtbl;
	68	unsigned long size; /* inflated size of full object */
7ef2d9a2 JH	69	z_stream z;
7ef2d9a2 JH	70	enum { z_unused, z_used, z_done, z_error } z_state;
46bf0438 JH	71
	72	union {
	73	struct {
	74	char buf; / from read_object() */
	75	unsigned long read_ptr;
	76	} incore;
	77
	78	struct {
93aa7bd5 JH	79	void *mapped;
	80	unsigned long mapsize;
	81	char hdr[32];
	82	int hdr_avail;
	83	int hdr_used;
46bf0438 JH	84	} loose;
	85
	86	struct {
7ef2d9a2 JH	87	struct packed_git *pack;
7ef2d9a2 JH	88	off_t pos;
46bf0438	89	} in_pack;
b6691092 JH	90
b6691092 JH	91	struct filtered_istream filtered;
46bf0438 JH	92	} u;
	93	};
	94
	95	int close_istream(struct git_istream *st)
	96	{
	97	return st->vtbl->close(st);
	98	}
	99
	100	ssize_t read_istream(struct git_istream st, char buf, size_t sz)
	101	{
	102	return st->vtbl->read(st, buf, sz);
	103	}
	104
	105	static enum input_source istream_source(const unsigned char *sha1,
	106	enum object_type *type,
	107	struct object_info *oi)
	108	{
	109	unsigned long size;
	110	int status;
	111
	112	oi->sizep = &size;
	113	status = sha1_object_info_extended(sha1, oi);
	114	if (status < 0)
	115	return stream_error;
	116	*type = status;
	117
	118	switch (oi->whence) {
	119	case OI_LOOSE:
	120	return loose;
	121	case OI_PACKED:
	122	if (!oi->u.packed.is_delta && big_file_threshold <= size)
	123	return pack_non_delta;
	124	/* fallthru */
	125	default:
	126	return incore;
	127	}
	128	}
	129
	130	struct git_istream open_istream(const unsigned char sha1,
	131	enum object_type *type,
b6691092 JH	132	unsigned long *size,
b6691092 JH	133	struct stream_filter *filter)
46bf0438 JH	134	{
	135	struct git_istream *st;
	136	struct object_info oi;
	137	const unsigned char *real = lookup_replace_object(sha1);
	138	enum input_source src = istream_source(real, type, &oi);
	139
	140	if (src < 0)
	141	return NULL;
	142
	143	st = xmalloc(sizeof(*st));
	144	if (open_istream_tbl[src](st, &oi, real, type)) {
	145	if (open_istream_incore(st, &oi, real, type)) {
	146	free(st);
	147	return NULL;
	148	}
	149	}
b6691092 JH	150	if (st && filter) {
	151	/* Add "&& !is_null_stream_filter(filter)" for performance */
	152	struct git_istream *nst = attach_stream_filter(st, filter);
	153	if (!nst)
	154	close_istream(st);
	155	st = nst;
	156	}
	157
46bf0438 JH	158	*size = st->size;
	159	return st;
	160	}
	161
7ef2d9a2 JH	162
	163	/*****************************************************************
	164	*
	165	* Common helpers
	166	*
	167	*****************************************************************/
	168
	169	static void close_deflated_stream(struct git_istream *st)
	170	{
	171	if (st->z_state == z_used)
	172	git_inflate_end(&st->z);
	173	}
	174
	175
b6691092 JH	176	/*****************************************************************
	177	*
	178	* Filtered stream
	179	*
	180	*****************************************************************/
	181
	182	static close_method_decl(filtered)
	183	{
	184	free_stream_filter(st->u.filtered.filter);
	185	return close_istream(st->u.filtered.upstream);
	186	}
	187
	188	static read_method_decl(filtered)
	189	{
	190	struct filtered_istream *fs = &(st->u.filtered);
	191	size_t filled = 0;
	192
	193	while (sz) {
	194	/* do we already have filtered output? */
	195	if (fs->o_ptr < fs->o_end) {
	196	size_t to_move = fs->o_end - fs->o_ptr;
	197	if (sz < to_move)
	198	to_move = sz;
	199	memcpy(buf + filled, fs->obuf + fs->o_ptr, to_move);
	200	fs->o_ptr += to_move;
	201	sz -= to_move;
	202	filled += to_move;
	203	continue;
	204	}
	205	fs->o_end = fs->o_ptr = 0;
	206
	207	/* do we have anything to feed the filter with? */
	208	if (fs->i_ptr < fs->i_end) {
	209	size_t to_feed = fs->i_end - fs->i_ptr;
	210	size_t to_receive = FILTER_BUFFER;
	211	if (stream_filter(fs->filter,
	212	fs->ibuf + fs->i_ptr, &to_feed,
	213	fs->obuf, &to_receive))
	214	return -1;
	215	fs->i_ptr = fs->i_end - to_feed;
	216	fs->o_end = FILTER_BUFFER - to_receive;
	217	continue;
	218	}
4ae66704 JH	219
	220	/* tell the filter to drain upon no more input */
	221	if (fs->input_finished) {
	222	size_t to_receive = FILTER_BUFFER;
	223	if (stream_filter(fs->filter,
	224	NULL, NULL,
	225	fs->obuf, &to_receive))
	226	return -1;
	227	fs->o_end = FILTER_BUFFER - to_receive;
	228	if (!fs->o_end)
	229	break;
	230	continue;
	231	}
b6691092 JH	232	fs->i_end = fs->i_ptr = 0;
	233
	234	/* refill the input from the upstream */
4ae66704 JH	235	if (!fs->input_finished) {
	236	fs->i_end = read_istream(fs->upstream, fs->ibuf, FILTER_BUFFER);
	237	if (fs->i_end < 0)
	238	break;
	239	if (fs->i_end)
	240	continue;
	241	}
	242	fs->input_finished = 1;
b6691092 JH	243	}
	244	return filled;
	245	}
	246
	247	static struct stream_vtbl filtered_vtbl = {
	248	close_istream_filtered,
	249	read_istream_filtered,
	250	};
	251
	252	static struct git_istream attach_stream_filter(struct git_istream st,
	253	struct stream_filter *filter)
	254	{
	255	struct git_istream ifs = xmalloc(sizeof(ifs));
	256	struct filtered_istream *fs = &(ifs->u.filtered);
	257
	258	ifs->vtbl = &filtered_vtbl;
	259	fs->upstream = st;
	260	fs->filter = filter;
	261	fs->i_end = fs->i_ptr = 0;
	262	fs->o_end = fs->o_ptr = 0;
4ae66704	263	fs->input_finished = 0;
b6691092 JH	264	ifs->size = -1; /* unknown */
	265	return ifs;
	266	}
	267
46bf0438 JH	268	/*****************************************************************
	269	*
	270	* Loose object stream
	271	*
	272	*****************************************************************/
	273
93aa7bd5 JH	274	static read_method_decl(loose)
	275	{
	276	size_t total_read = 0;
	277
	278	switch (st->z_state) {
	279	case z_done:
	280	return 0;
	281	case z_error:
	282	return -1;
	283	default:
	284	break;
	285	}
	286
	287	if (st->u.loose.hdr_used < st->u.loose.hdr_avail) {
	288	size_t to_copy = st->u.loose.hdr_avail - st->u.loose.hdr_used;
	289	if (sz < to_copy)
	290	to_copy = sz;
	291	memcpy(buf, st->u.loose.hdr + st->u.loose.hdr_used, to_copy);
	292	st->u.loose.hdr_used += to_copy;
	293	total_read += to_copy;
	294	}
	295
	296	while (total_read < sz) {
	297	int status;
	298
	299	st->z.next_out = (unsigned char *)buf + total_read;
	300	st->z.avail_out = sz - total_read;
	301	status = git_inflate(&st->z, Z_FINISH);
	302
	303	total_read = st->z.next_out - (unsigned char *)buf;
	304
	305	if (status == Z_STREAM_END) {
	306	git_inflate_end(&st->z);
	307	st->z_state = z_done;
	308	break;
	309	}
	310	if (status != Z_OK && status != Z_BUF_ERROR) {
	311	git_inflate_end(&st->z);
	312	st->z_state = z_error;
	313	return -1;
	314	}
	315	}
	316	return total_read;
	317	}
	318
	319	static close_method_decl(loose)
	320	{
	321	close_deflated_stream(st);
	322	munmap(st->u.loose.mapped, st->u.loose.mapsize);
	323	return 0;
	324	}
	325
	326	static struct stream_vtbl loose_vtbl = {
	327	close_istream_loose,
	328	read_istream_loose,
	329	};
	330
46bf0438 JH	331	static open_method_decl(loose)
46bf0438 JH	332	{
93aa7bd5 JH	333	st->u.loose.mapped = map_sha1_file(sha1, &st->u.loose.mapsize);
	334	if (!st->u.loose.mapped)
	335	return -1;
	336	if (unpack_sha1_header(&st->z,
	337	st->u.loose.mapped,
	338	st->u.loose.mapsize,
	339	st->u.loose.hdr,
	340	sizeof(st->u.loose.hdr)) < 0) {
	341	git_inflate_end(&st->z);
	342	munmap(st->u.loose.mapped, st->u.loose.mapsize);
	343	return -1;
	344	}
	345
	346	parse_sha1_header(st->u.loose.hdr, &st->size);
	347	st->u.loose.hdr_used = strlen(st->u.loose.hdr) + 1;
	348	st->u.loose.hdr_avail = st->z.total_out;
	349	st->z_state = z_used;
	350
	351	st->vtbl = &loose_vtbl;
	352	return 0;
46bf0438 JH	353	}
	354
	355
	356	/*****************************************************************
	357	*
	358	* Non-delta packed object stream
	359	*
	360	*****************************************************************/
	361
7ef2d9a2 JH	362	static read_method_decl(pack_non_delta)
	363	{
	364	size_t total_read = 0;
	365
	366	switch (st->z_state) {
	367	case z_unused:
	368	memset(&st->z, 0, sizeof(st->z));
	369	git_inflate_init(&st->z);
	370	st->z_state = z_used;
	371	break;
	372	case z_done:
	373	return 0;
	374	case z_error:
	375	return -1;
	376	case z_used:
	377	break;
	378	}
	379
	380	while (total_read < sz) {
	381	int status;
	382	struct pack_window *window = NULL;
	383	unsigned char *mapped;
	384
	385	mapped = use_pack(st->u.in_pack.pack, &window,
	386	st->u.in_pack.pos, &st->z.avail_in);
	387
	388	st->z.next_out = (unsigned char *)buf + total_read;
	389	st->z.avail_out = sz - total_read;
	390	st->z.next_in = mapped;
	391	status = git_inflate(&st->z, Z_FINISH);
	392
	393	st->u.in_pack.pos += st->z.next_in - mapped;
	394	total_read = st->z.next_out - (unsigned char *)buf;
	395	unuse_pack(&window);
	396
	397	if (status == Z_STREAM_END) {
	398	git_inflate_end(&st->z);
	399	st->z_state = z_done;
	400	break;
	401	}
	402	if (status != Z_OK && status != Z_BUF_ERROR) {
	403	git_inflate_end(&st->z);
	404	st->z_state = z_error;
	405	return -1;
	406	}
	407	}
	408	return total_read;
	409	}
	410
	411	static close_method_decl(pack_non_delta)
	412	{
	413	close_deflated_stream(st);
	414	return 0;
	415	}
	416
	417	static struct stream_vtbl pack_non_delta_vtbl = {
	418	close_istream_pack_non_delta,
	419	read_istream_pack_non_delta,
	420	};
	421
46bf0438 JH	422	static open_method_decl(pack_non_delta)
46bf0438 JH	423	{
7ef2d9a2 JH	424	struct pack_window *window;
	425	enum object_type in_pack_type;
	426
	427	st->u.in_pack.pack = oi->u.packed.pack;
	428	st->u.in_pack.pos = oi->u.packed.offset;
	429	window = NULL;
	430
	431	in_pack_type = unpack_object_header(st->u.in_pack.pack,
	432	&window,
	433	&st->u.in_pack.pos,
	434	&st->size);
	435	unuse_pack(&window);
	436	switch (in_pack_type) {
	437	default:
	438	return -1; /* we do not do deltas for now */
	439	case OBJ_COMMIT:
	440	case OBJ_TREE:
	441	case OBJ_BLOB:
	442	case OBJ_TAG:
	443	break;
	444	}
	445	st->z_state = z_unused;
	446	st->vtbl = &pack_non_delta_vtbl;
	447	return 0;
46bf0438 JH	448	}
	449
	450
	451	/*****************************************************************
	452	*
	453	* In-core stream
	454	*
	455	*****************************************************************/
	456
	457	static close_method_decl(incore)
	458	{
	459	free(st->u.incore.buf);
	460	return 0;
	461	}
	462
	463	static read_method_decl(incore)
	464	{
	465	size_t read_size = sz;
	466	size_t remainder = st->size - st->u.incore.read_ptr;
	467
	468	if (remainder <= read_size)
	469	read_size = remainder;
	470	if (read_size) {
	471	memcpy(buf, st->u.incore.buf + st->u.incore.read_ptr, read_size);
	472	st->u.incore.read_ptr += read_size;
	473	}
	474	return read_size;
	475	}
	476
	477	static struct stream_vtbl incore_vtbl = {
	478	close_istream_incore,
	479	read_istream_incore,
	480	};
	481
	482	static open_method_decl(incore)
	483	{
	484	st->u.incore.buf = read_sha1_file_extended(sha1, type, &st->size, 0);
	485	st->u.incore.read_ptr = 0;
	486	st->vtbl = &incore_vtbl;
	487
	488	return st->u.incore.buf ? 0 : -1;
	489	}