[thirdparty/git.git] / streaming.c

/*
 * Copyright (c) 2011, Google Inc.
 */
#include "cache.h"
#include "streaming.h"
#include "repository.h"
#include "object-store.h"
#include "packfile.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 struct object_id *,
			       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 struct object_id *oid, \
	 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 */
	git_zstream 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)
{
	int r = st->vtbl->close(st);
	free(st);
	return r;
}

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

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

	oi->typep = type;
	oi->sizep = &size;
	status = oid_object_info_extended(oid, oi, 0);
	if (status < 0)
		return stream_error;

	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 struct object_id *oid,
				 enum object_type *type,
				 unsigned long *size,
				 struct stream_filter *filter)
{
	struct git_istream *st;
	struct object_info oi = OBJECT_INFO_INIT;
	const struct object_id *real = lookup_replace_object(oid);
	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 (filter) {
		/* Add "&& !is_null_stream_filter(filter)" for performance */
		struct git_istream *nst = attach_stream_filter(st, filter);
		if (!nst) {
			close_istream(st);
			return NULL;
		}
		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)
				return -1;
			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 || total_read < sz)) {
			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(the_repository,
					   oid->hash, &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) ||
	    (parse_sha1_header(st->u.loose.hdr, &st->size) < 0)) {
		git_inflate_end(&st->z);
		munmap(st->u.loose.mapped, st->u.loose.mapsize);
		return -1;
	}

	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_object_file_extended(oid, type, &st->size, 0);
	st->u.incore.read_ptr = 0;
	st->vtbl = &incore_vtbl;

	return st->u.incore.buf ? 0 : -1;
}


/****************************************************************
 * Users of streaming interface
 ****************************************************************/

int stream_blob_to_fd(int fd, const struct object_id *oid, struct stream_filter *filter,
		      int can_seek)
{
	struct git_istream *st;
	enum object_type type;
	unsigned long sz;
	ssize_t kept = 0;
	int result = -1;

	st = open_istream(oid, &type, &sz, filter);
	if (!st) {
		if (filter)
			free_stream_filter(filter);
		return result;
	}
	if (type != OBJ_BLOB)
		goto close_and_exit;
	for (;;) {
		char buf[1024 * 16];
		ssize_t wrote, holeto;
		ssize_t readlen = read_istream(st, buf, sizeof(buf));

		if (readlen < 0)
			goto close_and_exit;
		if (!readlen)
			break;
		if (can_seek && sizeof(buf) == readlen) {
			for (holeto = 0; holeto < readlen; holeto++)
				if (buf[holeto])
					break;
			if (readlen == holeto) {
				kept += holeto;
				continue;
			}
		}

		if (kept && lseek(fd, kept, SEEK_CUR) == (off_t) -1)
			goto close_and_exit;
		else
			kept = 0;
		wrote = write_in_full(fd, buf, readlen);

		if (wrote < 0)
			goto close_and_exit;
	}
	if (kept && (lseek(fd, kept - 1, SEEK_CUR) == (off_t) -1 ||
		     xwrite(fd, "", 1) != 1))
		goto close_and_exit;
	result = 0;

 close_and_exit:
	close_istream(st);
	return result;
}
Commit	Line	Data
46bf0438 JH	1	/*
	2	* Copyright (c) 2011, Google Inc.
	3	*/
	4	#include "cache.h"
	5	#include "streaming.h"
e35454fa SB	6	#include "repository.h"
e35454fa SB	7	#include "object-store.h"
84f80ad5	8	#include "packfile.h"
46bf0438 JH	9
	10	enum input_source {
	11	stream_error = -1,
	12	incore = 0,
	13	loose = 1,
	14	pack_non_delta = 2
	15	};
	16
	17	typedef int (open_istream_fn)(struct git_istream ,
	18	struct object_info *,
575042a0	19	const struct object_id *,
46bf0438 JH	20	enum object_type *);
	21	typedef int (close_istream_fn)(struct git_istream );
	22	typedef ssize_t (read_istream_fn)(struct git_istream , char *, size_t);
	23
	24	struct stream_vtbl {
	25	close_istream_fn close;
	26	read_istream_fn read;
	27	};
	28
	29	#define open_method_decl(name) \
	30	int open_istream_ ##name \
	31	(struct git_istream st, struct object_info oi, \
575042a0	32	const struct object_id *oid, \
46bf0438 JH	33	enum object_type *type)
	34
	35	#define close_method_decl(name) \
	36	int close_istream_ ##name \
	37	(struct git_istream *st)
	38
	39	#define read_method_decl(name) \
	40	ssize_t read_istream_ ##name \
	41	(struct git_istream st, char buf, size_t sz)
	42
	43	/* forward declaration */
	44	static open_method_decl(incore);
	45	static open_method_decl(loose);
	46	static open_method_decl(pack_non_delta);
b6691092 JH	47	static struct git_istream attach_stream_filter(struct git_istream st,
	48	struct stream_filter *filter);
	49
46bf0438 JH	50
	51	static open_istream_fn open_istream_tbl[] = {
	52	open_istream_incore,
	53	open_istream_loose,
	54	open_istream_pack_non_delta,
	55	};
	56
b6691092 JH	57	#define FILTER_BUFFER (1024*16)
	58
	59	struct filtered_istream {
	60	struct git_istream *upstream;
	61	struct stream_filter *filter;
	62	char ibuf[FILTER_BUFFER];
	63	char obuf[FILTER_BUFFER];
	64	int i_end, i_ptr;
	65	int o_end, o_ptr;
4ae66704	66	int input_finished;
b6691092 JH	67	};
b6691092 JH	68
46bf0438 JH	69	struct git_istream {
	70	const struct stream_vtbl *vtbl;
	71	unsigned long size; /* inflated size of full object */
eb4f4076	72	git_zstream z;
7ef2d9a2	73	enum { z_unused, z_used, z_done, z_error } z_state;
46bf0438 JH	74
	75	union {
	76	struct {
	77	char buf; / from read_object() */
	78	unsigned long read_ptr;
	79	} incore;
	80
	81	struct {
93aa7bd5 JH	82	void *mapped;
	83	unsigned long mapsize;
	84	char hdr[32];
	85	int hdr_avail;
	86	int hdr_used;
46bf0438 JH	87	} loose;
	88
	89	struct {
7ef2d9a2 JH	90	struct packed_git *pack;
7ef2d9a2 JH	91	off_t pos;
46bf0438	92	} in_pack;
b6691092 JH	93
b6691092 JH	94	struct filtered_istream filtered;
46bf0438 JH	95	} u;
	96	};
	97
	98	int close_istream(struct git_istream *st)
	99	{
95dea6eb JK	100	int r = st->vtbl->close(st);
	101	free(st);
	102	return r;
46bf0438 JH	103	}
46bf0438 JH	104
6163cd8a	105	ssize_t read_istream(struct git_istream st, void buf, size_t sz)
46bf0438 JH	106	{
	107	return st->vtbl->read(st, buf, sz);
	108	}
	109
b383a13c	110	static enum input_source istream_source(const struct object_id *oid,
46bf0438 JH	111	enum object_type *type,
	112	struct object_info *oi)
	113	{
	114	unsigned long size;
	115	int status;
	116
5b086407	117	oi->typep = type;
46bf0438	118	oi->sizep = &size;
b383a13c	119	status = oid_object_info_extended(oid, oi, 0);
46bf0438 JH	120	if (status < 0)
46bf0438 JH	121	return stream_error;
46bf0438 JH	122
	123	switch (oi->whence) {
	124	case OI_LOOSE:
	125	return loose;
	126	case OI_PACKED:
754980d0	127	if (!oi->u.packed.is_delta && big_file_threshold < size)
46bf0438 JH	128	return pack_non_delta;
	129	/* fallthru */
	130	default:
	131	return incore;
	132	}
	133	}
	134
ef7b5195	135	struct git_istream open_istream(const struct object_id oid,
46bf0438	136	enum object_type *type,
b6691092 JH	137	unsigned long *size,
b6691092 JH	138	struct stream_filter *filter)
46bf0438 JH	139	{
46bf0438 JH	140	struct git_istream *st;
27b5c1a0	141	struct object_info oi = OBJECT_INFO_INIT;
b383a13c	142	const struct object_id *real = lookup_replace_object(oid);
46bf0438 JH	143	enum input_source src = istream_source(real, type, &oi);
	144
	145	if (src < 0)
	146	return NULL;
	147
	148	st = xmalloc(sizeof(*st));
b383a13c	149	if (open_istream_tbl[src](st, &oi, real, type)) {
b383a13c	150	if (open_istream_incore(st, &oi, real, type)) {
46bf0438 JH	151	free(st);
	152	return NULL;
	153	}
	154	}
6a907786	155	if (filter) {
b6691092 JH	156	/* Add "&& !is_null_stream_filter(filter)" for performance */
b6691092 JH	157	struct git_istream *nst = attach_stream_filter(st, filter);
78368f2c	158	if (!nst) {
b6691092	159	close_istream(st);
78368f2c JH	160	return NULL;
78368f2c JH	161	}
b6691092 JH	162	st = nst;
	163	}
	164
46bf0438 JH	165	*size = st->size;
	166	return st;
	167	}
	168
7ef2d9a2 JH	169
	170	/*****************************************************************
	171	*
	172	* Common helpers
	173	*
	174	*****************************************************************/
	175
	176	static void close_deflated_stream(struct git_istream *st)
	177	{
	178	if (st->z_state == z_used)
	179	git_inflate_end(&st->z);
	180	}
	181
	182
b6691092 JH	183	/*****************************************************************
	184	*
	185	* Filtered stream
	186	*
	187	*****************************************************************/
	188
	189	static close_method_decl(filtered)
	190	{
	191	free_stream_filter(st->u.filtered.filter);
	192	return close_istream(st->u.filtered.upstream);
	193	}
	194
	195	static read_method_decl(filtered)
	196	{
	197	struct filtered_istream *fs = &(st->u.filtered);
	198	size_t filled = 0;
	199
	200	while (sz) {
	201	/* do we already have filtered output? */
	202	if (fs->o_ptr < fs->o_end) {
	203	size_t to_move = fs->o_end - fs->o_ptr;
	204	if (sz < to_move)
	205	to_move = sz;
	206	memcpy(buf + filled, fs->obuf + fs->o_ptr, to_move);
	207	fs->o_ptr += to_move;
	208	sz -= to_move;
	209	filled += to_move;
	210	continue;
	211	}
	212	fs->o_end = fs->o_ptr = 0;
	213
	214	/* do we have anything to feed the filter with? */
	215	if (fs->i_ptr < fs->i_end) {
	216	size_t to_feed = fs->i_end - fs->i_ptr;
	217	size_t to_receive = FILTER_BUFFER;
	218	if (stream_filter(fs->filter,
	219	fs->ibuf + fs->i_ptr, &to_feed,
	220	fs->obuf, &to_receive))
	221	return -1;
	222	fs->i_ptr = fs->i_end - to_feed;
	223	fs->o_end = FILTER_BUFFER - to_receive;
	224	continue;
	225	}
4ae66704 JH	226
	227	/* tell the filter to drain upon no more input */
	228	if (fs->input_finished) {
	229	size_t to_receive = FILTER_BUFFER;
	230	if (stream_filter(fs->filter,
	231	NULL, NULL,
	232	fs->obuf, &to_receive))
	233	return -1;
	234	fs->o_end = FILTER_BUFFER - to_receive;
	235	if (!fs->o_end)
	236	break;
	237	continue;
	238	}
b6691092 JH	239	fs->i_end = fs->i_ptr = 0;
	240
	241	/* refill the input from the upstream */
4ae66704 JH	242	if (!fs->input_finished) {
	243	fs->i_end = read_istream(fs->upstream, fs->ibuf, FILTER_BUFFER);
	244	if (fs->i_end < 0)
42e7e2a5	245	return -1;
4ae66704 JH	246	if (fs->i_end)
	247	continue;
	248	}
	249	fs->input_finished = 1;
b6691092 JH	250	}
	251	return filled;
	252	}
	253
	254	static struct stream_vtbl filtered_vtbl = {
	255	close_istream_filtered,
	256	read_istream_filtered,
	257	};
	258
	259	static struct git_istream attach_stream_filter(struct git_istream st,
	260	struct stream_filter *filter)
	261	{
	262	struct git_istream ifs = xmalloc(sizeof(ifs));
	263	struct filtered_istream *fs = &(ifs->u.filtered);
	264
	265	ifs->vtbl = &filtered_vtbl;
	266	fs->upstream = st;
	267	fs->filter = filter;
	268	fs->i_end = fs->i_ptr = 0;
	269	fs->o_end = fs->o_ptr = 0;
4ae66704	270	fs->input_finished = 0;
b6691092 JH	271	ifs->size = -1; /* unknown */
	272	return ifs;
	273	}
	274
46bf0438 JH	275	/*****************************************************************
	276	*
	277	* Loose object stream
	278	*
	279	*****************************************************************/
	280
93aa7bd5 JH	281	static read_method_decl(loose)
	282	{
	283	size_t total_read = 0;
	284
	285	switch (st->z_state) {
	286	case z_done:
	287	return 0;
	288	case z_error:
	289	return -1;
	290	default:
	291	break;
	292	}
	293
	294	if (st->u.loose.hdr_used < st->u.loose.hdr_avail) {
	295	size_t to_copy = st->u.loose.hdr_avail - st->u.loose.hdr_used;
	296	if (sz < to_copy)
	297	to_copy = sz;
	298	memcpy(buf, st->u.loose.hdr + st->u.loose.hdr_used, to_copy);
	299	st->u.loose.hdr_used += to_copy;
	300	total_read += to_copy;
	301	}
	302
	303	while (total_read < sz) {
	304	int status;
	305
	306	st->z.next_out = (unsigned char *)buf + total_read;
	307	st->z.avail_out = sz - total_read;
	308	status = git_inflate(&st->z, Z_FINISH);
	309
	310	total_read = st->z.next_out - (unsigned char *)buf;
	311
	312	if (status == Z_STREAM_END) {
	313	git_inflate_end(&st->z);
	314	st->z_state = z_done;
	315	break;
	316	}
692f0bc7	317	if (status != Z_OK && (status != Z_BUF_ERROR \|\| total_read < sz)) {
93aa7bd5 JH	318	git_inflate_end(&st->z);
	319	st->z_state = z_error;
	320	return -1;
	321	}
	322	}
	323	return total_read;
	324	}
	325
	326	static close_method_decl(loose)
	327	{
	328	close_deflated_stream(st);
	329	munmap(st->u.loose.mapped, st->u.loose.mapsize);
	330	return 0;
	331	}
	332
	333	static struct stream_vtbl loose_vtbl = {
	334	close_istream_loose,
	335	read_istream_loose,
	336	};
	337
46bf0438 JH	338	static open_method_decl(loose)
46bf0438 JH	339	{
e35454fa	340	st->u.loose.mapped = map_sha1_file(the_repository,
cf0b1793	341	oid->hash, &st->u.loose.mapsize);
93aa7bd5 JH	342	if (!st->u.loose.mapped)
93aa7bd5 JH	343	return -1;
97026fe9 JH	344	if ((unpack_sha1_header(&st->z,
	345	st->u.loose.mapped,
	346	st->u.loose.mapsize,
	347	st->u.loose.hdr,
	348	sizeof(st->u.loose.hdr)) < 0) \|\|
	349	(parse_sha1_header(st->u.loose.hdr, &st->size) < 0)) {
93aa7bd5 JH	350	git_inflate_end(&st->z);
	351	munmap(st->u.loose.mapped, st->u.loose.mapsize);
	352	return -1;
	353	}
	354
93aa7bd5 JH	355	st->u.loose.hdr_used = strlen(st->u.loose.hdr) + 1;
	356	st->u.loose.hdr_avail = st->z.total_out;
	357	st->z_state = z_used;
	358
	359	st->vtbl = &loose_vtbl;
	360	return 0;
46bf0438 JH	361	}
	362
	363
	364	/*****************************************************************
	365	*
	366	* Non-delta packed object stream
	367	*
	368	*****************************************************************/
	369
7ef2d9a2 JH	370	static read_method_decl(pack_non_delta)
	371	{
	372	size_t total_read = 0;
	373
	374	switch (st->z_state) {
	375	case z_unused:
	376	memset(&st->z, 0, sizeof(st->z));
	377	git_inflate_init(&st->z);
	378	st->z_state = z_used;
	379	break;
	380	case z_done:
	381	return 0;
	382	case z_error:
	383	return -1;
	384	case z_used:
	385	break;
	386	}
	387
	388	while (total_read < sz) {
	389	int status;
	390	struct pack_window *window = NULL;
	391	unsigned char *mapped;
	392
	393	mapped = use_pack(st->u.in_pack.pack, &window,
	394	st->u.in_pack.pos, &st->z.avail_in);
	395
	396	st->z.next_out = (unsigned char *)buf + total_read;
	397	st->z.avail_out = sz - total_read;
	398	st->z.next_in = mapped;
	399	status = git_inflate(&st->z, Z_FINISH);
	400
	401	st->u.in_pack.pos += st->z.next_in - mapped;
	402	total_read = st->z.next_out - (unsigned char *)buf;
	403	unuse_pack(&window);
	404
	405	if (status == Z_STREAM_END) {
	406	git_inflate_end(&st->z);
	407	st->z_state = z_done;
	408	break;
	409	}
	410	if (status != Z_OK && status != Z_BUF_ERROR) {
	411	git_inflate_end(&st->z);
	412	st->z_state = z_error;
	413	return -1;
	414	}
	415	}
	416	return total_read;
	417	}
	418
	419	static close_method_decl(pack_non_delta)
	420	{
	421	close_deflated_stream(st);
	422	return 0;
	423	}
	424
	425	static struct stream_vtbl pack_non_delta_vtbl = {
	426	close_istream_pack_non_delta,
	427	read_istream_pack_non_delta,
	428	};
	429
46bf0438 JH	430	static open_method_decl(pack_non_delta)
46bf0438 JH	431	{
7ef2d9a2 JH	432	struct pack_window *window;
	433	enum object_type in_pack_type;
	434
	435	st->u.in_pack.pack = oi->u.packed.pack;
	436	st->u.in_pack.pos = oi->u.packed.offset;
	437	window = NULL;
	438
	439	in_pack_type = unpack_object_header(st->u.in_pack.pack,
	440	&window,
	441	&st->u.in_pack.pos,
	442	&st->size);
	443	unuse_pack(&window);
	444	switch (in_pack_type) {
	445	default:
	446	return -1; /* we do not do deltas for now */
	447	case OBJ_COMMIT:
	448	case OBJ_TREE:
	449	case OBJ_BLOB:
	450	case OBJ_TAG:
	451	break;
	452	}
	453	st->z_state = z_unused;
	454	st->vtbl = &pack_non_delta_vtbl;
	455	return 0;
46bf0438 JH	456	}
	457
	458
	459	/*****************************************************************
	460	*
	461	* In-core stream
	462	*
	463	*****************************************************************/
	464
	465	static close_method_decl(incore)
	466	{
	467	free(st->u.incore.buf);
	468	return 0;
	469	}
	470
	471	static read_method_decl(incore)
	472	{
	473	size_t read_size = sz;
	474	size_t remainder = st->size - st->u.incore.read_ptr;
	475
	476	if (remainder <= read_size)
	477	read_size = remainder;
	478	if (read_size) {
	479	memcpy(buf, st->u.incore.buf + st->u.incore.read_ptr, read_size);
	480	st->u.incore.read_ptr += read_size;
	481	}
	482	return read_size;
	483	}
	484
	485	static struct stream_vtbl incore_vtbl = {
	486	close_istream_incore,
	487	read_istream_incore,
	488	};
	489
	490	static open_method_decl(incore)
	491	{
b4f5aca4	492	st->u.incore.buf = read_object_file_extended(oid, type, &st->size, 0);
46bf0438 JH	493	st->u.incore.read_ptr = 0;
	494	st->vtbl = &incore_vtbl;
	495
	496	return st->u.incore.buf ? 0 : -1;
	497	}
47a02ff2 JH	498
	499
	500	/****************************************************************
	501	* Users of streaming interface
	502	****************************************************************/
	503
7eda0e4f	504	int stream_blob_to_fd(int fd, const struct object_id oid, struct stream_filter filter,
47a02ff2 JH	505	int can_seek)
	506	{
	507	struct git_istream *st;
	508	enum object_type type;
	509	unsigned long sz;
	510	ssize_t kept = 0;
	511	int result = -1;
	512
ef7b5195	513	st = open_istream(oid, &type, &sz, filter);
9ce4ad3e JK	514	if (!st) {
	515	if (filter)
	516	free_stream_filter(filter);
47a02ff2	517	return result;
9ce4ad3e	518	}
47a02ff2 JH	519	if (type != OBJ_BLOB)
	520	goto close_and_exit;
	521	for (;;) {
	522	char buf[1024 * 16];
	523	ssize_t wrote, holeto;
	524	ssize_t readlen = read_istream(st, buf, sizeof(buf));
	525
45d4bdae JK	526	if (readlen < 0)
45d4bdae JK	527	goto close_and_exit;
47a02ff2 JH	528	if (!readlen)
	529	break;
	530	if (can_seek && sizeof(buf) == readlen) {
	531	for (holeto = 0; holeto < readlen; holeto++)
	532	if (buf[holeto])
	533	break;
	534	if (readlen == holeto) {
	535	kept += holeto;
	536	continue;
	537	}
	538	}
	539
	540	if (kept && lseek(fd, kept, SEEK_CUR) == (off_t) -1)
	541	goto close_and_exit;
	542	else
	543	kept = 0;
	544	wrote = write_in_full(fd, buf, readlen);
	545
564bde9a	546	if (wrote < 0)
47a02ff2 JH	547	goto close_and_exit;
	548	}
	549	if (kept && (lseek(fd, kept - 1, SEEK_CUR) == (off_t) -1 \|\|
7edc02f4	550	xwrite(fd, "", 1) != 1))
47a02ff2 JH	551	goto close_and_exit;
	552	result = 0;
	553
	554	close_and_exit:
	555	close_istream(st);
	556	return result;
	557	}