archival/libunarchive/decompress_unlzma.c

/* vi: set sw=4 ts=4: */
/*
 * Small lzma deflate implementation.
 * Copyright (C) 2006  Aurelien Jacobs <aurel@gnuage.org>
 *
 * Based on LzmaDecode.c from the LZMA SDK 4.22 (http://www.7-zip.org/)
 * Copyright (C) 1999-2005  Igor Pavlov
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */

#include "libbb.h"
#include "unarchive.h"

#ifdef CONFIG_FEATURE_LZMA_FAST
#  define speed_inline ATTRIBUTE_ALWAYS_INLINE
#else
#  define speed_inline
#endif


typedef struct {
	int fd;
	uint8_t *ptr;

/* Was keeping rc on stack in unlzma and separately allocating buffer,
 * but with "buffer 'attached to' allocated rc" code is smaller: */
	/* uint8_t *buffer; */
#define RC_BUFFER ((uint8_t*)(rc+1))

	uint8_t *buffer_end;

/* Had provisions for variable buffer, but we don't need it here */
	/* int buffer_size; */
#define RC_BUFFER_SIZE 0x10000

	uint32_t code;
	uint32_t range;
	uint32_t bound;
} rc_t;

#define RC_TOP_BITS 24
#define RC_MOVE_BITS 5
#define RC_MODEL_TOTAL_BITS 11


/* Called twice: once at startup and once in rc_normalize() */
static void rc_read(rc_t * rc)
{
	int buffer_size = safe_read(rc->fd, RC_BUFFER, RC_BUFFER_SIZE);
	if (buffer_size <= 0)
		bb_error_msg_and_die("unexpected EOF");
	rc->ptr = RC_BUFFER;
	rc->buffer_end = RC_BUFFER + buffer_size;
}

/* Called once */
static rc_t* rc_init(int fd) /*, int buffer_size) */
{
	int i;
	rc_t* rc;

	rc = xmalloc(sizeof(rc_t) + RC_BUFFER_SIZE);

	rc->fd = fd;
	/* rc->buffer_size = buffer_size; */
	rc->buffer_end = RC_BUFFER + RC_BUFFER_SIZE;
	rc->ptr = rc->buffer_end;

	rc->code = 0;
	rc->range = 0xFFFFFFFF;
	for (i = 0; i < 5; i++) {
		if (rc->ptr >= rc->buffer_end)
			rc_read(rc);
		rc->code = (rc->code << 8) | *rc->ptr++;
	}
	return rc;
}

/* Called once  */
static ATTRIBUTE_ALWAYS_INLINE void rc_free(rc_t * rc)
{
	if (ENABLE_FEATURE_CLEAN_UP)
		free(rc);
}

/* Called twice, but one callsite is in speed_inline'd rc_is_bit_0_helper() */
static void rc_do_normalize(rc_t * rc)
{
	if (rc->ptr >= rc->buffer_end)
		rc_read(rc);
	rc->range <<= 8;
	rc->code = (rc->code << 8) | *rc->ptr++;
}
static ATTRIBUTE_ALWAYS_INLINE void rc_normalize(rc_t * rc)
{
	if (rc->range < (1 << RC_TOP_BITS)) {
		rc_do_normalize(rc);
	}
}

/* Called 9 times */
/* Why rc_is_bit_0_helper exists?
 * Because we want to always expose (rc->code < rc->bound) to optimizer
 */
static speed_inline uint32_t rc_is_bit_0_helper(rc_t * rc, uint16_t * p)
{
	rc_normalize(rc);
	rc->bound = *p * (rc->range >> RC_MODEL_TOTAL_BITS);
	return rc->bound;
}
static ATTRIBUTE_ALWAYS_INLINE int rc_is_bit_0(rc_t * rc, uint16_t * p)
{
	uint32_t t = rc_is_bit_0_helper(rc, p);
	return rc->code < t;
}

/* Called ~10 times, but very small, thus inlined */
static speed_inline void rc_update_bit_0(rc_t * rc, uint16_t * p)
{
	rc->range = rc->bound;
	*p += ((1 << RC_MODEL_TOTAL_BITS) - *p) >> RC_MOVE_BITS;
}
static speed_inline void rc_update_bit_1(rc_t * rc, uint16_t * p)
{
	rc->range -= rc->bound;
	rc->code -= rc->bound;
	*p -= *p >> RC_MOVE_BITS;
}

/* Called 4 times in unlzma loop */
static int rc_get_bit(rc_t * rc, uint16_t * p, int *symbol)
{
	if (rc_is_bit_0(rc, p)) {
		rc_update_bit_0(rc, p);
		*symbol *= 2;
		return 0;
	} else {
		rc_update_bit_1(rc, p);
		*symbol = *symbol * 2 + 1;
		return 1;
	}
}

/* Called once */
static ATTRIBUTE_ALWAYS_INLINE int rc_direct_bit(rc_t * rc)
{
	rc_normalize(rc);
	rc->range >>= 1;
	if (rc->code >= rc->range) {
		rc->code -= rc->range;
		return 1;
	}
	return 0;
}

/* Called twice */
static speed_inline void
rc_bit_tree_decode(rc_t * rc, uint16_t * p, int num_levels, int *symbol)
{
	int i = num_levels;

	*symbol = 1;
	while (i--)
		rc_get_bit(rc, p + *symbol, symbol);
	*symbol -= 1 << num_levels;
}


typedef struct {
	uint8_t pos;
	uint32_t dict_size;
	uint64_t dst_size;
} __attribute__ ((packed)) lzma_header_t;


/* #defines will force compiler to compute/optimize each one with each usage.
 * Have heart and use enum instead. */
enum {
	LZMA_BASE_SIZE = 1846,
	LZMA_LIT_SIZE  = 768,

	LZMA_NUM_POS_BITS_MAX = 4,

	LZMA_LEN_NUM_LOW_BITS  = 3,
	LZMA_LEN_NUM_MID_BITS  = 3,
	LZMA_LEN_NUM_HIGH_BITS = 8,

	LZMA_LEN_CHOICE     = 0,
	LZMA_LEN_CHOICE_2   = (LZMA_LEN_CHOICE + 1),
	LZMA_LEN_LOW        = (LZMA_LEN_CHOICE_2 + 1),
	LZMA_LEN_MID        = (LZMA_LEN_LOW \
	                      + (1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_LOW_BITS))),
	LZMA_LEN_HIGH       = (LZMA_LEN_MID \
	                      + (1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_MID_BITS))),
	LZMA_NUM_LEN_PROBS  = (LZMA_LEN_HIGH + (1 << LZMA_LEN_NUM_HIGH_BITS)),

	LZMA_NUM_STATES     = 12,
	LZMA_NUM_LIT_STATES = 7,

	LZMA_START_POS_MODEL_INDEX = 4,
	LZMA_END_POS_MODEL_INDEX   = 14,
	LZMA_NUM_FULL_DISTANCES    = (1 << (LZMA_END_POS_MODEL_INDEX >> 1)),

	LZMA_NUM_POS_SLOT_BITS = 6,
	LZMA_NUM_LEN_TO_POS_STATES = 4,

	LZMA_NUM_ALIGN_BITS = 4,

	LZMA_MATCH_MIN_LEN  = 2,

	LZMA_IS_MATCH       = 0,
	LZMA_IS_REP         = (LZMA_IS_MATCH + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX)),
	LZMA_IS_REP_G0      = (LZMA_IS_REP + LZMA_NUM_STATES),
	LZMA_IS_REP_G1      = (LZMA_IS_REP_G0 + LZMA_NUM_STATES),
	LZMA_IS_REP_G2      = (LZMA_IS_REP_G1 + LZMA_NUM_STATES),
	LZMA_IS_REP_0_LONG  = (LZMA_IS_REP_G2 + LZMA_NUM_STATES),
	LZMA_POS_SLOT       = (LZMA_IS_REP_0_LONG \
	                      + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX)),
	LZMA_SPEC_POS       = (LZMA_POS_SLOT \
	                      + (LZMA_NUM_LEN_TO_POS_STATES << LZMA_NUM_POS_SLOT_BITS)),
	LZMA_ALIGN          = (LZMA_SPEC_POS \
	                      + LZMA_NUM_FULL_DISTANCES - LZMA_END_POS_MODEL_INDEX),
	LZMA_LEN_CODER      = (LZMA_ALIGN + (1 << LZMA_NUM_ALIGN_BITS)),
	LZMA_REP_LEN_CODER  = (LZMA_LEN_CODER + LZMA_NUM_LEN_PROBS),
	LZMA_LITERAL        = (LZMA_REP_LEN_CODER + LZMA_NUM_LEN_PROBS),
};


USE_DESKTOP(long long) int
unlzma(int src_fd, int dst_fd)
{
	USE_DESKTOP(long long total_written = 0;)
	lzma_header_t header;
	int lc, pb, lp;
	uint32_t pos_state_mask;
	uint32_t literal_pos_mask;
	uint32_t pos;
	uint16_t *p;
	uint16_t *prob;
	uint16_t *prob_lit;
	int num_bits;
	int num_probs;
	rc_t *rc;
	int i, mi;
	uint8_t *buffer;
	uint8_t previous_byte = 0;
	size_t buffer_pos = 0, global_pos = 0;
	int len = 0;
	int state = 0;
	uint32_t rep0 = 1, rep1 = 1, rep2 = 1, rep3 = 1;

	xread(src_fd, &header, sizeof(header));

	if (header.pos >= (9 * 5 * 5))
		bb_error_msg_and_die("bad header");
	mi = header.pos / 9;
	lc = header.pos % 9;
	pb = mi / 5;
	lp = mi % 5;
	pos_state_mask = (1 << pb) - 1;
	literal_pos_mask = (1 << lp) - 1;

	header.dict_size = SWAP_LE32(header.dict_size);
	header.dst_size = SWAP_LE64(header.dst_size);

	if (header.dict_size == 0)
		header.dict_size = 1;

	buffer = xmalloc(MIN(header.dst_size, header.dict_size));

	num_probs = LZMA_BASE_SIZE + (LZMA_LIT_SIZE << (lc + lp));
	p = xmalloc(num_probs * sizeof(*p));
	num_probs = LZMA_LITERAL + (LZMA_LIT_SIZE << (lc + lp));
	for (i = 0; i < num_probs; i++)
		p[i] = (1 << RC_MODEL_TOTAL_BITS) >> 1;

	rc = rc_init(src_fd); /*, RC_BUFFER_SIZE); */

	while (global_pos + buffer_pos < header.dst_size) {
		int pos_state = (buffer_pos + global_pos) & pos_state_mask;

		prob =
			p + LZMA_IS_MATCH + (state << LZMA_NUM_POS_BITS_MAX) + pos_state;
		if (rc_is_bit_0(rc, prob)) {
			mi = 1;
			rc_update_bit_0(rc, prob);
			prob = (p + LZMA_LITERAL + (LZMA_LIT_SIZE
					* ((((buffer_pos + global_pos) & literal_pos_mask) << lc)
					+ (previous_byte >> (8 - lc)))));

			if (state >= LZMA_NUM_LIT_STATES) {
				int match_byte;

				pos = buffer_pos - rep0;
				while (pos >= header.dict_size)
					pos += header.dict_size;
				match_byte = buffer[pos];
				do {
					int bit;

					match_byte <<= 1;
					bit = match_byte & 0x100;
					prob_lit = prob + 0x100 + bit + mi;
					if (rc_get_bit(rc, prob_lit, &mi)) {
						if (!bit)
							break;
					} else {
						if (bit)
							break;
					}
				} while (mi < 0x100);
			}
			while (mi < 0x100) {
				prob_lit = prob + mi;
				rc_get_bit(rc, prob_lit, &mi);
			}
			previous_byte = (uint8_t) mi;

			buffer[buffer_pos++] = previous_byte;
			if (buffer_pos == header.dict_size) {
				buffer_pos = 0;
				global_pos += header.dict_size;
				if (full_write(dst_fd, buffer, header.dict_size) != header.dict_size)
					goto bad;
				USE_DESKTOP(total_written += header.dict_size;)
			}
			if (state < 4)
				state = 0;
			else if (state < 10)
				state -= 3;
			else
				state -= 6;
		} else {
			int offset;
			uint16_t *prob_len;

			rc_update_bit_1(rc, prob);
			prob = p + LZMA_IS_REP + state;
			if (rc_is_bit_0(rc, prob)) {
				rc_update_bit_0(rc, prob);
				rep3 = rep2;
				rep2 = rep1;
				rep1 = rep0;
				state = state < LZMA_NUM_LIT_STATES ? 0 : 3;
				prob = p + LZMA_LEN_CODER;
			} else {
				rc_update_bit_1(rc, prob);
				prob = p + LZMA_IS_REP_G0 + state;
				if (rc_is_bit_0(rc, prob)) {
					rc_update_bit_0(rc, prob);
					prob = (p + LZMA_IS_REP_0_LONG
							+ (state << LZMA_NUM_POS_BITS_MAX) + pos_state);
					if (rc_is_bit_0(rc, prob)) {
						rc_update_bit_0(rc, prob);

						state = state < LZMA_NUM_LIT_STATES ? 9 : 11;
						pos = buffer_pos - rep0;
						while (pos >= header.dict_size)
							pos += header.dict_size;
						previous_byte = buffer[pos];
						buffer[buffer_pos++] = previous_byte;
						if (buffer_pos == header.dict_size) {
							buffer_pos = 0;
							global_pos += header.dict_size;
							if (full_write(dst_fd, buffer, header.dict_size) != header.dict_size)
								goto bad;
							USE_DESKTOP(total_written += header.dict_size;)
						}
						continue;
					} else {
						rc_update_bit_1(rc, prob);
					}
				} else {
					uint32_t distance;

					rc_update_bit_1(rc, prob);
					prob = p + LZMA_IS_REP_G1 + state;
					if (rc_is_bit_0(rc, prob)) {
						rc_update_bit_0(rc, prob);
						distance = rep1;
					} else {
						rc_update_bit_1(rc, prob);
						prob = p + LZMA_IS_REP_G2 + state;
						if (rc_is_bit_0(rc, prob)) {
							rc_update_bit_0(rc, prob);
							distance = rep2;
						} else {
							rc_update_bit_1(rc, prob);
							distance = rep3;
							rep3 = rep2;
						}
						rep2 = rep1;
					}
					rep1 = rep0;
					rep0 = distance;
				}
				state = state < LZMA_NUM_LIT_STATES ? 8 : 11;
				prob = p + LZMA_REP_LEN_CODER;
			}

			prob_len = prob + LZMA_LEN_CHOICE;
			if (rc_is_bit_0(rc, prob_len)) {
				rc_update_bit_0(rc, prob_len);
				prob_len = (prob + LZMA_LEN_LOW
							+ (pos_state << LZMA_LEN_NUM_LOW_BITS));
				offset = 0;
				num_bits = LZMA_LEN_NUM_LOW_BITS;
			} else {
				rc_update_bit_1(rc, prob_len);
				prob_len = prob + LZMA_LEN_CHOICE_2;
				if (rc_is_bit_0(rc, prob_len)) {
					rc_update_bit_0(rc, prob_len);
					prob_len = (prob + LZMA_LEN_MID
								+ (pos_state << LZMA_LEN_NUM_MID_BITS));
					offset = 1 << LZMA_LEN_NUM_LOW_BITS;
					num_bits = LZMA_LEN_NUM_MID_BITS;
				} else {
					rc_update_bit_1(rc, prob_len);
					prob_len = prob + LZMA_LEN_HIGH;
					offset = ((1 << LZMA_LEN_NUM_LOW_BITS)
							  + (1 << LZMA_LEN_NUM_MID_BITS));
					num_bits = LZMA_LEN_NUM_HIGH_BITS;
				}
			}
			rc_bit_tree_decode(rc, prob_len, num_bits, &len);
			len += offset;

			if (state < 4) {
				int pos_slot;

				state += LZMA_NUM_LIT_STATES;
				prob =
					p + LZMA_POS_SLOT +
					((len <
					  LZMA_NUM_LEN_TO_POS_STATES ? len :
					  LZMA_NUM_LEN_TO_POS_STATES - 1)
					 << LZMA_NUM_POS_SLOT_BITS);
				rc_bit_tree_decode(rc, prob, LZMA_NUM_POS_SLOT_BITS,
								   &pos_slot);
				if (pos_slot >= LZMA_START_POS_MODEL_INDEX) {
					num_bits = (pos_slot >> 1) - 1;
					rep0 = 2 | (pos_slot & 1);
					if (pos_slot < LZMA_END_POS_MODEL_INDEX) {
						rep0 <<= num_bits;
						prob = p + LZMA_SPEC_POS + rep0 - pos_slot - 1;
					} else {
						num_bits -= LZMA_NUM_ALIGN_BITS;
						while (num_bits--)
							rep0 = (rep0 << 1) | rc_direct_bit(rc);
						prob = p + LZMA_ALIGN;
						rep0 <<= LZMA_NUM_ALIGN_BITS;
						num_bits = LZMA_NUM_ALIGN_BITS;
					}
					i = 1;
					mi = 1;
					while (num_bits--) {
						if (rc_get_bit(rc, prob + mi, &mi))
							rep0 |= i;
						i <<= 1;
					}
				} else
					rep0 = pos_slot;
				if (++rep0 == 0)
					break;
			}

			len += LZMA_MATCH_MIN_LEN;

			do {
				pos = buffer_pos - rep0;
				while (pos >= header.dict_size)
					pos += header.dict_size;
				previous_byte = buffer[pos];
				buffer[buffer_pos++] = previous_byte;
				if (buffer_pos == header.dict_size) {
					buffer_pos = 0;
					global_pos += header.dict_size;
					if (full_write(dst_fd, buffer, header.dict_size) != header.dict_size)
						goto bad;
					USE_DESKTOP(total_written += header.dict_size;)
				}
				len--;
			} while (len != 0 && buffer_pos < header.dst_size);
		}
	}


	if (full_write(dst_fd, buffer, buffer_pos) != buffer_pos) {
 bad:
		rc_free(rc);
		return -1;
	}
	rc_free(rc);
	USE_DESKTOP(total_written += buffer_pos;)
	return USE_DESKTOP(total_written) + 0;
}
1	niro	532	/* vi: set sw=4 ts=4: */
2			/*
3			* Small lzma deflate implementation.
4			* Copyright (C) 2006 Aurelien Jacobs <aurel@gnuage.org>
5			*
6			* Based on LzmaDecode.c from the LZMA SDK 4.22 (http://www.7-zip.org/)
7			* Copyright (C) 1999-2005 Igor Pavlov
8			*
9			* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
10			*/
11
12			#include "libbb.h"
13			#include "unarchive.h"
14
15			#ifdef CONFIG_FEATURE_LZMA_FAST
16			# define speed_inline ATTRIBUTE_ALWAYS_INLINE
17			#else
18			# define speed_inline
19			#endif
20
21
22			typedef struct {
23			int fd;
24			uint8_t *ptr;
25
26			/* Was keeping rc on stack in unlzma and separately allocating buffer,
27			* but with "buffer 'attached to' allocated rc" code is smaller: */
28			/* uint8_t buffer; /
29			#define RC_BUFFER ((uint8_t*)(rc+1))
30
31			uint8_t *buffer_end;
32
33			/* Had provisions for variable buffer, but we don't need it here */
34			/* int buffer_size; */
35			#define RC_BUFFER_SIZE 0x10000
36
37			uint32_t code;
38			uint32_t range;
39			uint32_t bound;
40			} rc_t;
41
42			#define RC_TOP_BITS 24
43			#define RC_MOVE_BITS 5
44			#define RC_MODEL_TOTAL_BITS 11
45
46
47			/* Called twice: once at startup and once in rc_normalize() */
48			static void rc_read(rc_t * rc)
49			{
50			int buffer_size = safe_read(rc->fd, RC_BUFFER, RC_BUFFER_SIZE);
51			if (buffer_size <= 0)
52			bb_error_msg_and_die("unexpected EOF");
53			rc->ptr = RC_BUFFER;
54			rc->buffer_end = RC_BUFFER + buffer_size;
55			}
56
57			/* Called once */
58			static rc_t* rc_init(int fd) /, int buffer_size) /
59			{
60			int i;
61			rc_t* rc;
62
63			rc = xmalloc(sizeof(rc_t) + RC_BUFFER_SIZE);
64
65			rc->fd = fd;
66			/* rc->buffer_size = buffer_size; */
67			rc->buffer_end = RC_BUFFER + RC_BUFFER_SIZE;
68			rc->ptr = rc->buffer_end;
69
70			rc->code = 0;
71			rc->range = 0xFFFFFFFF;
72			for (i = 0; i < 5; i++) {
73			if (rc->ptr >= rc->buffer_end)
74			rc_read(rc);
75			rc->code = (rc->code << 8) \| *rc->ptr++;
76			}
77			return rc;
78			}
79
80			/* Called once */
81			static ATTRIBUTE_ALWAYS_INLINE void rc_free(rc_t * rc)
82			{
83			if (ENABLE_FEATURE_CLEAN_UP)
84			free(rc);
85			}
86
87			/* Called twice, but one callsite is in speed_inline'd rc_is_bit_0_helper() */
88			static void rc_do_normalize(rc_t * rc)
89			{
90			if (rc->ptr >= rc->buffer_end)
91			rc_read(rc);
92			rc->range <<= 8;
93			rc->code = (rc->code << 8) \| *rc->ptr++;
94			}
95			static ATTRIBUTE_ALWAYS_INLINE void rc_normalize(rc_t * rc)
96			{
97			if (rc->range < (1 << RC_TOP_BITS)) {
98			rc_do_normalize(rc);
99			}
100			}
101
102			/* Called 9 times */
103			/* Why rc_is_bit_0_helper exists?
104			* Because we want to always expose (rc->code < rc->bound) to optimizer
105			*/
106			static speed_inline uint32_t rc_is_bit_0_helper(rc_t * rc, uint16_t * p)
107			{
108			rc_normalize(rc);
109			rc->bound = p (rc->range >> RC_MODEL_TOTAL_BITS);
110			return rc->bound;
111			}
112			static ATTRIBUTE_ALWAYS_INLINE int rc_is_bit_0(rc_t * rc, uint16_t * p)
113			{
114			uint32_t t = rc_is_bit_0_helper(rc, p);
115			return rc->code < t;
116			}
117
118			/* Called ~10 times, but very small, thus inlined */
119			static speed_inline void rc_update_bit_0(rc_t * rc, uint16_t * p)
120			{
121			rc->range = rc->bound;
122			p += ((1 << RC_MODEL_TOTAL_BITS) - p) >> RC_MOVE_BITS;
123			}
124			static speed_inline void rc_update_bit_1(rc_t * rc, uint16_t * p)
125			{
126			rc->range -= rc->bound;
127			rc->code -= rc->bound;
128			p -= p >> RC_MOVE_BITS;
129			}
130
131			/* Called 4 times in unlzma loop */
132			static int rc_get_bit(rc_t * rc, uint16_t * p, int *symbol)
133			{
134			if (rc_is_bit_0(rc, p)) {
135			rc_update_bit_0(rc, p);
136			symbol = 2;
137			return 0;
138			} else {
139			rc_update_bit_1(rc, p);
140			symbol = symbol * 2 + 1;
141			return 1;
142			}
143			}
144
145			/* Called once */
146			static ATTRIBUTE_ALWAYS_INLINE int rc_direct_bit(rc_t * rc)
147			{
148			rc_normalize(rc);
149			rc->range >>= 1;
150			if (rc->code >= rc->range) {
151			rc->code -= rc->range;
152			return 1;
153			}
154			return 0;
155			}
156
157			/* Called twice */
158			static speed_inline void
159			rc_bit_tree_decode(rc_t * rc, uint16_t * p, int num_levels, int *symbol)
160			{
161			int i = num_levels;
162
163			*symbol = 1;
164			while (i--)
165			rc_get_bit(rc, p + *symbol, symbol);
166			*symbol -= 1 << num_levels;
167			}
168
169
170			typedef struct {
171			uint8_t pos;
172			uint32_t dict_size;
173			uint64_t dst_size;
174			} __attribute__ ((packed)) lzma_header_t;
175
176
177			/* #defines will force compiler to compute/optimize each one with each usage.
178			* Have heart and use enum instead. */
179			enum {
180			LZMA_BASE_SIZE = 1846,
181			LZMA_LIT_SIZE = 768,
182
183			LZMA_NUM_POS_BITS_MAX = 4,
184
185			LZMA_LEN_NUM_LOW_BITS = 3,
186			LZMA_LEN_NUM_MID_BITS = 3,
187			LZMA_LEN_NUM_HIGH_BITS = 8,
188
189			LZMA_LEN_CHOICE = 0,
190			LZMA_LEN_CHOICE_2 = (LZMA_LEN_CHOICE + 1),
191			LZMA_LEN_LOW = (LZMA_LEN_CHOICE_2 + 1),
192			LZMA_LEN_MID = (LZMA_LEN_LOW \
193			+ (1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_LOW_BITS))),
194			LZMA_LEN_HIGH = (LZMA_LEN_MID \
195			+ (1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_MID_BITS))),
196			LZMA_NUM_LEN_PROBS = (LZMA_LEN_HIGH + (1 << LZMA_LEN_NUM_HIGH_BITS)),
197
198			LZMA_NUM_STATES = 12,
199			LZMA_NUM_LIT_STATES = 7,
200
201			LZMA_START_POS_MODEL_INDEX = 4,
202			LZMA_END_POS_MODEL_INDEX = 14,
203			LZMA_NUM_FULL_DISTANCES = (1 << (LZMA_END_POS_MODEL_INDEX >> 1)),
204
205			LZMA_NUM_POS_SLOT_BITS = 6,
206			LZMA_NUM_LEN_TO_POS_STATES = 4,
207
208			LZMA_NUM_ALIGN_BITS = 4,
209
210			LZMA_MATCH_MIN_LEN = 2,
211
212			LZMA_IS_MATCH = 0,
213			LZMA_IS_REP = (LZMA_IS_MATCH + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX)),
214			LZMA_IS_REP_G0 = (LZMA_IS_REP + LZMA_NUM_STATES),
215			LZMA_IS_REP_G1 = (LZMA_IS_REP_G0 + LZMA_NUM_STATES),
216			LZMA_IS_REP_G2 = (LZMA_IS_REP_G1 + LZMA_NUM_STATES),
217			LZMA_IS_REP_0_LONG = (LZMA_IS_REP_G2 + LZMA_NUM_STATES),
218			LZMA_POS_SLOT = (LZMA_IS_REP_0_LONG \
219			+ (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX)),
220			LZMA_SPEC_POS = (LZMA_POS_SLOT \
221			+ (LZMA_NUM_LEN_TO_POS_STATES << LZMA_NUM_POS_SLOT_BITS)),
222			LZMA_ALIGN = (LZMA_SPEC_POS \
223			+ LZMA_NUM_FULL_DISTANCES - LZMA_END_POS_MODEL_INDEX),
224			LZMA_LEN_CODER = (LZMA_ALIGN + (1 << LZMA_NUM_ALIGN_BITS)),
225			LZMA_REP_LEN_CODER = (LZMA_LEN_CODER + LZMA_NUM_LEN_PROBS),
226			LZMA_LITERAL = (LZMA_REP_LEN_CODER + LZMA_NUM_LEN_PROBS),
227			};
228
229
230			USE_DESKTOP(long long) int
231			unlzma(int src_fd, int dst_fd)
232			{
233			USE_DESKTOP(long long total_written = 0;)
234			lzma_header_t header;
235			int lc, pb, lp;
236			uint32_t pos_state_mask;
237			uint32_t literal_pos_mask;
238			uint32_t pos;
239			uint16_t *p;
240			uint16_t *prob;
241			uint16_t *prob_lit;
242			int num_bits;
243			int num_probs;
244			rc_t *rc;
245			int i, mi;
246			uint8_t *buffer;
247			uint8_t previous_byte = 0;
248			size_t buffer_pos = 0, global_pos = 0;
249			int len = 0;
250			int state = 0;
251			uint32_t rep0 = 1, rep1 = 1, rep2 = 1, rep3 = 1;
252
253			xread(src_fd, &header, sizeof(header));
254
255			if (header.pos >= (9 * 5 * 5))
256			bb_error_msg_and_die("bad header");
257			mi = header.pos / 9;
258			lc = header.pos % 9;
259			pb = mi / 5;
260			lp = mi % 5;
261			pos_state_mask = (1 << pb) - 1;
262			literal_pos_mask = (1 << lp) - 1;
263
264			header.dict_size = SWAP_LE32(header.dict_size);
265			header.dst_size = SWAP_LE64(header.dst_size);
266
267			if (header.dict_size == 0)
268			header.dict_size = 1;
269
270			buffer = xmalloc(MIN(header.dst_size, header.dict_size));
271
272			num_probs = LZMA_BASE_SIZE + (LZMA_LIT_SIZE << (lc + lp));
273			p = xmalloc(num_probs * sizeof(*p));
274			num_probs = LZMA_LITERAL + (LZMA_LIT_SIZE << (lc + lp));
275			for (i = 0; i < num_probs; i++)
276			p[i] = (1 << RC_MODEL_TOTAL_BITS) >> 1;
277
278			rc = rc_init(src_fd); /, RC_BUFFER_SIZE); /
279
280			while (global_pos + buffer_pos < header.dst_size) {
281			int pos_state = (buffer_pos + global_pos) & pos_state_mask;
282
283			prob =
284			p + LZMA_IS_MATCH + (state << LZMA_NUM_POS_BITS_MAX) + pos_state;
285			if (rc_is_bit_0(rc, prob)) {
286			mi = 1;
287			rc_update_bit_0(rc, prob);
288			prob = (p + LZMA_LITERAL + (LZMA_LIT_SIZE
289			* ((((buffer_pos + global_pos) & literal_pos_mask) << lc)
290			+ (previous_byte >> (8 - lc)))));
291
292			if (state >= LZMA_NUM_LIT_STATES) {
293			int match_byte;
294
295			pos = buffer_pos - rep0;
296			while (pos >= header.dict_size)
297			pos += header.dict_size;
298			match_byte = buffer[pos];
299			do {
300			int bit;
301
302			match_byte <<= 1;
303			bit = match_byte & 0x100;
304			prob_lit = prob + 0x100 + bit + mi;
305			if (rc_get_bit(rc, prob_lit, &mi)) {
306			if (!bit)
307			break;
308			} else {
309			if (bit)
310			break;
311			}
312			} while (mi < 0x100);
313			}
314			while (mi < 0x100) {
315			prob_lit = prob + mi;
316			rc_get_bit(rc, prob_lit, &mi);
317			}
318			previous_byte = (uint8_t) mi;
319
320			buffer[buffer_pos++] = previous_byte;
321			if (buffer_pos == header.dict_size) {
322			buffer_pos = 0;
323			global_pos += header.dict_size;
324			if (full_write(dst_fd, buffer, header.dict_size) != header.dict_size)
325			goto bad;
326			USE_DESKTOP(total_written += header.dict_size;)
327			}
328			if (state < 4)
329			state = 0;
330			else if (state < 10)
331			state -= 3;
332			else
333			state -= 6;
334			} else {
335			int offset;
336			uint16_t *prob_len;
337
338			rc_update_bit_1(rc, prob);
339			prob = p + LZMA_IS_REP + state;
340			if (rc_is_bit_0(rc, prob)) {
341			rc_update_bit_0(rc, prob);
342			rep3 = rep2;
343			rep2 = rep1;
344			rep1 = rep0;
345			state = state < LZMA_NUM_LIT_STATES ? 0 : 3;
346			prob = p + LZMA_LEN_CODER;
347			} else {
348			rc_update_bit_1(rc, prob);
349			prob = p + LZMA_IS_REP_G0 + state;
350			if (rc_is_bit_0(rc, prob)) {
351			rc_update_bit_0(rc, prob);
352			prob = (p + LZMA_IS_REP_0_LONG
353			+ (state << LZMA_NUM_POS_BITS_MAX) + pos_state);
354			if (rc_is_bit_0(rc, prob)) {
355			rc_update_bit_0(rc, prob);
356
357			state = state < LZMA_NUM_LIT_STATES ? 9 : 11;
358			pos = buffer_pos - rep0;
359			while (pos >= header.dict_size)
360			pos += header.dict_size;
361			previous_byte = buffer[pos];
362			buffer[buffer_pos++] = previous_byte;
363			if (buffer_pos == header.dict_size) {
364			buffer_pos = 0;
365			global_pos += header.dict_size;
366			if (full_write(dst_fd, buffer, header.dict_size) != header.dict_size)
367			goto bad;
368			USE_DESKTOP(total_written += header.dict_size;)
369			}
370			continue;
371			} else {
372			rc_update_bit_1(rc, prob);
373			}
374			} else {
375			uint32_t distance;
376
377			rc_update_bit_1(rc, prob);
378			prob = p + LZMA_IS_REP_G1 + state;
379			if (rc_is_bit_0(rc, prob)) {
380			rc_update_bit_0(rc, prob);
381			distance = rep1;
382			} else {
383			rc_update_bit_1(rc, prob);
384			prob = p + LZMA_IS_REP_G2 + state;
385			if (rc_is_bit_0(rc, prob)) {
386			rc_update_bit_0(rc, prob);
387			distance = rep2;
388			} else {
389			rc_update_bit_1(rc, prob);
390			distance = rep3;
391			rep3 = rep2;
392			}
393			rep2 = rep1;
394			}
395			rep1 = rep0;
396			rep0 = distance;
397			}
398			state = state < LZMA_NUM_LIT_STATES ? 8 : 11;
399			prob = p + LZMA_REP_LEN_CODER;
400			}
401
402			prob_len = prob + LZMA_LEN_CHOICE;
403			if (rc_is_bit_0(rc, prob_len)) {
404			rc_update_bit_0(rc, prob_len);
405			prob_len = (prob + LZMA_LEN_LOW
406			+ (pos_state << LZMA_LEN_NUM_LOW_BITS));
407			offset = 0;
408			num_bits = LZMA_LEN_NUM_LOW_BITS;
409			} else {
410			rc_update_bit_1(rc, prob_len);
411			prob_len = prob + LZMA_LEN_CHOICE_2;
412			if (rc_is_bit_0(rc, prob_len)) {
413			rc_update_bit_0(rc, prob_len);
414			prob_len = (prob + LZMA_LEN_MID
415			+ (pos_state << LZMA_LEN_NUM_MID_BITS));
416			offset = 1 << LZMA_LEN_NUM_LOW_BITS;
417			num_bits = LZMA_LEN_NUM_MID_BITS;
418			} else {
419			rc_update_bit_1(rc, prob_len);
420			prob_len = prob + LZMA_LEN_HIGH;
421			offset = ((1 << LZMA_LEN_NUM_LOW_BITS)
422			+ (1 << LZMA_LEN_NUM_MID_BITS));
423			num_bits = LZMA_LEN_NUM_HIGH_BITS;
424			}
425			}
426			rc_bit_tree_decode(rc, prob_len, num_bits, &len);
427			len += offset;
428
429			if (state < 4) {
430			int pos_slot;
431
432			state += LZMA_NUM_LIT_STATES;
433			prob =
434			p + LZMA_POS_SLOT +
435			((len <
436			LZMA_NUM_LEN_TO_POS_STATES ? len :
437			LZMA_NUM_LEN_TO_POS_STATES - 1)
438			<< LZMA_NUM_POS_SLOT_BITS);
439			rc_bit_tree_decode(rc, prob, LZMA_NUM_POS_SLOT_BITS,
440			&pos_slot);
441			if (pos_slot >= LZMA_START_POS_MODEL_INDEX) {
442			num_bits = (pos_slot >> 1) - 1;
443			rep0 = 2 \| (pos_slot & 1);
444			if (pos_slot < LZMA_END_POS_MODEL_INDEX) {
445			rep0 <<= num_bits;
446			prob = p + LZMA_SPEC_POS + rep0 - pos_slot - 1;
447			} else {
448			num_bits -= LZMA_NUM_ALIGN_BITS;
449			while (num_bits--)
450			rep0 = (rep0 << 1) \| rc_direct_bit(rc);
451			prob = p + LZMA_ALIGN;
452			rep0 <<= LZMA_NUM_ALIGN_BITS;
453			num_bits = LZMA_NUM_ALIGN_BITS;
454			}
455			i = 1;
456			mi = 1;
457			while (num_bits--) {
458			if (rc_get_bit(rc, prob + mi, &mi))
459			rep0 \|= i;
460			i <<= 1;
461			}
462			} else
463			rep0 = pos_slot;
464			if (++rep0 == 0)
465			break;
466			}
467
468			len += LZMA_MATCH_MIN_LEN;
469
470			do {
471			pos = buffer_pos - rep0;
472			while (pos >= header.dict_size)
473			pos += header.dict_size;
474			previous_byte = buffer[pos];
475			buffer[buffer_pos++] = previous_byte;
476			if (buffer_pos == header.dict_size) {
477			buffer_pos = 0;
478			global_pos += header.dict_size;
479			if (full_write(dst_fd, buffer, header.dict_size) != header.dict_size)
480			goto bad;
481			USE_DESKTOP(total_written += header.dict_size;)
482			}
483			len--;
484			} while (len != 0 && buffer_pos < header.dst_size);
485			}
486			}
487
488
489			if (full_write(dst_fd, buffer, buffer_pos) != buffer_pos) {
490			bad:
491			rc_free(rc);
492			return -1;
493			}
494			rc_free(rc);
495			USE_DESKTOP(total_written += buffer_pos;)
496			return USE_DESKTOP(total_written) + 0;
497			}