[deliverable/linux.git] / fs / jffs2 / compr_rubin.c

/*
 * JFFS2 -- Journalling Flash File System, Version 2.
 *
 * Copyright © 2001-2007 Red Hat, Inc.
 *
 * Created by Arjan van de Ven <arjanv@redhat.com>
 *
 * For licensing information, see the file 'LICENCE' in this directory.
 *
 */

#include <linux/string.h>
#include <linux/types.h>
#include <linux/jffs2.h>
#include <linux/errno.h>
#include "compr.h"


#define RUBIN_REG_SIZE   16
#define UPPER_BIT_RUBIN    (((long) 1)<<(RUBIN_REG_SIZE-1))
#define LOWER_BITS_RUBIN   ((((long) 1)<<(RUBIN_REG_SIZE-1))-1)


struct rubin_state {
	unsigned long p;
	unsigned long q;
	unsigned long rec_q;
	long bit_number;
	struct pushpull pp;
	int bit_divider;
	int bits[8];
};

#define BIT_DIVIDER_MIPS 1043
static int bits_mips[8] = { 277,249,290,267,229,341,212,241}; /* mips32 */

#include <linux/errno.h>

struct pushpull {
	unsigned char *buf;
	unsigned int buflen;
	unsigned int ofs;
	unsigned int reserve;
};


static inline void init_pushpull(struct pushpull *pp, char *buf, unsigned buflen, unsigned ofs, unsigned reserve)
{
	pp->buf = buf;
	pp->buflen = buflen;
	pp->ofs = ofs;
	pp->reserve = reserve;
}

static inline int pushbit(struct pushpull *pp, int bit, int use_reserved)
{
	if (pp->ofs >= pp->buflen - (use_reserved?0:pp->reserve)) {
		return -ENOSPC;
	}

	if (bit) {
		pp->buf[pp->ofs >> 3] |= (1<<(7-(pp->ofs &7)));
	}
	else {
		pp->buf[pp->ofs >> 3] &= ~(1<<(7-(pp->ofs &7)));
	}
	pp->ofs++;

	return 0;
}

static inline int pushedbits(struct pushpull *pp)
{
	return pp->ofs;
}

static inline int pullbit(struct pushpull *pp)
{
	int bit;

	bit = (pp->buf[pp->ofs >> 3] >> (7-(pp->ofs & 7))) & 1;

	pp->ofs++;
	return bit;
}

static inline int pulledbits(struct pushpull *pp)
{
	return pp->ofs;
}


static void init_rubin(struct rubin_state *rs, int div, int *bits)
{
	int c;

	rs->q = 0;
	rs->p = (long) (2 * UPPER_BIT_RUBIN);
	rs->bit_number = (long) 0;
	rs->bit_divider = div;
	for (c=0; c<8; c++)
		rs->bits[c] = bits[c];
}


static int encode(struct rubin_state *rs, long A, long B, int symbol)
{

	long i0, i1;
	int ret;

	while ((rs->q >= UPPER_BIT_RUBIN) || ((rs->p + rs->q) <= UPPER_BIT_RUBIN)) {
		rs->bit_number++;

		ret = pushbit(&rs->pp, (rs->q & UPPER_BIT_RUBIN) ? 1 : 0, 0);
		if (ret)
			return ret;
		rs->q &= LOWER_BITS_RUBIN;
		rs->q <<= 1;
		rs->p <<= 1;
	}
	i0 = A * rs->p / (A + B);
	if (i0 <= 0) {
		i0 = 1;
	}
	if (i0 >= rs->p) {
		i0 = rs->p - 1;
	}
	i1 = rs->p - i0;

	if (symbol == 0)
		rs->p = i0;
	else {
		rs->p = i1;
		rs->q += i0;
	}
	return 0;
}


static void end_rubin(struct rubin_state *rs)
{

	int i;

	for (i = 0; i < RUBIN_REG_SIZE; i++) {
		pushbit(&rs->pp, (UPPER_BIT_RUBIN & rs->q) ? 1 : 0, 1);
		rs->q &= LOWER_BITS_RUBIN;
		rs->q <<= 1;
	}
}


static void init_decode(struct rubin_state *rs, int div, int *bits)
{
	init_rubin(rs, div, bits);

	/* behalve lower */
	rs->rec_q = 0;

	for (rs->bit_number = 0; rs->bit_number++ < RUBIN_REG_SIZE; rs->rec_q = rs->rec_q * 2 + (long) (pullbit(&rs->pp)))
		;
}

static void __do_decode(struct rubin_state *rs, unsigned long p, unsigned long q)
{
	register unsigned long lower_bits_rubin = LOWER_BITS_RUBIN;
	unsigned long rec_q;
	int c, bits = 0;

	/*
	 * First, work out how many bits we need from the input stream.
	 * Note that we have already done the initial check on this
	 * loop prior to calling this function.
	 */
	do {
		bits++;
		q &= lower_bits_rubin;
		q <<= 1;
		p <<= 1;
	} while ((q >= UPPER_BIT_RUBIN) || ((p + q) <= UPPER_BIT_RUBIN));

	rs->p = p;
	rs->q = q;

	rs->bit_number += bits;

	/*
	 * Now get the bits.  We really want this to be "get n bits".
	 */
	rec_q = rs->rec_q;
	do {
		c = pullbit(&rs->pp);
		rec_q &= lower_bits_rubin;
		rec_q <<= 1;
		rec_q += c;
	} while (--bits);
	rs->rec_q = rec_q;
}

static int decode(struct rubin_state *rs, long A, long B)
{
	unsigned long p = rs->p, q = rs->q;
	long i0, threshold;
	int symbol;

	if (q >= UPPER_BIT_RUBIN || ((p + q) <= UPPER_BIT_RUBIN))
		__do_decode(rs, p, q);

	i0 = A * rs->p / (A + B);
	if (i0 <= 0) {
		i0 = 1;
	}
	if (i0 >= rs->p) {
		i0 = rs->p - 1;
	}

	threshold = rs->q + i0;
	symbol = rs->rec_q >= threshold;
	if (rs->rec_q >= threshold) {
		rs->q += i0;
		i0 = rs->p - i0;
	}

	rs->p = i0;

	return symbol;
}


static int out_byte(struct rubin_state *rs, unsigned char byte)
{
	int i, ret;
	struct rubin_state rs_copy;
	rs_copy = *rs;

	for (i=0;i<8;i++) {
		ret = encode(rs, rs->bit_divider-rs->bits[i],rs->bits[i],byte&1);
		if (ret) {
			/* Failed. Restore old state */
			*rs = rs_copy;
			return ret;
		}
		byte=byte>>1;
	}
	return 0;
}

static int in_byte(struct rubin_state *rs)
{
	int i, result = 0, bit_divider = rs->bit_divider;

	for (i = 0; i < 8; i++)
		result |= decode(rs, bit_divider - rs->bits[i], rs->bits[i]) << i;

	return result;
}


static int rubin_do_compress(int bit_divider, int *bits, unsigned char *data_in,
		      unsigned char *cpage_out, uint32_t *sourcelen, uint32_t *dstlen)
	{
	int outpos = 0;
	int pos=0;
	struct rubin_state rs;

	init_pushpull(&rs.pp, cpage_out, *dstlen * 8, 0, 32);

	init_rubin(&rs, bit_divider, bits);

	while (pos < (*sourcelen) && !out_byte(&rs, data_in[pos]))
		pos++;

	end_rubin(&rs);

	if (outpos > pos) {
		/* We failed */
		return -1;
	}

	/* Tell the caller how much we managed to compress,
	 * and how much space it took */

	outpos = (pushedbits(&rs.pp)+7)/8;

	if (outpos >= pos)
		return -1; /* We didn't actually compress */
	*sourcelen = pos;
	*dstlen = outpos;
	return 0;
}
#if 0
/* _compress returns the compressed size, -1 if bigger */
int jffs2_rubinmips_compress(unsigned char *data_in, unsigned char *cpage_out,
		   uint32_t *sourcelen, uint32_t *dstlen, void *model)
{
	return rubin_do_compress(BIT_DIVIDER_MIPS, bits_mips, data_in, cpage_out, sourcelen, dstlen);
}
#endif
static int jffs2_dynrubin_compress(unsigned char *data_in,
				   unsigned char *cpage_out,
				   uint32_t *sourcelen, uint32_t *dstlen,
				   void *model)
{
	int bits[8];
	unsigned char histo[256];
	int i;
	int ret;
	uint32_t mysrclen, mydstlen;

	mysrclen = *sourcelen;
	mydstlen = *dstlen - 8;

	if (*dstlen <= 12)
		return -1;

	memset(histo, 0, 256);
	for (i=0; i<mysrclen; i++) {
		histo[data_in[i]]++;
	}
	memset(bits, 0, sizeof(int)*8);
	for (i=0; i<256; i++) {
		if (i&128)
			bits[7] += histo[i];
		if (i&64)
			bits[6] += histo[i];
		if (i&32)
			bits[5] += histo[i];
		if (i&16)
			bits[4] += histo[i];
		if (i&8)
			bits[3] += histo[i];
		if (i&4)
			bits[2] += histo[i];
		if (i&2)
			bits[1] += histo[i];
		if (i&1)
			bits[0] += histo[i];
	}

	for (i=0; i<8; i++) {
		bits[i] = (bits[i] * 256) / mysrclen;
		if (!bits[i]) bits[i] = 1;
		if (bits[i] > 255) bits[i] = 255;
		cpage_out[i] = bits[i];
	}

	ret = rubin_do_compress(256, bits, data_in, cpage_out+8, &mysrclen, &mydstlen);
	if (ret)
		return ret;

	/* Add back the 8 bytes we took for the probabilities */
	mydstlen += 8;

	if (mysrclen <= mydstlen) {
		/* We compressed */
		return -1;
	}

	*sourcelen = mysrclen;
	*dstlen = mydstlen;
	return 0;
}

static void rubin_do_decompress(int bit_divider, int *bits, unsigned char *cdata_in,
			 unsigned char *page_out, uint32_t srclen, uint32_t destlen)
{
	int outpos = 0;
	struct rubin_state rs;

	init_pushpull(&rs.pp, cdata_in, srclen, 0, 0);
	init_decode(&rs, bit_divider, bits);

	while (outpos < destlen) {
		page_out[outpos++] = in_byte(&rs);
	}
}


static int jffs2_rubinmips_decompress(unsigned char *data_in,
				      unsigned char *cpage_out,
				      uint32_t sourcelen, uint32_t dstlen,
				      void *model)
{
	rubin_do_decompress(BIT_DIVIDER_MIPS, bits_mips, data_in, cpage_out, sourcelen, dstlen);
        return 0;
}

static int jffs2_dynrubin_decompress(unsigned char *data_in,
				     unsigned char *cpage_out,
				     uint32_t sourcelen, uint32_t dstlen,
				     void *model)
{
	int bits[8];
	int c;

	for (c=0; c<8; c++)
		bits[c] = data_in[c];

	rubin_do_decompress(256, bits, data_in+8, cpage_out, sourcelen-8, dstlen);
        return 0;
}

static struct jffs2_compressor jffs2_rubinmips_comp = {
    .priority = JFFS2_RUBINMIPS_PRIORITY,
    .name = "rubinmips",
    .compr = JFFS2_COMPR_DYNRUBIN,
    .compress = NULL, /*&jffs2_rubinmips_compress,*/
    .decompress = &jffs2_rubinmips_decompress,
#ifdef JFFS2_RUBINMIPS_DISABLED
    .disabled = 1,
#else
    .disabled = 0,
#endif
};

int jffs2_rubinmips_init(void)
{
    return jffs2_register_compressor(&jffs2_rubinmips_comp);
}

void jffs2_rubinmips_exit(void)
{
    jffs2_unregister_compressor(&jffs2_rubinmips_comp);
}

static struct jffs2_compressor jffs2_dynrubin_comp = {
    .priority = JFFS2_DYNRUBIN_PRIORITY,
    .name = "dynrubin",
    .compr = JFFS2_COMPR_RUBINMIPS,
    .compress = jffs2_dynrubin_compress,
    .decompress = &jffs2_dynrubin_decompress,
#ifdef JFFS2_DYNRUBIN_DISABLED
    .disabled = 1,
#else
    .disabled = 0,
#endif
};

int jffs2_dynrubin_init(void)
{
    return jffs2_register_compressor(&jffs2_dynrubin_comp);
}

void jffs2_dynrubin_exit(void)
{
    jffs2_unregister_compressor(&jffs2_dynrubin_comp);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* JFFS2 -- Journalling Flash File System, Version 2.
	3	*
c00c310e	4	* Copyright © 2001-2007 Red Hat, Inc.
1da177e4 LT	5	*
	6	* Created by Arjan van de Ven <arjanv@redhat.com>
	7	*
	8	* For licensing information, see the file 'LICENCE' in this directory.
	9	*
1da177e4 LT	10	*/
1da177e4 LT	11
1da177e4 LT	12	#include <linux/string.h>
	13	#include <linux/types.h>
	14	#include <linux/jffs2.h>
c00c310e	15	#include <linux/errno.h>
1da177e4 LT	16	#include "compr.h"
1da177e4 LT	17
c00c310e DW	18
	19	#define RUBIN_REG_SIZE 16
	20	#define UPPER_BIT_RUBIN (((long) 1)<<(RUBIN_REG_SIZE-1))
	21	#define LOWER_BITS_RUBIN ((((long) 1)<<(RUBIN_REG_SIZE-1))-1)
	22
	23
	24	struct rubin_state {
	25	unsigned long p;
	26	unsigned long q;
	27	unsigned long rec_q;
	28	long bit_number;
	29	struct pushpull pp;
	30	int bit_divider;
	31	int bits[8];
	32	};
	33
	34	#define BIT_DIVIDER_MIPS 1043
	35	static int bits_mips[8] = { 277,249,290,267,229,341,212,241}; /* mips32 */
	36
	37	#include <linux/errno.h>
	38
	39	struct pushpull {
	40	unsigned char *buf;
	41	unsigned int buflen;
	42	unsigned int ofs;
	43	unsigned int reserve;
	44	};
	45
	46
	47	static inline void init_pushpull(struct pushpull pp, char buf, unsigned buflen, unsigned ofs, unsigned reserve)
	48	{
	49	pp->buf = buf;
	50	pp->buflen = buflen;
	51	pp->ofs = ofs;
	52	pp->reserve = reserve;
	53	}
	54
	55	static inline int pushbit(struct pushpull *pp, int bit, int use_reserved)
	56	{
	57	if (pp->ofs >= pp->buflen - (use_reserved?0:pp->reserve)) {
	58	return -ENOSPC;
	59	}
	60
	61	if (bit) {
	62	pp->buf[pp->ofs >> 3] \|= (1<<(7-(pp->ofs &7)));
	63	}
	64	else {
	65	pp->buf[pp->ofs >> 3] &= ~(1<<(7-(pp->ofs &7)));
	66	}
	67	pp->ofs++;
	68
	69	return 0;
	70	}
	71
	72	static inline int pushedbits(struct pushpull *pp)
	73	{
	74	return pp->ofs;
	75	}
	76
	77	static inline int pullbit(struct pushpull *pp)
	78	{
	79	int bit;
	80
	81	bit = (pp->buf[pp->ofs >> 3] >> (7-(pp->ofs & 7))) & 1;
82
83	pp->ofs++;
84	return bit;
85	}
86
87	static inline int pulledbits(struct pushpull *pp)
88	{
89	return pp->ofs;
90	}
91
92
1da177e4	93	static void init_rubin(struct rubin_state rs, int div, int bits)
182ec4ee	94	{
1da177e4 LT	95	int c;
	96
	97	rs->q = 0;
	98	rs->p = (long) (2 * UPPER_BIT_RUBIN);
	99	rs->bit_number = (long) 0;
	100	rs->bit_divider = div;
	101	for (c=0; c<8; c++)
	102	rs->bits[c] = bits[c];
	103	}
	104
	105
	106	static int encode(struct rubin_state *rs, long A, long B, int symbol)
	107	{
	108
	109	long i0, i1;
	110	int ret;
	111
	112	while ((rs->q >= UPPER_BIT_RUBIN) \|\| ((rs->p + rs->q) <= UPPER_BIT_RUBIN)) {
	113	rs->bit_number++;
182ec4ee	114
1da177e4 LT	115	ret = pushbit(&rs->pp, (rs->q & UPPER_BIT_RUBIN) ? 1 : 0, 0);
	116	if (ret)
	117	return ret;
	118	rs->q &= LOWER_BITS_RUBIN;
	119	rs->q <<= 1;
	120	rs->p <<= 1;
	121	}
	122	i0 = A * rs->p / (A + B);
	123	if (i0 <= 0) {
	124	i0 = 1;
	125	}
	126	if (i0 >= rs->p) {
	127	i0 = rs->p - 1;
	128	}
	129	i1 = rs->p - i0;
	130
	131	if (symbol == 0)
	132	rs->p = i0;
	133	else {
	134	rs->p = i1;
	135	rs->q += i0;
	136	}
	137	return 0;
	138	}
	139
	140
	141	static void end_rubin(struct rubin_state *rs)
182ec4ee	142	{
1da177e4 LT	143
	144	int i;
	145
	146	for (i = 0; i < RUBIN_REG_SIZE; i++) {
	147	pushbit(&rs->pp, (UPPER_BIT_RUBIN & rs->q) ? 1 : 0, 1);
	148	rs->q &= LOWER_BITS_RUBIN;
	149	rs->q <<= 1;
	150	}
	151	}
	152
	153
	154	static void init_decode(struct rubin_state rs, int div, int bits)
	155	{
182ec4ee	156	init_rubin(rs, div, bits);
1da177e4 LT	157
	158	/* behalve lower */
	159	rs->rec_q = 0;
	160
	161	for (rs->bit_number = 0; rs->bit_number++ < RUBIN_REG_SIZE; rs->rec_q = rs->rec_q * 2 + (long) (pullbit(&rs->pp)))
	162	;
	163	}
	164
	165	static void __do_decode(struct rubin_state *rs, unsigned long p, unsigned long q)
	166	{
	167	register unsigned long lower_bits_rubin = LOWER_BITS_RUBIN;
	168	unsigned long rec_q;
	169	int c, bits = 0;
	170
	171	/*
	172	* First, work out how many bits we need from the input stream.
	173	* Note that we have already done the initial check on this
	174	* loop prior to calling this function.
	175	*/
	176	do {
	177	bits++;
	178	q &= lower_bits_rubin;
	179	q <<= 1;
	180	p <<= 1;
	181	} while ((q >= UPPER_BIT_RUBIN) \|\| ((p + q) <= UPPER_BIT_RUBIN));
	182
	183	rs->p = p;
	184	rs->q = q;
	185
	186	rs->bit_number += bits;
	187
	188	/*
	189	* Now get the bits. We really want this to be "get n bits".
	190	*/
	191	rec_q = rs->rec_q;
	192	do {
	193	c = pullbit(&rs->pp);
	194	rec_q &= lower_bits_rubin;
	195	rec_q <<= 1;
	196	rec_q += c;
	197	} while (--bits);
	198	rs->rec_q = rec_q;
	199	}
	200
	201	static int decode(struct rubin_state *rs, long A, long B)
	202	{
	203	unsigned long p = rs->p, q = rs->q;
	204	long i0, threshold;
	205	int symbol;
	206
	207	if (q >= UPPER_BIT_RUBIN \|\| ((p + q) <= UPPER_BIT_RUBIN))
	208	__do_decode(rs, p, q);
	209
	210	i0 = A * rs->p / (A + B);
	211	if (i0 <= 0) {
	212	i0 = 1;
	213	}
	214	if (i0 >= rs->p) {
	215	i0 = rs->p - 1;
	216	}
	217
	218	threshold = rs->q + i0;
	219	symbol = rs->rec_q >= threshold;
	220	if (rs->rec_q >= threshold) {
221	rs->q += i0;
222	i0 = rs->p - i0;
223	}
224
225	rs->p = i0;
226
227	return symbol;
228	}
229
230
231
232	static int out_byte(struct rubin_state *rs, unsigned char byte)
233	{
234	int i, ret;
235	struct rubin_state rs_copy;
236	rs_copy = *rs;
237
238	for (i=0;i<8;i++) {
239	ret = encode(rs, rs->bit_divider-rs->bits[i],rs->bits[i],byte&1);
240	if (ret) {
241	/* Failed. Restore old state */
242	*rs = rs_copy;
243	return ret;
244	}
245	byte=byte>>1;
246	}
247	return 0;
248	}
249
250	static int in_byte(struct rubin_state *rs)
251	{
252	int i, result = 0, bit_divider = rs->bit_divider;
253
254	for (i = 0; i < 8; i++)
255	result \|= decode(rs, bit_divider - rs->bits[i], rs->bits[i]) << i;
256
257	return result;
258	}
259
260
261
182ec4ee	262	static int rubin_do_compress(int bit_divider, int bits, unsigned char data_in,
1da177e4 LT	263	unsigned char cpage_out, uint32_t sourcelen, uint32_t *dstlen)
	264	{
	265	int outpos = 0;
	266	int pos=0;
	267	struct rubin_state rs;
	268
	269	init_pushpull(&rs.pp, cpage_out, dstlen 8, 0, 32);
	270
	271	init_rubin(&rs, bit_divider, bits);
182ec4ee	272
1da177e4 LT	273	while (pos < (*sourcelen) && !out_byte(&rs, data_in[pos]))
1da177e4 LT	274	pos++;
182ec4ee	275
1da177e4 LT	276	end_rubin(&rs);
	277
	278	if (outpos > pos) {
	279	/* We failed */
	280	return -1;
	281	}
182ec4ee TG	282
182ec4ee TG	283	/* Tell the caller how much we managed to compress,
1da177e4	284	* and how much space it took */
182ec4ee	285
1da177e4	286	outpos = (pushedbits(&rs.pp)+7)/8;
182ec4ee	287
1da177e4 LT	288	if (outpos >= pos)
	289	return -1; /* We didn't actually compress */
	290	*sourcelen = pos;
	291	*dstlen = outpos;
	292	return 0;
182ec4ee	293	}
1da177e4 LT	294	#if 0
1da177e4 LT	295	/* _compress returns the compressed size, -1 if bigger */
182ec4ee	296	int jffs2_rubinmips_compress(unsigned char data_in, unsigned char cpage_out,
1da177e4 LT	297	uint32_t sourcelen, uint32_t dstlen, void *model)
	298	{
	299	return rubin_do_compress(BIT_DIVIDER_MIPS, bits_mips, data_in, cpage_out, sourcelen, dstlen);
	300	}
	301	#endif
75c96f85 AB	302	static int jffs2_dynrubin_compress(unsigned char *data_in,
	303	unsigned char *cpage_out,
	304	uint32_t sourcelen, uint32_t dstlen,
	305	void *model)
1da177e4 LT	306	{
	307	int bits[8];
	308	unsigned char histo[256];
	309	int i;
	310	int ret;
	311	uint32_t mysrclen, mydstlen;
	312
	313	mysrclen = *sourcelen;
	314	mydstlen = *dstlen - 8;
	315
	316	if (*dstlen <= 12)
	317	return -1;
	318
	319	memset(histo, 0, 256);
	320	for (i=0; i<mysrclen; i++) {
	321	histo[data_in[i]]++;
	322	}
	323	memset(bits, 0, sizeof(int)*8);
	324	for (i=0; i<256; i++) {
	325	if (i&128)
	326	bits[7] += histo[i];
	327	if (i&64)
	328	bits[6] += histo[i];
	329	if (i&32)
	330	bits[5] += histo[i];
	331	if (i&16)
	332	bits[4] += histo[i];
	333	if (i&8)
	334	bits[3] += histo[i];
	335	if (i&4)
	336	bits[2] += histo[i];
	337	if (i&2)
	338	bits[1] += histo[i];
	339	if (i&1)
	340	bits[0] += histo[i];
	341	}
	342
	343	for (i=0; i<8; i++) {
	344	bits[i] = (bits[i] * 256) / mysrclen;
	345	if (!bits[i]) bits[i] = 1;
	346	if (bits[i] > 255) bits[i] = 255;
	347	cpage_out[i] = bits[i];
	348	}
	349
	350	ret = rubin_do_compress(256, bits, data_in, cpage_out+8, &mysrclen, &mydstlen);
182ec4ee	351	if (ret)
1da177e4 LT	352	return ret;
	353
	354	/* Add back the 8 bytes we took for the probabilities */
	355	mydstlen += 8;
	356
	357	if (mysrclen <= mydstlen) {
	358	/* We compressed */
	359	return -1;
	360	}
	361
	362	*sourcelen = mysrclen;
	363	*dstlen = mydstlen;
	364	return 0;
	365	}
	366
182ec4ee	367	static void rubin_do_decompress(int bit_divider, int bits, unsigned char cdata_in,
1da177e4 LT	368	unsigned char *page_out, uint32_t srclen, uint32_t destlen)
	369	{
	370	int outpos = 0;
	371	struct rubin_state rs;
182ec4ee	372
1da177e4 LT	373	init_pushpull(&rs.pp, cdata_in, srclen, 0, 0);
1da177e4 LT	374	init_decode(&rs, bit_divider, bits);
182ec4ee	375
1da177e4 LT	376	while (outpos < destlen) {
	377	page_out[outpos++] = in_byte(&rs);
	378	}
182ec4ee	379	}
1da177e4 LT	380
1da177e4 LT	381
75c96f85 AB	382	static int jffs2_rubinmips_decompress(unsigned char *data_in,
	383	unsigned char *cpage_out,
	384	uint32_t sourcelen, uint32_t dstlen,
	385	void *model)
1da177e4 LT	386	{
	387	rubin_do_decompress(BIT_DIVIDER_MIPS, bits_mips, data_in, cpage_out, sourcelen, dstlen);
	388	return 0;
	389	}
	390
75c96f85 AB	391	static int jffs2_dynrubin_decompress(unsigned char *data_in,
	392	unsigned char *cpage_out,
	393	uint32_t sourcelen, uint32_t dstlen,
	394	void *model)
1da177e4 LT	395	{
	396	int bits[8];
	397	int c;
	398
	399	for (c=0; c<8; c++)
	400	bits[c] = data_in[c];
	401
	402	rubin_do_decompress(256, bits, data_in+8, cpage_out, sourcelen-8, dstlen);
	403	return 0;
	404	}
	405
	406	static struct jffs2_compressor jffs2_rubinmips_comp = {
	407	.priority = JFFS2_RUBINMIPS_PRIORITY,
	408	.name = "rubinmips",
	409	.compr = JFFS2_COMPR_DYNRUBIN,
	410	.compress = NULL, /&jffs2_rubinmips_compress,/
	411	.decompress = &jffs2_rubinmips_decompress,
	412	#ifdef JFFS2_RUBINMIPS_DISABLED
	413	.disabled = 1,
	414	#else
	415	.disabled = 0,
	416	#endif
	417	};
	418
	419	int jffs2_rubinmips_init(void)
	420	{
	421	return jffs2_register_compressor(&jffs2_rubinmips_comp);
	422	}
	423
	424	void jffs2_rubinmips_exit(void)
	425	{
	426	jffs2_unregister_compressor(&jffs2_rubinmips_comp);
	427	}
	428
	429	static struct jffs2_compressor jffs2_dynrubin_comp = {
	430	.priority = JFFS2_DYNRUBIN_PRIORITY,
	431	.name = "dynrubin",
	432	.compr = JFFS2_COMPR_RUBINMIPS,
	433	.compress = jffs2_dynrubin_compress,
	434	.decompress = &jffs2_dynrubin_decompress,
	435	#ifdef JFFS2_DYNRUBIN_DISABLED
	436	.disabled = 1,
	437	#else
	438	.disabled = 0,
	439	#endif
	440	};
	441
	442	int jffs2_dynrubin_init(void)
	443	{
	444	return jffs2_register_compressor(&jffs2_dynrubin_comp);
	445	}
	446
	447	void jffs2_dynrubin_exit(void)
	448	{
	449	jffs2_unregister_compressor(&jffs2_dynrubin_comp);
	450	}