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[JFFS2] Clean up fs/jffs2/compr_rubin.c 

Triggered by a smaller cleanup from Jianjun Kong <jianjun@zeuux.org>

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This commit is contained in:
David Woodhouse 2008-12-10 15:34:49 +00:00
parent 26cdb67c74
commit 0bc4382ae9
1 changed files with 64 additions and 56 deletions
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120
fs/jffs2/compr_rubin.c
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@ -22,9 +22,7 @@
#define BIT_DIVIDER_MIPS 1043 #define BIT_DIVIDER_MIPS 1043
static int bits_mips[8] = { 277,249,290,267,229,341,212,241}; /* mips32 */ static int bits_mips[8] = { 277, 249, 290, 267, 229, 341, 212, 241};
#include <linux/errno.h>
struct pushpull { struct pushpull {
unsigned char *buf; unsigned char *buf;
@ -43,7 +41,9 @@ struct rubin_state {
int bits[8]; int bits[8];
}; };
static inline void init_pushpull(struct pushpull *pp, char *buf, unsigned buflen, unsigned ofs, unsigned reserve) static inline void init_pushpull(struct pushpull *pp, char *buf,
unsigned buflen, unsigned ofs,
unsigned reserve)
{ {
pp->buf = buf; pp->buf = buf;
pp->buflen = buflen; pp->buflen = buflen;
@ -53,16 +53,14 @@ static inline void init_pushpull(struct pushpull *pp, char *buf, unsigned buflen
static inline int pushbit(struct pushpull *pp, int bit, int use_reserved) static inline int pushbit(struct pushpull *pp, int bit, int use_reserved)
{ {
if (pp->ofs >= pp->buflen - (use_reserved?0:pp->reserve)) { if (pp->ofs >= pp->buflen - (use_reserved?0:pp->reserve))
return -ENOSPC; return -ENOSPC;
}
if (bit) { if (bit)
pp->buf[pp->ofs >> 3] |= (1<<(7-(pp->ofs &7))); pp->buf[pp->ofs >> 3] |= (1<<(7-(pp->ofs & 7)));
} else
else { pp->buf[pp->ofs >> 3] &= ~(1<<(7-(pp->ofs & 7)));
pp->buf[pp->ofs >> 3] &= ~(1<<(7-(pp->ofs &7)));
}
pp->ofs++; pp->ofs++;
return 0; return 0;
@ -97,6 +95,7 @@ static void init_rubin(struct rubin_state *rs, int div, int *bits)
rs->p = (long) (2 * UPPER_BIT_RUBIN); rs->p = (long) (2 * UPPER_BIT_RUBIN);
rs->bit_number = (long) 0; rs->bit_number = (long) 0;
rs->bit_divider = div; rs->bit_divider = div;
for (c=0; c<8; c++) for (c=0; c<8; c++)
rs->bits[c] = bits[c]; rs->bits[c] = bits[c];
} }
@ -108,7 +107,8 @@ static int encode(struct rubin_state *rs, long A, long B, int symbol)
long i0, i1; long i0, i1;
int ret; int ret;
while ((rs->q >= UPPER_BIT_RUBIN) || ((rs->p + rs->q) <= UPPER_BIT_RUBIN)) { while ((rs->q >= UPPER_BIT_RUBIN) ||
((rs->p + rs->q) <= UPPER_BIT_RUBIN)) {
rs->bit_number++; rs->bit_number++;
ret = pushbit(&rs->pp, (rs->q & UPPER_BIT_RUBIN) ? 1 : 0, 0); ret = pushbit(&rs->pp, (rs->q & UPPER_BIT_RUBIN) ? 1 : 0, 0);
@ -119,12 +119,12 @@ static int encode(struct rubin_state *rs, long A, long B, int symbol)
rs->p <<= 1; rs->p <<= 1;
} }
i0 = A * rs->p / (A + B); i0 = A * rs->p / (A + B);
if (i0 <= 0) { if (i0 <= 0)
i0 = 1; i0 = 1;
}
if (i0 >= rs->p) { if (i0 >= rs->p)
i0 = rs->p - 1; i0 = rs->p - 1;
}
i1 = rs->p - i0; i1 = rs->p - i0;
if (symbol == 0) if (symbol == 0)
@ -157,11 +157,13 @@ static void init_decode(struct rubin_state *rs, int div, int *bits)
/* behalve lower */ /* behalve lower */
rs->rec_q = 0; 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))) 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) static void __do_decode(struct rubin_state *rs, unsigned long p,
unsigned long q)
{ {
register unsigned long lower_bits_rubin = LOWER_BITS_RUBIN; register unsigned long lower_bits_rubin = LOWER_BITS_RUBIN;
unsigned long rec_q; unsigned long rec_q;
@ -207,12 +209,11 @@ static int decode(struct rubin_state *rs, long A, long B)
__do_decode(rs, p, q); __do_decode(rs, p, q);
i0 = A * rs->p / (A + B); i0 = A * rs->p / (A + B);
if (i0 <= 0) { if (i0 <= 0)
i0 = 1; i0 = 1;
}
if (i0 >= rs->p) { if (i0 >= rs->p)
i0 = rs->p - 1; i0 = rs->p - 1;
}
threshold = rs->q + i0; threshold = rs->q + i0;
symbol = rs->rec_q >= threshold; symbol = rs->rec_q >= threshold;
@ -234,14 +235,15 @@ static int out_byte(struct rubin_state *rs, unsigned char byte)
struct rubin_state rs_copy; struct rubin_state rs_copy;
rs_copy = *rs; rs_copy = *rs;
for (i=0;i<8;i++) { for (i=0; i<8; i++) {
ret = encode(rs, rs->bit_divider-rs->bits[i],rs->bits[i],byte&1); ret = encode(rs, rs->bit_divider-rs->bits[i],
rs->bits[i], byte & 1);
if (ret) { if (ret) {
/* Failed. Restore old state */ /* Failed. Restore old state */
*rs = rs_copy; *rs = rs_copy;
return ret; return ret;
} }
byte=byte>>1; byte >>= 1 ;
} }
return 0; return 0;
} }
@ -251,7 +253,8 @@ static int in_byte(struct rubin_state *rs)
int i, result = 0, bit_divider = rs->bit_divider; int i, result = 0, bit_divider = rs->bit_divider;
for (i = 0; i < 8; i++) for (i = 0; i < 8; i++)
result |= decode(rs, bit_divider - rs->bits[i], rs->bits[i]) << i; result |= decode(rs, bit_divider - rs->bits[i],
rs->bits[i]) << i;
return result; return result;
} }
@ -259,7 +262,8 @@ static int in_byte(struct rubin_state *rs)
static int rubin_do_compress(int bit_divider, int *bits, unsigned char *data_in, static int rubin_do_compress(int bit_divider, int *bits, unsigned char *data_in,
unsigned char *cpage_out, uint32_t *sourcelen, uint32_t *dstlen) unsigned char *cpage_out, uint32_t *sourcelen,
uint32_t *dstlen)
{ {
int outpos = 0; int outpos = 0;
int pos=0; int pos=0;
@ -295,7 +299,8 @@ static int rubin_do_compress(int bit_divider, int *bits, unsigned char *data_in,
int jffs2_rubinmips_compress(unsigned char *data_in, unsigned char *cpage_out, int jffs2_rubinmips_compress(unsigned char *data_in, unsigned char *cpage_out,
uint32_t *sourcelen, uint32_t *dstlen, void *model) uint32_t *sourcelen, uint32_t *dstlen, void *model)
{ {
return rubin_do_compress(BIT_DIVIDER_MIPS, bits_mips, data_in, cpage_out, sourcelen, dstlen); return rubin_do_compress(BIT_DIVIDER_MIPS, bits_mips, data_in,
cpage_out, sourcelen, dstlen);
} }
#endif #endif
static int jffs2_dynrubin_compress(unsigned char *data_in, static int jffs2_dynrubin_compress(unsigned char *data_in,
@ -316,9 +321,8 @@ static int jffs2_dynrubin_compress(unsigned char *data_in,
return -1; return -1;
memset(histo, 0, 256); memset(histo, 0, 256);
for (i=0; i<mysrclen; i++) { for (i=0; i<mysrclen; i++)
histo[data_in[i]]++; histo[data_in[i]]++;
}
memset(bits, 0, sizeof(int)*8); memset(bits, 0, sizeof(int)*8);
for (i=0; i<256; i++) { for (i=0; i<256; i++) {
if (i&128) if (i&128)
@ -346,7 +350,8 @@ static int jffs2_dynrubin_compress(unsigned char *data_in,
cpage_out[i] = bits[i]; cpage_out[i] = bits[i];
} }
ret = rubin_do_compress(256, bits, data_in, cpage_out+8, &mysrclen, &mydstlen); ret = rubin_do_compress(256, bits, data_in, cpage_out+8, &mysrclen,
&mydstlen);
if (ret) if (ret)
return ret; return ret;
@ -363,8 +368,10 @@ static int jffs2_dynrubin_compress(unsigned char *data_in,
return 0; return 0;
} }
static void rubin_do_decompress(int bit_divider, int *bits, unsigned char *cdata_in, static void rubin_do_decompress(int bit_divider, int *bits,
unsigned char *page_out, uint32_t srclen, uint32_t destlen) unsigned char *cdata_in,
unsigned char *page_out, uint32_t srclen,
uint32_t destlen)
{ {
int outpos = 0; int outpos = 0;
struct rubin_state rs; struct rubin_state rs;
@ -372,9 +379,8 @@ static void rubin_do_decompress(int bit_divider, int *bits, unsigned char *cdata
init_pushpull(&rs.pp, cdata_in, srclen, 0, 0); init_pushpull(&rs.pp, cdata_in, srclen, 0, 0);
init_decode(&rs, bit_divider, bits); init_decode(&rs, bit_divider, bits);
while (outpos < destlen) { while (outpos < destlen)
page_out[outpos++] = in_byte(&rs); page_out[outpos++] = in_byte(&rs);
}
} }
@ -383,7 +389,8 @@ static int jffs2_rubinmips_decompress(unsigned char *data_in,
uint32_t sourcelen, uint32_t dstlen, uint32_t sourcelen, uint32_t dstlen,
void *model) void *model)
{ {
rubin_do_decompress(BIT_DIVIDER_MIPS, bits_mips, data_in, cpage_out, sourcelen, dstlen); rubin_do_decompress(BIT_DIVIDER_MIPS, bits_mips, data_in,
cpage_out, sourcelen, dstlen);
return 0; return 0;
} }
@ -398,52 +405,53 @@ static int jffs2_dynrubin_decompress(unsigned char *data_in,
for (c=0; c<8; c++) for (c=0; c<8; c++)
bits[c] = data_in[c]; bits[c] = data_in[c];
rubin_do_decompress(256, bits, data_in+8, cpage_out, sourcelen-8, dstlen); rubin_do_decompress(256, bits, data_in+8, cpage_out, sourcelen-8,
dstlen);
return 0; return 0;
} }
static struct jffs2_compressor jffs2_rubinmips_comp = { static struct jffs2_compressor jffs2_rubinmips_comp = {
.priority = JFFS2_RUBINMIPS_PRIORITY, .priority = JFFS2_RUBINMIPS_PRIORITY,
.name = "rubinmips", .name = "rubinmips",
.compr = JFFS2_COMPR_DYNRUBIN, .compr = JFFS2_COMPR_DYNRUBIN,
.compress = NULL, /*&jffs2_rubinmips_compress,*/ .compress = NULL, /*&jffs2_rubinmips_compress,*/
.decompress = &jffs2_rubinmips_decompress, .decompress = &jffs2_rubinmips_decompress,
#ifdef JFFS2_RUBINMIPS_DISABLED #ifdef JFFS2_RUBINMIPS_DISABLED
.disabled = 1, .disabled = 1,
#else #else
.disabled = 0, .disabled = 0,
#endif #endif
}; };
int jffs2_rubinmips_init(void) int jffs2_rubinmips_init(void)
{ {
return jffs2_register_compressor(&jffs2_rubinmips_comp); return jffs2_register_compressor(&jffs2_rubinmips_comp);
} }
void jffs2_rubinmips_exit(void) void jffs2_rubinmips_exit(void)
{ {
jffs2_unregister_compressor(&jffs2_rubinmips_comp); jffs2_unregister_compressor(&jffs2_rubinmips_comp);
} }
static struct jffs2_compressor jffs2_dynrubin_comp = { static struct jffs2_compressor jffs2_dynrubin_comp = {
.priority = JFFS2_DYNRUBIN_PRIORITY, .priority = JFFS2_DYNRUBIN_PRIORITY,
.name = "dynrubin", .name = "dynrubin",
.compr = JFFS2_COMPR_RUBINMIPS, .compr = JFFS2_COMPR_RUBINMIPS,
.compress = jffs2_dynrubin_compress, .compress = jffs2_dynrubin_compress,
.decompress = &jffs2_dynrubin_decompress, .decompress = &jffs2_dynrubin_decompress,
#ifdef JFFS2_DYNRUBIN_DISABLED #ifdef JFFS2_DYNRUBIN_DISABLED
.disabled = 1, .disabled = 1,
#else #else
.disabled = 0, .disabled = 0,
#endif #endif
}; };
int jffs2_dynrubin_init(void) int jffs2_dynrubin_init(void)
{ {
return jffs2_register_compressor(&jffs2_dynrubin_comp); return jffs2_register_compressor(&jffs2_dynrubin_comp);
} }
void jffs2_dynrubin_exit(void) void jffs2_dynrubin_exit(void)
{ {
jffs2_unregister_compressor(&jffs2_dynrubin_comp); jffs2_unregister_compressor(&jffs2_dynrubin_comp);
} }