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simplify access to buffer, making code a bit smaller

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This commit is contained in:
Denis Vlasenko 2007-01-05 13:59:05 +00:00
parent 89d49a4236
commit 98b8e9487d
1 changed files with 90 additions and 80 deletions
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170
archival/libunarchive/decompress_unlzma.c
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@ -22,7 +22,7 @@
typedef struct {
int fd;
uint8_t *ptr;
uint8_t *buffer;
// uint8_t *buffer;
uint8_t *buffer_end;
int buffer_size;
uint32_t code;
@ -30,6 +30,8 @@ typedef struct {
uint32_t bound;
} rc_t;
//#define RC_BUFFER ((uint8_t*)(void*)(rc+1))
#define RC_BUFFER ((uint8_t*)(rc+1))
#define RC_TOP_BITS 24
#define RC_MOVE_BITS 5
@ -39,22 +41,24 @@ typedef struct {
/* Called twice: once at startup and once in rc_normalize() */
static void rc_read(rc_t * rc)
{
rc->buffer_size = read(rc->fd, rc->buffer, rc->buffer_size);
rc->buffer_size = read(rc->fd, RC_BUFFER, rc->buffer_size);
if (rc->buffer_size <= 0)
bb_error_msg_and_die("unexpected EOF");
rc->ptr = rc->buffer;
rc->buffer_end = rc->buffer + rc->buffer_size;
rc->ptr = RC_BUFFER;
rc->buffer_end = RC_BUFFER + rc->buffer_size;
}
/* Called once */
static void rc_init(rc_t * rc, int fd, int buffer_size)
static rc_t* rc_init(int fd, int buffer_size)
{
int i;
rc_t* rc;
rc = xmalloc(sizeof(rc_t) + buffer_size);
rc->fd = fd;
rc->buffer = xmalloc(buffer_size);
rc->buffer_size = buffer_size;
rc->buffer_end = rc->buffer + rc->buffer_size;
rc->buffer_end = RC_BUFFER + rc->buffer_size;
rc->ptr = rc->buffer_end;
rc->code = 0;
@ -64,13 +68,14 @@ static void rc_init(rc_t * rc, int fd, int buffer_size)
rc_read(rc);
rc->code = (rc->code << 8) | *rc->ptr++;
}
return rc;
}
/* Called once. TODO: bb_maybe_free() */
/* Called once */
static ATTRIBUTE_ALWAYS_INLINE void rc_free(rc_t * rc)
{
if (ENABLE_FEATURE_CLEAN_UP)
free(rc->buffer);
free(rc);
}
/* Called twice, but one callsite is in speed_inline'd rc_is_bit_0_helper() */
@ -163,53 +168,58 @@ typedef struct {
} __attribute__ ((packed)) lzma_header_t;
#define LZMA_BASE_SIZE 1846
#define LZMA_LIT_SIZE 768
/* #defines will make compiler to compute/optimize each one with each usage.
* Have heart and use enum instead. */
enum {
LZMA_BASE_SIZE = 1846,
LZMA_LIT_SIZE = 768,
#define LZMA_NUM_POS_BITS_MAX 4
LZMA_NUM_POS_BITS_MAX = 4,
#define LZMA_LEN_NUM_LOW_BITS 3
#define LZMA_LEN_NUM_MID_BITS 3
#define LZMA_LEN_NUM_HIGH_BITS 8
LZMA_LEN_NUM_LOW_BITS = 3,
LZMA_LEN_NUM_MID_BITS = 3,
LZMA_LEN_NUM_HIGH_BITS = 8,
#define LZMA_LEN_CHOICE 0
#define LZMA_LEN_CHOICE_2 (LZMA_LEN_CHOICE + 1)
#define LZMA_LEN_LOW (LZMA_LEN_CHOICE_2 + 1)
#define LZMA_LEN_MID (LZMA_LEN_LOW \
+ (1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_LOW_BITS)))
#define LZMA_LEN_HIGH (LZMA_LEN_MID \
+(1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_MID_BITS)))
#define LZMA_NUM_LEN_PROBS (LZMA_LEN_HIGH + (1 << LZMA_LEN_NUM_HIGH_BITS))
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)),
#define LZMA_NUM_STATES 12
#define LZMA_NUM_LIT_STATES 7
LZMA_NUM_STATES = 12,
LZMA_NUM_LIT_STATES = 7,
#define LZMA_START_POS_MODEL_INDEX 4
#define LZMA_END_POS_MODEL_INDEX 14
#define LZMA_NUM_FULL_DISTANCES (1 << (LZMA_END_POS_MODEL_INDEX >> 1))
LZMA_START_POS_MODEL_INDEX = 4,
LZMA_END_POS_MODEL_INDEX = 14,
LZMA_NUM_FULL_DISTANCES = (1 << (LZMA_END_POS_MODEL_INDEX >> 1)),
#define LZMA_NUM_POS_SLOT_BITS 6
#define LZMA_NUM_LEN_TO_POS_STATES 4
LZMA_NUM_POS_SLOT_BITS = 6,
LZMA_NUM_LEN_TO_POS_STATES = 4,
#define LZMA_NUM_ALIGN_BITS 4
LZMA_NUM_ALIGN_BITS = 4,
#define LZMA_MATCH_MIN_LEN 2
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),
};
#define LZMA_IS_MATCH 0
#define LZMA_IS_REP (LZMA_IS_MATCH + (LZMA_NUM_STATES <<LZMA_NUM_POS_BITS_MAX))
#define LZMA_IS_REP_G0 (LZMA_IS_REP + LZMA_NUM_STATES)
#define LZMA_IS_REP_G1 (LZMA_IS_REP_G0 + LZMA_NUM_STATES)
#define LZMA_IS_REP_G2 (LZMA_IS_REP_G1 + LZMA_NUM_STATES)
#define LZMA_IS_REP_0_LONG (LZMA_IS_REP_G2 + LZMA_NUM_STATES)
#define LZMA_POS_SLOT (LZMA_IS_REP_0_LONG \
+ (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX))
#define LZMA_SPEC_POS (LZMA_POS_SLOT \
+(LZMA_NUM_LEN_TO_POS_STATES << LZMA_NUM_POS_SLOT_BITS))
#define LZMA_ALIGN (LZMA_SPEC_POS \
+ LZMA_NUM_FULL_DISTANCES - LZMA_END_POS_MODEL_INDEX)
#define LZMA_LEN_CODER (LZMA_ALIGN + (1 << LZMA_NUM_ALIGN_BITS))
#define LZMA_REP_LEN_CODER (LZMA_LEN_CODER + LZMA_NUM_LEN_PROBS)
#define LZMA_LITERAL (LZMA_REP_LEN_CODER + LZMA_NUM_LEN_PROBS)
USE_DESKTOP(long long) int
unlzma(int src_fd, int dst_fd)
@ -225,7 +235,7 @@ unlzma(int src_fd, int dst_fd)
uint16_t *prob_lit;
int num_bits;
int num_probs;
rc_t rc;
rc_t *rc;
int i, mi;
uint8_t *buffer;
uint8_t previous_byte = 0;
@ -260,16 +270,16 @@ unlzma(int src_fd, int dst_fd)
for (i = 0; i < num_probs; i++)
p[i] = (1 << RC_MODEL_TOTAL_BITS) >> 1;
rc_init(&rc, src_fd, 0x10000);
rc = rc_init(src_fd, 0x10000);
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)) {
if (rc_is_bit_0(rc, prob)) {
mi = 1;
rc_update_bit_0(&rc, prob);
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)))));
@ -287,7 +297,7 @@ unlzma(int src_fd, int dst_fd)
match_byte <<= 1;
bit = match_byte & 0x100;
prob_lit = prob + 0x100 + bit + mi;
if (rc_get_bit(&rc, prob_lit, &mi)) {
if (rc_get_bit(rc, prob_lit, &mi)) {
if (!bit)
break;
} else {
@ -298,7 +308,7 @@ unlzma(int src_fd, int dst_fd)
}
while (mi < 0x100) {
prob_lit = prob + mi;
rc_get_bit(&rc, prob_lit, &mi);
rc_get_bit(rc, prob_lit, &mi);
}
previous_byte = (uint8_t) mi;
@ -320,24 +330,24 @@ unlzma(int src_fd, int dst_fd)
int offset;
uint16_t *prob_len;
rc_update_bit_1(&rc, prob);
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);
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);
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);
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);
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;
@ -354,24 +364,24 @@ unlzma(int src_fd, int dst_fd)
}
continue;
} else {
rc_update_bit_1(&rc, prob);
rc_update_bit_1(rc, prob);
}
} else {
uint32_t distance;
rc_update_bit_1(&rc, prob);
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);
if (rc_is_bit_0(rc, prob)) {
rc_update_bit_0(rc, prob);
distance = rep1;
} else {
rc_update_bit_1(&rc, prob);
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);
if (rc_is_bit_0(rc, prob)) {
rc_update_bit_0(rc, prob);
distance = rep2;
} else {
rc_update_bit_1(&rc, prob);
rc_update_bit_1(rc, prob);
distance = rep3;
rep3 = rep2;
}
@ -385,30 +395,30 @@ unlzma(int src_fd, int dst_fd)
}
prob_len = prob + LZMA_LEN_CHOICE;
if (rc_is_bit_0(&rc, prob_len)) {
rc_update_bit_0(&rc, prob_len);
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);
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);
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);
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);
rc_bit_tree_decode(rc, prob_len, num_bits, &len);
len += offset;
if (state < 4) {
@ -421,7 +431,7 @@ unlzma(int src_fd, int dst_fd)
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,
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;
@ -432,7 +442,7 @@ unlzma(int src_fd, int dst_fd)
} else {
num_bits -= LZMA_NUM_ALIGN_BITS;
while (num_bits--)
rep0 = (rep0 << 1) | rc_direct_bit(&rc);
rep0 = (rep0 << 1) | rc_direct_bit(rc);
prob = p + LZMA_ALIGN;
rep0 <<= LZMA_NUM_ALIGN_BITS;
num_bits = LZMA_NUM_ALIGN_BITS;
@ -440,7 +450,7 @@ unlzma(int src_fd, int dst_fd)
i = 1;
mi = 1;
while (num_bits--) {
if (rc_get_bit(&rc, prob + mi, &mi))
if (rc_get_bit(rc, prob + mi, &mi))
rep0 |= i;
i <<= 1;
}
@ -473,6 +483,6 @@ unlzma(int src_fd, int dst_fd)
// FIXME: error check
write(dst_fd, buffer, buffer_pos);
USE_DESKTOP(total_written += buffer_pos;)
rc_free(&rc);
rc_free(rc);
return USE_DESKTOP(total_written) + 0;
}