isa-l/igzip/igzip_stateless_base.c

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#include <stdint.h>
#include "igzip_lib.h"
#include "huffman.h"
#include "huff_codes.h"
#include "bitbuf2.h"
static inline void update_state(struct isal_zstream *stream, struct isal_zstate *state,
uint8_t * end_in, uint8_t * start_in)
{
uint32_t count;
stream->avail_in = end_in - stream->next_in;
stream->total_in += stream->next_in - start_in;
count = buffer_used(&state->bitbuf);
stream->next_out = buffer_ptr(&state->bitbuf);
stream->avail_out -= count;
stream->total_out += count;
}
void isal_deflate_body_stateless_base(struct isal_zstream *stream)
{
uint32_t literal = 0, hash;
uint8_t *start_in, *end_in, *end, *next_hash;
uint16_t match_length;
uint32_t dist;
uint64_t code, code_len, code2, code_len2, i;
struct isal_zstate *state = &stream->internal_state;
uint16_t *last_seen = state->head;
if (stream->avail_in == 0)
return;
set_buf(&state->bitbuf, stream->next_out, stream->avail_out);
start_in = stream->next_in;
end_in = stream->next_in + stream->avail_in;
while (stream->next_in < end_in - 3) {
if (is_full(&state->bitbuf)) {
update_state(stream, state, end_in, start_in);
return;
}
literal = *(uint32_t *) stream->next_in;
hash = compute_hash(literal) & HASH_MASK;
dist = (uint64_t) (stream->next_in - last_seen[hash]) & 0xFFFF;
last_seen[hash] = (uint64_t) stream->next_in;
if (dist - 1 < IGZIP_HIST_SIZE - 1 && stream->next_in - dist >= start_in) { /* The -1 are to handle the case when dist = 0 */
match_length =
compare258(stream->next_in - dist, stream->next_in,
end_in - stream->next_in);
if (match_length >= SHORTEST_MATCH) {
next_hash = stream->next_in;
#ifdef ISAL_LIMIT_HASH_UPDATE
end = next_hash + 3;
#else
end = next_hash + match_length;
#endif
if (end > end_in - 3)
end = end_in - 3;
next_hash++;
for (; next_hash < end; next_hash++) {
literal = *(uint32_t *) next_hash;
hash = compute_hash(literal) & HASH_MASK;
last_seen[hash] = (uint64_t) next_hash;
}
get_len_code(stream->hufftables, match_length, &code,
&code_len);
get_dist_code(stream->hufftables, dist, &code2, &code_len2);
code |= code2 << code_len;
code_len += code_len2;
write_bits(&state->bitbuf, code, code_len);
stream->next_in += match_length;
continue;
}
}
get_lit_code(stream->hufftables, literal & 0xFF, &code, &code_len);
write_bits(&state->bitbuf, code, code_len);
stream->next_in++;
}
if (is_full(&state->bitbuf)) {
update_state(stream, state, end_in, start_in);
return;
}
literal = *(uint32_t *) (end_in - 4);
for (i = 4; i > end_in - stream->next_in; i--)
literal = literal >> 8;
hash = compute_hash(literal) & HASH_MASK;
dist = (uint64_t) (stream->next_in - last_seen[hash]) & 0xFFFF;
if (dist - 1 < IGZIP_HIST_SIZE - 1 && stream->next_in - dist >= start_in) {
match_length =
compare258(stream->next_in - dist, stream->next_in,
end_in - stream->next_in);
if (match_length >= SHORTEST_MATCH) {
get_len_code(stream->hufftables, match_length, &code, &code_len);
get_dist_code(stream->hufftables, dist, &code2, &code_len2);
code |= code2 << code_len;
code_len += code_len2;
write_bits(&state->bitbuf, code, code_len);
stream->next_in += 3;
if (is_full(&state->bitbuf)) {
update_state(stream, state, end_in, start_in);
return;
}
get_lit_code(stream->hufftables, 256, &code, &code_len);
write_bits(&state->bitbuf, code, code_len);
if (is_full(&state->bitbuf)) {
update_state(stream, state, end_in, start_in);
return;
}
state->has_eob = 1;
update_state(stream, state, end_in, start_in);
return;
}
}
while (stream->next_in < end_in) {
get_lit_code(stream->hufftables, literal & 0xFF, &code, &code_len);
write_bits(&state->bitbuf, code, code_len);
stream->next_in++;
if (is_full(&state->bitbuf)) {
update_state(stream, state, end_in, start_in);
return;
}
literal >>= 8;
}
get_lit_code(stream->hufftables, 256, &code, &code_len);
write_bits(&state->bitbuf, code, code_len);
state->has_eob = 1;
update_state(stream, state, end_in, start_in);
return;
}