/* ===========================================================================
* Initialize the "longest match" routines for a new file
*/
void lm_init (int pack_level, /* 1: best speed, 9: best compression */
ush *flags) /* general purpose bit flag */
{
register unsigned j;
if (pack_level < 1 || pack_level > 9) gzip_error ("bad pack level");
/* Initialize the hash table. */
memzero((char*)head, HASH_SIZE*sizeof(*head));
/* prev will be initialized on the fly */
/* rsync params */
rsync_chunk_end = 0xFFFFFFFFUL;
rsync_sum = 0;
/* Set the default configuration parameters:
*/
max_lazy_match = configuration_table[pack_level].max_lazy;
good_match = configuration_table[pack_level].good_length;
#ifndef FULL_SEARCH
nice_match = configuration_table[pack_level].nice_length;
#endif
max_chain_length = configuration_table[pack_level].max_chain;
if (pack_level == 1) {
*flags |= FAST;
} else if (pack_level == 9) {
*flags |= SLOW;
}
/* ??? reduce max_chain_length for binary files */
strstart = 0;
block_start = 0L;
lookahead = read_buf((char*)window,
sizeof(int) <= 2 ? (unsigned)WSIZE : 2*WSIZE);
if (lookahead == 0 || lookahead == (unsigned)EOF) {
eofile = 1, lookahead = 0;
return;
}
eofile = 0;
/* Make sure that we always have enough lookahead. This is important
* if input comes from a device such as a tty.
*/
while (lookahead < MIN_LOOKAHEAD && !eofile) fill_window();
ins_h = 0;
for (j=0; j<MIN_MATCH-1; j++) UPDATE_HASH(ins_h, window[j]);
/* If lookahead < MIN_MATCH, ins_h is garbage, but this is
* not important since only literal bytes will be emitted.
*/
}
void gzip_header::process(char c)
{
uint8_t value = static_cast<uint8_t>(c);
switch (state_) {
case s_id1:
if (value != gzip::magic::id1)
boost::throw_exception(gzip_error(gzip::bad_header));
state_ = s_id2;
break;
case s_id2:
if (value != gzip::magic::id2)
boost::throw_exception(gzip_error(gzip::bad_header));
state_ = s_cm;
break;
case s_cm:
if (value != gzip::method::deflate)
boost::throw_exception(gzip_error(gzip::bad_method));
state_ = s_flg;
break;
case s_flg:
flags_ = value;
state_ = s_mtime;
break;
case s_mtime:
mtime_ += value << (offset_ * 8);
if (offset_ == 3) {
state_ = s_xfl;
offset_ = 0;
}
else {
++offset_;
}
break;
case s_xfl:
state_ = s_os;
break;
case s_os:
os_ = value;
if (flags_ & gzip::flags::extra) {
state_ = s_xlen;
}
else if (flags_ & gzip::flags::name) {
state_ = s_name;
}
else if (flags_ & gzip::flags::comment) {
state_ = s_comment;
}
else if (flags_ & gzip::flags::header_crc) {
state_ = s_hcrc;
}
else {
state_ = s_done;
}
break;
case s_xlen:
xlen_ += value << (offset_ * 8);
if (offset_ == 1) {
state_ = s_extra;
offset_ = 0;
}
else {
++offset_;
}
break;
case s_extra:
if (--xlen_ == 0) {
if (flags_ & gzip::flags::name) {
state_ = s_name;
}
else if (flags_ & gzip::flags::comment) {
state_ = s_comment;
}
else if (flags_ & gzip::flags::header_crc) {
state_ = s_hcrc;
}
else {
state_ = s_done;
}
}
break;
case s_name:
if (c != 0) {
file_name_ += c;
}
else if (flags_ & gzip::flags::comment) {
state_ = s_comment;
}
else if (flags_ & gzip::flags::header_crc) {
state_ = s_hcrc;
}
else {
state_ = s_done;
}
break;
case s_comment:
if (c != 0) {
comment_ += c;
}
else if (flags_ & gzip::flags::header_crc) {
state_ = s_hcrc;
}
else {
state_ = s_done;
}
break;
case s_hcrc:
if (offset_ == 1) {
state_ = s_done;
offset_ = 0;
}
else {
++offset_;
}
break;
default:
BOOST_ASSERT(0);
}
}