static int zread(void *, char *, int);
#define tab_prefixof(i) (zs->zs_codetab[i])
#define tab_suffixof(i) ((char_type *)(zs->zs_htab))[i]
#define de_stack ((char_type *)&tab_suffixof(1 << BITS))
#define BITS 16
#define HSIZE 69001
#define BIT_MASK 0x1f
#define BLOCK_MASK 0x80
#define CHECK_GAP 10000
#define BUFSIZE (64 * 1024)
#define INIT_BITS 9
#define FIRST 257
#define CLEAR 256
#define MAXCODE(n_bits) ((1 << (n_bits)) - 1)
typedef long code_int;
typedef long count_int;
typedef u_char char_type;
static char_type magic_header[] =
{'\037', '\235'};
static char_type rmask[9] =
{0x00, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f, 0xff};
static off_t total_compressed_bytes;
static size_t compressed_prelen;
static char *compressed_pre;
struct s_zstate {
FILE *zs_fp;
char zs_mode;
enum {
S_START, S_MIDDLE, S_EOF
} zs_state;
int zs_n_bits;
int zs_maxbits;
code_int zs_maxcode;
code_int zs_maxmaxcode;
count_int zs_htab [HSIZE];
u_short zs_codetab [HSIZE];
code_int zs_hsize;
code_int zs_free_ent;
int zs_block_compress;
int zs_clear_flg;
long zs_ratio;
count_int zs_checkpoint;
int zs_offset;
long zs_in_count;
long zs_bytes_out;
long zs_out_count;
char_type zs_buf[BITS];
union {
struct {
long zs_fcode;
code_int zs_ent;
code_int zs_hsize_reg;
int zs_hshift;
} w;
struct {
char_type *zs_stackp;
int zs_finchar;
code_int zs_code, zs_oldcode, zs_incode;
int zs_roffset, zs_size;
char_type zs_gbuf[BITS];
} r;
} u;
};
static code_int getcode(struct s_zstate *zs);
static off_t
zuncompress(FILE *in, FILE *out, char *pre, size_t prelen,
off_t *compressed_bytes)
{
off_t bin, bout = 0;
char *buf;
buf = malloc(BUFSIZE);
if (buf == NULL)
return -1;
compressed_prelen = prelen;
if (prelen != 0)
compressed_pre = pre;
else
compressed_pre = NULL;
while ((bin = fread(buf, 1, sizeof(buf), in)) != 0) {
if (tflag == 0 && (off_t)fwrite(buf, 1, bin, out) != bin) {
free(buf);
return -1;
}
bout += bin;
}
if (compressed_bytes)
*compressed_bytes = total_compressed_bytes;
free(buf);
return bout;
}
static int
zclose(void *zs)
{
free(zs);
return 0;
}
FILE *
zdopen(int fd)
{
struct s_zstate *zs;
if ((zs = calloc(1, sizeof(struct s_zstate))) == NULL)
return (NULL);
zs->zs_state = S_START;
zs->zs_hsize = HSIZE;
zs->zs_free_ent = 0;
zs->zs_block_compress = BLOCK_MASK;
zs->zs_clear_flg = 0;
zs->zs_ratio = 0;
zs->zs_checkpoint = CHECK_GAP;
zs->zs_in_count = 1;
zs->zs_out_count = 0;
zs->u.r.zs_roffset = 0;
zs->u.r.zs_size = 0;
if ((zs->zs_fp = fdopen(fd, "r")) == NULL) {
free(zs);
return NULL;
}
return funopen(zs, zread, NULL, NULL, zclose);
}
static int
zread(void *cookie, char *rbp, int num)
{
u_int count, i;
struct s_zstate *zs;
u_char *bp, header[3];
if (num == 0)
return (0);
zs = cookie;
count = num;
bp = (u_char *)rbp;
switch (zs->zs_state) {
case S_START:
zs->zs_state = S_MIDDLE;
break;
case S_MIDDLE:
goto middle;
case S_EOF:
goto eof;
}
for (i = 0; i < 3 && compressed_prelen; i++, compressed_prelen--)
header[i] = *compressed_pre++;
if (fread(header + i, 1, sizeof(header) - i, zs->zs_fp) !=
sizeof(header) - i ||
memcmp(header, magic_header, sizeof(magic_header)) != 0) {
errno = EFTYPE;
return (-1);
}
total_compressed_bytes = 0;
zs->zs_maxbits = header[2];
zs->zs_block_compress = zs->zs_maxbits & BLOCK_MASK;
zs->zs_maxbits &= BIT_MASK;
zs->zs_maxmaxcode = 1L << zs->zs_maxbits;
if (zs->zs_maxbits > BITS || zs->zs_maxbits < 12) {
errno = EFTYPE;
return (-1);
}
zs->zs_maxcode = MAXCODE(zs->zs_n_bits = INIT_BITS);
for (zs->u.r.zs_code = 255; zs->u.r.zs_code >= 0; zs->u.r.zs_code--) {
tab_prefixof(zs->u.r.zs_code) = 0;
tab_suffixof(zs->u.r.zs_code) = (char_type) zs->u.r.zs_code;
}
zs->zs_free_ent = zs->zs_block_compress ? FIRST : 256;
zs->u.r.zs_oldcode = -1;
zs->u.r.zs_stackp = de_stack;
while ((zs->u.r.zs_code = getcode(zs)) > -1) {
if ((zs->u.r.zs_code == CLEAR) && zs->zs_block_compress) {
for (zs->u.r.zs_code = 255; zs->u.r.zs_code >= 0;
zs->u.r.zs_code--)
tab_prefixof(zs->u.r.zs_code) = 0;
zs->zs_clear_flg = 1;
zs->zs_free_ent = FIRST;
zs->u.r.zs_oldcode = -1;
continue;
}
zs->u.r.zs_incode = zs->u.r.zs_code;
if (zs->u.r.zs_code >= zs->zs_free_ent) {
if (zs->u.r.zs_code > zs->zs_free_ent ||
zs->u.r.zs_oldcode == -1) {
errno = EINVAL;
return (-1);
}
*zs->u.r.zs_stackp++ = zs->u.r.zs_finchar;
zs->u.r.zs_code = zs->u.r.zs_oldcode;
}
while (zs->u.r.zs_code >= 256) {
*zs->u.r.zs_stackp++ = tab_suffixof(zs->u.r.zs_code);
zs->u.r.zs_code = tab_prefixof(zs->u.r.zs_code);
}
*zs->u.r.zs_stackp++ = zs->u.r.zs_finchar = tab_suffixof(zs->u.r.zs_code);
middle: do {
if (count-- == 0)
return (num);
*bp++ = *--zs->u.r.zs_stackp;
} while (zs->u.r.zs_stackp > de_stack);
if ((zs->u.r.zs_code = zs->zs_free_ent) < zs->zs_maxmaxcode &&
zs->u.r.zs_oldcode != -1) {
tab_prefixof(zs->u.r.zs_code) = (u_short) zs->u.r.zs_oldcode;
tab_suffixof(zs->u.r.zs_code) = zs->u.r.zs_finchar;
zs->zs_free_ent = zs->u.r.zs_code + 1;
}
zs->u.r.zs_oldcode = zs->u.r.zs_incode;
}
zs->zs_state = S_EOF;
eof: return (num - count);
}
static code_int
getcode(struct s_zstate *zs)
{
code_int gcode;
int r_off, bits, i;
char_type *bp;
bp = zs->u.r.zs_gbuf;
if (zs->zs_clear_flg > 0 || zs->u.r.zs_roffset >= zs->u.r.zs_size ||
zs->zs_free_ent > zs->zs_maxcode) {
if (zs->zs_free_ent > zs->zs_maxcode) {
zs->zs_n_bits++;
if (zs->zs_n_bits == zs->zs_maxbits)
zs->zs_maxcode = zs->zs_maxmaxcode;
else
zs->zs_maxcode = MAXCODE(zs->zs_n_bits);
}
if (zs->zs_clear_flg > 0) {
zs->zs_maxcode = MAXCODE(zs->zs_n_bits = INIT_BITS);
zs->zs_clear_flg = 0;
}
for (i = 0; i < zs->zs_n_bits && compressed_prelen; i++, compressed_prelen--)
zs->u.r.zs_gbuf[i] = *compressed_pre++;
zs->u.r.zs_size = fread(zs->u.r.zs_gbuf + i, 1, zs->zs_n_bits - i, zs->zs_fp);
zs->u.r.zs_size += i;
if (zs->u.r.zs_size <= 0)
return (-1);
zs->u.r.zs_roffset = 0;
total_compressed_bytes += zs->u.r.zs_size;
zs->u.r.zs_size = (zs->u.r.zs_size << 3) - (zs->zs_n_bits - 1);
}
r_off = zs->u.r.zs_roffset;
bits = zs->zs_n_bits;
bp += (r_off >> 3);
r_off &= 7;
gcode = (*bp++ >> r_off);
bits -= (8 - r_off);
r_off = 8 - r_off;
if (bits >= 8) {
gcode |= *bp++ << r_off;
r_off += 8;
bits -= 8;
}
gcode |= (*bp & rmask[bits]) << r_off;
zs->u.r.zs_roffset += zs->zs_n_bits;
return (gcode);
}