#include "deflate.h"

#ifdef DEBUG

# include <ctype.h>

#endif

#define MAX_BL_BITS 7

#define END_BLOCK 256

#define REP_3_6 16

#define REPZ_3_10 17

#define REPZ_11_138 18

local const int extra_lbits[LENGTH_CODES] /* extra bits for each length code */

= {0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,0};

local const int extra_dbits[D_CODES] /* extra bits for each distance code */

= {0,0,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,13,13};

local const int extra_blbits[BL_CODES]/* extra bits for each bit length code */

= {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7};

local const uch bl_order[BL_CODES]

= {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15};

#define DIST_CODE_LEN 512 /* see definition of array dist_code below */

#if defined(GEN_TREES_H) || !defined(STDC)

local ct_data static_ltree[L_CODES+2];

local ct_data static_dtree[D_CODES];

uch _dist_code[DIST_CODE_LEN];

uch _length_code[MAX_MATCH-MIN_MATCH+1];

local int base_length[LENGTH_CODES];

local int base_dist[D_CODES];

#else

# include "trees.h"

#endif /* GEN_TREES_H */

struct static_tree_desc_s {

const ct_data *static_tree; /* static tree or NULL */

const intf *extra_bits; /* extra bits for each code or NULL */

int extra_base; /* base index for extra_bits */

int elems; /* max number of elements in the tree */

int max_length; /* max bit length for the codes */

};

local static_tree_desc static_l_desc =

{static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};

local static_tree_desc static_d_desc =

{static_dtree, extra_dbits, 0, D_CODES, MAX_BITS};

local static_tree_desc static_bl_desc =

{(const ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS};

local void tr_static_init OF((void));

local void init_block OF((deflate_state *s));

local void pqdownheap OF((deflate_state *s, ct_data *tree, int k));

local void gen_bitlen OF((deflate_state *s, tree_desc *desc));

local void gen_codes OF((ct_data *tree, int max_code, ushf *bl_count));

local void build_tree OF((deflate_state *s, tree_desc *desc));

local void scan_tree OF((deflate_state *s, ct_data *tree, int max_code));

local void send_tree OF((deflate_state *s, ct_data *tree, int max_code));

local int build_bl_tree OF((deflate_state *s));

local void send_all_trees OF((deflate_state *s, int lcodes, int dcodes,

int blcodes));

local void compress_block OF((deflate_state *s, const ct_data *ltree,

const ct_data *dtree));

local int detect_data_type OF((deflate_state *s));

local unsigned bi_reverse OF((unsigned value, int length));

local void bi_windup OF((deflate_state *s));

local void bi_flush OF((deflate_state *s));

local void copy_block OF((deflate_state *s, charf *buf, unsigned len,

int header));

#ifdef GEN_TREES_H

local void gen_trees_header OF((void));

#endif

#ifndef DEBUG

# define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)

/* Send a code of the given tree. c and tree must not have side effects */

#else /* DEBUG */

# define send_code(s, c, tree) \

{ if (z_verbose>2) fprintf(stderr,"\ncd %3d ",(c)); \

send_bits(s, tree[c].Code, tree[c].Len); }

#endif

#define put_short(s, w) { \

put_byte(s, (uch)((w) & 0xff)); \

put_byte(s, (uch)((ush)(w) >> 8)); \

}

#ifdef DEBUG

local void send_bits OF((deflate_state *s, int value, int length));

local void send_bits(s, value, length)

deflate_state *s;

int value; /* value to send */

int length; /* number of bits */

{

Tracevv((stderr," l %2d v %4x ", length, value));

Assert(length > 0 && length <= 15, "invalid length");

s->bits_sent += (ulg)length;

/* If not enough room in bi_buf, use (valid) bits from bi_buf and

if (s->bi_valid > (int)Buf_size - length) {

s->bi_buf |= (ush)value << s->bi_valid;

put_short(s, s->bi_buf);

s->bi_buf = (ush)value >> (Buf_size - s->bi_valid);

s->bi_valid += length - Buf_size;

} else {

s->bi_buf |= (ush)value << s->bi_valid;

s->bi_valid += length;

}

}

#else /* !DEBUG */

#define send_bits(s, value, length) \

{ int len = length;\

if (s->bi_valid > (int)Buf_size - len) {\

int val = value;\

s->bi_buf |= (ush)val << s->bi_valid;\

put_short(s, s->bi_buf);\

s->bi_buf = (ush)val >> (Buf_size - s->bi_valid);\

s->bi_valid += len - Buf_size;\

} else {\

s->bi_buf |= (ush)(value) << s->bi_valid;\

s->bi_valid += len;\

}\

}

#endif /* DEBUG */

local void tr_static_init()

{

#if defined(GEN_TREES_H) || !defined(STDC)

static int static_init_done = 0;

int n; /* iterates over tree elements */

int bits; /* bit counter */

int length; /* length value */

int code; /* code value */

int dist; /* distance index */

ush bl_count[MAX_BITS+1];

/* number of codes at each bit length for an optimal tree */

if (static_init_done) return;

/* For some embedded targets, global variables are not initialized: */

#ifdef NO_INIT_GLOBAL_POINTERS

static_l_desc.static_tree = static_ltree;

static_l_desc.extra_bits = extra_lbits;

static_d_desc.static_tree = static_dtree;

static_d_desc.extra_bits = extra_dbits;

static_bl_desc.extra_bits = extra_blbits;

#endif

/* Initialize the mapping length (0..255) -> length code (0..28) */

length = 0;

for (code = 0; code < LENGTH_CODES-1; code++) {

base_length[code] = length;

for (n = 0; n < (1<<extra_lbits[code]); n++) {

_length_code[length++] = (uch)code;

}

}

Assert (length == 256, "tr_static_init: length != 256");

/* Note that the length 255 (match length 258) can be represented

_length_code[length-1] = (uch)code;

/* Initialize the mapping dist (0..32K) -> dist code (0..29) */

dist = 0;

for (code = 0 ; code < 16; code++) {

base_dist[code] = dist;

for (n = 0; n < (1<<extra_dbits[code]); n++) {

_dist_code[dist++] = (uch)code;

}

}

Assert (dist == 256, "tr_static_init: dist != 256");

dist >>= 7; /* from now on, all distances are divided by 128 */

for ( ; code < D_CODES; code++) {

base_dist[code] = dist << 7;

for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {

_dist_code[256 + dist++] = (uch)code;

}

}

Assert (dist == 256, "tr_static_init: 256+dist != 512");

/* Construct the codes of the static literal tree */

for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;

n = 0;

while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;

while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;

while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;

while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;

/* Codes 286 and 287 do not exist, but we must include them in the

gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);

/* The static distance tree is trivial: */

for (n = 0; n < D_CODES; n++) {

static_dtree[n].Len = 5;

static_dtree[n].Code = bi_reverse((unsigned)n, 5);

}

static_init_done = 1;

# ifdef GEN_TREES_H

gen_trees_header();

# endif

#endif /* defined(GEN_TREES_H) || !defined(STDC) */

}

#ifdef GEN_TREES_H

# ifndef DEBUG

# include <stdio.h>

# endif

# define SEPARATOR(i, last, width) \

((i) == (last)? "\n};\n\n" : \

((i) % (width) == (width)-1 ? ",\n" : ", "))

void gen_trees_header()

{

FILE *header = fopen("trees.h", "w");

int i;

Assert (header != NULL, "Can't open trees.h");

fprintf(header,

"/* header created automatically with -DGEN_TREES_H */\n\n");

fprintf(header, "local const ct_data static_ltree[L_CODES+2] = {\n");

for (i = 0; i < L_CODES+2; i++) {

fprintf(header, "{{%3u},{%3u}}%s", static_ltree[i].Code,

static_ltree[i].Len, SEPARATOR(i, L_CODES+1, 5));

}

fprintf(header, "local const ct_data static_dtree[D_CODES] = {\n");

for (i = 0; i < D_CODES; i++) {

fprintf(header, "{{%2u},{%2u}}%s", static_dtree[i].Code,

static_dtree[i].Len, SEPARATOR(i, D_CODES-1, 5));

}

fprintf(header, "const uch ZLIB_INTERNAL _dist_code[DIST_CODE_LEN] = {\n");

for (i = 0; i < DIST_CODE_LEN; i++) {

fprintf(header, "%2u%s", _dist_code[i],

SEPARATOR(i, DIST_CODE_LEN-1, 20));

}

fprintf(header,

"const uch ZLIB_INTERNAL _length_code[MAX_MATCH-MIN_MATCH+1]= {\n");

for (i = 0; i < MAX_MATCH-MIN_MATCH+1; i++) {

fprintf(header, "%2u%s", _length_code[i],

SEPARATOR(i, MAX_MATCH-MIN_MATCH, 20));

}

fprintf(header, "local const int base_length[LENGTH_CODES] = {\n");

for (i = 0; i < LENGTH_CODES; i++) {

fprintf(header, "%1u%s", base_length[i],

SEPARATOR(i, LENGTH_CODES-1, 20));

}

fprintf(header, "local const int base_dist[D_CODES] = {\n");

for (i = 0; i < D_CODES; i++) {

fprintf(header, "%5u%s", base_dist[i],

SEPARATOR(i, D_CODES-1, 10));

}

fclose(header);

}

#endif /* GEN_TREES_H */

void ZLIB_INTERNAL _tr_init(s)

deflate_state *s;

{

tr_static_init();

s->l_desc.dyn_tree = s->dyn_ltree;

s->l_desc.stat_desc = &static_l_desc;

s->d_desc.dyn_tree = s->dyn_dtree;

s->d_desc.stat_desc = &static_d_desc;

s->bl_desc.dyn_tree = s->bl_tree;

s->bl_desc.stat_desc = &static_bl_desc;

s->bi_buf = 0;

s->bi_valid = 0;

#ifdef DEBUG

s->compressed_len = 0L;

s->bits_sent = 0L;

#endif

/* Initialize the first block of the first file: */

init_block(s);

}

local void init_block(s)

deflate_state *s;

{

int n; /* iterates over tree elements */

/* Initialize the trees. */

for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0;

for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0;

for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0;

s->dyn_ltree[END_BLOCK].Freq = 1;

s->opt_len = s->static_len = 0L;

s->last_lit = s->matches = 0;

}

#define SMALLEST 1

#define pqremove(s, tree, top) \

{\

top = s->heap[SMALLEST]; \

s->heap[SMALLEST] = s->heap[s->heap_len--]; \

pqdownheap(s, tree, SMALLEST); \

}

#define smaller(tree, n, m, depth) \

(tree[n].Freq < tree[m].Freq || \

(tree[n].Freq == tree[m].Freq && depth[n] <= depth[m]))

local void pqdownheap(s, tree, k)

deflate_state *s;

ct_data *tree; /* the tree to restore */

int k; /* node to move down */

{

int v = s->heap[k];

int j = k << 1; /* left son of k */

while (j <= s->heap_len) {

/* Set j to the smallest of the two sons: */

if (j < s->heap_len &&

smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {

j++;

}

/* Exit if v is smaller than both sons */

if (smaller(tree, v, s->heap[j], s->depth)) break;

/* Exchange v with the smallest son */

s->heap[k] = s->heap[j]; k = j;

/* And continue down the tree, setting j to the left son of k */

j <<= 1;

}

s->heap[k] = v;

}

local void gen_bitlen(s, desc)

deflate_state *s;

tree_desc *desc; /* the tree descriptor */

{

ct_data *tree = desc->dyn_tree;

int max_code = desc->max_code;

const ct_data *stree = desc->stat_desc->static_tree;

const intf *extra = desc->stat_desc->extra_bits;

int base = desc->stat_desc->extra_base;

int max_length = desc->stat_desc->max_length;

int h; /* heap index */

int n, m; /* iterate over the tree elements */

int bits; /* bit length */

int xbits; /* extra bits */

ush f; /* frequency */

int overflow = 0; /* number of elements with bit length too large */

for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;

/* In a first pass, compute the optimal bit lengths (which may

tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */

for (h = s->heap_max+1; h < HEAP_SIZE; h++) {

n = s->heap[h];

bits = tree[tree[n].Dad].Len + 1;

if (bits > max_length) bits = max_length, overflow++;

tree[n].Len = (ush)bits;

/* We overwrite tree[n].Dad which is no longer needed */

if (n > max_code) continue; /* not a leaf node */

s->bl_count[bits]++;

xbits = 0;

if (n >= base) xbits = extra[n-base];

f = tree[n].Freq;

s->opt_len += (ulg)f * (bits + xbits);

if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits);

}

if (overflow == 0) return;

Trace((stderr,"\nbit length overflow\n"));

/* This happens for example on obj2 and pic of the Calgary corpus */

/* Find the first bit length which could increase: */

do {

bits = max_length-1;

while (s->bl_count[bits] == 0) bits--;

s->bl_count[bits]--; /* move one leaf down the tree */

s->bl_count[bits+1] += 2; /* move one overflow item as its brother */

s->bl_count[max_length]--;

/* The brother of the overflow item also moves one step up,

overflow -= 2;

} while (overflow > 0);

/* Now recompute all bit lengths, scanning in increasing frequency.

for (bits = max_length; bits != 0; bits--) {

n = s->bl_count[bits];

while (n != 0) {

m = s->heap[--h];

if (m > max_code) continue;

if ((unsigned) tree[m].Len != (unsigned) bits) {

Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));

s->opt_len += ((long)bits - (long)tree[m].Len)

*(long)tree[m].Freq;

tree[m].Len = (ush)bits;

}

n--;

}

}

}

local void gen_codes (tree, max_code, bl_count)

ct_data *tree; /* the tree to decorate */

int max_code; /* largest code with non zero frequency */

ushf *bl_count; /* number of codes at each bit length */

{

ush next_code[MAX_BITS+1]; /* next code value for each bit length */

ush code = 0; /* running code value */

int bits; /* bit index */

int n; /* code index */

/* The distribution counts are first used to generate the code values

for (bits = 1; bits <= MAX_BITS; bits++) {

next_code[bits] = code = (code + bl_count[bits-1]) << 1;

}

/* Check that the bit counts in bl_count are consistent. The last code

Assert (code + bl_count[MAX_BITS]-1 == (1<<MAX_BITS)-1,

"inconsistent bit counts");

Tracev((stderr,"\ngen_codes: max_code %d ", max_code));

for (n = 0; n <= max_code; n++) {

int len = tree[n].Len;

if (len == 0) continue;

/* Now reverse the bits */

tree[n].Code = bi_reverse(next_code[len]++, len);

Tracecv(tree != static_ltree, (stderr,"\nn %3d %c l %2d c %4x (%x) ",

n, (isgraph(n) ? n : ' '), len, tree[n].Code, next_code[len]-1));

}

}

local void build_tree(s, desc)

deflate_state *s;

tree_desc *desc; /* the tree descriptor */

{

ct_data *tree = desc->dyn_tree;

const ct_data *stree = desc->stat_desc->static_tree;

int elems = desc->stat_desc->elems;

int n, m; /* iterate over heap elements */

int max_code = -1; /* largest code with non zero frequency */

int node; /* new node being created */

/* Construct the initial heap, with least frequent element in

s->heap_len = 0, s->heap_max = HEAP_SIZE;

for (n = 0; n < elems; n++) {

if (tree[n].Freq != 0) {

s->heap[++(s->heap_len)] = max_code = n;

s->depth[n] = 0;

} else {

tree[n].Len = 0;

}

}

/* The pkzip format requires that at least one distance code exists,

while (s->heap_len < 2) {

node = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0);

tree[node].Freq = 1;

s->depth[node] = 0;

s->opt_len--; if (stree) s->static_len -= stree[node].Len;

/* node is 0 or 1 so it does not have extra bits */

}

desc->max_code = max_code;

/* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,

for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);

/* Construct the Huffman tree by repeatedly combining the least two

node = elems; /* next internal node of the tree */

do {

pqremove(s, tree, n); /* n = node of least frequency */

m = s->heap[SMALLEST]; /* m = node of next least frequency */

s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */

s->heap[--(s->heap_max)] = m;

/* Create a new node father of n and m */

tree[node].Freq = tree[n].Freq + tree[m].Freq;

s->depth[node] = (uch)((s->depth[n] >= s->depth[m] ?

s->depth[n] : s->depth[m]) + 1);

tree[n].Dad = tree[m].Dad = (ush)node;

#ifdef DUMP_BL_TREE

if (tree == s->bl_tree) {

fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)",

node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq);

}

#endif

/* and insert the new node in the heap */

s->heap[SMALLEST] = node++;

pqdownheap(s, tree, SMALLEST);

} while (s->heap_len >= 2);

s->heap[--(s->heap_max)] = s->heap[SMALLEST];

/* At this point, the fields freq and dad are set. We can now

gen_bitlen(s, (tree_desc *)desc);

/* The field len is now set, we can generate the bit codes */

gen_codes ((ct_data *)tree, max_code, s->bl_count);

}

local void scan_tree (s, tree, max_code)

deflate_state *s;

ct_data *tree; /* the tree to be scanned */

int max_code; /* and its largest code of non zero frequency */

{

int n; /* iterates over all tree elements */

int prevlen = -1; /* last emitted length */

int curlen; /* length of current code */

int nextlen = tree[0].Len; /* length of next code */

int count = 0; /* repeat count of the current code */

int max_count = 7; /* max repeat count */

int min_count = 4; /* min repeat count */

if (nextlen == 0) max_count = 138, min_count = 3;

tree[max_code+1].Len = (ush)0xffff; /* guard */

for (n = 0; n <= max_code; n++) {

curlen = nextlen; nextlen = tree[n+1].Len;

if (++count < max_count && curlen == nextlen) {

continue;

} else if (count < min_count) {

s->bl_tree[curlen].Freq += count;

} else if (curlen != 0) {

if (curlen != prevlen) s->bl_tree[curlen].Freq++;

s->bl_tree[REP_3_6].Freq++;

} else if (count <= 10) {

s->bl_tree[REPZ_3_10].Freq++;

} else {

s->bl_tree[REPZ_11_138].Freq++;

}

count = 0; prevlen = curlen;

if (nextlen == 0) {

max_count = 138, min_count = 3;

} else if (curlen == nextlen) {

max_count = 6, min_count = 3;

} else {

max_count = 7, min_count = 4;

}

}

}

local void send_tree (s, tree, max_code)

deflate_state *s;

ct_data *tree; /* the tree to be scanned */

int max_code; /* and its largest code of non zero frequency */

{

int n; /* iterates over all tree elements */

int prevlen = -1; /* last emitted length */

int curlen; /* length of current code */

int nextlen = tree[0].Len; /* length of next code */

int count = 0; /* repeat count of the current code */

int max_count = 7; /* max repeat count */

int min_count = 4; /* min repeat count */

/* tree[max_code+1].Len = -1; */ /* guard already set */

if (nextlen == 0) max_count = 138, min_count = 3;

for (n = 0; n <= max_code; n++) {

curlen = nextlen; nextlen = tree[n+1].Len;

if (++count < max_count && curlen == nextlen) {

continue;

} else if (count < min_count) {

do { send_code(s, curlen, s->bl_tree); } while (--count != 0);

} else if (curlen != 0) {

if (curlen != prevlen) {

send_code(s, curlen, s->bl_tree); count--;

}

Assert(count >= 3 && count <= 6, " 3_6?");

send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2);

} else if (count <= 10) {

send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3);

} else {

send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7);

}

count = 0; prevlen = curlen;

if (nextlen == 0) {

max_count = 138, min_count = 3;

} else if (curlen == nextlen) {

max_count = 6, min_count = 3;

} else {

max_count = 7, min_count = 4;

}

}

}

local int build_bl_tree(s)

deflate_state *s;

{

int max_blindex; /* index of last bit length code of non zero freq */

/* Determine the bit length frequencies for literal and distance trees */

scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code);

scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code);

/* Build the bit length tree: */

build_tree(s, (tree_desc *)(&(s->bl_desc)));

/* opt_len now includes the length of the tree representations, except

/* Determine the number of bit length codes to send. The pkzip format

for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {

if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;

}

/* Update opt_len to include the bit length tree and counts */

s->opt_len += 3*(max_blindex+1) + 5+5+4;

Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld",

s->opt_len, s->static_len));

return max_blindex;

}

local void send_all_trees(s, lcodes, dcodes, blcodes)

deflate_state *s;

int lcodes, dcodes, blcodes; /* number of codes for each tree */

{

int rank; /* index in bl_order */

Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes");

Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES,

"too many codes");

Tracev((stderr, "\nbl counts: "));

send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */

send_bits(s, dcodes-1, 5);

send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */

for (rank = 0; rank < blcodes; rank++) {

Tracev((stderr, "\nbl code %2d ", bl_order[rank]));

send_bits(s, s->bl_tree[bl_order[rank]].Len, 3);

}

Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));

send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */

Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));

send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */

Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));

}

void ZLIB_INTERNAL _tr_stored_block(s, buf, stored_len, last)

deflate_state *s;

charf *buf; /* input block */

ulg stored_len; /* length of input block */

int last; /* one if this is the last block for a file */

{

send_bits(s, (STORED_BLOCK<<1)+last, 3); /* send block type */

#ifdef DEBUG

s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L;

s->compressed_len += (stored_len + 4) << 3;

#endif

copy_block(s, buf, (unsigned)stored_len, 1); /* with header */

}

void ZLIB_INTERNAL _tr_flush_bits(s)

deflate_state *s;

{

bi_flush(s);

}

void ZLIB_INTERNAL _tr_align(s)

deflate_state *s;

{

send_bits(s, STATIC_TREES<<1, 3);

send_code(s, END_BLOCK, static_ltree);

#ifdef DEBUG

s->compressed_len += 10L; /* 3 for block type, 7 for EOB */

#endif

bi_flush(s);

}

void ZLIB_INTERNAL _tr_flush_block(s, buf, stored_len, last)

deflate_state *s;

charf *buf; /* input block, or NULL if too old */

ulg stored_len; /* length of input block */

int last; /* one if this is the last block for a file */

{

ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */

int max_blindex = 0; /* index of last bit length code of non zero freq */

/* Build the Huffman trees unless a stored block is forced */

if (s->level > 0) {

/* Check if the file is binary or text */

if (s->strm->data_type == Z_UNKNOWN)

s->strm->data_type = detect_data_type(s);

/* Construct the literal and distance trees */

build_tree(s, (tree_desc *)(&(s->l_desc)));

Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len,

s->static_len));

build_tree(s, (tree_desc *)(&(s->d_desc)));

Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len,

s->static_len));

/* At this point, opt_len and static_len are the total bit lengths of

/* Build the bit length tree for the above two trees, and get the index

max_blindex = build_bl_tree(s);

/* Determine the best encoding. Compute the block lengths in bytes. */

opt_lenb = (s->opt_len+3+7)>>3;

static_lenb = (s->static_len+3+7)>>3;

Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ",

opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len,

s->last_lit));

if (static_lenb <= opt_lenb) opt_lenb = static_lenb;

} else {

Assert(buf != (char*)0, "lost buf");

opt_lenb = static_lenb = stored_len + 5; /* force a stored block */

}

#ifdef FORCE_STORED

if (buf != (char*)0) { /* force stored block */

#else

if (stored_len+4 <= opt_lenb && buf != (char*)0) {

/* 4: two words for the lengths */

#endif

/* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.

_tr_stored_block(s, buf, stored_len, last);

#ifdef FORCE_STATIC

} else if (static_lenb >= 0) { /* force static trees */

#else

} else if (s->strategy == Z_FIXED || static_lenb == opt_lenb) {

#endif

send_bits(s, (STATIC_TREES<<1)+last, 3);

compress_block(s, (const ct_data *)static_ltree,

(const ct_data *)static_dtree);

#ifdef DEBUG

s->compressed_len += 3 + s->static_len;

#endif

} else {

send_bits(s, (DYN_TREES<<1)+last, 3);

send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1,

max_blindex+1);

compress_block(s, (const ct_data *)s->dyn_ltree,

(const ct_data *)s->dyn_dtree);

#ifdef DEBUG

s->compressed_len += 3 + s->opt_len;

#endif

}

Assert (s->compressed_len == s->bits_sent, "bad compressed size");

/* The above check is made mod 2^32, for files larger than 512 MB

init_block(s);

if (last) {

bi_windup(s);

#ifdef DEBUG

s->compressed_len += 7; /* align on byte boundary */

#endif

}

Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,

s->compressed_len-7*last));

}

int ZLIB_INTERNAL _tr_tally (s, dist, lc)

deflate_state *s;

unsigned dist; /* distance of matched string */

unsigned lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */

{

s->d_buf[s->last_lit] = (ush)dist;

s->l_buf[s->last_lit++] = (uch)lc;

if (dist == 0) {

/* lc is the unmatched char */

s->dyn_ltree[lc].Freq++;

} else {

s->matches++;

/* Here, lc is the match length - MIN_MATCH */

dist--; /* dist = match distance - 1 */

Assert((ush)dist < (ush)MAX_DIST(s) &&

(ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) &&

(ush)d_code(dist) < (ush)D_CODES, "_tr_tally: bad match");

s->dyn_ltree[_length_code[lc]+LITERALS+1].Freq++;

s->dyn_dtree[d_code(dist)].Freq++;

}

#ifdef TRUNCATE_BLOCK

/* Try to guess if it is profitable to stop the current block here */

if ((s->last_lit & 0x1fff) == 0 && s->level > 2) {

/* Compute an upper bound for the compressed length */

ulg out_length = (ulg)s->last_lit*8L;

ulg in_length = (ulg)((long)s->strstart - s->block_start);

int dcode;

for (dcode = 0; dcode < D_CODES; dcode++) {

out_length += (ulg)s->dyn_dtree[dcode].Freq *

(5L+extra_dbits[dcode]);

}

out_length >>= 3;

Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ",

s->last_lit, in_length, out_length,

100L - out_length*100L/in_length));

if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1;

}

#endif

return (s->last_lit == s->lit_bufsize-1);

/* We avoid equality with lit_bufsize because of wraparound at 64K

}

local void compress_block(s, ltree, dtree)

deflate_state *s;

const ct_data *ltree; /* literal tree */

const ct_data *dtree; /* distance tree */

{

unsigned dist; /* distance of matched string */

int lc; /* match length or unmatched char (if dist == 0) */

unsigned lx = 0; /* running index in l_buf */

unsigned code; /* the code to send */

int extra; /* number of extra bits to send */

if (s->last_lit != 0) do {

dist = s->d_buf[lx];

lc = s->l_buf[lx++];

if (dist == 0) {

send_code(s, lc, ltree); /* send a literal byte */

Tracecv(isgraph(lc), (stderr," '%c' ", lc));

} else {

/* Here, lc is the match length - MIN_MATCH */

code = _length_code[lc];

send_code(s, code+LITERALS+1, ltree); /* send the length code */

extra = extra_lbits[code];

if (extra != 0) {

lc -= base_length[code];

send_bits(s, lc, extra); /* send the extra length bits */

}

dist--; /* dist is now the match distance - 1 */

code = d_code(dist);

Assert (code < D_CODES, "bad d_code");

send_code(s, code, dtree); /* send the distance code */

extra = extra_dbits[code];

if (extra != 0) {

dist -= base_dist[code];

send_bits(s, dist, extra); /* send the extra distance bits */

}

} /* literal or match pair ? */

/* Check that the overlay between pending_buf and d_buf+l_buf is ok: */

Assert((uInt)(s->pending) < s->lit_bufsize + 2*lx,

"pendingBuf overflow");

} while (lx < s->last_lit);

send_code(s, END_BLOCK, ltree);

}

local int detect_data_type(s)

deflate_state *s;

{

/* black_mask is the bit mask of black-listed bytes

unsigned long black_mask = 0xf3ffc07fUL;

int n;

/* Check for non-textual ("black-listed") bytes. */

for (n = 0; n <= 31; n++, black_mask >>= 1)

if ((black_mask & 1) && (s->dyn_ltree[n].Freq != 0))

return Z_BINARY;

/* Check for textual ("white-listed") bytes. */

if (s->dyn_ltree[9].Freq != 0 || s->dyn_ltree[10].Freq != 0

|| s->dyn_ltree[13].Freq != 0)

return Z_TEXT;

for (n = 32; n < LITERALS; n++)

if (s->dyn_ltree[n].Freq != 0)

return Z_TEXT;

/* There are no "black-listed" or "white-listed" bytes:

return Z_BINARY;

}

local unsigned bi_reverse(code, len)

unsigned code; /* the value to invert */

int len; /* its bit length */

{

register unsigned res = 0;

do {

res |= code & 1;

code >>= 1, res <<= 1;

} while (--len > 0);

return res >> 1;

}

local void bi_flush(s)

deflate_state *s;

{

if (s->bi_valid == 16) {

put_short(s, s->bi_buf);

s->bi_buf = 0;

s->bi_valid = 0;

} else if (s->bi_valid >= 8) {

put_byte(s, (Byte)s->bi_buf);

s->bi_buf >>= 8;

s->bi_valid -= 8;

}

}

local void bi_windup(s)

deflate_state *s;

{

if (s->bi_valid > 8) {

put_short(s, s->bi_buf);

} else if (s->bi_valid > 0) {

put_byte(s, (Byte)s->bi_buf);

}

s->bi_buf = 0;

s->bi_valid = 0;

#ifdef DEBUG

s->bits_sent = (s->bits_sent+7) & ~7;

#endif

}

local void copy_block(s, buf, len, header)

deflate_state *s;

charf *buf; /* the input data */

unsigned len; /* its length */

int header; /* true if block header must be written */

{

bi_windup(s); /* align on byte boundary */

if (header) {

put_short(s, (ush)len);

put_short(s, (ush)~len);

#ifdef DEBUG

s->bits_sent += 2*16;

#endif

}

#ifdef DEBUG

s->bits_sent += (ulg)len<<3;

#endif

while (len--) {

put_byte(s, *buf++);

}

}