/* trees.c -- output deflated data using Huffman coding
 * Copyright (C) 1995-2017 Jean-loup Gailly
 * detect_data_type() function provided freely by Cosmin Truta, 2006
 * For conditions of distribution and use, see copyright notice in zlib.h
 */

#include "deflate.h"

#ifdef ZLIB_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]
   = {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]
   = {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

#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

struct static_tree_desc_s {
    const ct_data *static_tree;
    const intf *extra_bits;
    int     extra_base;
    int     elems;
    int     max_length;
};

local const static_tree_desc  static_l_desc =
{static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS};

local const static_tree_desc  static_d_desc =
{static_dtree, extra_dbits, 0,          D_CODES, MAX_BITS};

local const 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));

#ifdef GEN_TREES_H
local void gen_trees_header OF((void));
#endif

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

#else
#  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 ZLIB_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;
    int length;
{
    Tracevv((stderr," l %2d v %4x ", length, value));
    Assert(length > 0 && length <= 15, "invalid length");
    s->bits_sent += (ulg)length;
    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

#define send_bits(s, value, length) \
{ int len = length;\
  if (s->bi_valid > (int)Buf_size - len) {\
    int val = (int)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
local void tr_static_init()
{
#if defined(GEN_TREES_H) || !defined(STDC)
    static int static_init_done = 0;
    int n;
    int bits;
    int length;
    int code;
    int dist;
    ush bl_count[MAX_BITS+1];

    if (static_init_done) return;
#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
    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");
    _length_code[length-1] = (uch)code;
    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;
    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");
    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]++;
    gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
    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
}
#ifdef GEN_TREES_H
#  ifndef ZLIB_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
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 ZLIB_DEBUG
    s->compressed_len = 0L;
    s->bits_sent = 0L;
#endif
    init_block(s);
}
local void init_block(s)
    deflate_state *s;
{
    int n;
    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;
    int k;
{
    int v = s->heap[k];
    int j = k << 1;
    while (j <= s->heap_len) {
        if (j < s->heap_len &&
            smaller(tree, s->heap[j+1], s->heap[j], s->depth)) {
            j++;
        }
        if (smaller(tree, v, s->heap[j], s->depth)) break;
        s->heap[k] = s->heap[j];  k = j;
        j <<= 1;
    }
    s->heap[k] = v;
}
local void gen_bitlen(s, desc)
    deflate_state *s;
    tree_desc *desc;
{
    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;
    int n, m;
    int bits;
    int xbits;
    ush f;
    int overflow = 0;

    for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0;
    tree[s->heap[s->heap_max]].Len = 0;

    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;

        if (n > max_code) continue;

        s->bl_count[bits]++;
        xbits = 0;
        if (n >= base) xbits = extra[n-base];
        f = tree[n].Freq;
        s->opt_len += (ulg)f * (unsigned)(bits + xbits);
        if (stree) s->static_len += (ulg)f * (unsigned)(stree[n].Len + xbits);
    }
    if (overflow == 0) return;

    Tracev((stderr,"\nbit length overflow\n"));
    do {
        bits = max_length-1;
        while (s->bl_count[bits] == 0) bits--;
        s->bl_count[bits]--;
        s->bl_count[bits+1] += 2;
        s->bl_count[max_length]--;
        overflow -= 2;
    } while (overflow > 0);
    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) {
                Tracev((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
                s->opt_len += ((ulg)bits - tree[m].Len) * tree[m].Freq;
                tree[m].Len = (ush)bits;
            }
            n--;
        }
    }
}
local void gen_codes (tree, max_code, bl_count)
    ct_data *tree;
    int max_code;
    ushf *bl_count;
{
    ush next_code[MAX_BITS+1];
    unsigned code = 0;
    int bits;
    int n;
    for (bits = 1; bits <= MAX_BITS; bits++) {
        code = (code + bl_count[bits-1]) << 1;
        next_code[bits] = (ush)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;
        tree[n].Code = (ush)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;
{
    ct_data *tree         = desc->dyn_tree;
    const ct_data *stree  = desc->stat_desc->static_tree;
    int elems             = desc->stat_desc->elems;
    int n, m;
    int max_code = -1;
    int node;
    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;
        }
    }
    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;
    }
    desc->max_code = max_code;
    for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n);
    node = elems;
    do {
        pqremove(s, tree, n);
        m = s->heap[SMALLEST];

        s->heap[--(s->heap_max)] = n;
        s->heap[--(s->heap_max)] = 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
        s->heap[SMALLEST] = node++;
        pqdownheap(s, tree, SMALLEST);

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

    s->heap[--(s->heap_max)] = s->heap[SMALLEST];
    gen_bitlen(s, (tree_desc *)desc);
    gen_codes ((ct_data *)tree, max_code, s->bl_count);
}
local void scan_tree (s, tree, max_code)
    deflate_state *s;
    ct_data *tree;
    int max_code;
{
    int n;
    int prevlen = -1;
    int curlen;
    int nextlen = tree[0].Len;
    int count = 0;
    int max_count = 7;
    int min_count = 4;

    if (nextlen == 0) max_count = 138, min_count = 3;
    tree[max_code+1].Len = (ush)0xffff;

    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;
    int max_code;
{
    int n;
    int prevlen = -1;
    int curlen;
    int nextlen = tree[0].Len;
    int count = 0;
    int max_count = 7;
    int min_count = 4;
    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;
    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_tree(s, (tree_desc *)(&(s->bl_desc)));
    for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) {
        if (s->bl_tree[bl_order[max_blindex]].Len != 0) break;
    }
    s->opt_len += 3*((ulg)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;
{
    int rank;

    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);
    send_bits(s, dcodes-1,   5);
    send_bits(s, blcodes-4,  4);
    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);
    Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));

    send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1);
    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;
    ulg stored_len;
    int last;
{
    send_bits(s, (STORED_BLOCK<<1)+last, 3);
    bi_windup(s);
    put_short(s, (ush)stored_len);
    put_short(s, (ush)~stored_len);
    zmemcpy(s->pending_buf + s->pending, (Bytef *)buf, stored_len);
    s->pending += stored_len;
#ifdef ZLIB_DEBUG
    s->compressed_len = (s->compressed_len + 3 + 7) & (ulg)~7L;
    s->compressed_len += (stored_len + 4) << 3;
    s->bits_sent += 2*16;
    s->bits_sent += stored_len<<3;
#endif
}
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 ZLIB_DEBUG
    s->compressed_len += 10L;
#endif
    bi_flush(s);
}
void ZLIB_INTERNAL _tr_flush_block(s, buf, stored_len, last)
    deflate_state *s;
    charf *buf;
    ulg stored_len;
    int last;
{
    ulg opt_lenb, static_lenb;
    int max_blindex = 0;
    if (s->level > 0) {
        if (s->strm->data_type == Z_UNKNOWN)
            s->strm->data_type = detect_data_type(s);
        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));
        max_blindex = build_bl_tree(s);
        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;
    }

#ifdef FORCE_STORED
    if (buf != (char*)0) {
#else
    if (stored_len+4 <= opt_lenb && buf != (char*)0) {
#endif
        _tr_stored_block(s, buf, stored_len, last);

#ifdef FORCE_STATIC
    } else if (static_lenb >= 0) {
#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 ZLIB_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 ZLIB_DEBUG
        s->compressed_len += 3 + s->opt_len;
#endif
    }
    Assert (s->compressed_len == s->bits_sent, "bad compressed size");
    init_block(s);

    if (last) {
        bi_windup(s);
#ifdef ZLIB_DEBUG
        s->compressed_len += 7;
#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;
    unsigned lc;
{
    s->d_buf[s->last_lit] = (ush)dist;
    s->l_buf[s->last_lit++] = (uch)lc;
    if (dist == 0) {
        s->dyn_ltree[lc].Freq++;
    } else {
        s->matches++;
        dist--;
        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
    if ((s->last_lit & 0x1fff) == 0 && s->level > 2) {
        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);
}
local void compress_block(s, ltree, dtree)
    deflate_state *s;
    const ct_data *ltree;
    const ct_data *dtree;
{
    unsigned dist;
    int lc;
    unsigned lx = 0;
    unsigned code;
    int extra;

    if (s->last_lit != 0) do {
        dist = s->d_buf[lx];
        lc = s->l_buf[lx++];
        if (dist == 0) {
            send_code(s, lc, ltree);
            Tracecv(isgraph(lc), (stderr," '%c' ", lc));
        } else {
            code = _length_code[lc];
            send_code(s, code+LITERALS+1, ltree);
            extra = extra_lbits[code];
            if (extra != 0) {
                lc -= base_length[code];
                send_bits(s, lc, extra);
            }
            dist--;
            code = d_code(dist);
            Assert (code < D_CODES, "bad d_code");

            send_code(s, code, dtree);
            extra = extra_dbits[code];
            if (extra != 0) {
                dist -= (unsigned)base_dist[code];
                send_bits(s, dist, extra);
            }
        }
        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;
{
    unsigned long black_mask = 0xf3ffc07fUL;
    int n;
    for (n = 0; n <= 31; n++, black_mask >>= 1)
        if ((black_mask & 1) && (s->dyn_ltree[n].Freq != 0))
            return Z_BINARY;
    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;
    return Z_BINARY;
}
local unsigned bi_reverse(code, len)
    unsigned code;
    int len;
{
    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 ZLIB_DEBUG
    s->bits_sent = (s->bits_sent+7) & ~7;
#endif
}
