; trees.asm -- output deflated data using Huffman coding
; Copyright (C) 1995-2012 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
; ALGORITHM
; The "deflation" process uses several Huffman trees. The more
; common source values are represented by shorter bit sequences.
; Each code tree is stored in a compressed form which is itself
; a Huffman encoding of the lengths of all the code strings (in
; ascending order by source values). The actual code strings are
; reconstructed from the lengths in the inflate process, as described
; in the deflate specification.
; REFERENCES
; Deutsch, L.P.,"'Deflate' Compressed Data Format Specification".
; Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc
; Storer, James A.
; Data Compression: Methods and Theory, pp. 49-50.
; Computer Science Press, 1988. ISBN 0-7167-8156-5.
; Sedgewick, R.
; Algorithms, p290.
; Addison-Wesley, 1983. ISBN 0-201-06672-6.
; ===========================================================================
; Constants
MAX_BL_BITS equ 7
; Bit length codes must not exceed MAX_BL_BITS bits
END_BLOCK equ 256
; end of block literal code
REP_3_6 equ 16
; repeat previous bit length 3-6 times (2 bits of repeat count)
REPZ_3_10 equ 17
; repeat a zero length 3-10 times (3 bits of repeat count)
REPZ_11_138 equ 18
; repeat a zero length 11-138 times (7 bits of repeat count)
align 4
extra_lbits dd \ ;int [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
align 4
extra_dbits dd \ ;int [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
align 4
extra_blbits dd \ ;int [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
align 4
bl_order db 16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15
; The lengths of the bit length codes are sent in order of decreasing
; probability, to avoid transmitting the lengths for unused bit length codes.
; ===========================================================================
; Local data. These are initialized only once.
DIST_CODE_LEN equ 512 ;see definition of array dist_code below
if GEN_TREES_H eq 1 ;| !(STDC)
; non ANSI compilers may not accept trees.inc
align 4
static_ltree rb sizeof.ct_data * (L_CODES+2)
; The static literal tree. Since the bit lengths are imposed, there is no
; need for the L_CODES extra codes used during heap construction. However
; The codes 286 and 287 are needed to build a canonical tree (see _tr_init
; below).
align 4
static_dtree rb sizeof.ct_data * D_CODES
; The static distance tree. (Actually a trivial tree since all codes use
; 5 bits.)
align 4
_dist_code rb DIST_CODE_LEN ;uch[]
; Distance codes. The first 256 values correspond to the distances
; 3 .. 258, the last 256 values correspond to the top 8 bits of
; the 15 bit distances.
align 4
_length_code rb MAX_MATCH-MIN_MATCH+1 ;uch[]
; length code for each normalized match length (0 == MIN_MATCH)
align 4
base_length rd LENGTH_CODES ;int[]
; First normalized length for each code (0 = MIN_MATCH)
align 4
base_dist rd D_CODES ;int[]
; First normalized distance for each code (0 = distance of 1)
else
include 'trees.inc'
end if ;GEN_TREES_H
struct static_tree_desc ;_s
static_tree dd ? ;const ct_data * ;static tree or NULL
extra_bits dd ? ;const intf * ;extra bits for each code or NULL
extra_base dd ? ;int ;base index for extra_bits
elems dd ? ;int ;max number of elements in the tree
max_length dd ? ;int ;max bit length for the codes
ends
align 4
static_l_desc static_tree_desc static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS
align 4
static_d_desc static_tree_desc static_dtree, extra_dbits, 0, D_CODES, MAX_BITS
align 4
static_bl_desc static_tree_desc 0, extra_blbits, 0, BL_CODES, MAX_BL_BITS
; ===========================================================================
; Local (static) routines in this file.
macro send_code s, c, tree
{
if DEBUG eq 1
; if (z_verbose>2) fprintf(stderr,"\ncd %3d ",(c))
end if
push eax ebx
if c eq eax
else
mov eax,c
end if
imul eax,sizeof.ct_data
add eax,tree
movzx ebx,word[eax+Len]
push ebx
movzx ebx,word[eax+Code]
push ebx
stdcall send_bits, s ;tree[c].Code, tree[c].Len
pop ebx eax
}
; Send a code of the given tree[c] and tree must not have side effects
; ===========================================================================
; Output a short LSB first on the stream.
; IN assertion: there is enough room in pendingBuf.
macro put_short s, w
{
mov eax,[s+deflate_state.pending]
add eax,[s+deflate_state.pending_buf]
mov word[eax],w
add dword[s+deflate_state.pending],2
}
; ===========================================================================
; Send a value on a given number of bits.
; IN assertion: length <= 16 and value fits in length bits.
;void (s, value, length)
; deflate_state* s
; int value ;value to send
; int length ;number of bits
align 4
proc send_bits uses eax ecx edi, s:dword, value:dword, length:dword
; Tracevv((stderr," l %2d v %4x ", length, value));
zlib_debug 'send_bits value = %d',[value]
;if DEBUG eq 1
mov eax,[length]
cmp eax,0
jle @f
cmp eax,15
jle .end1
@@:
zlib_assert 'invalid length' ;Assert(..>0 && ..<=15)
.end1:
mov edi,[s]
add [edi+deflate_state.bits_sent],eax
; If not enough room in bi_buf, use (valid) bits from bi_buf and
; (16 - bi_valid) bits from value, leaving (width - (16-bi_valid))
; unused bits in value.
mov ecx,Buf_size
sub ecx,eax
cmp [edi+deflate_state.bi_valid],ecx
jle @f ;if (..>..)
mov eax,[value]
mov ecx,[edi+deflate_state.bi_valid]
shl eax,cl
or [edi+deflate_state.bi_buf],ax
mov cx,[edi+deflate_state.bi_buf]
put_short edi, cx
mov eax,[value]
mov ecx,Buf_size
sub ecx,[edi+deflate_state.bi_valid]
shr eax,cl
mov [edi+deflate_state.bi_buf],ax
mov eax,[length]
sub eax,Buf_size
jmp .end0
@@: ;else
mov eax,[value]
mov ecx,[edi+deflate_state.bi_valid]
shl eax,cl
or [edi+deflate_state.bi_buf],ax
mov eax,[length]
.end0:
add [edi+deflate_state.bi_valid],eax
;else ;!DEBUG
;{ int len = length;
; if (s->bi_valid > (int)Buf_size - len) {
; int val = value;
; s->bi_buf |= (uint_16)val << s->bi_valid;
; put_short(s, s->bi_buf);
; s->bi_buf = (uint_16)val >> (Buf_size - s->bi_valid);
; s->bi_valid += len - Buf_size;
; } else {
; s->bi_buf |= (uint_16)(value) << s->bi_valid;
; s->bi_valid += len;
; }
;}
;end if ;DEBUG
ret
endp
; the arguments must not have side effects
; ===========================================================================
; Initialize the various 'constant' tables.
;int static_init_done = 0
;void ()
align 4
proc tr_static_init
if GEN_TREES_H eq 1
; int n ;iterates over tree elements
; int bits ;bit counter
; int length ;length value
; int code ;code value
; int dist ;distance index
; uint_16 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:
;if 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;
;end if
; 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
; in two different ways: code 284 + 5 bits or code 285, so we
; overwrite length_code[255] to use the best encoding:
; _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
; tree construction to get a canonical Huffman tree (longest code
; all ones)
; 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;
if GEN_TREES_H eq 1
call gen_trees_header
end if
end if ;(GEN_TREES_H) | !(STDC)
ret
endp
; ===========================================================================
; Genererate the file trees.h describing the static trees.
;# define SEPARATOR(i, last, width) \
; ((i) == (last)? "\n};\n\n" : \
; ((i) % (width) == (width)-1 ? ",\n" : ", "))
;void ()
align 4
proc gen_trees_header
; FILE *header = fopen("trees.inc", "w");
; int i;
; Assert (header != NULL, "Can't open trees.inc");
; 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);
ret
endp
; ===========================================================================
; Initialize the tree data structures for a new zlib stream.
;void (s)
; deflate_state* s
align 4
proc _tr_init uses eax edi, s:dword
mov edi,[s]
zlib_debug '_tr_init'
call tr_static_init
mov eax,edi
add eax,deflate_state.dyn_ltree
mov [edi+deflate_state.l_desc.dyn_tree],eax
mov [edi+deflate_state.l_desc.stat_desc],static_l_desc
add eax,deflate_state.dyn_dtree-deflate_state.dyn_ltree
mov [edi+deflate_state.d_desc.dyn_tree],eax
mov [edi+deflate_state.d_desc.stat_desc],static_d_desc
add eax,deflate_state.bl_tree-deflate_state.dyn_dtree
mov [edi+deflate_state.bl_desc.dyn_tree],eax
mov [edi+deflate_state.bl_desc.stat_desc],static_bl_desc;
mov word[edi+deflate_state.bi_buf],0
mov dword[edi+deflate_state.bi_valid],0
if DEBUG eq 1
mov dword[edi+deflate_state.compressed_len],0
mov dword[edi+deflate_state.bits_sent],0
end if
; Initialize the first block of the first file:
stdcall init_block,edi
ret
endp
; ===========================================================================
; Initialize a new block.
;void (s)
; deflate_state* s
align 4
proc init_block uses eax ecx edi, s:dword
mov edi,[s]
; Initialize the trees.
mov eax,edi
add eax,deflate_state.dyn_ltree+Freq
mov ecx,L_CODES
@@:
mov word[eax],0
add eax,sizeof.ct_data
loop @b
mov eax,edi
add eax,deflate_state.dyn_dtree+Freq
mov ecx,D_CODES
@@:
mov word[eax],0
add eax,sizeof.ct_data
loop @b
mov eax,edi
add eax,deflate_state.bl_tree+Freq
mov ecx,BL_CODES
@@:
mov word[eax],0
add eax,sizeof.ct_data
loop @b
mov word[edi+sizeof.ct_data*END_BLOCK+deflate_state.dyn_ltree+Freq],1
mov dword[edi+deflate_state.static_len],0
mov dword[edi+deflate_state.opt_len],0
mov dword[edi+deflate_state.matches],0
mov dword[edi+deflate_state.last_lit],0
ret
endp
SMALLEST equ 1
; Index within the heap array of least frequent node in the Huffman tree
; ===========================================================================
; Remove the smallest element from the heap and recreate the heap with
; one less element. Updates heap and heap_len.
macro pqremove s, tree, top
{
mov eax,s
add eax,deflate_state.heap+2*SMALLEST
movzx top,word[eax]
push ebx
mov ebx,[s+deflate_state.heap_len]
mov bx,[s+deflate_state.heap+2*ebx]
mov word[eax],bx
dec dword[s+deflate_state.heap_len]
pop ebx
stdcall pqdownheap, s, tree, SMALLEST
}
; ===========================================================================
; Compares to subtrees, using the tree depth as tie breaker when
; the subtrees have equal frequency. This minimizes the worst case length.
macro smaller tree, n, m, depth, m_end
{
;if (..<.. || (..==.. && depth[n] <= depth[m]))
local .end0
movzx eax,n
imul eax,sizeof.ct_data
add eax,tree
mov ax,word[eax+Freq]
movzx ebx,m
imul ebx,sizeof.ct_data
add ebx,tree
mov bx,word[ebx+Freq]
cmp ax,bx
jl .end0
jne m_end
movzx eax,n
mov al,byte[eax+depth]
movzx ebx,m
cmp al,byte[ebx+depth]
jg m_end
.end0:
}
; ===========================================================================
; Restore the heap property by moving down the tree starting at node k,
; exchanging a node with the smallest of its two sons if necessary, stopping
; when the heap property is re-established (each father smaller than its
; two sons).
;void (s, tree, k)
; deflate_state* s
; ct_data* tree ;the tree to restore
; int k ;node to move down
align 4
proc pqdownheap, s:dword, tree:dword, k:dword
pushad
;ecx - v dw
mov edi,[s]
mov esi,[k]
zlib_debug 'pqdownheap k = %d',esi
mov cx,[edi+deflate_state.heap+2*esi]
shl esi,1
;esi = j ;left son of k
.cycle0: ;while (..<=..)
cmp esi,[edi+deflate_state.heap_len]
jg .cycle0end
; Set j to the smallest of the two sons:
;;cmp esi,[edi+deflate_state.heap_len]
jge .end1 ;if (..<.. &&
mov edx,esi
shl edx,1
add edx,edi
add edx,deflate_state.heap
smaller [tree], word[edx+2], word[edx], edi+deflate_state.depth, .end1
inc esi
.end1:
; Exit if v is smaller than both sons
mov dx,[edi+deflate_state.heap+2*esi]
smaller [tree], cx, dx, edi+deflate_state.depth, .end2
jmp .cycle0end ;break
.end2:
; Exchange v with the smallest son
;;mov dx,[edi+deflate_state.heap+2*esi]
mov eax,[k]
mov [edi+deflate_state.heap+2*eax],dx
mov [k],esi
; And continue down the tree, setting j to the left son of k
shl esi,1
jmp .cycle0
align 4
.cycle0end:
mov eax,[k]
mov [edi+deflate_state.heap+2*eax],cx
popad
ret
endp
; ===========================================================================
; Compute the optimal bit lengths for a tree and update the total bit length
; for the current block.
; IN assertion: the fields freq and dad are set, heap[heap_max] and
; above are the tree nodes sorted by increasing frequency.
; OUT assertions: the field len is set to the optimal bit length, the
; array bl_count contains the frequencies for each bit length.
; The length opt_len is updated; static_len is also updated if stree is
; not null.
;void (s, desc)
; deflate_state* s
; tree_desc* desc ;the tree descriptor
align 4
proc gen_bitlen, s:dword, desc:dword
locals
tree dd ? ;ct_data* ;= desc.dyn_tree
max_code dd ? ;int ;= desc.max_code
stree dd ? ;ct_data* ;= desc.stat_desc.static_tree
extra dd ? ;intf* ;= desc.stat_desc.extra_bits
base dd ? ;int ;= desc.stat_desc.extra_base
max_length dd ? ;int ;= desc.stat_desc.max_length
h dd ? ;int ;heap index
m dd ? ;int ;iterate over the tree elements
bits dd ? ;int ;bit length
xbits dd ? ;int ;extra bits
f dw ? ;uint_16 ;frequency
overflow dd 0 ;int ;number of elements with bit length too large
endl
pushad
zlib_debug 'gen_bitlen'
mov edi,[s]
mov edx,[desc]
mov eax,[edx+tree_desc.dyn_tree]
mov [tree],eax
mov eax,[edx+tree_desc.max_code]
mov [max_code],eax
mov ebx,[edx+tree_desc.stat_desc]
mov eax,[ebx+static_tree_desc.static_tree]
mov [stree],eax
mov eax,[ebx+static_tree_desc.extra_bits]
mov [extra],eax
mov eax,[ebx+static_tree_desc.extra_base]
mov [base],eax
mov eax,[ebx+static_tree_desc.max_length]
mov [max_length],eax
xor ecx,ecx
.cycle0:
cmp ecx,MAX_BITS
jg .cycle0end ;for (..;..<=..;..)
mov word[edi+deflate_state.bl_count+2*ecx],0
inc ecx
jmp .cycle0
align 4
.cycle0end:
; In a first pass, compute the optimal bit lengths (which may
; overflow in the case of the bit length tree).
mov eax,[edi+deflate_state.heap_max]
movzx eax,word[edi+deflate_state.heap+2*eax]
imul eax,sizeof.ct_data
add eax,[tree]
mov word[eax+Len],0 ;root of the heap
mov eax,[edi+deflate_state.heap_max]
inc eax
mov [h],eax
.cycle1:
cmp dword[h],HEAP_SIZE
jge .cycle1end ;for (..;..<..;..)
mov eax,[h]
movzx ecx,word[edi+deflate_state.heap+2*eax]
;ecx = n
mov eax,sizeof.ct_data
imul eax,ecx
add eax,[tree]
movzx eax,word[eax+Dad]
imul eax,sizeof.ct_data
add eax,[tree]
movzx eax,word[eax+Len]
inc eax
mov [bits],eax ;bits = tree[tree[n].Dad].Len + 1
mov eax,[max_length]
cmp [bits],eax
jle @f ;if (..>..)
mov [bits],eax
inc dword[overflow]
@@:
mov esi,[bits]
mov eax,sizeof.ct_data
imul eax,ecx
add eax,[tree]
mov word[eax+Len],si
; We overwrite tree[n].Dad which is no longer needed
cmp ecx,[max_code]
jle @f
inc dword[h]
jmp .cycle1 ;if (..>..) continue ;not a leaf node
@@:
mov eax,[bits]
shl eax,1 ;*= sizeof.uint_16
inc word[eax+edi+deflate_state.bl_count]
mov dword[xbits],0
cmp ecx,[base]
jl @f ;if (..>=..)
mov eax,ecx
sub eax,[base]
shl eax,2 ;*= sizeof.dd
add eax,[extra]
mov eax,[eax]
mov [xbits],eax
@@:
mov eax,sizeof.ct_data
imul eax,ecx
add eax,[tree]
movzx eax,word[eax+Freq]
mov [f],ax
mov esi,[bits]
add esi,[xbits]
imul eax,esi
add [edi+deflate_state.opt_len],eax
cmp dword[stree],0
je @f ;if (..)
movzx eax,word[f]
mov esi,sizeof.ct_data
imul esi,ecx
add esi,[tree]
movzx esi,word[esi+Len]
add esi,[xbits]
imul eax,esi
add [edi+deflate_state.static_len],eax
@@:
inc dword[h]
jmp .cycle1
align 4
.cycle1end:
cmp dword[overflow],0
je .end_f ;if (..==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:
.cycle2: ;do
mov eax,[max_length]
dec eax
mov [bits],eax
shl eax,1 ;*= sizeof.dw
add eax,edi
add eax,deflate_state.bl_count
@@:
cmp word[eax],0
jne @f ;while (..==0) bits--
dec dword[bits]
sub eax,2
jmp @b
align 4
@@:
dec word[eax] ;move one leaf down the tree
add word[eax+2],2 ;move one overflow item as its brother
mov eax,[max_length]
dec word[edi+deflate_state.bl_count+2*eax]
; The brother of the overflow item also moves one step up,
; but this does not affect bl_count[max_length]
sub dword[overflow],2
cmp dword[overflow],0
jg .cycle2 ;while (..>0)
; Now recompute all bit lengths, scanning in increasing frequency.
; h is still equal to HEAP_SIZE. (It is simpler to reconstruct all
; lengths instead of fixing only the wrong ones. This idea is taken
; from 'ar' written by Haruhiko Okumura.)
mov eax,[max_length]
mov [bits],eax
.cycle3:
cmp dword[bits],0
je .end_f ;for (..;..!=0;..)
mov eax,[bits]
shl eax,1 ;*= sizeof.dw
movzx ecx,word[eax+edi+deflate_state.bl_count]
.cycle4: ;while (..!=0)
cmp ecx,0
je .cycle4end
dec dword[h]
mov eax,[h]
movzx eax,word[edi+deflate_state.heap+2*eax]
mov [m],eax ;m = s.heap[--h]
cmp eax,[max_code]
jg .cycle4 ;if (..>..) continue
mov esi,[m]
imul esi,sizeof.ct_data
add esi,[tree] ;esi = &tree[m]
mov eax,[bits]
cmp word[esi+Len],ax
je @f ;if (..!=..)
; Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
movzx ebx,word[esi+Len]
sub eax,ebx
movzx ebx,word[esi+Freq]
imul eax,ebx ;eax = (bits - tree[m].Len) * tree[m].Freq
add [edi+deflate_state.opt_len],eax
mov eax,[bits]
mov word[esi+Len],ax
@@:
dec ecx
jmp .cycle4
align 4
.cycle4end:
dec dword[bits]
jmp .cycle3
align 4
.end_f:
popad
ret
endp
; ===========================================================================
; Generate the codes for a given tree and bit counts (which need not be
; optimal).
; IN assertion: the array bl_count contains the bit length statistics for
; the given tree and the field len is set for all tree elements.
; OUT assertion: the field code is set for all tree elements of non
; zero code length.
;void (tree, max_code, bl_count)
; ct_data *tree ;the tree to decorate
; int max_code ;largest code with non zero frequency
; uint_16p bl_count ;number of codes at each bit length
align 4
proc gen_codes uses eax ebx ecx edx edi, tree:dword, max_code:dword, bl_count:dword
locals
u_code dw 0 ;uint_16 ;running code value
bits dd 1 ;int ;bit index
next_code rw MAX_BITS+1 ;uint_16[] ;next code value for each bit length
endl
; The distribution counts are first used to generate the code values
; without bit reversal.
zlib_debug 'gen_codes'
mov ebx,ebp
sub ebx,2*(MAX_BITS+1)
.cycle0: ;for (..;..<=..;..)
cmp dword[bits],MAX_BITS
jg .cycle0end
mov eax,[bits]
dec eax
shl eax,1
add eax,[bl_count]
mov ax,word[eax]
add ax,[u_code]
shl ax,1 ;ax = (u_code + bl_count[bits-1]) << 1
mov [u_code],ax
mov ecx,[bits]
mov word[ebx+2*ecx],ax ;next_code[bits] = u_code
inc dword[bits]
jmp .cycle0
.cycle0end:
; Check that the bit counts in bl_count are consistent. The last code
; must be all ones.
mov eax,[bl_count]
mov ax,word[eax+2*MAX_BITS]
add ax,[u_code]
dec ax
cmp ax,(1 shl MAX_BITS)-1
je @f
zlib_assert 'inconsistent bit counts' ;Assert(..==..)
@@:
; Tracev((stderr,"\ngen_codes: max_code %d ", max_code));
xor ecx,ecx ;n = 0
.cycle1: ;for (..;..<=..;..)
cmp ecx,[max_code]
jg .cycle1end
mov edx,sizeof.ct_data
imul edx,ecx
add edx,[tree] ;edx = &tree[n]
movzx edi,word[edx+Len]
cmp edi,0
jne @f ;if (..==0) continue
inc ecx
jmp .cycle1
@@:
; Now reverse the bits
movzx eax,word[ebx+2*edi]
stdcall bi_reverse, eax, edi
mov word[edx+Code],ax
inc word[ebx+2*edi]
; 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));
inc ecx
jmp .cycle1
.cycle1end:
ret
endp
; ===========================================================================
; Construct one Huffman tree and assigns the code bit strings and lengths.
; Update the total bit length for the current block.
; IN assertion: the field freq is set for all tree elements.
; OUT assertions: the fields len and code are set to the optimal bit length
; and corresponding code. The length opt_len is updated; static_len is
; also updated if stree is not null. The field max_code is set.
;void (s, desc)
; deflate_state* s
; tree_desc *desc ;the tree descriptor
align 4
proc build_tree uses eax ebx ecx edx edi, s:dword, desc:dword
locals
tree dd ? ;ct_data* ;= desc.dyn_tree
stree dd ? ;ct_data* ;= desc.stat_desc.static_tree
elems dd ? ;int ;= desc.stat_desc.elems
m dd ? ;int ;iterate over heap elements
max_code dd -1 ;int ;largest code with non zero frequency
node dd ? ;int ;new node being created
endl
; Construct the initial heap, with least frequent element in
; heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1].
; heap[0] is not used.
mov ebx,[desc]
mov eax,[ebx+tree_desc.dyn_tree]
mov [tree],eax
mov ecx,[ebx+tree_desc.stat_desc]
mov eax,[ecx+static_tree_desc.static_tree]
mov [stree],eax
mov ecx,[ecx+static_tree_desc.elems]
mov [elems],ecx
mov edi,[s]
zlib_debug 'build_tree cycle0 ecx = %d',ecx
mov dword[edi+deflate_state.heap_len],0
mov dword[edi+deflate_state.heap_max],HEAP_SIZE
mov edx,[tree]
xor ecx,ecx
.cycle0: ;for (..;..<..;..)
cmp ecx,[elems]
jge .cycle0end
cmp word[edx+Freq],0
je @f ;if (..!=0)
inc dword[edi+deflate_state.heap_len]
mov eax,[edi+deflate_state.heap_len]
mov [max_code],ecx
mov [edi+deflate_state.heap+2*eax],cx
mov byte[edi+deflate_state.depth+ecx],0
jmp .end0
align 4
@@: ;else
mov word[edx+Len],0
.end0:
add edx,sizeof.ct_data
inc ecx
jmp .cycle0
align 4
.cycle0end:
; The pkzip format requires that at least one distance code exists,
; and that at least one bit should be sent even if there is only one
; possible code. So to avoid special checks later on we force at least
; two codes of non zero frequency.
.cycle1: ;while (..<..)
cmp dword[edi+deflate_state.heap_len],2
jge .cycle1end
inc dword[edi+deflate_state.heap_len]
xor eax,eax
cmp dword[max_code],2
jge @f
inc dword[max_code]
mov eax,[max_code]
@@:
mov ecx,[edi+deflate_state.heap_len]
mov [edi+deflate_state.heap+2*ecx],ax
mov [node],eax
imul eax,sizeof.ct_data
add eax,[tree]
mov word[eax+Freq],1
mov eax,[node]
mov byte[edi+deflate_state.depth+eax],0
dec dword[edi+deflate_state.opt_len]
cmp dword[stree],0
je .cycle1 ;if (..)
mov eax,[node]
imul eax,sizeof.ct_data
add eax,[stree]
movzx eax,word[eax+Len]
sub [edi+deflate_state.static_len],eax
; node is 0 or 1 so it does not have extra bits
jmp .cycle1
align 4
.cycle1end:
mov eax,[max_code]
mov [ebx+tree_desc.max_code],eax
; The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree,
; establish sub-heaps of increasing lengths:
mov ecx,[edi+deflate_state.heap_len]
shr ecx,1
.cycle2: ;for (..;..>=..;..)
cmp ecx,1
jl .cycle2end
stdcall pqdownheap, edi, [tree], ecx
dec ecx
jmp .cycle2
align 4
.cycle2end:
; Construct the Huffman tree by repeatedly combining the least two
; frequent nodes.
mov eax,[elems]
mov [node],eax ;next internal node of the tree
.cycle3: ;do
pqremove edi, [tree], ecx ;n = node of least frequency
movzx edx,word[eax]
mov [m],edx ;m = node of next least frequency
mov eax,[edi+deflate_state.heap_max]
dec eax
mov [edi+deflate_state.heap+2*eax],cx ;keep the nodes sorted by frequency
dec eax
mov [edi+deflate_state.heap_max],eax
mov [edi+deflate_state.heap+2*eax],dx
; Create a new node father of n and m
;;mov edx,[m]
imul edx,sizeof.ct_data
add edx,[tree]
mov ax,word[edx+Freq]
mov edx,ecx
imul edx,sizeof.ct_data
add edx,[tree]
add ax,word[edx+Freq]
mov edx,[node]
imul edx,sizeof.ct_data
add edx,[tree]
mov word[edx+Freq],ax
mov eax,ecx
add eax,edi
mov al,byte[eax+deflate_state.depth]
mov edx,[m]
add edx,edi
mov ah,byte[edx+deflate_state.depth]
cmp al,ah
jge @f ;if (al>=ah) al=al : al=ah
mov al,ah
@@:
inc al
mov edx,[node]
add edx,edi
mov byte[edx+deflate_state.depth],al
mov eax,[node]
mov edx,[m]
imul edx,sizeof.ct_data
add edx,[tree]
mov [edx+Dad],ax
mov edx,ecx
imul edx,sizeof.ct_data
add edx,[tree]
mov [edx+Dad],ax
;if DUMP_BL_TREE eq 1
; 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);
; }
;end if
; and insert the new node in the heap
mov ecx,[node]
mov [edi+deflate_state.heap+2*SMALLEST],cx
inc dword[node]
stdcall pqdownheap, edi, [tree], SMALLEST
cmp dword[edi+deflate_state.heap_len],2
jge .cycle3 ;while (..>=..)
mov cx,[edi+deflate_state.heap+2*SMALLEST]
dec dword[edi+deflate_state.heap_max]
mov eax,[edi+deflate_state.heap_max]
mov [edi+deflate_state.heap+2*eax],cx
; At this point, the fields freq and dad are set. We can now
; generate the bit lengths.
stdcall gen_bitlen, edi, [desc]
; The field len is now set, we can generate the bit codes
mov eax,edi
add eax,deflate_state.bl_count
stdcall gen_codes, [tree], [max_code], eax
ret
endp
; ===========================================================================
; Scan a literal or distance tree to determine the frequencies of the codes
; in the bit length tree.
;void (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
align 4
proc scan_tree uses eax ebx ecx edi, s:dword, tree:dword, max_code:dword
locals
n dd ? ;int ;iterates over all tree elements
prevlen dd -1 ;int ;last emitted length
curlen dd ? ;int ;length of current code
nextlen dd ? ;int ;= tree[0].Len ;length of next code
count dd 0 ;int ;repeat count of the current code
max_count dd 7 ;int ;max repeat count
min_count dd 4 ;int ;min repeat count
endl
mov edi,[s]
zlib_debug 'scan_tree'
mov eax,[tree]
movzx eax,word[eax+Len]
mov [nextlen],eax
test eax,eax
jnz @f ;if (..==0)
mov dword[max_count],138
mov dword[min_count],3
@@:
mov eax,[max_code]
inc eax
imul eax,sizeof.ct_data
add eax,[tree]
mov word[eax+Len],0xffff ;guard
xor ecx,ecx
align 4
.cycle0:
cmp ecx,[max_code]
jg .cycle0end ;for (..;..<=..;..)
mov eax,[nextlen]
mov [curlen],eax
inc ecx
mov eax,sizeof.ct_data
imul eax,ecx
add eax,[tree]
movzx eax,word[eax+Len]
mov [nextlen],eax
inc dword[count]
mov ebx,[count]
cmp ebx,[max_count]
jge .end0
mov eax,[nextlen]
cmp [curlen],eax
je .cycle0 ;if (..<.. && ..==..) continue
align 4
.end0:
cmp ebx,[min_count]
jge .end1 ;else if (..<..)
mov eax,[curlen]
imul eax,sizeof.ct_data
add eax,edi
add word[eax+deflate_state.bl_tree+Freq],bx
jmp .end4
align 4
.end1:
cmp dword[curlen],0
je .end2 ;else if (..!=0)
mov eax,[curlen]
cmp eax,[prevlen]
je @f ;if (..!=..)
imul eax,sizeof.ct_data
add eax,edi
inc word[eax+deflate_state.bl_tree+Freq]
@@:
mov eax,REP_3_6
imul eax,sizeof.ct_data
add eax,edi
inc word[eax+deflate_state.bl_tree+Freq]
jmp .end4
align 4
.end2:
cmp ebx,10
jg .end3 ;else if (..<=..)
mov eax,REPZ_3_10
imul eax,sizeof.ct_data
add eax,edi
inc word[eax+deflate_state.bl_tree+Freq]
jmp .end4
align 4
.end3: ;else
mov eax,REPZ_11_138
imul eax,sizeof.ct_data
add eax,edi
inc word[eax+deflate_state.bl_tree+Freq]
.end4:
mov dword[count],0
mov eax,[curlen]
mov [prevlen],eax
cmp dword[nextlen],0
jne .end5 ;if (..==0)
mov dword[max_count],138
mov dword[min_count],3
jmp .cycle0
align 4
.end5:
cmp eax,[nextlen]
jne .end6 ;else if (..==..)
mov dword[max_count],6
mov dword[min_count],3
jmp .cycle0
align 4
.end6: ;else
mov dword[max_count],7
mov dword[min_count],4
jmp .cycle0
align 4
.cycle0end:
ret
endp
; ===========================================================================
; Send a literal or distance tree in compressed form, using the codes in
; bl_tree.
;void (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
align 4
proc send_tree uses eax ebx ecx edi, s:dword, tree:dword, max_code:dword
locals
n dd ? ;int ;iterates over all tree elements
prevlen dd -1 ;int ;last emitted length
curlen dd ? ;int ;length of current code
nextlen dd ? ;int ;= tree[0].Len ;length of next code
count dd 0 ;int ;repeat count of the current code
max_count dd 7 ;int ;max repeat count
min_count dd 4 ;int ;min repeat count
endl
mov edi,[s]
zlib_debug 'send_tree'
; *** tree[max_code+1].Len = -1 ;guard already set
mov eax,[tree]
movzx eax,word[eax+Len]
mov [nextlen],eax
xor ecx,ecx
test eax,eax
jnz .cycle0 ;if (..==0)
mov dword[max_count],138
mov dword[min_count],3
align 4
.cycle0: ;for (..;..<=..;..)
cmp ecx,[max_code]
jg .cycle0end
mov eax,[nextlen]
mov [curlen],eax
mov eax,ecx
inc eax
imul eax,sizeof.ct_data
add eax,[tree]
movzx eax,word[eax+Len]
mov [nextlen],eax
inc dword[count]
mov ebx,[count]
cmp ebx,[max_count]
jge .end0
mov eax,[nextlen]
cmp [curlen],eax
jne .end0 ;if (..<.. && ..==..)
inc ecx
jmp .cycle0 ;continue
align 4
.end0:
cmp ebx,[min_count]
jge .end1 ;else if (..<..)
@@: ;do
mov ebx,edi
add ebx,deflate_state.bl_tree
send_code edi, [curlen], ebx
dec dword[count]
jnz @b ;while (..!=0)
jmp .end4
align 4
.end1:
cmp dword[curlen],0
je .end2 ;else if (..!=0)
mov eax,[curlen]
cmp eax,[prevlen]
je @f ;if (..!=..)
mov ebx,edi
add ebx,deflate_state.bl_tree
send_code edi, eax, ebx
dec dword[count]
@@:
cmp dword[count],3
jl @f
cmp dword[count],6
jle .end8
@@:
zlib_assert ' 3_6?' ;Assert(..>=.. && ..<=..)
.end8:
mov ebx,edi
add ebx,deflate_state.bl_tree
send_code edi, REP_3_6, ebx
mov ebx,[count]
sub ebx,3
stdcall send_bits, edi, ebx, 2
jmp .end4
.end2:
cmp ebx,10
jg .end3 ;else if (..<=..)
mov ebx,edi
add ebx,deflate_state.bl_tree
send_code edi, REPZ_3_10, ebx
mov ebx,[count]
sub ebx,3
stdcall send_bits, edi, ebx, 3
jmp .end4
.end3: ;else
mov ebx,edi
add ebx,deflate_state.bl_tree
send_code edi, REPZ_11_138, ebx
mov ebx,[count]
sub ebx,11
stdcall send_bits, edi, ebx, 7
.end4:
mov dword[curlen],0
mov eax,[curlen]
mov [prevlen],eax
mov [nextlen],eax
cmp eax,0
jne .end5 ;if (..==0)
mov dword[max_count],138
mov dword[min_count],3
jmp .end7
.end5:
mov eax,[curlen]
cmp eax,[nextlen]
jne .end6 ;else if (..==..)
mov dword[max_count],6
mov dword[min_count],3
jmp .end7
.end6: ;else
mov dword[max_count],7
mov dword[min_count],4
.end7:
inc ecx
jmp .cycle0
align 4
.cycle0end:
ret
endp
; ===========================================================================
; Construct the Huffman tree for the bit lengths and return the index in
; bl_order of the last bit length code to send.
;int (s)
; deflate_state* s
align 4
proc build_bl_tree uses edi, s:dword
locals
max_blindex dd ? ;int ;index of last bit length code of non zero freq
endl
mov edi,[s]
; Determine the bit length frequencies for literal and distance trees
mov eax,edi
add eax,deflate_state.dyn_ltree
stdcall scan_tree, edi, eax, [edi+deflate_state.l_desc.max_code]
add eax,deflate_state.dyn_dtree-deflate_state.dyn_ltree
stdcall scan_tree, edi, eax, [edi+deflate_state.d_desc.max_code]
; Build the bit length tree:
add eax,deflate_state.bl_desc-deflate_state.dyn_dtree
stdcall build_tree, edi, eax
; opt_len now includes the length of the tree representations, except
; the lengths of the bit lengths codes and the 5+5+4 bits for the counts.
; Determine the number of bit length codes to send. The pkzip format
; requires that at least 4 bit length codes be sent. (appnote.txt says
; 3 but the actual value used is 4.)
mov dword[max_blindex],BL_CODES-1
.cycle0: ;for (..;..>=..;..)
cmp dword[max_blindex],3
jl .cycle0end
dec dword[max_blindex]
mov eax,[max_blindex]
add eax,bl_order
movzx eax,byte[eax]
imul eax,sizeof.ct_data
add eax,edi
cmp word[eax+deflate_state.bl_tree+Len],0
jne .cycle0end ;if (..!=0) break
jmp .cycle0
align 4
.cycle0end:
; Update opt_len to include the bit length tree and counts
mov eax,[max_blindex]
inc eax
imul eax,3
add eax,5+5+4
add [edi+deflate_state.opt_len],eax
; Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld", s->opt_len, s->static_len));
mov eax,[max_blindex]
ret
endp
; ===========================================================================
; Send the header for a block using dynamic Huffman trees: the counts, the
; lengths of the bit length codes, the literal tree and the distance tree.
; IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4.
;void (s, lcodes, dcodes, blcodes)
; deflate_state* s
; int lcodes, dcodes, blcodes ;number of codes for each tree
align 4
proc send_all_trees uses eax ebx ecx edi, s:dword, lcodes:dword, dcodes:dword, blcodes:dword
;ecx = index in bl_order
zlib_debug 'send_all_trees'
cmp dword[lcodes],257
jl @f
cmp dword[dcodes],1
jl @f
cmp dword[blcodes],4
jge .end0
@@:
zlib_assert 'not enough codes' ;Assert(..>=.. && ..>=.. && ..>=..)
.end0:
cmp dword[lcodes],L_CODES
jg @f
cmp dword[dcodes],D_CODES
jg @f
cmp dword[blcodes],BL_CODES
jle .end1
@@:
zlib_assert 'too many codes' ;Assert(..<=.. && ..<=.. && ..<=..)
.end1:
; Tracev((stderr, "\nbl counts: "));
mov edi,[s]
mov eax,[lcodes]
sub eax,257
stdcall send_bits, edi, eax, 5 ;not +255 as stated in appnote.txt
mov eax,[dcodes]
dec eax
stdcall send_bits, edi, eax, 5
mov eax,[blcodes]
sub eax,4
stdcall send_bits, edi, eax, 4 ;not -3 as stated in appnote.txt
xor ecx,ecx
.cycle0:
cmp ecx,[blcodes]
jge .cycle0end ;for (..;..<..;..)
; Tracev((stderr, "\nbl code %2d ", bl_order[ecx]));
mov eax,ecx
add eax,bl_order
movzx eax,byte[eax]
imul eax,sizeof.ct_data
add eax,edi
movzx eax,word[eax+deflate_state.bl_tree+Len]
stdcall send_bits, edi, eax, 3
inc ecx
jmp .cycle0
align 4
.cycle0end:
; Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent));
mov ebx,[lcodes]
dec ebx
mov eax,edi
add eax,deflate_state.dyn_ltree
stdcall send_tree, edi, eax, ebx ;literal tree
; Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent));
mov ebx,[dcodes]
dec ebx
add eax,deflate_state.dyn_dtree-deflate_state.dyn_ltree
stdcall send_tree, edi, eax, ebx ;distance tree
; Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent));
ret
endp
; ===========================================================================
; Send a stored block
;void (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
align 4
proc _tr_stored_block uses eax edi, s:dword, buf:dword, stored_len:dword, last:dword
mov edi,[s]
mov eax,[last]
add eax,STORED_BLOCK shl 1
stdcall send_bits, edi, eax, 3 ;send block type
if DEBUG eq 1
mov eax,[edi+deflate_state.compressed_len]
add eax,3+7
and eax,not 7
mov [edi+deflate_state.compressed_len],eax
mov eax,[stored_len]
add eax,4
shl eax,3
add [edi+deflate_state.compressed_len],eax
end if
stdcall copy_block, edi, [buf], [stored_len], 1 ;with header
ret
endp
; ===========================================================================
; Flush the bits in the bit buffer to pending output (leaves at most 7 bits)
;void (s)
; deflate_state* s
align 4
proc _tr_flush_bits, s:dword
stdcall bi_flush, [s]
ret
endp
; ===========================================================================
; Send one empty static block to give enough lookahead for inflate.
; This takes 10 bits, of which 7 may remain in the bit buffer.
;void (s)
; deflate_state* s
align 4
proc _tr_align uses edi, s:dword
mov edi,[s]
stdcall send_bits, edi, STATIC_TREES shl 1, 3
send_code edi, END_BLOCK, static_ltree
if DEBUG eq 1
add [edi+deflate_state.compressed_len],10 ;3 for block type, 7 for EOB
end if
stdcall bi_flush, edi
ret
endp
; ===========================================================================
; Determine the best encoding for the current block: dynamic trees, static
; trees or store, and output the encoded block to the zip file.
;void (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
align 4
proc _tr_flush_block uses eax ebx edi, s:dword, buf:dword, stored_len:dword, last:dword
locals
opt_lenb dd ? ;ulg
static_lenb dd ? ;opt_len and static_len in bytes
max_blindex dd 0 ;int ;index of last bit length code of non zero freq
endl
; Build the Huffman trees unless a stored block is forced
mov edi,[s]
zlib_debug '_tr_flush_block'
cmp word[edi+deflate_state.level],0
jle .end0 ;if (..>0)
; Check if the file is binary or text
mov ebx,[edi+deflate_state.strm]
cmp dword[ebx+z_stream.data_type],Z_UNKNOWN
jne @f ;if (..==..)
stdcall detect_data_type, edi
mov [ebx+z_stream.data_type],eax
@@:
; Construct the literal and distance trees
mov eax,edi
add eax,deflate_state.l_desc
stdcall build_tree, edi, eax
; Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len, s->static_len));
mov eax,edi
add eax,deflate_state.d_desc
stdcall build_tree, edi, eax
; 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
; the compressed block data, excluding the tree representations.
; Build the bit length tree for the above two trees, and get the index
; in bl_order of the last bit length code to send.
stdcall build_bl_tree, edi
mov [max_blindex],eax
; Determine the best encoding. Compute the block lengths in bytes.
mov eax,[edi+deflate_state.opt_len]
add eax,3+7
shr eax,3
mov [opt_lenb],eax
mov eax,[edi+deflate_state.static_len]
add eax,3+7
shr eax,3
mov [static_lenb],eax
; 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));
cmp eax,[opt_lenb]
jg .end1 ;if (..<=..)
mov [opt_lenb],eax
jmp .end1
.end0: ;else
cmp dword[buf],0
jne @f
zlib_assert 'lost buf' ;Assert(..!=0)
@@:
mov eax,[stored_len]
add eax,5
mov [static_lenb],eax
mov [opt_lenb],eax ;force a stored block
.end1:
if FORCE_STORED eq 1
cmp dword[buf],0
je .end2 ;if (..!=0) ;force stored block
else
mov eax,[stored_len]
add eax,4
cmp eax,[opt_lenb]
jg .end2
cmp dword[buf],0
je .end2 ;if (..<=.. && ..!=0)
;4: two words for the lengths
end if
; The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE.
; Otherwise we can't have processed more than WSIZE input bytes since
; the last block flush, because compression would have been
; successful. If LIT_BUFSIZE <= WSIZE, it is never too late to
; transform a block into a stored block.
stdcall _tr_stored_block, edi, [buf], [stored_len], [last]
jmp .end4
.end2:
if FORCE_STATIC eq 1
cmp dword[static_lenb],0
jl .end3 ;else if (..>=0) ;force static trees
else
cmp word[edi+deflate_state.strategy],Z_FIXED
je @f
mov eax,[opt_lenb]
cmp [static_lenb],eax
je @f ;else if (..==.. || ..==..)
jmp .end3
@@:
end if
mov eax,STATIC_TREES shl 1
add eax,[last]
stdcall send_bits, edi, eax, 3
stdcall compress_block, edi, static_ltree, static_dtree
if DEBUG eq 1
mov eax,[edi+deflate_state.static_len]
add eax,3
add [edi+deflate_state.compressed_len],eax
end if
jmp .end4
.end3: ;else
mov eax,DYN_TREES shl 1
add eax,[last]
stdcall send_bits, edi, eax, 3
mov eax,[max_blindex]
inc eax
push eax
mov eax,[edi+deflate_state.d_desc.max_code]
inc eax
push eax
mov eax,[edi+deflate_state.l_desc.max_code]
inc eax
stdcall send_all_trees, edi, eax ;, ..., ...
mov eax,edi
add eax,deflate_state.dyn_dtree
push eax
add eax,deflate_state.dyn_ltree-deflate_state.dyn_dtree
stdcall compress_block, edi, eax ;, ...
if DEBUG eq 1
mov eax,[edi+deflate_state.opt_len]
add eax,3
add [edi+deflate_state.compressed_len],eax
end if
.end4:
; Assert (s->compressed_len == s->bits_sent, "bad compressed size");
; The above check is made mod 2^32, for files larger than 512 MB
; and uLong implemented on 32 bits.
stdcall init_block,edi
cmp dword[last],0
je @f ;if (..)
stdcall bi_windup,edi
if DEBUG eq 1
add [edi+deflate_state.compressed_len],7 ;align on byte boundary
end if
@@:
; Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
; s->compressed_len-7*last));
ret
endp
; ===========================================================================
; Save the match info and tally the frequency counts. Return true if
; the current block must be flushed.
;int (s, dist, lc)
; deflate_state* s
; unsigned dist ;distance of matched string
; unsigned lc ;match length-MIN_MATCH or unmatched char (if dist==0)
align 4
proc _tr_tally uses ebx edi, s:dword, dist:dword, lc:dword
mov edi,[s]
zlib_debug '_tr_tally'
mov eax,[edi+deflate_state.last_lit]
shl eax,1
add eax,[edi+deflate_state.d_buf]
mov ebx,[dist]
mov word[eax],bx
mov eax,[edi+deflate_state.last_lit]
add eax,[edi+deflate_state.l_buf]
mov ebx,[lc]
mov byte[eax],bl
inc dword[edi+deflate_state.last_lit]
cmp dword[dist],0
jne @f ;if (..==0)
; lc is the unmatched char
mov eax,[lc]
imul eax,sizeof.ct_data
add eax,edi
inc word[eax+deflate_state.dyn_ltree+Freq]
jmp .end0
align 4
@@: ;else
inc dword[edi+deflate_state.matches]
; Here, lc is the match length - MIN_MATCH
dec dword[dist] ;dist = match distance - 1
MAX_DIST edi
cmp word[dist],ax
jge @f
cmp word[lc],MAX_MATCH-MIN_MATCH
jg @f
d_code [dist]
cmp ax,D_CODES
jl .end2
@@:
zlib_assert '_tr_tally: bad match' ;Assert(..<.. && ..<=.. && ..<..)
.end2:
mov eax,[lc]
movzx eax,byte[eax+_length_code]
add eax,LITERALS+1
imul eax,sizeof.ct_data
inc word[edi+eax+deflate_state.dyn_ltree+Freq]
d_code [dist]
imul eax,sizeof.ct_data
inc word[edi+eax+deflate_state.dyn_dtree+Freq]
.end0:
if TRUNCATE_BLOCK eq 1
; Try to guess if it is profitable to stop the current block here
mov eax,[edi+deflate_state.last_lit]
and eax,0x1fff
cmp eax,0
jne .end1
cmp word[edi+deflate_state.level],2
jle .end1 ;if (..==.. && ..>..)
; 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;
.end1:
end if
mov ebx,[edi+deflate_state.last_lit]
mov edi,[edi+deflate_state.lit_bufsize]
dec edi
xor eax,eax
cmp ebx,edi
jne @f
inc eax ;return (..==..)
@@:
; We avoid equality with lit_bufsize because of wraparound at 64K
; on 16 bit machines and because stored blocks are restricted to
; 64K-1 bytes.
ret
endp
; ===========================================================================
; Send the block data compressed using the given Huffman trees
;void (s, ltree, dtree)
; deflate_state* s
; ct_data *ltree ;literal tree
; ct_data *dtree ;distance tree
align 4
proc compress_block uses eax edi, s:dword, ltree:dword, dtree:dword
locals
dist dd ? ;unsigned ;distance of matched string
lc dd ? ;int ;match length or unmatched char (if dist == 0)
lx dd 0 ;unsigned ;running index in l_buf
u_code dd ? ;unsigned ;the code to send
extra dd ? ;int ;number of extra bits to send
endl
mov edi,[s]
cmp dword[edi+deflate_state.last_lit],0
je .end0 ;if (..!=0)
.cycle0: ; do
mov eax,[lx]
shl eax,1
add eax,[edi+deflate_state.d_buf]
movzx eax,word[eax]
mov [dist],eax
mov eax,[lx]
add eax,[edi+deflate_state.l_buf]
movzx eax,byte[eax]
mov [lc],eax
inc dword[lx]
cmp dword[dist],0
jne @f ;if (..==0)
send_code edi, [lc], [ltree] ;send a literal byte
; Tracecv(isgraph(lc), (stderr," '%c' ", lc));
jmp .end1
@@: ;else
; Here, lc is the match length - MIN_MATCH
mov eax,[lc]
add eax,_length_code
movzx eax,byte[eax]
mov [u_code],eax
add eax,LITERALS+1
send_code edi, eax, [ltree] ;send the length code
mov eax,[u_code]
shl eax,2
add eax,extra_lbits
mov eax,[eax]
mov [extra],eax
cmp eax,0
je @f ;if (..!=0)
mov eax,[u_code]
shl eax,2
add eax,base_length
mov eax,[eax]
sub [lc],eax
stdcall send_bits, edi, [lc], [extra] ;send the extra length bits
@@:
dec dword[dist] ;dist is now the match distance - 1
d_code [dist]
mov [u_code],eax
cmp eax,D_CODES
jl @f
zlib_assert 'bad d_code' ;Assert(..<..)
@@:
send_code edi, [u_code], [dtree] ;send the distance code
mov eax,[u_code]
shl eax,2
add eax,extra_dbits
mov eax,[eax]
mov [extra],eax
cmp eax,0
je .end1 ;if (..!=0)
mov eax,[u_code]
shl eax,2
add eax,base_dist
mov eax,[eax]
sub [dist],eax
stdcall send_bits, edi, [dist], [extra] ;send the extra distance bits
.end1: ;literal or match pair ?
; Check that the overlay between pending_buf and d_buf+l_buf is ok:
mov eax,[lx]
shl eax,1
add eax,[edi+deflate_state.lit_bufsize]
cmp [edi+deflate_state.pending],eax
jl @f
zlib_assert 'pendingBuf overflow' ;Assert(..<..)
@@:
mov eax,[edi+deflate_state.last_lit]
cmp [lx],eax
jl .cycle0 ;while (..<..)
align 4
.end0:
send_code edi, END_BLOCK, [ltree]
ret
endp
; ===========================================================================
; Check if the data type is TEXT or BINARY, using the following algorithm:
; - TEXT if the two conditions below are satisfied:
; a) There are no non-portable control characters belonging to the
; "black list" (0..6, 14..25, 28..31).
; b) There is at least one printable character belonging to the
; "white list" (9 {TAB}, 10 {LF}, 13 {CR}, 32..255).
; - BINARY otherwise.
; - The following partially-portable control characters form a
; "gray list" that is ignored in this detection algorithm:
; (7 {BEL}, 8 {BS}, 11 {VT}, 12 {FF}, 26 {SUB}, 27 {ESC}).
; IN assertion: the fields Freq of dyn_ltree are set.
;int (s)
; deflate_state* s
align 4
proc detect_data_type uses ebx ecx edi, s:dword
; black_mask is the bit mask of black-listed bytes
; set bits 0..6, 14..25, and 28..31
; 0xf3ffc07f = binary 11110011111111111100000001111111
locals
black_mask dd 0xf3ffc07f
endl
mov edi,[s]
zlib_debug 'detect_data_type'
; Check for non-textual ("black-listed") bytes.
xor ecx,ecx
mov ebx,edi
add ebx,deflate_state.dyn_ltree+Freq
.cycle0:
cmp ecx,31
jg .cycle0end ;for (..;..<=..;..,..)
bt dword[black_mask],0
jnc @f
cmp word[ebx],0
je @f ;if (..&.. && ..!=0)
mov eax,Z_BINARY
jmp .end_f
@@:
shr dword[black_mask],1
add ebx,sizeof.ct_data
inc ecx
jmp .cycle0
.cycle0end:
; Check for textual ("white-listed") bytes.
mov ebx,edi
add ebx,deflate_state.dyn_ltree+Freq+9*sizeof.ct_data
cmp word[ebx],0
jne @f
add ebx,sizeof.ct_data
cmp word[ebx],0
jne @f
add ebx,3*sizeof.ct_data
cmp word[ebx],0
je .end0
@@: ;if (..!=0 || ..!=0 || ..!= 0)
mov eax,Z_TEXT
jmp .end_f
.end0:
mov ecx,32
mov ebx,edi
add ebx,deflate_state.dyn_ltree+Freq+32*sizeof.ct_data
.cycle1:
cmp ecx,LITERALS
jge .cycle1end ;for (..;..<..;..,..)
cmp word[ebx],0
je @f ;if (..!=0)
mov eax,Z_TEXT
jmp .end_f
@@:
add ebx,sizeof.ct_data
inc ecx
jmp .cycle1
.cycle1end:
; There are no "black-listed" or "white-listed" bytes:
; this stream either is empty or has tolerated ("gray-listed") bytes only.
mov eax,Z_BINARY
.end_f:
ret
endp
; ===========================================================================
; Reverse the first len bits of a code, using straightforward code (a faster
; method would use a table)
; IN assertion: 1 <= len <= 15
;unsigned (code, len)
; unsigned code ;the value to invert
; int len ;its bit length
align 4
proc bi_reverse uses ebx, p1code:dword, len:dword
zlib_debug 'bi_reverse'
xor eax,eax
@@: ;do
mov ebx,[p1code]
and ebx,1
or eax,ebx
shr dword[p1code],1
shl eax,1
dec dword[len]
cmp dword[len],0
jg @b ;while (..>..)
shr eax,1
ret
endp
; ===========================================================================
; Flush the bit buffer, keeping at most 7 bits in it.
;void (s)
; deflate_state* s
align 4
proc bi_flush uses eax ecx edi, s:dword
mov edi,[s]
cmp dword[edi+deflate_state.bi_valid],16
jne @f ;if (..==..)
mov cx,[edi+deflate_state.bi_buf]
put_short edi,cx
mov word[edi+deflate_state.bi_buf],0
mov dword[edi+deflate_state.bi_valid],0
jmp .end0
@@: ;else if (..>=..)
cmp dword[edi+deflate_state.bi_valid],8
jl .end0
mov cl,byte[edi+deflate_state.bi_buf]
put_byte edi,cl
shr word[edi+deflate_state.bi_buf],8
sub dword[edi+deflate_state.bi_valid],8
.end0:
ret
endp
; ===========================================================================
; Flush the bit buffer and align the output on a byte boundary
;void (s)
; deflate_state* s
align 4
proc bi_windup uses eax ecx edi, s:dword
mov edi,[s]
cmp dword[edi+deflate_state.bi_valid],8
jle @f ;if (..>..)
mov cx,[edi+deflate_state.bi_buf]
put_short edi, cx
jmp .end0
@@: ;else if (..>0)
cmp dword[edi+deflate_state.bi_valid],0
jle .end0
mov cl,byte[edi+deflate_state.bi_buf]
put_byte edi, cl
.end0:
mov word[edi+deflate_state.bi_buf],0
mov dword[edi+deflate_state.bi_valid],0
if DEBUG eq 1
mov eax,[edi+deflate_state.bits_sent]
add eax,7
and eax,not 7
mov [edi+deflate_state.bits_sent],eax
end if
ret
endp
; ===========================================================================
; Copy a stored block, storing first the length and its
; one's complement if requested.
;void (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
align 4
proc copy_block uses eax ebx ecx edi esi, s:dword, buf:dword, len:dword, p4header:dword
mov edi,[s]
stdcall bi_windup,edi ;align on byte boundary
cmp dword[p4header],0
je @f ;if (..)
mov ecx,[len]
put_short edi, cx
not cx
put_short edi, cx
if DEBUG eq 1
add dword[edi+deflate_state.bits_sent],2*16
end if
@@:
if DEBUG eq 1
mov ecx,[len]
shl ecx,3
add [edi+deflate_state.bits_sent],ecx
end if
mov ecx,[len]
mov esi,[buf]
jmp .end0
align 4
@@: ;while (len--)
lodsb
mov bl,al
put_byte edi, bl
.end0:
loop @b
ret
endp