Unit InfBlock;
{ infblock.h and
infblock.c -- interpret and process block types to last block
Copyright (C) 1995-1998 Mark Adler
Pascal tranlastion
Copyright (C) 1998 by Jacques Nomssi Nzali
For conditions of distribution and use, see copyright notice in readme.txt
}
interface
{$ifdef fpc}
{$goto on}
{$endif}
{$I zconf.inc}
uses
{$IFDEF STRUTILS_DEBUG}
strutils,
{$ENDIF}
zutil, zbase;
function inflate_blocks_new(var z : z_stream;
c : check_func; { check function }
w : uInt { window size }
) : pInflate_blocks_state;
function inflate_blocks (var s : inflate_blocks_state;
var z : z_stream;
r : int { initial return code }
) : int;
procedure inflate_blocks_reset (var s : inflate_blocks_state;
var z : z_stream;
c : puLong); { check value on output }
function inflate_blocks_free(s : pInflate_blocks_state;
var z : z_stream) : int;
procedure inflate_set_dictionary(var s : inflate_blocks_state;
const d : array of byte; { dictionary }
n : uInt); { dictionary length }
function inflate_blocks_sync_point(var s : inflate_blocks_state) : int;
implementation
uses
infcodes, inftrees, infutil;
{ Tables for deflate from PKZIP's appnote.txt. }
Const
border : Array [0..18] Of Word { Order of the bit length code lengths }
= (16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15);
{ Notes beyond the 1.93a appnote.txt:
1. Distance pointers never point before the beginning of the output
stream.
2. Distance pointers can point back across blocks, up to 32k away.
3. There is an implied maximum of 7 bits for the bit length table and
15 bits for the actual data.
4. If only one code exists, then it is encoded using one bit. (Zero
would be more efficient, but perhaps a little confusing.) If two
codes exist, they are coded using one bit each (0 and 1).
5. There is no way of sending zero distance codes--a dummy must be
sent if there are none. (History: a pre 2.0 version of PKZIP would
store blocks with no distance codes, but this was discovered to be
too harsh a criterion.) Valid only for 1.93a. 2.04c does allow
zero distance codes, which is sent as one code of zero bits in
length.
6. There are up to 286 literal/length codes. Code 256 represents the
end-of-block. Note however that the static length tree defines
288 codes just to fill out the Huffman codes. Codes 286 and 287
cannot be used though, since there is no length base or extra bits
defined for them. Similarily, there are up to 30 distance codes.
However, static trees define 32 codes (all 5 bits) to fill out the
Huffman codes, but the last two had better not show up in the data.
7. Unzip can check dynamic Huffman blocks for complete code sets.
The exception is that a single code would not be complete (see #4).
8. The five bits following the block type is really the number of
literal codes sent minus 257.
9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
(1+6+6). Therefore, to output three times the length, you output
three codes (1+1+1), whereas to output four times the same length,
you only need two codes (1+3). Hmm.
10. In the tree reconstruction algorithm, Code = Code + Increment
only if BitLength(i) is not zero. (Pretty obvious.)
11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19)
12. Note: length code 284 can represent 227-258, but length code 285
really is 258. The last length deserves its own, short code
since it gets used a lot in very redundant files. The length
258 is special since 258 - 3 (the min match length) is 255.
13. The literal/length and distance code bit lengths are read as a
single stream of lengths. It is possible (and advantageous) for
a repeat code (16, 17, or 18) to go across the boundary between
the two sets of lengths. }
procedure inflate_blocks_reset (var s : inflate_blocks_state;
var z : z_stream;
c : puLong); { check value on output }
begin
if (c <> Z_NULL) then
c^ := s.check;
if (s.mode = BTREE) or (s.mode = DTREE) then
ZFREE(z, s.sub.trees.blens);
if (s.mode = CODES) then
inflate_codes_free(s.sub.decode.codes, z);
s.mode := ZTYPE;
s.bitk := 0;
s.bitb := 0;
s.write := s.window;
s.read := s.window;
if Assigned(s.checkfn) then
begin
s.check := s.checkfn(uLong(0), pBytef(NIL), 0);
z.adler := s.check;
end;
{$IFDEF STRUTILS_DEBUG}
Tracev('inflate: blocks reset');
{$ENDIF}
end;
function inflate_blocks_new(var z : z_stream;
c : check_func; { check function }
w : uInt { window size }
) : pInflate_blocks_state;
var
s : pInflate_blocks_state;
begin
s := pInflate_blocks_state( ZALLOC(z,1, sizeof(inflate_blocks_state)) );
if (s = Z_NULL) then
begin
inflate_blocks_new := s;
exit;
end;
s^.hufts := huft_ptr( ZALLOC(z, sizeof(inflate_huft), MANY) );
if (s^.hufts = Z_NULL) then
begin
ZFREE(z, s);
inflate_blocks_new := Z_NULL;
exit;
end;
s^.window := pBytef( ZALLOC(z, 1, w) );
if (s^.window = Z_NULL) then
begin
ZFREE(z, s^.hufts);
ZFREE(z, s);
inflate_blocks_new := Z_NULL;
exit;
end;
s^.zend := s^.window;
Inc(s^.zend, w);
s^.checkfn := c;
s^.mode := ZTYPE;
{$IFDEF STRUTILS_DEBUG}
Tracev('inflate: blocks allocated');
{$ENDIF}
inflate_blocks_reset(s^, z, Z_NULL);
inflate_blocks_new := s;
end;
function inflate_blocks (var s : inflate_blocks_state;
var z : z_stream;
r : int) : int; { initial return code }
label
start_btree, start_dtree,
start_blkdone, start_dry,
start_codes;
var
t : uInt; { temporary storage }
b : uLong; { bit buffer }
k : uInt; { bits in bit buffer }
p : pBytef; { input data pointer }
n : uInt; { bytes available there }
q : pBytef; { output window write pointer }
m : uInt; { bytes to end of window or read pointer }
{ fixed code blocks }
var
bl, bd : uInt;
tl, td : pInflate_huft;
var
h : pInflate_huft;
i, j, c : uInt;
var
cs : pInflate_codes_state;
begin
{ copy input/output information to locals }
p := z.next_in;
n := z.avail_in;
b := s.bitb;
k := s.bitk;
q := s.write;
if ptr2int(q) < ptr2int(s.read) then
m := uInt(ptr2int(s.read)-ptr2int(q)-1)
else
m := uInt(ptr2int(s.zend)-ptr2int(q));
{ decompress an inflated block }
{ process input based on current state }
while True do
Case s.mode of
ZTYPE:
begin
{NEEDBITS(3);}
while (k < 3) do
begin
{NEEDBYTE;}
if (n <> 0) then
r :=Z_OK
else
begin
{UPDATE}
s.bitb := b;
s.bitk := k;
z.avail_in := n;
Inc(z.total_in, ptr2int(p)-ptr2int(z.next_in));
z.next_in := p;
s.write := q;
inflate_blocks := inflate_flush(s,z,r);
exit;
end;
Dec(n);
b := b or (uLong(p^) shl k);
Inc(p);
Inc(k, 8);
end;
t := uInt(b) and 7;
s.last := boolean(t and 1);
case (t shr 1) of
0: { stored }
begin
{$IFDEF STRUTILS_DEBUG}
if s.last then
Tracev('inflate: stored block (last)')
else
Tracev('inflate: stored block');
{$ENDIF}
{DUMPBITS(3);}
b := b shr 3;
Dec(k, 3);
t := k and 7; { go to byte boundary }
{DUMPBITS(t);}
b := b shr t;
Dec(k, t);
s.mode := LENS; { get length of stored block }
end;
1: { fixed }
begin
begin
{$IFDEF STRUTILS_DEBUG}
if s.last then
Tracev('inflate: fixed codes blocks (last)')
else
Tracev('inflate: fixed codes blocks');
{$ENDIF}
inflate_trees_fixed(bl, bd, tl, td, z);
s.sub.decode.codes := inflate_codes_new(bl, bd, tl, td, z);
if (s.sub.decode.codes = Z_NULL) then
begin
r := Z_MEM_ERROR;
{ update pointers and return }
s.bitb := b;
s.bitk := k;
z.avail_in := n;
Inc(z.total_in, ptr2int(p) - ptr2int(z.next_in));
z.next_in := p;
s.write := q;
inflate_blocks := inflate_flush(s,z,r);
exit;
end;
end;
{DUMPBITS(3);}
b := b shr 3;
Dec(k, 3);
s.mode := CODES;
end;
2: { dynamic }
begin
{$IFDEF STRUTILS_DEBUG}
if s.last then
Tracev('inflate: dynamic codes block (last)')
else
Tracev('inflate: dynamic codes block');
{$ENDIF}
{DUMPBITS(3);}
b := b shr 3;
Dec(k, 3);
s.mode := TABLE;
end;
3:
begin { illegal }
{DUMPBITS(3);}
b := b shr 3;
Dec(k, 3);
s.mode := BLKBAD;
z.msg := 'invalid block type';
r := Z_DATA_ERROR;
{ update pointers and return }
s.bitb := b;
s.bitk := k;
z.avail_in := n;
Inc(z.total_in, ptr2int(p) - ptr2int(z.next_in));
z.next_in := p;
s.write := q;
inflate_blocks := inflate_flush(s,z,r);
exit;
end;
end;
end;
LENS:
begin
{NEEDBITS(32);}
while (k < 32) do
begin
{NEEDBYTE;}
if (n <> 0) then
r :=Z_OK
else
begin
{UPDATE}
s.bitb := b;
s.bitk := k;
z.avail_in := n;
Inc(z.total_in, ptr2int(p)-ptr2int(z.next_in));
z.next_in := p;
s.write := q;
inflate_blocks := inflate_flush(s,z,r);
exit;
end;
Dec(n);
b := b or (uLong(p^) shl k);
Inc(p);
Inc(k, 8);
end;
if (((not b) shr 16) and $ffff) <> (b and $ffff) then
begin
s.mode := BLKBAD;
z.msg := 'invalid stored block lengths';
r := Z_DATA_ERROR;
{ update pointers and return }
s.bitb := b;
s.bitk := k;
z.avail_in := n;
Inc(z.total_in, ptr2int(p) - ptr2int(z.next_in));
z.next_in := p;
s.write := q;
inflate_blocks := inflate_flush(s,z,r);
exit;
end;
s.sub.left := uInt(b) and $ffff;
k := 0;
b := 0; { dump bits }
{$IFDEF STRUTILS_DEBUG}
Tracev('inflate: stored length '+IntToStr(s.sub.left));
{$ENDIF}
if s.sub.left <> 0 then
s.mode := STORED
else
if s.last then
s.mode := DRY
else
s.mode := ZTYPE;
end;
STORED:
begin
if (n = 0) then
begin
{ update pointers and return }
s.bitb := b;
s.bitk := k;
z.avail_in := n;
Inc(z.total_in, ptr2int(p) - ptr2int(z.next_in));
z.next_in := p;
s.write := q;
inflate_blocks := inflate_flush(s,z,r);
exit;
end;
{NEEDOUT}
if (m = 0) then
begin
{WRAP}
if (q = s.zend) and (s.read <> s.window) then
begin
q := s.window;
if ptr2int(q) < ptr2int(s.read) then
m := uInt(ptr2int(s.read)-ptr2int(q)-1)
else
m := uInt(ptr2int(s.zend)-ptr2int(q));
end;
if (m = 0) then
begin
{FLUSH}
s.write := q;
r := inflate_flush(s,z,r);
q := s.write;
if ptr2int(q) < ptr2int(s.read) then
m := uInt(ptr2int(s.read)-ptr2int(q)-1)
else
m := uInt(ptr2int(s.zend)-ptr2int(q));
{WRAP}
if (q = s.zend) and (s.read <> s.window) then
begin
q := s.window;
if ptr2int(q) < ptr2int(s.read) then
m := uInt(ptr2int(s.read)-ptr2int(q)-1)
else
m := uInt(ptr2int(s.zend)-ptr2int(q));
end;
if (m = 0) then
begin
{UPDATE}
s.bitb := b;
s.bitk := k;
z.avail_in := n;
Inc(z.total_in, ptr2int(p)-ptr2int(z.next_in));
z.next_in := p;
s.write := q;
inflate_blocks := inflate_flush(s,z,r);
exit;
end;
end;
end;
r := Z_OK;
t := s.sub.left;
if (t > n) then
t := n;
if (t > m) then
t := m;
zmemcpy(q, p, t);
Inc(p, t); Dec(n, t);
Inc(q, t); Dec(m, t);
Dec(s.sub.left, t);
if (s.sub.left = 0) then
begin
{$IFDEF STRUTILS_DEBUG}
if (ptr2int(q) >= ptr2int(s.read)) then
Tracev('inflate: stored end '+
IntToStr(z.total_out + ptr2int(q) - ptr2int(s.read)) + ' total out')
else
Tracev('inflate: stored end '+
IntToStr(z.total_out + ptr2int(s.zend) - ptr2int(s.read) +
ptr2int(q) - ptr2int(s.window)) + ' total out');
{$ENDIF}
if s.last then
s.mode := DRY
else
s.mode := ZTYPE;
end;
end;
TABLE:
begin
{NEEDBITS(14);}
while (k < 14) do
begin
{NEEDBYTE;}
if (n <> 0) then
r :=Z_OK
else
begin
{UPDATE}
s.bitb := b;
s.bitk := k;
z.avail_in := n;
Inc(z.total_in, ptr2int(p)-ptr2int(z.next_in));
z.next_in := p;
s.write := q;
inflate_blocks := inflate_flush(s,z,r);
exit;
end;
Dec(n);
b := b or (uLong(p^) shl k);
Inc(p);
Inc(k, 8);
end;
t := uInt(b) and $3fff;
s.sub.trees.table := t;
{$ifndef PKZIP_BUG_WORKAROUND}
if ((t and $1f) > 29) or (((t shr 5) and $1f) > 29) then
begin
s.mode := BLKBAD;
z.msg := 'too many length or distance symbols';
r := Z_DATA_ERROR;
{ update pointers and return }
s.bitb := b;
s.bitk := k;
z.avail_in := n;
Inc(z.total_in, ptr2int(p) - ptr2int(z.next_in));
z.next_in := p;
s.write := q;
inflate_blocks := inflate_flush(s,z,r);
exit;
end;
{$endif}
t := 258 + (t and $1f) + ((t shr 5) and $1f);
s.sub.trees.blens := puIntArray( ZALLOC(z, t, sizeof(uInt)) );
if (s.sub.trees.blens = Z_NULL) then
begin
r := Z_MEM_ERROR;
{ update pointers and return }
s.bitb := b;
s.bitk := k;
z.avail_in := n;
Inc(z.total_in, ptr2int(p) - ptr2int(z.next_in));
z.next_in := p;
s.write := q;
inflate_blocks := inflate_flush(s,z,r);
exit;
end;
{DUMPBITS(14);}
b := b shr 14;
Dec(k, 14);
s.sub.trees.index := 0;
{$IFDEF STRUTILS_DEBUG}
Tracev('inflate: table sizes ok');
{$ENDIF}
s.mode := BTREE;
{ fall trough case is handled by the while }
{ try GOTO for speed - Nomssi }
goto start_btree;
end;
BTREE:
begin
start_btree:
while (s.sub.trees.index < 4 + (s.sub.trees.table shr 10)) do
begin
{NEEDBITS(3);}
while (k < 3) do
begin
{NEEDBYTE;}
if (n <> 0) then
r :=Z_OK
else
begin
{UPDATE}
s.bitb := b;
s.bitk := k;
z.avail_in := n;
Inc(z.total_in, ptr2int(p)-ptr2int(z.next_in));
z.next_in := p;
s.write := q;
inflate_blocks := inflate_flush(s,z,r);
exit;
end;
Dec(n);
b := b or (uLong(p^) shl k);
Inc(p);
Inc(k, 8);
end;
s.sub.trees.blens^[border[s.sub.trees.index]] := uInt(b) and 7;
Inc(s.sub.trees.index);
{DUMPBITS(3);}
b := b shr 3;
Dec(k, 3);
end;
while (s.sub.trees.index < 19) do
begin
s.sub.trees.blens^[border[s.sub.trees.index]] := 0;
Inc(s.sub.trees.index);
end;
s.sub.trees.bb := 7;
t := inflate_trees_bits(s.sub.trees.blens^, s.sub.trees.bb,
s.sub.trees.tb, s.hufts^, z);
if (t <> Z_OK) then
begin
ZFREE(z, s.sub.trees.blens);
r := t;
if (r = Z_DATA_ERROR) then
s.mode := BLKBAD;
{ update pointers and return }
s.bitb := b;
s.bitk := k;
z.avail_in := n;
Inc(z.total_in, ptr2int(p) - ptr2int(z.next_in));
z.next_in := p;
s.write := q;
inflate_blocks := inflate_flush(s,z,r);
exit;
end;
s.sub.trees.index := 0;
{$IFDEF STRUTILS_DEBUG}
Tracev('inflate: bits tree ok');
{$ENDIF}
s.mode := DTREE;
{ fall through again }
goto start_dtree;
end;
DTREE:
begin
start_dtree:
while TRUE do
begin
t := s.sub.trees.table;
if not (s.sub.trees.index < 258 +
(t and $1f) + ((t shr 5) and $1f)) then
break;
t := s.sub.trees.bb;
{NEEDBITS(t);}
while (k < t) do
begin
{NEEDBYTE;}
if (n <> 0) then
r :=Z_OK
else
begin
{UPDATE}
s.bitb := b;
s.bitk := k;
z.avail_in := n;
Inc(z.total_in, ptr2int(p)-ptr2int(z.next_in));
z.next_in := p;
s.write := q;
inflate_blocks := inflate_flush(s,z,r);
exit;
end;
Dec(n);
b := b or (uLong(p^) shl k);
Inc(p);
Inc(k, 8);
end;
h := s.sub.trees.tb;
Inc(h, uInt(b) and inflate_mask[t]);
t := h^.Bits;
c := h^.Base;
if (c < 16) then
begin
{DUMPBITS(t);}
b := b shr t;
Dec(k, t);
s.sub.trees.blens^[s.sub.trees.index] := c;
Inc(s.sub.trees.index);
end
else { c = 16..18 }
begin
if c = 18 then
begin
i := 7;
j := 11;
end
else
begin
i := c - 14;
j := 3;
end;
{NEEDBITS(t + i);}
while (k < t + i) do
begin
{NEEDBYTE;}
if (n <> 0) then
r :=Z_OK
else
begin
{UPDATE}
s.bitb := b;
s.bitk := k;
z.avail_in := n;
Inc(z.total_in, ptr2int(p)-ptr2int(z.next_in));
z.next_in := p;
s.write := q;
inflate_blocks := inflate_flush(s,z,r);
exit;
end;
Dec(n);
b := b or (uLong(p^) shl k);
Inc(p);
Inc(k, 8);
end;
{DUMPBITS(t);}
b := b shr t;
Dec(k, t);
Inc(j, uInt(b) and inflate_mask[i]);
{DUMPBITS(i);}
b := b shr i;
Dec(k, i);
i := s.sub.trees.index;
t := s.sub.trees.table;
if (i + j > 258 + (t and $1f) + ((t shr 5) and $1f)) or
((c = 16) and (i < 1)) then
begin
ZFREE(z, s.sub.trees.blens);
s.mode := BLKBAD;
z.msg := 'invalid bit length repeat';
r := Z_DATA_ERROR;
{ update pointers and return }
s.bitb := b;
s.bitk := k;
z.avail_in := n;
Inc(z.total_in, ptr2int(p) - ptr2int(z.next_in));
z.next_in := p;
s.write := q;
inflate_blocks := inflate_flush(s,z,r);
exit;
end;
if c = 16 then
c := s.sub.trees.blens^[i - 1]
else
c := 0;
repeat
s.sub.trees.blens^[i] := c;
Inc(i);
Dec(j);
until (j=0);
s.sub.trees.index := i;
end;
end; { while }
s.sub.trees.tb := Z_NULL;
begin
bl := 9; { must be <= 9 for lookahead assumptions }
bd := 6; { must be <= 9 for lookahead assumptions }
t := s.sub.trees.table;
t := inflate_trees_dynamic(257 + (t and $1f),
1 + ((t shr 5) and $1f),
s.sub.trees.blens^, bl, bd, tl, td, s.hufts^, z);
ZFREE(z, s.sub.trees.blens);
if (t <> Z_OK) then
begin
if (t = uInt(Z_DATA_ERROR)) then
s.mode := BLKBAD;
r := t;
{ update pointers and return }
s.bitb := b;
s.bitk := k;
z.avail_in := n;
Inc(z.total_in, ptr2int(p) - ptr2int(z.next_in));
z.next_in := p;
s.write := q;
inflate_blocks := inflate_flush(s,z,r);
exit;
end;
{$IFDEF STRUTILS_DEBUG}
Tracev('inflate: trees ok');
{$ENDIF}
{ c renamed to cs }
cs := inflate_codes_new(bl, bd, tl, td, z);
if (cs = Z_NULL) then
begin
r := Z_MEM_ERROR;
{ update pointers and return }
s.bitb := b;
s.bitk := k;
z.avail_in := n;
Inc(z.total_in, ptr2int(p) - ptr2int(z.next_in));
z.next_in := p;
s.write := q;
inflate_blocks := inflate_flush(s,z,r);
exit;
end;
s.sub.decode.codes := cs;
end;
s.mode := CODES;
{ yet another falltrough }
goto start_codes;
end;
CODES:
begin
start_codes:
{ update pointers }
s.bitb := b;
s.bitk := k;
z.avail_in := n;
Inc(z.total_in, ptr2int(p) - ptr2int(z.next_in));
z.next_in := p;
s.write := q;
r := inflate_codes(s, z, r);
if (r <> Z_STREAM_END) then
begin
inflate_blocks := inflate_flush(s, z, r);
exit;
end;
r := Z_OK;
inflate_codes_free(s.sub.decode.codes, z);
{ load local pointers }
p := z.next_in;
n := z.avail_in;
b := s.bitb;
k := s.bitk;
q := s.write;
if ptr2int(q) < ptr2int(s.read) then
m := uInt(ptr2int(s.read)-ptr2int(q)-1)
else
m := uInt(ptr2int(s.zend)-ptr2int(q));
{$IFDEF STRUTILS_DEBUG}
if (ptr2int(q) >= ptr2int(s.read)) then
Tracev('inflate: codes end '+
IntToStr(z.total_out + ptr2int(q) - ptr2int(s.read)) + ' total out')
else
Tracev('inflate: codes end '+
IntToStr(z.total_out + ptr2int(s.zend) - ptr2int(s.read) +
ptr2int(q) - ptr2int(s.window)) + ' total out');
{$ENDIF}
if (not s.last) then
begin
s.mode := ZTYPE;
continue; { break for switch statement in C-code }
end;
{$ifndef patch112}
if (k > 7) then { return unused byte, if any }
begin
{$IFDEF STRUTILS_DEBUG}
Assert(k < 16, 'inflate_codes grabbed too many bytes');
{$ENDIF}
Dec(k, 8);
Inc(n);
Dec(p); { can always return one }
end;
{$endif}
s.mode := DRY;
{ another falltrough }
goto start_dry;
end;
DRY:
begin
start_dry:
{FLUSH}
s.write := q;
r := inflate_flush(s,z,r);
q := s.write;
{ not needed anymore, we are done:
if ptr2int(q) < ptr2int(s.read) then
m := uInt(ptr2int(s.read)-ptr2int(q)-1)
else
m := uInt(ptr2int(s.zend)-ptr2int(q));
}
if (s.read <> s.write) then
begin
{ update pointers and return }
s.bitb := b;
s.bitk := k;
z.avail_in := n;
Inc(z.total_in, ptr2int(p) - ptr2int(z.next_in));
z.next_in := p;
s.write := q;
inflate_blocks := inflate_flush(s,z,r);
exit;
end;
s.mode := BLKDONE;
goto start_blkdone;
end;
BLKDONE:
begin
start_blkdone:
r := Z_STREAM_END;
{ update pointers and return }
s.bitb := b;
s.bitk := k;
z.avail_in := n;
Inc(z.total_in, ptr2int(p) - ptr2int(z.next_in));
z.next_in := p;
s.write := q;
inflate_blocks := inflate_flush(s,z,r);
exit;
end;
BLKBAD:
begin
r := Z_DATA_ERROR;
{ update pointers and return }
s.bitb := b;
s.bitk := k;
z.avail_in := n;
Inc(z.total_in, ptr2int(p) - ptr2int(z.next_in));
z.next_in := p;
s.write := q;
inflate_blocks := inflate_flush(s,z,r);
exit;
end;
else
begin
r := Z_STREAM_ERROR;
{ update pointers and return }
s.bitb := b;
s.bitk := k;
z.avail_in := n;
Inc(z.total_in, ptr2int(p) - ptr2int(z.next_in));
z.next_in := p;
s.write := q;
inflate_blocks := inflate_flush(s,z,r);
exit;
end;
end; { Case s.mode of }
end;
function inflate_blocks_free(s : pInflate_blocks_state;
var z : z_stream) : int;
begin
inflate_blocks_reset(s^, z, Z_NULL);
ZFREE(z, s^.window);
ZFREE(z, s^.hufts);
ZFREE(z, s);
{$IFDEF STRUTILS_DEBUG}
Trace('inflate: blocks freed');
{$ENDIF}
inflate_blocks_free := Z_OK;
end;
procedure inflate_set_dictionary(var s : inflate_blocks_state;
const d : array of byte; { dictionary }
n : uInt); { dictionary length }
begin
zmemcpy(s.window, pBytef(@d), n);
s.write := s.window;
Inc(s.write, n);
s.read := s.write;
end;
{ Returns true if inflate is currently at the end of a block generated
by Z_SYNC_FLUSH or Z_FULL_FLUSH.
IN assertion: s <> Z_NULL }
function inflate_blocks_sync_point(var s : inflate_blocks_state) : int;
begin
inflate_blocks_sync_point := int(s.mode = LENS);
end;
end.
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