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abb3f82ceb
fpc/compiler/cutils.pas
peter abb3f82ceb * getheapstatus fixes
2005-03-04 16:49:22 +00:00

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{
$Id$
Copyright (c) 1998-2002 by Florian Klaempfl
This unit implements some support functions
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published
by the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
****************************************************************************
}
{# This unit contains some generic support functions which are used
in the different parts of the compiler.
}
unit cutils;
{$i fpcdefs.inc}
interface
type
{$ifdef ver1_0}
ptrint = longint;
{$endif ver1_0}
pstring = ^string;
get_var_value_proc=function(const s:string):string of object;
Tcharset=set of char;
var
internalerrorproc : procedure(i:longint);
{$ifndef HASGETFPCHEAPSTATUS}
type
TFPCHeapStatus = THeapStatus;
function GetFPCHeapStatus:TFPCHeapStatus;
{$endif HASGETFPCHEAPSTATUS}
{# Returns the minimal value between @var(a) and @var(b) }
function min(a,b : longint) : longint;{$ifdef USEINLINE}inline;{$endif}
function min(a,b : int64) : int64;{$ifdef USEINLINE}inline;{$endif}
{# Returns the maximum value between @var(a) and @var(b) }
function max(a,b : longint) : longint;{$ifdef USEINLINE}inline;{$endif}
function max(a,b : int64) : int64;{$ifdef USEINLINE}inline;{$endif}
{# Returns the value in @var(x) swapped to different endian }
Function SwapInt64(x : int64): int64;{$ifdef USEINLINE}inline;{$endif}
{# Returns the value in @var(x) swapped to different endian }
function SwapLong(x : longint): longint;{$ifdef USEINLINE}inline;{$endif}
{# Returns the value in @va(x) swapped to different endian }
function SwapWord(x : word): word;{$ifdef USEINLINE}inline;{$endif}
{# Return value @var(i) aligned on @var(a) boundary }
function align(i,a:longint):longint;{$ifdef USEINLINE}inline;{$endif}
function used_align(varalign,minalign,maxalign:longint):longint;
function size_2_align(len : longint) : longint;
procedure Replace(var s:string;s1:string;const s2:string);
procedure Replace(var s:AnsiString;s1:string;const s2:string);
procedure ReplaceCase(var s:string;const s1,s2:string);
function upper(const s : string) : string;
function lower(const s : string) : string;
function trimbspace(const s:string):string;
function trimspace(const s:string):string;
function space (b : longint): string;
function PadSpace(const s:string;len:longint):string;
function GetToken(var s:string;endchar:char):string;
procedure uppervar(var s : string);
function hexstr(val : cardinal;cnt : cardinal) : string;
function realtostr(e:extended):string;{$ifdef USEINLINE}inline;{$endif}
function tostr(i : qword) : string;{$ifdef USEINLINE}inline;{$endif}overload;
function tostr(i : int64) : string;{$ifdef USEINLINE}inline;{$endif}overload;
function tostr(i : longint) : string;{$ifdef USEINLINE}inline;{$endif}overload;
function tostr_with_plus(i : int64) : string;{$ifdef USEINLINE}inline;{$endif}
function DStr(l:longint):string;
{# Returns true if the string s is a number }
function is_number(const s : string) : boolean;{$ifdef USEINLINE}inline;{$endif}
{# Returns true if value is a power of 2, the actual
exponent value is returned in power.
}
function ispowerof2(value : int64;var power : longint) : boolean;
function backspace_quote(const s:string;const qchars:Tcharset):string;
function octal_quote(const s:string;const qchars:Tcharset):string;
function maybequoted(const s:string):string;
{# If the string is quoted, in accordance with pascal, it is
dequoted and returned in s, and the function returns true.
If it is not quoted, or if the quoting is bad, s is not touched,
and false is returned.
}
function DePascalQuote(var s: string): Boolean;
function CompareText(S1, S2: string): longint;
{ releases the string p and assignes nil to p }
{ if p=nil then freemem isn't called }
procedure stringdispose(var p : pstring);{$ifdef USEINLINE}inline;{$endif}
{ allocates mem for a copy of s, copies s to this mem and returns }
{ a pointer to this mem }
function stringdup(const s : string) : pstring;{$ifdef USEINLINE}inline;{$endif}
{# Allocates memory for the string @var(s) and copies s as zero
terminated string to that allocated memory and returns a pointer
to that mem
}
function strpnew(const s : string) : pchar;
procedure strdispose(var p : pchar);
function string_evaluate(s:string;get_var_value:get_var_value_proc;
const vars:array of string):Pchar;
{# makes the character @var(c) lowercase, with spanish, french and german
character set
}
function lowercase(c : char) : char;
{ makes zero terminated string to a pascal string }
{ the data in p is modified and p is returned }
function pchar2pstring(p : pchar) : pstring;
{ ambivalent to pchar2pstring }
function pstring2pchar(p : pstring) : pchar;
{ Speed/Hash value }
Function GetSpeedValue(Const s:String):cardinal;
{ Ansistring (pchar+length) support }
procedure ansistringdispose(var p : pchar;length : longint);
function compareansistrings(p1,p2 : pchar;length1,length2 : longint) : longint;
function concatansistrings(p1,p2 : pchar;length1,length2 : longint) : pchar;
function DeleteFile(const fn:string):boolean;
{Lzw encode/decode to compress strings -> save memory.}
function minilzw_encode(const s:string):string;
function minilzw_decode(const s:string):string;
implementation
uses
strings
;
{$ifndef HASGETFPCHEAPSTATUS}
function GetFPCHeapStatus:TFPCHeapStatus;
begin
GetHeapStatus(result);
end;
{$endif HASGETFPCHEAPSTATUS}
var
uppertbl,
lowertbl : array[char] of char;
function min(a,b : longint) : longint;{$ifdef USEINLINE}inline;{$endif}
{
return the minimal of a and b
}
begin
if a>b then
min:=b
else
min:=a;
end;
function min(a,b : int64) : int64;{$ifdef USEINLINE}inline;{$endif}
{
return the minimal of a and b
}
begin
if a>b then
min:=b
else
min:=a;
end;
function max(a,b : longint) : longint;{$ifdef USEINLINE}inline;{$endif}
{
return the maximum of a and b
}
begin
if a<b then
max:=b
else
max:=a;
end;
function max(a,b : int64) : int64;{$ifdef USEINLINE}inline;{$endif}
{
return the maximum of a and b
}
begin
if a<b then
max:=b
else
max:=a;
end;
Function SwapLong(x : longint): longint;{$ifdef USEINLINE}inline;{$endif}
var
y : word;
z : word;
Begin
y := x shr 16;
y := word(longint(y) shl 8) or (y shr 8);
z := x and $FFFF;
z := word(longint(z) shl 8) or (z shr 8);
SwapLong := (longint(z) shl 16) or longint(y);
End;
Function SwapInt64(x : int64): int64;{$ifdef USEINLINE}inline;{$endif}
Begin
result:=swaplong(longint(hi(x)));
result:=result or (swaplong(longint(lo(x))) shl 32);
End;
Function SwapWord(x : word): word;{$ifdef USEINLINE}inline;{$endif}
var
z : byte;
Begin
z := x shr 8;
x := x and $ff;
x := (x shl 8);
SwapWord := x or z;
End;
function align(i,a:longint):longint;{$ifdef USEINLINE}inline;{$endif}
{
return value <i> aligned <a> boundary
}
begin
{ for 0 and 1 no aligning is needed }
if a<=1 then
result:=i
else
begin
if i<0 then
result:=((i-a+1) div a) * a
else
result:=((i+a-1) div a) * a;
end;
end;
function size_2_align(len : longint) : longint;
begin
if len>16 then
size_2_align:=32
else if len>8 then
size_2_align:=16
else if len>4 then
size_2_align:=8
else if len>2 then
size_2_align:=4
else if len>1 then
size_2_align:=2
else
size_2_align:=1;
end;
function used_align(varalign,minalign,maxalign:longint):longint;
begin
{ varalign : minimum alignment required for the variable
minalign : Minimum alignment of this structure, 0 = undefined
maxalign : Maximum alignment of this structure, 0 = undefined }
if (minalign>0) and
(varalign<minalign) then
used_align:=minalign
else
begin
if (maxalign>0) and
(varalign>maxalign) then
used_align:=maxalign
else
used_align:=varalign;
end;
end;
procedure Replace(var s:string;s1:string;const s2:string);
var
last,
i : longint;
begin
s1:=upper(s1);
last:=0;
repeat
i:=pos(s1,upper(s));
if i=last then
i:=0;
if (i>0) then
begin
Delete(s,i,length(s1));
Insert(s2,s,i);
last:=i;
end;
until (i=0);
end;
procedure Replace(var s:AnsiString;s1:string;const s2:string);
var
last,
i : longint;
begin
s1:=upper(s1);
last:=0;
repeat
i:=pos(s1,upper(s));
if i=last then
i:=0;
if (i>0) then
begin
Delete(s,i,length(s1));
Insert(s2,s,i);
last:=i;
end;
until (i=0);
end;
procedure ReplaceCase(var s:string;const s1,s2:string);
var
last,
i : longint;
begin
last:=0;
repeat
i:=pos(s1,s);
if i=last then
i:=0;
if (i>0) then
begin
Delete(s,i,length(s1));
Insert(s2,s,i);
last:=i;
end;
until (i=0);
end;
function upper(const s : string) : string;
{
return uppercased string of s
}
var
i : longint;
begin
for i:=1 to length(s) do
upper[i]:=uppertbl[s[i]];
upper[0]:=s[0];
end;
function lower(const s : string) : string;
{
return lowercased string of s
}
var
i : longint;
begin
for i:=1 to length(s) do
lower[i]:=lowertbl[s[i]];
lower[0]:=s[0];
end;
procedure uppervar(var s : string);
{
uppercase string s
}
var
i : longint;
begin
for i:=1 to length(s) do
s[i]:=uppertbl[s[i]];
end;
procedure initupperlower;
var
c : char;
begin
for c:=#0 to #255 do
begin
lowertbl[c]:=c;
uppertbl[c]:=c;
case c of
'A'..'Z' :
lowertbl[c]:=char(byte(c)+32);
'a'..'z' :
uppertbl[c]:=char(byte(c)-32);
end;
end;
end;
function hexstr(val : cardinal;cnt : cardinal) : string;
const
HexTbl : array[0..15] of char='0123456789ABCDEF';
var
i,j : cardinal;
begin
{ calculate required length }
i:=0;
j:=val;
while (j>0) do
begin
inc(i);
j:=j shr 4;
end;
{ generate fillers }
j:=0;
while (i+j<cnt) do
begin
inc(j);
hexstr[j]:='0';
end;
{ generate hex }
inc(j,i);
hexstr[0]:=chr(j);
while (val>0) do
begin
hexstr[j]:=hextbl[val and $f];
dec(j);
val:=val shr 4;
end;
end;
function DStr(l:longint):string;
var
TmpStr : string[32];
i : longint;
begin
Str(l,TmpStr);
i:=Length(TmpStr);
while (i>3) do
begin
dec(i,3);
if TmpStr[i]<>'-' then
insert('.',TmpStr,i+1);
end;
DStr:=TmpStr;
end;
function trimbspace(const s:string):string;
{
return s with all leading spaces and tabs removed
}
var
i,j : longint;
begin
j:=1;
i:=length(s);
while (j<i) and (s[j] in [#9,' ']) do
inc(j);
trimbspace:=Copy(s,j,i-j+1);
end;
function trimspace(const s:string):string;
{
return s with all leading and ending spaces and tabs removed
}
var
i,j : longint;
begin
i:=length(s);
while (i>0) and (s[i] in [#9,' ']) do
dec(i);
j:=1;
while (j<i) and (s[j] in [#9,' ']) do
inc(j);
trimspace:=Copy(s,j,i-j+1);
end;
function space (b : longint): string;
var
s: string;
begin
space[0] := chr(b);
s[0] := chr(b);
FillChar (S[1],b,' ');
space:=s;
end;
function PadSpace(const s:string;len:longint):string;
{
return s with spaces add to the end
}
begin
if length(s)<len then
PadSpace:=s+Space(len-length(s))
else
PadSpace:=s;
end;
function GetToken(var s:string;endchar:char):string;
var
i : longint;
begin
GetToken:='';
s:=TrimSpace(s);
if s[1]='''' then
begin
i:=1;
while (i<length(s)) do
begin
inc(i);
if s[i]='''' then
begin
{ Remove double quote }
if (i<length(s)) and
(s[i+1]='''') then
begin
Delete(s,i,1);
inc(i);
end
else
begin
GetToken:=Copy(s,2,i-2);
Delete(s,1,i);
exit;
end;
end;
end;
GetToken:=s;
s:='';
end
else
begin
i:=pos(EndChar,s);
if i=0 then
begin
GetToken:=s;
s:='';
exit;
end
else
begin
GetToken:=Copy(s,1,i-1);
Delete(s,1,i);
exit;
end;
end;
end;
function realtostr(e:extended):string;{$ifdef USEINLINE}inline;{$endif}
begin
str(e,result);
end;
function tostr(i : qword) : string;{$ifdef USEINLINE}inline;{$endif}overload;
{
return string of value i
}
begin
str(i,result);
end;
function tostr(i : int64) : string;{$ifdef USEINLINE}inline;{$endif}overload;
{
return string of value i
}
begin
str(i,result);
end;
function tostr(i : longint) : string;{$ifdef USEINLINE}inline;{$endif}overload;
{
return string of value i
}
begin
str(i,result);
end;
function tostr_with_plus(i : int64) : string;{$ifdef USEINLINE}inline;{$endif}
{
return string of value i, but always include a + when i>=0
}
begin
str(i,result);
if i>=0 then
result:='+'+result;
end;
function is_number(const s : string) : boolean;{$ifdef USEINLINE}inline;{$endif}
{
is string a correct number ?
}
var
w : integer;
l : longint;
begin
val(s,l,w);
is_number:=(w=0);
end;
function ispowerof2(value : int64;var power : longint) : boolean;
{
return if value is a power of 2. And if correct return the power
}
var
hl : int64;
i : longint;
begin
if value and (value - 1) <> 0 then
begin
ispowerof2 := false;
exit
end;
hl:=1;
ispowerof2:=true;
for i:=0 to 63 do
begin
if hl=value then
begin
power:=i;
exit;
end;
hl:=hl shl 1;
end;
ispowerof2:=false;
end;
function backspace_quote(const s:string;const qchars:Tcharset):string;
var i:byte;
begin
backspace_quote:='';
for i:=1 to length(s) do
begin
if (s[i]=#10) and (#10 in qchars) then
backspace_quote:=backspace_quote+'\n'
else if (s[i]=#13) and (#13 in qchars) then
backspace_quote:=backspace_quote+'\r'
else
begin
if s[i] in qchars then
backspace_quote:=backspace_quote+'\';
backspace_quote:=backspace_quote+s[i];
end;
end;
end;
function octal_quote(const s:string;const qchars:Tcharset):string;
var i:byte;
begin
octal_quote:='';
for i:=1 to length(s) do
begin
if s[i] in qchars then
begin
if ord(s[i])<64 then
octal_quote:=octal_quote+'\'+octstr(ord(s[i]),3)
else
octal_quote:=octal_quote+'\'+octstr(ord(s[i]),4);
end
else
octal_quote:=octal_quote+s[i];
end;
end;
function maybequoted(const s:string):string;
var
s1 : string;
i : integer;
quoted : boolean;
begin
quoted:=false;
s1:='"';
for i:=1 to length(s) do
begin
case s[i] of
'"' :
begin
quoted:=true;
s1:=s1+'\"';
end;
' ',
#128..#255 :
begin
quoted:=true;
s1:=s1+s[i];
end;
else
s1:=s1+s[i];
end;
end;
if quoted then
maybequoted:=s1+'"'
else
maybequoted:=s;
end;
function DePascalQuote(var s: string): Boolean;
var
destPos, sourcePos, len: Integer;
t: string;
ch: Char;
begin
DePascalQuote:= false;
len:= length(s);
if (len >= 1) and (s[1] = '''') then
begin
{Remove quotes, exchange '' against ' }
destPos := 0;
sourcepos:=1;
while (sourcepos<len) do
begin
inc(sourcePos);
ch := s[sourcePos];
if ch = '''' then
begin
inc(sourcePos);
if (sourcePos <= len) and (s[sourcePos] = '''') then
{Add the quote as part of string}
else
begin
SetLength(t, destPos);
s:= t;
Exit(true);
end;
end;
inc(destPos);
t[destPos] := ch;
end;
end;
end;
function pchar2pstring(p : pchar) : pstring;
var
w,i : longint;
begin
w:=strlen(p);
for i:=w-1 downto 0 do
p[i+1]:=p[i];
p[0]:=chr(w);
pchar2pstring:=pstring(p);
end;
function pstring2pchar(p : pstring) : pchar;
var
w,i : longint;
begin
w:=length(p^);
for i:=1 to w do
p^[i-1]:=p^[i];
p^[w]:=#0;
pstring2pchar:=pchar(p);
end;
function lowercase(c : char) : char;
begin
case c of
#65..#90 : c := chr(ord (c) + 32);
#154 : c:=#129; { german }
#142 : c:=#132; { german }
#153 : c:=#148; { german }
#144 : c:=#130; { french }
#128 : c:=#135; { french }
#143 : c:=#134; { swedish/norge (?) }
#165 : c:=#164; { spanish }
#228 : c:=#229; { greek }
#226 : c:=#231; { greek }
#232 : c:=#227; { greek }
end;
lowercase := c;
end;
function strpnew(const s : string) : pchar;
var
p : pchar;
begin
getmem(p,length(s)+1);
strpcopy(p,s);
strpnew:=p;
end;
procedure strdispose(var p : pchar);
begin
if assigned(p) then
begin
freemem(p,strlen(p)+1);
p:=nil;
end;
end;
procedure stringdispose(var p : pstring);{$ifdef USEINLINE}inline;{$endif}
begin
if assigned(p) then
begin
freemem(p,length(p^)+1);
p:=nil;
end;
end;
function stringdup(const s : string) : pstring;{$ifdef USEINLINE}inline;{$endif}
begin
getmem(result,length(s)+1);
result^:=s;
end;
function CompareText(S1, S2: string): longint;
begin
UpperVar(S1);
UpperVar(S2);
if S1<S2 then
CompareText:=-1
else
if S1>S2 then
CompareText:= 1
else
CompareText:=0;
end;
function string_evaluate(s:string;get_var_value:get_var_value_proc;
const vars:array of string):Pchar;
{S contains a prototype of a stabstring. Stabstr_evaluate will expand
variables and parameters.
Output is s in ASCIIZ format, with the following expanded:
${varname} - The variable name is expanded.
$n - The parameter n is expanded.
$$ - Is expanded to $
}
const maxvalue=9;
maxdata=1023;
var i,j:byte;
varname:string[63];
varno,varcounter:byte;
varvalues:array[0..9] of Pstring;
{1 kb of parameters is the limit. 256 extra bytes are allocated to
ensure buffer integrity.}
varvaluedata:array[0..maxdata+256] of char;
varptr:Pchar;
len:cardinal;
r:Pchar;
begin
{Two pass approach, first, calculate the length and receive variables.}
i:=1;
len:=0;
varcounter:=0;
varptr:=@varvaluedata;
while i<=length(s) do
begin
if (s[i]='$') and (i<length(s)) then
begin
if s[i+1]='$' then
begin
inc(len);
inc(i);
end
else if (s[i+1]='{') and (length(s)>2) and (i<length(s)-2) then
begin
varname:='';
inc(i,2);
repeat
inc(varname[0]);
varname[length(varname)]:=s[i];
s[i]:=char(varcounter);
inc(i);
until s[i]='}';
varvalues[varcounter]:=Pstring(varptr);
if varptr>@varvaluedata+maxdata then
internalerrorproc(200411152);
Pstring(varptr)^:=get_var_value(varname);
inc(len,length(Pstring(varptr)^));
inc(varptr,length(Pstring(varptr)^)+1);
inc(varcounter);
end
else if s[i+1] in ['0'..'9'] then
begin
inc(len,length(vars[byte(s[i+1])-byte('1')]));
inc(i);
end;
end
else
inc(len);
inc(i);
end;
{Second pass, writeout stabstring.}
getmem(r,len+1);
string_evaluate:=r;
i:=1;
while i<=length(s) do
begin
if (s[i]='$') and (i<length(s)) then
begin
if s[i+1]='$' then
begin
r^:='$';
inc(r);
inc(i);
end
else if (s[i+1]='{') and (length(s)>2) and (i<length(s)-2) then
begin
varname:='';
inc(i,2);
varno:=byte(s[i]);
repeat
inc(i);
until s[i]='}';
for j:=1 to length(varvalues[varno]^) do
begin
r^:=varvalues[varno]^[j];
inc(r);
end;
end
else if s[i+1] in ['0'..'9'] then
begin
for j:=1 to length(vars[byte(s[i+1])-byte('1')]) do
begin
r^:=vars[byte(s[i+1])-byte('1')][j];
inc(r);
end;
inc(i);
end
end
else
begin
r^:=s[i];
inc(r);
end;
inc(i);
end;
r^:=#0;
end;
{*****************************************************************************
GetSpeedValue
*****************************************************************************}
{$ifdef ver1_0}
{$R-}
{$endif}
var
Crc32Tbl : array[0..255] of cardinal;
procedure MakeCRC32Tbl;
var
crc : cardinal;
i,n : integer;
begin
for i:=0 to 255 do
begin
crc:=i;
for n:=1 to 8 do
if odd(longint(crc)) then
crc:=cardinal(crc shr 1) xor cardinal($edb88320)
else
crc:=cardinal(crc shr 1);
Crc32Tbl[i]:=crc;
end;
end;
Function GetSpeedValue(Const s:String):cardinal;
var
i : integer;
InitCrc : cardinal;
begin
InitCrc:=cardinal($ffffffff);
for i:=1 to Length(s) do
InitCrc:=Crc32Tbl[byte(InitCrc) xor ord(s[i])] xor (InitCrc shr 8);
GetSpeedValue:=InitCrc;
end;
{*****************************************************************************
Ansistring (PChar+Length)
*****************************************************************************}
procedure ansistringdispose(var p : pchar;length : longint);
begin
if assigned(p) then
begin
freemem(p,length+1);
p:=nil;
end;
end;
{ enable ansistring comparison }
{ 0 means equal }
{ 1 means p1 > p2 }
{ -1 means p1 < p2 }
function compareansistrings(p1,p2 : pchar;length1,length2 : longint) : longint;
var
i,j : longint;
begin
compareansistrings:=0;
j:=min(length1,length2);
i:=0;
while (i<j) do
begin
if p1[i]>p2[i] then
begin
compareansistrings:=1;
exit;
end
else
if p1[i]<p2[i] then
begin
compareansistrings:=-1;
exit;
end;
inc(i);
end;
if length1>length2 then
compareansistrings:=1
else
if length1<length2 then
compareansistrings:=-1;
end;
function concatansistrings(p1,p2 : pchar;length1,length2 : longint) : pchar;
var
p : pchar;
begin
getmem(p,length1+length2+1);
move(p1[0],p[0],length1);
move(p2[0],p[length1],length2+1);
concatansistrings:=p;
end;
{*****************************************************************************
File Functions
*****************************************************************************}
function DeleteFile(const fn:string):boolean;
var
f : file;
begin
{$I-}
assign(f,fn);
erase(f);
{$I-}
DeleteFile:=(IOResult=0);
end;
{*****************************************************************************
Ultra basic KISS Lzw (de)compressor
*****************************************************************************}
{This is an extremely basic implementation of the Lzw algorithm. It
compresses 7-bit ASCII strings into 8-bit compressed strings.
The Lzw dictionary is preinitialized with 0..127, therefore this
part of the dictionary does not need to be stored in the arrays.
The Lzw code size is allways 8 bit, so we do not need complex code
that can write partial bytes.}
function minilzw_encode(const s:string):string;
var t,u,i:byte;
c:char;
data:array[128..255] of char;
previous:array[128..255] of byte;
lzwptr:byte;
next_avail:set of 0..255;
label l1;
begin
minilzw_encode:='';
if s<>'' then
begin
lzwptr:=127;
t:=byte(s[1]);
i:=2;
u:=128;
next_avail:=[];
while i<=length(s) do
begin
c:=s[i];
if not(t in next_avail) or (u>lzwptr) then goto l1;
while (previous[u]<>t) or (data[u]<>c) do
begin
inc(u);
if u>lzwptr then goto l1;
end;
t:=u;
inc(i);
continue;
l1:
{It's a pity that we still need those awfull tricks
with this modern compiler. Without this performance
of the entire procedure drops about 3 times.}
inc(minilzw_encode[0]);
minilzw_encode[length(minilzw_encode)]:=char(t);
if lzwptr=255 then
begin
lzwptr:=127;
next_avail:=[];
end
else
begin
inc(lzwptr);
data[lzwptr]:=c;
previous[lzwptr]:=t;
include(next_avail,t);
end;
t:=byte(c);
u:=128;
inc(i);
end;
inc(minilzw_encode[0]);
minilzw_encode[length(minilzw_encode)]:=char(t);
end;
end;
function minilzw_decode(const s:string):string;
var oldc,newc,c:char;
i,j:byte;
data:array[128..255] of char;
previous:array[128..255] of byte;
lzwptr:byte;
t:string;
begin
minilzw_decode:='';
if s<>'' then
begin
lzwptr:=127;
oldc:=s[1];
c:=oldc;
i:=2;
minilzw_decode:=oldc;
while i<=length(s) do
begin
newc:=s[i];
if byte(newc)>lzwptr then
begin
t:=c;
c:=oldc;
end
else
begin
c:=newc;
t:='';
end;
while c>=#128 do
begin
inc(t[0]);
t[length(t)]:=data[byte(c)];
byte(c):=previous[byte(c)];
end;
inc(minilzw_decode[0]);
minilzw_decode[length(minilzw_decode)]:=c;
for j:=length(t) downto 1 do
begin
inc(minilzw_decode[0]);
minilzw_decode[length(minilzw_decode)]:=t[j];
end;
if lzwptr=255 then
lzwptr:=127
else
begin
inc(lzwptr);
previous[lzwptr]:=byte(oldc);
data[lzwptr]:=c;
end;
oldc:=newc;
inc(i);
end;
end;
end;
procedure defaulterror(i:longint);
begin
writeln('Internal error ',i);
runerror(255);
end;
initialization
internalerrorproc:=@defaulterror;
makecrc32tbl;
initupperlower;
end.
{
$Log$
Revision 1.50 2005-03-04 16:49:22 peter
* getheapstatus fixes
Revision 1.49 2005/02/14 17:13:06 peter
* truncate log
Revision 1.48 2005/01/20 17:05:53 peter
* use val() for decoding integers
}
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