fpc/rtl/inc/wstrings.inc
2000-11-06 23:17:15 +00:00

521 lines
12 KiB
PHP

{
$Id$
This file is part of the Free Pascal run time library.
Copyright (c) 1999-2000 by Florian Klaempfl,
member of the Free Pascal development team.
This file implements support routines for WideStrings with FPC
See the file COPYING.FPC, included in this distribution,
for details about the copyright.
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.
**********************************************************************}
{
This file contains the implementation of the WideString type,
and all things that are needed for it.
WideString is defined as a 'silent' pwidechar :
a pwidechar that points to :
@-12 : Longint for maximum size;
@-8 : Longint for size;
@-4 : Longint for reference count;
@ : String + Terminating #0;
Pwidechar(Widestring) is a valid typecast.
So WS[i] is converted to the address @WS+i-1.
Constants should be assigned a reference count of -1
Meaning that they can't be disposed of.
}
Type
PWideRec = ^TWideRec;
TWideRec = Packed Record
Maxlen,
len,
ref : Longint;
First : WideChar;
end;
Const
WideRecLen = SizeOf(TWideRec);
WideFirstOff = SizeOf(TWideRec)-1;
(*
Procedure UniqueWideString(Var S : WideString); [Public,Alias : 'FPC_WIDESTR_UNIQUE'];
{
Make sure reference count of S is 1,
using copy-on-write semantics.
}
begin
end;
*)
{****************************************************************************
Internal functions, not in interface.
****************************************************************************}
{$ifdef WideStrDebug}
Procedure DumpWideRec(S : Pointer);
begin
If S=Nil then
Writeln ('String is nil')
Else
Begin
With PWideRec(S-WideFirstOff)^ do
begin
Write ('(Maxlen: ',maxlen);
Write (' Len:',len);
Writeln (' Ref: ',ref,')');
end;
end;
end;
{$endif}
Function NewWideString(Len : Longint) : Pointer;
{
Allocate a new WideString on the heap.
initialize it to zero length and reference count 1.
}
Var
P : Pointer;
begin
{ Also add +1 for a terminating zero }
GetMem(P,Len+Len+WideRecLen);
If P<>Nil then
begin
PWideRec(P)^.Maxlen:=Len; { Maximal length }
PWideRec(P)^.Len:=0; { Initial length }
PWideRec(P)^.Ref:=1; { Set reference count }
PWideRec(P)^.First:=#0; { Terminating #0 }
P:=P+WideFirstOff; { Points to string now }
end;
NewWideString:=P;
end;
Procedure DisposeWideString(Var S : Pointer);
{
Deallocates a WideString From the heap.
}
begin
If S=Nil then
exit;
Dec (Longint(S),WideFirstOff);
FreeMem (S);
S:=Nil;
end;
Procedure WideStr_Decr_Ref (Var S : Pointer);[Public,Alias:'FPC_WIDESTR_DECR_REF'];
{
Decreases the ReferenceCount of a non constant widestring;
If the reference count is zero, deallocate the string;
}
Type
plongint = ^longint;
Var
l : plongint;
Begin
{ Zero string }
If S=Nil then exit;
{ check for constant strings ...}
l:=@PWIDEREC(S-WideFirstOff)^.Ref;
If l^<0 then exit;
Dec(l^);
If l^=0 then
{ Ref count dropped to zero }
DisposeWideString (S); { Remove...}
{ this pointer is not valid anymore, so set it to zero }
S:=nil;
end;
Procedure WideStr_Incr_Ref (Var S : Pointer);[Public,Alias:'FPC_WIDESTR_INCR_REF'];
Begin
If S=Nil then
exit;
{ Let's be paranoid : Constant string ??}
If PWideRec(S-WideFirstOff)^.Ref<0 then exit;
Inc(PWideRec(S-WideFirstOff)^.Ref);
end;
Procedure WideStr_Assign (Var S1 : Pointer;S2 : Pointer);[Public,Alias:'FPC_WIDESTR_ASSIGN'];
{
Assigns S2 to S1 (S1:=S2), taking in account reference counts.
}
begin
If S2<>nil then
If PWideRec(S2-WideFirstOff)^.Ref>0 then
Inc(PWideRec(S2-WideFirstOff)^.ref);
{ Decrease the reference count on the old S1 }
widestr_decr_ref (S1);
{ And finally, have S1 pointing to S2 (or its copy) }
S1:=S2;
end;
Procedure WideStr_Concat (S1,S2 : Pointer;var S3 : Pointer);[Public, alias: 'FPC_WIDESTR_CONCAT'];
{
Concatenates 2 WideStrings : S1+S2.
Result Goes to S3;
}
Var
Size,Location : Longint;
begin
{ create new result }
if S3<>nil then
WideStr_Decr_Ref(S3);
{ only assign if s1 or s2 is empty }
if (S1=Nil) then
WideStr_Assign(S3,S2)
else
if (S2=Nil) then
WideStr_Assign(S3,S1)
else
begin
Size:=PWideRec(S2-WideFirstOff)^.Len;
Location:=Length(WideString(S1));
SetLength (WideString(S3),Size+Location);
Move (S1^,S3^,Location);
Move (S2^,(S3+location)^,Size+1);
end;
end;
(* !!!:
Procedure Char_To_WideStr(var S1 : Pointer; c : Char);[Public, alias: 'FPC_CHAR_TO_WIDESTR'];
{
Converts a ShortString to a WideString;
}
begin
Setlength (WideString(S1),1);
PByte(Pointer(S1))^:=byte(c);
{ Terminating Zero }
PByte(Pointer(S1)+1)^:=0;
end;
Procedure PChar_To_WideStr(var a : widestring;p : pchar);[Public,Alias : 'FPC_PCHAR_TO_WIDESTR'];
Var
L : Longint;
begin
if pointer(a)<>nil then
begin
WideStr_Decr_Ref(Pointer(a));
pointer(a):=nil;
end;
if (not assigned(p)) or (p[0]=#0) Then
Pointer(a):=nil
else
begin
//!! Horribly inneficient, but I see no other way...
L:=1;
While P[l]<>#0 do
inc (l);
Pointer(a):=NewWidestring(L);
SetLength(A,L);
Move (P[0],Pointer(A)^,L)
end;
end;
Procedure CharArray_To_WideStr(var a : widestring;p : pchar;l:longint);[Public,Alias : 'FPC_CHARARRAY_TO_WIDESTR'];
var
i : longint;
hp : pchar;
begin
if p[0]=#0 Then
Pointer(a):=nil
else
begin
Pointer(a):=NewWidestring(L);
hp:=p;
i:=0;
while (i<l) and (hp^<>#0) do
begin
inc(hp);
inc(i);
end;
SetLength(A,i);
Move (P[0],Pointer(A)^,i)
end;
end;
*)
Function WideStr_Compare(S1,S2 : Pointer): Longint;[Public,Alias : 'FPC_WIDESTR_COMPARE'];
{
Compares 2 WideStrings;
The result is
<0 if S1<S2
0 if S1=S2
>0 if S1>S2
}
Var
i,MaxI,Temp : Longint;
begin
i:=0;
Maxi:=Length(WideString(S1));
temp:=Length(WideString(S2));
If MaxI>Temp then
MaxI:=Temp;
Temp:=0;
While (i<MaxI) and (Temp=0) do
begin
Temp:= PWord(S1+I)^ - PWord(S2+i)^;
inc(i);
end;
if temp=0 then
temp:=Length(WideString(S1))-Length(WideString(S2));
WideStr_Compare:=Temp;
end;
Procedure WideStr_CheckZero(p : pointer);[Public,Alias : 'FPC_WIDESTR_CHECKZERO'];
begin
if p=nil then
HandleErrorFrame(201,get_frame);
end;
Procedure WideStr_CheckRange(len,index : longint);[Public,Alias : 'FPC_WIDESTR_RANGECHECK'];
begin
if (index>len) or (Index<1) then
HandleErrorFrame(201,get_frame);
end;
{$ifndef INTERNSETLENGTH}
Procedure SetLength (Var S : WideString; l : Longint);
{$else INTERNSETLENGTH}
Procedure WideStr_SetLength (Var S : WideString; l : Longint);[Public,Alias : 'FPC_WIDESTR_SETLENGTH'];
{$endif INTERNSETLENGTH}
{
Sets The length of string S to L.
Makes sure S is unique, and contains enough room.
}
Var
Temp : Pointer;
begin
if (l>0) then
begin
if Pointer(S)=nil then
begin
{ Need a complete new string...}
Pointer(s):=NewWideString(l);
end
else
If (PWideRec(Pointer(S)-WideFirstOff)^.Maxlen < L) or
(PWideRec(Pointer(S)-WideFirstOff)^.Ref <> 1) then
begin
{ Reallocation is needed... }
Temp:=Pointer(NewWideString(L));
if Length(S)>0 then
Move(Pointer(S)^,Temp^,L+L);
ansistr_decr_ref(Pointer(S));
Pointer(S):=Temp;
end;
{ Force nil termination in case it gets shorter }
PByte(Pointer(S)+l)^:=0;
PWideRec(Pointer(S)-WideFirstOff)^.Len:=l;
end
else
begin
{ Length=0 }
if Pointer(S)<>nil then
ansistr_decr_ref (Pointer(S));
Pointer(S):=Nil;
end;
end;
{*****************************************************************************
Public functions, In interface.
*****************************************************************************}
Function Length (Const S : WideString) : Longint;
{
Returns the length of an WideString.
Takes in acount that zero strings are NIL;
}
begin
If Pointer(S)=Nil then
Length:=0
else
Length:=PWideRec(Pointer(S)-WideFirstOff)^.Len;
end;
Procedure UniqueString(Var S : WideString); [Public,Alias : 'FPC_WIDESTR_UNIQUE'];
{
Make sure reference count of S is 1,
using copy-on-write semantics.
}
Var
SNew : Pointer;
begin
If Pointer(S)=Nil then
exit;
if PWideRec(Pointer(S)-WideFirstOff)^.Ref<>1 then
begin
SNew:=NewWideString (PWideRec(Pointer(S)-WideFirstOff)^.len);
Move (Pointer(S)^,SNew^,(PWideRec(Pointer(S)-WideFirstOff)^.len+1)*2);
PWideRec(SNew-WideFirstOff)^.len:=PWideRec(Pointer(S)-WideFirstOff)^.len;
ansistr_decr_ref (Pointer(S)); { Thread safe }
Pointer(S):=SNew;
end;
end;
Function Copy (Const S : WideString; Index,Size : Longint) : WideString;
var
ResultAddress : Pointer;
begin
ResultAddress:=Nil;
dec(index);
if Index < 0 then
Index := 0;
{ Check Size. Accounts for Zero-length S, the double check is needed because
Size can be maxint and will get <0 when adding index }
if (Size>Length(S)) or
(Index+Size>Length(S)) then
Size:=Length(S)-Index;
If Size>0 then
begin
If Index<0 Then
Index:=0;
ResultAddress:=Pointer(NewWideString (Size));
if ResultAddress<>Nil then
begin
Move (Pointer(Pointer(S)+index)^,ResultAddress^,Size*2);
PWideRec(ResultAddress-WideFirstOff)^.Len:=Size;
PWord(ResultAddress+Size*2)^:=0;
end;
end;
Pointer(Copy):=ResultAddress;
end;
Function Pos (Const Substr : WideString; Const Source : WideString) : Longint;
var
substrlen,
maxi,
i,j : longint;
e : boolean;
{ S : WideString;
se : Pointer; }
begin
i := 0;
j := 0;
substrlen:=Length(SubStr);
maxi:=length(source)-substrlen;
e:=(substrlen>0);
while (e) and (i <= maxi) do
begin
inc (i);
{!!!: if Source[i]=SubStr[1] then
begin
S:=copy(Source,i,substrlen);
Se:=pointer(SubStr);
if WideStr_Compare(se,Pointer(S))=0 then
begin
j := i;
break;
end;
end;}
end;
pos := j;
end;
Procedure Delete (Var S : WideString; Index,Size: Longint);
Var
LS : Longint;
begin
If Length(S)=0 then
exit;
if index<=0 then
begin
inc(Size,index-1);
index:=1;
end;
LS:=PWideRec(Pointer(S)-WideFirstOff)^.Len;
if (Index<=LS) and (Size>0) then
begin
UniqueString (S);
if Size+Index>LS then
Size:=LS-Index+1;
if Index+Size<=LS then
begin
Dec(Index);
Move(PByte(Pointer(S))[Index+Size],PByte(Pointer(S))[Index],(LS-Index+1)*2);
end;
Setlength(s,LS-Size);
end;
end;
Procedure Insert (Const Source : WideString; Var S : WideString; Index : Longint);
var
Temp : WideString;
LS : Longint;
begin
If Length(Source)=0 then
exit;
if index <= 0 then
index := 1;
Ls:=Length(S);
if index > LS then
index := LS+1;
Dec(Index);
Pointer(Temp) := NewWideString(Length(Source)+LS);
SetLength(Temp,Length(Source)+LS);
If Index>0 then
move (Pointer(S)^,Pointer(Temp)^,Index*2);
Move (Pointer(Source)^,PByte(Temp)[Index],Length(Source)*2);
If (LS-Index)>0 then
Move(PByte(Pointer(S))[Index],PByte(temp)[Length(Source)+index],(LS-Index)*2);
S:=Temp;
end;
{!!!:Procedure SetString (Var S : WideString; Buf : PWideChar; Len : Longint);
begin
SetLength(S,Len);
Move (Buf[0],S[1],Len*2);
end;}
{
$Log$
Revision 1.6 2000-11-06 23:17:15 peter
* removed some warnings
Revision 1.5 2000/11/06 20:34:24 peter
* changed ver1_0 defines to temporary defs
Revision 1.4 2000/10/21 18:20:17 florian
* a lot of small changes:
- setlength is internal
- win32 graph unit extended
....
Revision 1.3 2000/08/08 22:12:36 sg
* Implemented WideString helper functions (but they are not tested yet
due to the lack of full compiler support for WideString/WideChar!)
Revision 1.2 2000/07/13 11:33:46 michael
+ removed logs
}