Re: Base64Encoder for Stream
- From: "Jason" <jason@xxxxxxxxxx>
- Date: Mon, 13 Mar 2006 17:31:17 +0200
Im using the FastStrings library, maybe its faster than the code you
provided?
"Eddie Shipman" <mrbaseball34@xxxxxxxxxxxxxxxxx> wrote in message
news:MPG.1e7f42aeb1f675869897b5@xxxxxxxxxxxxxxxxxxxxx
In article <441551e1@xxxxxxxxxxxxxxxxxxxxxx>, jason@xxxxxxxxxx says...
Hello,
do you know any fast way to base64encode a MemoryStream?
Now Im converting stream to String, Im encoding and then string to
stream.
Here is a converted one from Andreas Horstmeier's TCP/IP component
suite:
unit uBase64;
{
Unit source cut from Andreas Horstmeier's TCP/IP component suite.
}
interface
uses
sysutils,
windows,
classes;
type
ta_8u=packed array [0..65530] of byte;
t_encoding=(uuencode,base64,mime);
function encode_base64(data: TStream):TStringList;
function decode_base64(source:TStringList):TMemoryStream;
function encode_line(mode:t_encoding; const buf; size:Integer):String;
function decode_line(mode:t_encoding; const inp:String):String;
function poscn(c:char; const s:String; n: Integer):Integer;
const
bin2b64:String='ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123
456789+/';
b642bin:String='~~~~~~~~~~~^~~~_TUVWXYZ[\]~~~|~~~ !"#$%&''()
*+,-./0123456789~~~~~~:;<=>?@ABCDEFGHIJKLMNOPQRS';
bin2uue:String='`!"#$%&''()*+,-./0123456789:;<=>?
@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_';
uue2bin:String=' !"#$%&''()*+,-./0123456789:;<=>?
@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_ ';
linesize = 45;
implementation
function poscn(c:char; const s:String; n: Integer):Integer;
var
i: Integer;
begin
if n=0 then n:=1;
if n>0 then
begin
for i:=1 to length(s) do
begin
if s[i]<>c then
begin
dec(n);
Result:=i;
if n=0 then
begin
EXIT;
end;
end;
end;
end
else
begin
for i:=length(s) downto 1 do
begin
if s[i]<>c then
begin
inc(n);
Result:=i;
if n=0 then
begin
EXIT;
end;
end;
end;
end;
poscn:=0;
end;
function decode_line(mode:t_encoding; const inp:String):String;
var
count,pos1,pos2: Integer;
offset: shortint;
s: String;
sOut: String;
begin
s:=inp;
setlength(sOut,length(s)*3 div 4 +3);
fillchar(sOut[1],length(s)*3 div 4 +3,#0);
if (mode=uuencode) and not (s[1] in [' '..'M','`']) then
count:=0
else
begin
count:=0;
pos1:=0;
case mode of
uuencode:
begin
count:=(ord(s[1]) - $20) and $3f;
for pos1:=2 to length(s)-1 do
s[pos1]:=char(ord(uue2bin[ord(s[pos1])-$20+1])-$20);
pos1:=2;
end;// uuencode
base64,mime:
begin
count:=poscn('=',s,-1)*3 div 4;
for pos1:=1 to length(s) do
s[pos1]:=char(ord(b642bin[ord(s[pos1])-$20+1])-$20);
pos1:=1;
end;// base64, mime
end;// case
pos2:=1;
offset:=2;
while pos2<=count do
begin
if (pos1>length(s)) or ((mode<>uuencode) and (s[pos1]='\')) then
begin
if offset<>2 then
inc(pos2);
count:=pos2-1;
end
else
if ((mode<>uuencode) and (s[pos1]='^')) then
inc(pos1)
else
if offset>0 then
begin
sOut[pos2]:=char(ord(sOut[pos2]) or (ord(s[pos1]) shl
offset));
inc(pos1);
offset:=offset-6;
end
else
if offset<0 then
begin
offset:=abs(offset);
sOut[pos2]:=char(ord(sOut[pos2]) or (ord(s[pos1]) shr
offset));
inc(pos2);
offset:=8-offset;
end
else
begin
sOut[pos2]:=char(ord(sOut[pos2]) or ord(s[pos1]));
inc(pos1);
inc(pos2);
offset:=2;
end;// if ((mode<>uuencode) and (s[pos1]='^'))
end;// while pos2<=count
end;// if (mode=uuencode) and not (s[1] in [' '..'M','`'])
decode_line:=copy(sOut,1,count);
end;// function decode_line
function encode_line(mode:t_encoding; const buf; size:Integer):String;
var
buff: ta_8u absolute buf;
offset: shortint;
pos1,pos2: byte;
i: byte;
sOut: String;
begin
setlength(sOut,size*4 div 3 + 4);
fillchar(sOut[1],size*4 div 3 +2,#0);
if mode=uuencode then
begin
sOut[1]:=char(((size-1) and $3f)+$21);
size:=((size+2) div 3)*3;
end;// if
offset:=2;
pos1:=0;
pos2:=0;
case mode of
uuencode: pos2:=2;
base64, mime: pos2:=1;
end;// case
sOut[pos2]:=#0;
while pos1<size do
begin
if offset > 0 then
begin
sOut[pos2]:=char(ord(sOut[pos2]) or ((buff[pos1] and ($3f shl
offset)) shr offset));
offset:=offset-6;
inc(pos2);
sOut[pos2]:=#0;
end
else
if offset < 0 then
begin
offset:=abs(offset);
sOut[pos2]:=char(ord(sOut[pos2]) or ((buff[pos1] and ($3f shr
offset)) shl offset));
offset:=8-offset;
inc(pos1);
end
else
begin
sOut[pos2]:=char(ord(sOut[pos2]) or ((buff[pos1] and $3f)));
inc(pos2);
inc(pos1);
sOut[pos2]:=#0;
offset:=2;
end;
end;
case mode of
uuencode:
begin
if offset=2 then dec(pos2);
for i:=2 to pos2 do
sOut[i]:=bin2uue[ord(sOut[i])+1];
end;// uuencode
base64, mime:
begin
if offset=2 then dec(pos2);
for i:=1 to pos2 do
sOut[i]:=bin2b64[ord(sOut[i])+1];
while (pos2 and 3)<>0 do
begin
inc(pos2);
sOut[pos2]:='=';
end;
end;// base64, mime
end;// case
encode_line:=copy(sOut,1,pos2);
end;// function encode_line
function encode_base64(data: TStream):TStringList;
var
buf: pointer;
size: Integer;
begin
buf:=NIL;
try
Result:=TStringList.Create;
getmem(buf,linesize);
data.seek(0,0);
size:=linesize;
while size>0 do
begin
size:=data.read(buf^,linesize);
if size>0 then
Result.add(encode_line(base64,buf^,size));
end;// while
finally
if buf<>NIL then
freemem(buf,linesize);
end;// try
end;// function encode_base64
function decode_base64(source:TStringList):TMemoryStream;
var
i: Integer;
s: String;
begin
Result:=TMemoryStream.Create;
for i:=0 to source.count-1 do
begin
s:=decode_line(base64,source[i]);
Result.write(s[1],length(s));
end;// for
end;// function decode_base64
end.
.
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