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* Made descendent of TOwnerStream

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git-svn-id: trunk@13439 -
This commit is contained in:
michael 2009-07-25 10:55:36 +00:00
parent 177651a132
commit 24f2c7c5cc
1 changed files with 28 additions and 32 deletions
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60
packages/fcl-base/src/base64.pp
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@ -30,14 +30,13 @@ uses classes, sysutils;
type
TBase64EncodingStream = class(TStream)
TBase64EncodingStream = class(TOwnerStream)
protected
OutputStream: TStream;
TotalBytesProcessed, BytesWritten: LongWord;
Buf: array[0..2] of Byte;
BufSize: Integer; // # of bytes used in Buf
public
constructor Create(AOutputStream: TStream);
constructor Create(ASource: TStream);
destructor Destroy; override;
function Write(const Buffer; Count: Longint): Longint; override;
@ -60,23 +59,22 @@ type
{ TBase64DecodingStream }
TBase64DecodingStream = class(TStream)
TBase64DecodingStream = class(TOwnerStream)
private
FMode: TBase64DecodingMode;
procedure SetMode(const AValue: TBase64DecodingMode);
function GetSize: Int64; override;
function GetPosition: Int64; override;
protected
InputStream: TStream;
CurPos, // 0-based (decoded) position of this stream (nr. of decoded & Read bytes since last reset)
DecodedSize: Int64; // length of decoded stream ((expected) decoded bytes since last Reset until Mode-dependent end of stream)
ReadBase64ByteCount: Int64; // number of valid base64 bytes read from input stream since last Reset
Buf: array[0..2] of Byte; // last 3 decoded bytes
BufPos: Integer; // offset in Buf of byte which is to be read next; if >2, next block must be read from InputStream & decoded
BufPos: Integer; // offset in Buf of byte which is to be read next; if >2, next block must be read from Source & decoded
FEOF: Boolean; // if true, all decoded bytes have been read
public
constructor Create(AInputStream: TStream);
constructor Create(AInputStream: TStream; AMode: TBase64DecodingMode);
constructor Create(ASource: TStream);
constructor Create(ASource: TStream; AMode: TBase64DecodingMode);
procedure Reset;
function Read(var Buffer; Count: Longint): Longint; override;
@ -126,10 +124,9 @@ const
Alphabet = ['a'..'z','A'..'Z','0'..'9','+','/','=']; // all 65 chars that are in the base64 encoding alphabet
constructor TBase64EncodingStream.Create(AOutputStream: TStream);
constructor TBase64EncodingStream.Create(ASource: TStream);
begin
inherited Create;
OutputStream := AOutputStream;
inherited Create(ASource);
end;
destructor TBase64EncodingStream.Destroy;
@ -143,14 +140,14 @@ begin
WriteBuf[1] := EncodingTable[(Buf[0] and 3) shl 4];
WriteBuf[2] := '=';
WriteBuf[3] := '=';
OutputStream.Write(WriteBuf, 4);
Source.Write(WriteBuf, 4);
end;
2: begin
WriteBuf[0] := EncodingTable[Buf[0] shr 2];
WriteBuf[1] := EncodingTable[(Buf[0] and 3) shl 4 or (Buf[1] shr 4)];
WriteBuf[2] := EncodingTable[(Buf[1] and 15) shl 2];
WriteBuf[3] := '=';
OutputStream.Write(WriteBuf, 4);
Source.Write(WriteBuf, 4);
end;
end;
inherited Destroy;
@ -179,7 +176,7 @@ begin
WriteBuf[1] := EncodingTable[(Buf[0] and 3) shl 4 or (Buf[1] shr 4)];
WriteBuf[2] := EncodingTable[(Buf[1] and 15) shl 2 or (Buf[2] shr 6)];
WriteBuf[3] := EncodingTable[Buf[2] and 63];
OutputStream.Write(WriteBuf, 4);
Source.Write(WriteBuf, 4);
Inc(BytesWritten, 4);
BufSize := 0;
end;
@ -215,15 +212,15 @@ var
i: Integer;
c: Char;
begin
// Note: this method only works on Seekable InputStreams (for bdmStrict we also get the Size property)
// Note: this method only works on Seekable Sources (for bdmStrict we also get the Size property)
if DecodedSize<>-1 then Exit(DecodedSize);
ipos := InputStream.Position; // save position in input stream
ipos := Source.Position; // save position in input stream
case Mode of
bdmMIME: begin
// read until end of input stream or first occurence of a '='
Result := ReadBase64ByteCount; // keep number of valid base64 bytes since last Reset in Result
repeat
count := InputStream.Read(scanBuf, SizeOf(scanBuf));
count := Source.Read(scanBuf, SizeOf(scanBuf));
for i := 0 to count-1 do begin
c := scanBuf[i];
if c in Alphabet-['='] then // base64 encoding characters except '='
@ -244,13 +241,13 @@ begin
end;
bdmStrict:begin
// seek to end of input stream, read last two bytes and determine size
// from InputStream size and the number of leading '=' bytes
// from Source size and the number of leading '=' bytes
// NB we don't raise an exception here if the input does not contains an integer multiple of 4 bytes
ipos := InputStream.Position;
isize := InputStream.Size;
ipos := Source.Position;
isize := Source.Size;
Result := ((ReadBase64ByteCount + (isize - ipos) + 3) div 4) * 3;
InputStream.Seek(-2, soFromEnd);
InputStream.Read(endBytes, 2);
Source.Seek(-2, soFromEnd);
Source.Read(endBytes, 2);
if endBytes[1] = '=' then begin // last byte
Dec(Result);
if endBytes[0] = '=' then // second to last byte
@ -258,7 +255,7 @@ begin
end;
end;
end;
InputStream.Position := ipos; // restore position in input stream
Source.Position := ipos; // restore position in input stream
// store calculated DecodedSize
DecodedSize := Result;
end;
@ -268,22 +265,21 @@ begin
Result := CurPos;
end;
constructor TBase64DecodingStream.Create(AInputStream: TStream);
constructor TBase64DecodingStream.Create(ASource: TStream);
begin
Create(AInputStream, bdmMIME); // MIME mode is default
Create(ASource, bdmMIME); // MIME mode is default
end;
constructor TBase64DecodingStream.Create(AInputStream: TStream; AMode: TBase64DecodingMode);
constructor TBase64DecodingStream.Create(ASource: TStream; AMode: TBase64DecodingMode);
begin
inherited Create;
InputStream := AInputStream;
inherited Create(ASource);
Mode := AMode;
Reset;
end;
procedure TBase64DecodingStream.Reset;
begin
ReadBase64ByteCount := 0; // number of bytes Read form InputStream since last call to Reset
ReadBase64ByteCount := 0; // number of bytes Read form Source since last call to Reset
CurPos := 0; // position in decoded byte sequence since last Reset
DecodedSize := -1; // indicates unknown; will be set after first call to GetSize or when reaching end of stream
BufPos := 3; // signals we need to read & decode a new block of 4 bytes
@ -324,7 +320,7 @@ begin
ReadOK := 0; // number of base64 bytes already read into ReadBuf
while ToRead > 0 do begin
OrgToRead := ToRead;
HaveRead := InputStream.Read(ReadBuf[ReadOK], ToRead);
HaveRead := Source.Read(ReadBuf[ReadOK], ToRead);
//WriteLn('ToRead = ', ToRead, ', HaveRead = ', HaveRead, ', ReadOK=', ReadOk);
if HaveRead > 0 then begin // if any new bytes; in ReadBuf[ReadOK .. ReadOK + HaveRead-1]
for i := ReadOK to ReadOK + HaveRead - 1 do begin
@ -359,11 +355,11 @@ begin
else if (ReadBuf[0] = PC) or (ReadBuf[1] = PC) then
raise EBase64DecodingException.CreateFmt(SStrictMisplacedPadChar,[]) // =BBB or B=BB
else if (ReadBuf[2] = PC) then begin
if (ReadBuf[3] <> PC) or (InputStream.Position < InputStream.Size) then
if (ReadBuf[3] <> PC) or (Source.Position < Source.Size) then
raise EBase64DecodingException.CreateFmt(SStrictMisplacedPadChar,[]); // BB=B or BB==, but not at end of input stream
DetectedEnd(CurPos + 1) // only one byte left to read; BB==, at end of input stream
end else if (ReadBuf[3] = PC) then begin
if (InputStream.Position < InputStream.Size) then
if (Source.Position < Source.Size) then
raise EBase64DecodingException.CreateFmt(SStrictMisplacedPadChar,[]); // BBB=, but not at end of input stream
DetectedEnd(CurPos + 2); // only two bytes left to read; BBB=, at end of input stream
end;