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| ///////////////////////////////////////////////////////////////////////////
// //
// Copyright (c) 2015 by Charta Software B.V. //
// All rights reserved //
// //
// Version: 1.7.0.83525 //
// Web site: https://pascal.chartasoftware.com/ //
// //
// This code and information are provided "as is" without warranty of //
// any kind. Dissemination of this information or reproduction of //
// this material is strictly forbidden unless prior written permission //
// is obtained from Charta Software B.V.. //
// //
///////////////////////////////////////////////////////////////////////////
unit Stream.Input;
interface
uses
Boolean,
FloatingPoint._32,
FloatingPoint._64,
Integer._16.Positive,
Integer._32.Positive,
Integer._64.Positive,
Integer._8.Positive;
type
TInputStream = class(TObject)
public
function Available(): TPositiveInteger32; virtual;
function AtEnd(): TBoolean; virtual;
procedure Read(var Buffer; Count: TPositiveInteger32); virtual; abstract;
procedure Skip(Count: TPositiveInteger64); virtual;
function ReadLittleEndian8(): TPositiveInteger8;
function ReadLittleEndian16(): TPositiveInteger16;
function ReadLittleEndian24(): TPositiveInteger32;
function ReadLittleEndian32(): TPositiveInteger32;
function ReadLittleEndian64(): TPositiveInteger64;
function ReadLittleEndianFloatingPoint32(): TFloatingPoint32;
function ReadLittleEndianFloatingPoint64(): TFloatingPoint64;
function ReadBigEndian8(): TPositiveInteger32;
function ReadBigEndian16(): TPositiveInteger32;
function ReadBigEndian24(): TPositiveInteger32;
function ReadBigEndian32(): TPositiveInteger32;
function ReadBigEndian64(): TPositiveInteger64;
function ReadBigEndianFloatingPoint32(): TFloatingPoint32;
function ReadBigEndianFloatingPoint64(): TFloatingPoint64;
end;
implementation
uses
Byte;
{ TInputStream }
function TInputStream.AtEnd(): TBoolean;
begin
Result := False;
end;
function TInputStream.Available(): TPositiveInteger32;
begin
Result := 0;
end;
function TInputStream.ReadBigEndian16(): TPositiveInteger32;
var
Bytes: array [0..1] of TByte;
begin
Read(Bytes, SizeOf(Bytes));
Result := (Bytes[0] shl 8) or (Bytes[1] shl 0);
end;
function TInputStream.ReadBigEndian24(): TPositiveInteger32;
var
Bytes: array [0..2] of TByte;
begin
Read(Bytes, SizeOf(Bytes));
Result := (Bytes[0] shl 16) or (Bytes[1] shl 8) or (Bytes[2] shl 0);
end;
function TInputStream.ReadBigEndian32(): TPositiveInteger32;
var
Bytes: array [0..3] of TByte;
begin
Read(Bytes, SizeOf(Bytes));
Result := (Bytes[0] shl 24) or (Bytes[1] shl 16) or (Bytes[2] shl 8) or (Bytes[3] shl 0);
end;
function TInputStream.ReadBigEndian64(): TPositiveInteger64;
var
Bytes: array [0..7] of TByte;
begin
Read(Bytes, SizeOf(Bytes));
Result :=
(Bytes[0] shl 24)
or (Bytes[1] shl 16)
or (Bytes[2] shl 8)
or (Bytes[3] shl 0);
// TODO: Currently Charta Pascal selects TInteger32 variant of the shl operator which produces wrong results.
// The type cast can be removed once that problem is resolved.
Result :=
(Result shl 32)
or {$IF Defined(CHARTA_PASCAL)}TPositiveInteger32{$ENDIF}(
(Bytes[4] shl 24)
or (Bytes[5] shl 16)
or (Bytes[6] shl 8)
or (Bytes[7] shl 0)
);
end;
function TInputStream.ReadBigEndian8(): TPositiveInteger32;
var
Value: TByte;
begin
Read(Value, SizeOf(Value));
Result := Value;
end;
function TInputStream.ReadBigEndianFloatingPoint32(): TFloatingPoint32;
type
TFloatingPoint32Bytes = array [0..3] of TByte;
begin
Result := TFloatingPoint32(TFloatingPoint32Bytes(ReadBigEndian32()));
end;
function TInputStream.ReadBigEndianFloatingPoint64(): TFloatingPoint64;
type
TFloatingPoint64Bytes = array [0..7] of TByte;
begin
Result := TFloatingPoint64(TFloatingPoint64Bytes(ReadBigEndian64()));
end;
function TInputStream.ReadLittleEndian16(): TPositiveInteger16;
var
Bytes: array [0..1] of TByte;
begin
Read(Bytes, SizeOf(Bytes));
Result := (Bytes[1] shl 8) or (Bytes[0] shl 0);
end;
function TInputStream.ReadLittleEndian24(): TPositiveInteger32;
var
Bytes: array [0..2] of TByte;
begin
Read(Bytes, SizeOf(Bytes));
Result := (Bytes[2] shl 16) or (Bytes[1] shl 8) or (Bytes[0] shl 0);
end;
function TInputStream.ReadLittleEndian32(): TPositiveInteger32;
var
Bytes: array [0..3] of TByte;
begin
Read(Bytes, SizeOf(Bytes));
Result := (Bytes[3] shl 24) or (Bytes[2] shl 16) or (Bytes[1] shl 8) or (Bytes[0] shl 0);
end;
function TInputStream.ReadLittleEndian64(): TPositiveInteger64;
var
Bytes: array [0..7] of TByte;
begin
Read(Bytes, SizeOf(Bytes));
Result :=
(Bytes[7] shl 24)
or (Bytes[6] shl 16)
or (Bytes[5] shl 8)
or (Bytes[4] shl 0);
// TODO: Currently Charta Pascal selects TInteger32 variant of the shl operator which produces wrong results.
// The type cast can be removed once that problem is resolved.
Result :=
(Result shl 32)
or {$IF Defined(CHARTA_PASCAL)}TPositiveInteger32{$ENDIF}(
(Bytes[3] shl 24)
or (Bytes[2] shl 16)
or (Bytes[1] shl 8)
or (Bytes[0] shl 0)
);
end;
function TInputStream.ReadLittleEndian8(): TPositiveInteger8;
begin
Read(Result, 1);
end;
function TInputStream.ReadLittleEndianFloatingPoint32(): TFloatingPoint32;
type
TFloatingPoint32Bytes = array [0..3] of TByte;
begin
Result := TFloatingPoint32(TFloatingPoint32Bytes(ReadLittleEndian32()));
end;
function TInputStream.ReadLittleEndianFloatingPoint64(): TFloatingPoint64;
type
TFloatingPoint64Bytes = array [0..7] of TByte;
begin
Result := TFloatingPoint64(TFloatingPoint64Bytes(ReadLittleEndian64()));
end;
procedure TInputStream.Skip(Count: TPositiveInteger64);
var
Buffer: array [0..1023] of TByte;
ToReadCount: TPositiveInteger64;
begin
while Count > 0 do
begin
ToReadCount := MinimumPositiveInteger64(Count, SizeOf(Buffer));
Read(Buffer[0], ToReadCount);
Dec(Count, ToReadCount);
end;
end;
end.
|