3e6dd484f7
git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@5282 8e941d3f-bd1b-0410-a28a-d453659cc2b4
112 lines
2.8 KiB
ObjectPascal
112 lines
2.8 KiB
ObjectPascal
unit uvirtuallayer_stream;
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{$mode objfpc}{$H+}
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interface
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uses
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Classes, SysUtils,
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uvirtuallayer_types;
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type
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{ TVirtualLayer_Stream }
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TVirtualLayer_Stream=class(TStream)
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private
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FRootVirtualLayer: Pointer;
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FHandle: TvlHandle;
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protected
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FFilename: UTF8String;
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function GetPosition: Int64; override;
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procedure SetPosition(const Pos: Int64); override;
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{ function GetSize: Int64; virtual;
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procedure SetSize64(const NewSize: Int64); virtual;
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procedure SetSize(NewSize: Longint); virtual;overload;
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procedure SetSize(const NewSize: Int64); virtual;overload;
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}
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public
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property Filename: UTF8String Read FFilename;
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function Read(var Buffer; Count: Longint): Longint; override;
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function Write(const Buffer; Count: Longint): Longint; override;
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function Seek(Offset: Longint; Origin: Word): Longint; override; overload;
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function Seek(const Offset: Int64; Origin: TSeekOrigin): Int64; override; overload;
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Constructor Create(const AVirtualLayer: Pointer; const AFileName: UTF8String;const AMode: cardinal);
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Destructor Destroy(); override;
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end;
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implementation
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uses uvirtuallayer;
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function VL(L: Pointer): TVirtualLayer; inline;
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begin
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Result:=TVirtualLayer(L);
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end;
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{ TVirtualLayer_Stream }
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function TVirtualLayer_Stream.GetPosition: Int64;
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begin
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Result:=VL(FRootVirtualLayer).Seek(FHandle,0,fsFromCurrent);
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end;
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procedure TVirtualLayer_Stream.SetPosition(const Pos: Int64);
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var
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NewPos: int64;
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begin
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NewPos:=VL(FRootVirtualLayer).Seek(FHandle,Pos,fsFromBeginning);
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if NewPos<0 Then begin
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//Raise exception ??? which one :-?
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end;
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end;
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function TVirtualLayer_Stream.Read(var Buffer; Count: Longint): Longint;
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begin
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Result:=VL(FRootVirtualLayer).Read(FHandle,@Buffer,Count);
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end;
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function TVirtualLayer_Stream.Write(const Buffer; Count: Longint): Longint;
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begin
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Result:=VL(FRootVirtualLayer).Write(FHandle,@Buffer,Count);
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end;
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function TVirtualLayer_Stream.Seek(Offset: Longint; Origin: Word): Longint;
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begin
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Result:=VL(FRootVirtualLayer).Seek(FHandle,Offset,Origin);
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end;
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function TVirtualLayer_Stream.Seek(const Offset: Int64; Origin: TSeekOrigin): Int64;
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var
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Org: Word;
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begin
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Case Origin of
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soCurrent: Org:=fsFromCurrent;
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soEnd: Org:=fsFromEnd;
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soBeginning:Org:=fsFromBeginning;
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end;
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Result:=VL(FRootVirtualLayer).Seek(FHandle,Offset,Org);
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end;
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constructor TVirtualLayer_Stream.Create(const AVirtualLayer: Pointer;
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const AFileName: UTF8String; const AMode: cardinal);
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begin
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FRootVirtualLayer:=AVirtualLayer;
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FHandle:=VL(FRootVirtualLayer).OpenFile(AFileName,AMode);
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if FHandle=nil Then begin
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Raise EStreamError.Create('Unable to open '+AFileName);
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end;
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FFilename:=AFileName;
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end;
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destructor TVirtualLayer_Stream.Destroy();
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begin
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if FHandle<>nil Then begin
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VL(FRootVirtualLayer).CloseFile(FHandle);
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end;
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inherited Destroy();
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end;
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end.
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