mirror of
https://gitlab.com/freepascal.org/fpc/source.git
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520 lines
14 KiB
ObjectPascal
520 lines
14 KiB
ObjectPascal
{
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$Id$
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Async_IO: Mananging class for asynchronous input/output
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Copyright (C) 2000 by Sebastian Guenther (sg@freepascal.org)
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See the file COPYING.FPC, included in this distribution,
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for details about the copyright.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
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}
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{$MODE objfpc}
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{$H+}
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unit AsyncIO;
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interface
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{$i asyncioh.inc}
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type
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TAsyncIOManager = class;
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TAsyncIONotify = procedure(UserData: TObject) of object;
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TAsyncIONotifyInfo = record
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Method: TAsyncIONotify;
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UserData: TObject;
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end;
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// -------------------------------------------------------------------
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// TAsyncIOManager
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// -------------------------------------------------------------------
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TAsyncIOManager = class
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protected
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DoBreak: Boolean;
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IOdata : TIOdata;
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ReadNotifies, WriteNotifies: array[0..MaxHandle] of TAsyncIONotifyInfo;
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HighestHandle: Integer;
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FTimeout: Integer;
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TimeoutNotify: TAsyncIONotifyInfo;
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procedure CalcHighestHandle(max: Integer);
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procedure ExecuteNotify(const Notify: TAsyncIONotifyInfo);
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function GetHandleAsync(AHandle: Integer): Boolean;
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procedure SetHandleAsync(AHandle: Integer; AValue: Boolean);
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public
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constructor Create;
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procedure Run;
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procedure BreakRun;
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procedure SetReadHandler(AHandle: Integer; AMethod: TAsyncIONotify; AUserData: TObject);
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procedure ClearReadHandler(AHandle: Integer);
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function GetReadHandler(AHandle: Integer): TAsyncIONotify;
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procedure SetWriteHandler(AHandle: Integer; AMethod: TAsyncIONotify; AUserData: TObject);
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procedure ClearWriteHandler(AHandle: Integer);
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function GetWriteHandler(AHandle: Integer): TAsyncIONotify;
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procedure SetTimeoutHandler(AMethod: TAsyncIONotify; AUserData: TObject);
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procedure ClearTimeoutHandler;
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function GetTimeoutHandler: TAsyncIONotify;
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property Timeout: Integer read FTimeout write FTimeout;
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property HandleAsync[AHandle: Integer]: Boolean read GetHandleAsync write SetHandleAsync;
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end;
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// -------------------------------------------------------------------
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// Line reader classes
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// -------------------------------------------------------------------
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TLineNotify = procedure(const line: String) of object;
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PBoolean = ^Boolean;
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TGenericLineReader = class
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protected
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FDestroyedFlag: PBoolean;
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RealBuffer, FBuffer: PChar;
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FBytesInBuffer: Integer;
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FOnLine: TLineNotify;
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function Read(var ABuffer; count: Integer): Integer; virtual; abstract;
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procedure NoData; virtual; abstract;
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public
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destructor Destroy; override;
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procedure Run; // Process as many lines as possible
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property Buffer: PChar read FBuffer;
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property BytesInBuffer: Integer read FBytesInBuffer;
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property OnLine: TLineNotify read FOnLine write FOnLine;
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end;
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TAsyncStreamLineReader = class(TGenericLineReader)
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protected
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FManager: TAsyncIOManager;
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FDataStream: TStream;
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FBlockingStream: THandleStream;
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FOnEOF: TNotifyEvent;
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function Read(var ABuffer; count: Integer): Integer; override;
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procedure NoData; override;
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procedure StreamDataAvailable(UserData: TObject);
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public
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constructor Create(AManager: TAsyncIOManager; AStream: THandleStream);
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constructor Create(AManager: TAsyncIOManager;
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ADataStream: TStream; ABlockingStream: THandleStream);
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destructor Destroy; override;
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property DataStream: TStream read FDataStream;
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property BlockingStream: THandleStream read FBlockingStream;
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property OnEOF: TNotifyEvent read FOnEOF write FOnEOF;
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end;
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// -------------------------------------------------------------------
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// TWriteBuffer
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// -------------------------------------------------------------------
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TWriteBuffer = class(TStream)
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protected
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FBuffer: PChar;
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FBytesInBuffer: Integer;
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FOnBufferEmpty: TNotifyEvent;
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function Seek(Offset: LongInt; Origin: Word): LongInt; override;
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function Write(const ABuffer; Count: LongInt): LongInt; override;
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function DoRealWrite(const ABuffer; Count: Integer): Integer; virtual; abstract;
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procedure WritingFailed; virtual; abstract;
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procedure WantWrite; virtual; abstract;
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procedure BufferEmpty; virtual;
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constructor Create;
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public
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EndOfLineMarker: String;
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destructor Destroy; override;
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procedure WriteLine(const line: String);
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procedure Run; // Write as many data as possible
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property BytesInBuffer: Integer read FBytesInBuffer;
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property OnBufferEmpty: TNotifyEvent read FOnBufferEmpty write FOnBufferEmpty;
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end;
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TAsyncWriteStream = class(TWriteBuffer)
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protected
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FManager: TAsyncIOManager;
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FDataStream: TStream;
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FBlockingStream: THandleStream;
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function DoRealWrite(const ABuffer; Count: Integer): Integer; override;
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procedure WritingFailed; override;
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procedure WantWrite; override;
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procedure BufferEmpty; override;
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procedure CanWrite(UserData: TObject);
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public
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constructor Create(AManager: TAsyncIOManager; AStream: THandleStream);
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constructor Create(AManager: TAsyncIOManager;
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ADataStream: TStream; ABlockingStream: THandleStream);
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destructor Destroy; override;
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property DataStream: TStream read FDataStream;
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property BlockingStream: THandleStream read FBlockingStream;
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end;
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// ===================================================================
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// ===================================================================
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implementation
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uses SysUtils;
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{$i asyncio.inc}
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// -------------------------------------------------------------------
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// TAsyncIOManager
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// -------------------------------------------------------------------
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procedure TAsyncIOManager.ExecuteNotify(const Notify: TAsyncIONotifyInfo);
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begin
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if Assigned(Notify.Method) then
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Notify.Method(Notify.UserData);
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end;
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procedure TAsyncIOManager.SetTimeoutHandler(AMethod: TAsyncIONotify; AUserData: TObject);
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begin
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TimeoutNotify.Method := AMethod;
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TimeoutNotify.UserData := AUserData;
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end;
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procedure TAsyncIOManager.ClearTimeoutHandler;
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begin
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TimeoutNotify.Method := nil;
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end;
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function TAsyncIOManager.GetTimeoutHandler: TAsyncIONotify;
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begin
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Result := TimeoutNotify.Method;
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end;
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// -------------------------------------------------------------------
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// TGenericLineReader
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// -------------------------------------------------------------------
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destructor TGenericLineReader.Destroy;
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begin
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if Assigned(FDestroyedFlag) then
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FDestroyedFlag^ := True;
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if Assigned(RealBuffer) then
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begin
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FreeMem(RealBuffer);
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RealBuffer := nil;
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end;
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inherited Destroy;
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end;
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procedure TGenericLineReader.Run;
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var
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NewData: array[0..1023] of Byte;
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p: PChar;
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BytesRead, OldBufSize, CurBytesInBuffer, LastEndOfLine, i, LineLength: Integer;
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line: String;
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FirstRun, DestroyedFlag: Boolean;
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begin
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FirstRun := True;
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DestroyedFlag := False;
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while True do
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begin
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BytesRead := Read(NewData, SizeOf(NewData));
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//WriteLn('Linereader: ', BytesRead, ' bytes read');
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if BytesRead <= 0 then begin
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if FirstRun then
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NoData;
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break;
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end;
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FirstRun := False;
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OldBufSize := FBytesInBuffer;
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// Append the new received data to the read buffer
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Inc(FBytesInBuffer, BytesRead);
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ReallocMem(RealBuffer, FBytesInBuffer);
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Move(NewData, RealBuffer[OldBufSize], BytesRead);
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{Process all potential lines in the current buffer. Attention: FBuffer and
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FBytesInBuffer MUST be updated for each line, as they can be accessed from
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within the FOnLine handler!}
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LastEndOfLine := 0;
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if OldBufSize > 0 then
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i := OldBufSize - 1
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else
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i := 0;
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CurBytesInBuffer := FBytesInBuffer;
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while i <= CurBytesInBuffer - 1 do
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begin
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if (RealBuffer[i] = #13) or (RealBuffer[i] = #10) then
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begin
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LineLength := i - LastEndOfLine;
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SetLength(line, LineLength);
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if LineLength > 0 then
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Move(RealBuffer[LastEndOfLine], line[1], LineLength);
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if (i < CurBytesInBuffer - 1) and (RealBuffer[i] = #13) and
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(RealBuffer[i + 1] = #10) then
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Inc(i);
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LastEndOfLine := i + 1;
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if Assigned(FOnLine) then
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begin
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FBuffer := RealBuffer + LastEndOfLine;
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FBytesInBuffer := CurBytesInBuffer - LastEndOfLine;
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FDestroyedFlag := @DestroyedFlag;
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FOnLine(line);
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FDestroyedFlag := nil;
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if DestroyedFlag then
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exit;
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end;
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end;
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Inc(i);
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end;
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FBytesInBuffer := CurBytesInBuffer;
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if LastEndOfLine > 0 then
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begin
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// Remove all processed lines from the buffer
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Dec(FBytesInBuffer, LastEndOfLine);
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GetMem(p, FBytesInBuffer);
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Move(RealBuffer[LastEndOfLine], p^, FBytesInBuffer);
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FreeMem(RealBuffer);
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RealBuffer := p;
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end;
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FBuffer := RealBuffer;
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end;
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end;
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// -------------------------------------------------------------------
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// TAsyncStreamLineReader
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// -------------------------------------------------------------------
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function TAsyncStreamLineReader.Read(var ABuffer; count: Integer): Integer;
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begin
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Result := FDataStream.Read(ABuffer, count);
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end;
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procedure TAsyncStreamLineReader.NoData;
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var
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s: String;
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begin
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if (FDataStream = FBlockingStream) or (FDataStream.Position = FDataStream.Size) then
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begin
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if (FBytesInBuffer > 0) and Assigned(FOnLine) then
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begin
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if FBuffer[FBytesInBuffer - 1] in [#13, #10] then
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Dec(FBytesInBuffer);
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SetLength(s, FBytesInBuffer);
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Move(FBuffer^, s[1], FBytesInBuffer);
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FOnLine(s);
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end;
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FManager.ClearReadHandler(FBlockingStream.Handle);
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if Assigned(FOnEOF) then
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FOnEOF(Self);
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end;
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end;
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procedure TAsyncStreamLineReader.StreamDataAvailable(UserData: TObject);
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begin
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Run;
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end;
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constructor TAsyncStreamLineReader.Create(AManager: TAsyncIOManager; AStream: THandleStream);
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begin
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Self.Create(AManager, AStream, AStream);
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end;
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constructor TAsyncStreamLineReader.Create(AManager: TAsyncIOManager;
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ADataStream: TStream; ABlockingStream: THandleStream);
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begin
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ASSERT(Assigned(ADataStream) and Assigned(ABlockingStream));
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inherited Create;
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FManager := AManager;
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FDataStream := ADataStream;
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FBlockingStream := ABlockingStream;
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AManager.SetReadHandler(FBlockingStream.Handle, @StreamDataAvailable, nil);
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AManager.HandleAsync[FBlockingStream.Handle] := True;
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end;
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destructor TAsyncStreamLineReader.Destroy;
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var
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Handler: TMethod;
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begin
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Handler := TMethod(FManager.GetReadHandler(FBlockingStream.Handle));
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if (Handler.Code = Pointer(@StreamDataAvailable)) and
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(Handler.Data = Pointer(Self)) then
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FManager.ClearReadHandler(FBlockingStream.Handle);
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inherited Destroy;
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end;
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// -------------------------------------------------------------------
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// TWriteBuffer
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// -------------------------------------------------------------------
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procedure TWriteBuffer.BufferEmpty;
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begin
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if Assigned(FOnBufferEmpty) then
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FOnBufferEmpty(Self);
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end;
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constructor TWriteBuffer.Create;
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begin
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inherited Create;
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FBuffer := nil;
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FBytesInBuffer := 0;
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EndOfLineMarker := #10;
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end;
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destructor TWriteBuffer.Destroy;
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begin
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if Assigned(FBuffer) then
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FreeMem(FBuffer);
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inherited Destroy;
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end;
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function TWriteBuffer.Seek(Offset: LongInt; Origin: Word): LongInt;
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begin
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if ((Offset = 0) and ((Origin = soFromCurrent) or (Origin = soFromEnd))) or
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((Offset = FBytesInBuffer) and (Origin = soFromBeginning)) then
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Result := FBytesInBuffer
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else
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raise EStreamError.Create('Invalid stream operation');
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end;
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function TWriteBuffer.Write(const ABuffer; Count: LongInt): LongInt;
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begin
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ReallocMem(FBuffer, FBytesInBuffer + Count);
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Move(ABuffer, FBuffer[FBytesInBuffer], Count);
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Inc(FBytesInBuffer, Count);
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WantWrite;
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Result := Count;
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end;
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procedure TWriteBuffer.WriteLine(const line: String);
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var
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s: String;
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begin
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s := line + EndOfLineMarker;
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WriteBuffer(s[1], Length(s));
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end;
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procedure TWriteBuffer.Run;
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var
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CurStart, written: Integer;
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NewBuf: PChar;
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failed: Boolean;
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begin
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CurStart := 0;
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failed := True;
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repeat
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if FBytesInBuffer = 0 then begin
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BufferEmpty;
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exit;
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end;
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written := DoRealWrite(FBuffer[CurStart], FBytesInBuffer - CurStart);
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if written > 0 then begin
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Inc(CurStart, written);
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failed := False;
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GetMem(NewBuf, FBytesInBuffer - CurStart);
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Move(FBuffer[CurStart], NewBuf[0], FBytesInBuffer - CurStart);
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FreeMem(FBuffer);
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FBuffer := NewBuf;
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Dec(FBytesInBuffer, CurStart);
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end;
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until written <= 0;
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if failed then
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WritingFailed;
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end;
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// -------------------------------------------------------------------
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// TAsyncWriteStream
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// -------------------------------------------------------------------
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function TAsyncWriteStream.DoRealWrite(const ABuffer; Count: Integer): Integer;
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begin
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Result := FDataStream.Write(ABuffer, count);
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end;
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procedure TAsyncWriteStream.WritingFailed;
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begin
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if FDataStream <> FBlockingStream then
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FManager.ClearWriteHandler(FBlockingStream.Handle);
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end;
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procedure TAsyncWriteStream.WantWrite;
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begin
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FManager.SetWriteHandler(FBlockingStream.Handle, @CanWrite, nil);
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end;
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procedure TAsyncWriteStream.BufferEmpty;
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begin
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FManager.ClearWriteHandler(FBlockingStream.Handle);
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inherited BufferEmpty;
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end;
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procedure TAsyncWriteStream.CanWrite(UserData: TObject);
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begin
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Run;
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end;
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constructor TAsyncWriteStream.Create(AManager: TAsyncIOManager; AStream: THandleStream);
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begin
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Self.Create(AManager, AStream, AStream);
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end;
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constructor TAsyncWriteStream.Create(AManager: TAsyncIOManager;
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ADataStream: TStream; ABlockingStream: THandleStream);
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begin
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ASSERT(Assigned(ADataStream) and Assigned(ABlockingStream));
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inherited Create;
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FManager := AManager;
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FDataStream := ADataStream;
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FBlockingStream := ABlockingStream;
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AManager.HandleAsync[FBlockingStream.Handle] := True;
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end;
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destructor TAsyncWriteStream.Destroy;
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begin
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FManager.ClearWriteHandler(FBlockingStream.Handle);
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inherited Destroy;
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end;
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end.
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{
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$Log$
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Revision 1.4 2002-09-07 15:15:24 peter
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* old logs removed and tabs fixed
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}
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