72 lines
1.2 KiB
ObjectPascal
72 lines
1.2 KiB
ObjectPascal
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unit demo_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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type
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Ts20 = string[20];
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TdemoRec = record
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aChar: Char;
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anInt: integer;
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aString: Ts20;
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aDate: TDateTime;
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end;
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{ TdemoStream }
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TdemoStream = class(TMemoryStream)
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private
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function GenerateRandomRec(num: integer): TdemoRec;
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public
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rec: TdemoRec;
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constructor Create(numRecords: integer);
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function RecAsString: string;
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end;
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implementation
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uses math;
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{ TdemoStream }
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function TdemoStream.GenerateRandomRec(num: integer): TdemoRec;
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begin
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Result.aChar := Chr(65 + Random(26));
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Result.aDate := TDateTime(RandomRange(100, trunc(Now)) + Random/10000);
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Result.anInt := num;
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Result.aString := Format('example string %d', [num]);
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end;
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constructor TdemoStream.Create(numRecords: integer);
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var i: integer;
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begin
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// Initialize random number generator
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Randomize;
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// Call the inherited constructor
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inherited Create;
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Position := 0;
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for i := 0 to numRecords-1 do
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Write(GenerateRandomRec(i), SizeOf(TdemoRec));
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end;
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function TdemoStream.RecAsString: string;
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begin
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Read(rec, SizeOf(rec));
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Result := Format(
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'%5d %s %17s %s',
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[rec.anInt, rec.aChar, rec.aString, FormatDateTime('dd-mm-yyyy:mm:ss', rec.aDate)]
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);
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end;
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end.
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