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{*****************************************************************************}
{ }
{ Tnt Delphi Unicode Controls }
{ http://www.tntware.com/delphicontrols/unicode/ }
{ Extended TTntMemIniFile (compatible with all versions) }
{ }
{ Copyright (c) 1999-2007 Stanley Xu }
{ http://getgosurf.com/?go=supportFeedback&ln=en }
{ }
{*****************************************************************************}
{*****************************************************************************}
{ }
{ BACKGROUND: }
{ TTntMemIniFile buffers all changes to the INI file in memory. To write }
{ the data from memory back to the associated INI file, call the }
{ UpdateFile() method. However, the whole content of this INI file will }
{ be overwritten. Even those sections that are not used. This will make }
{ troubles, if two instances try to change the same file at the same }
{ time, without some method of managing access the instances may well end }
{ up overwriting each other's work. }
{ }
{ IDEA: }
{ TTntMemIniFileEx implementes a simple idea: To check the timestamp }
{ before each operation. If the file is modified, TTntMemIniFileEx will }
{ reload the file to keep the content updated. }
{ }
{ CONCLUSION: }
{ # TTntMemIniFileEx and TTntMemIniFile are ideal for read-only access. }
{ For instance: To read localization files, etc. }
{ # To perform mass WriteString() operations, please use the following }
{ code. }
{ BeginUpdate(); }
{ try }
{ for I := 0 to 10000 do }
{ WriteString(...); }
{ finally; }
{ EndUpdate(); }
{ UpdateFile; }
{ end; }
{ }
{*****************************************************************************}
unit TntIniFilesEx;
{$INCLUDE TntCompilers.inc}
interface
uses
TntClasses, TntIniFiles;
type
TTntMemIniFileEx = class(TTntMemIniFile)
private
FUpdateCount: Integer;
FModified: Boolean;
FLastAccessed: Integer;
function FileRealLastAccessedTime: Integer;
procedure GetLatestVersion;
protected
procedure LoadValues; // Extended
public
constructor Create(const FileName: WideString); override;
procedure BeginUpdate; virtual;
procedure EndUpdate; virtual;
function ReadString(const Section, Ident, Default: WideString): WideString; override;
procedure WriteString(const Section, Ident, Value: WideString); override;
procedure ReadSection(const Section: WideString; Strings: TTntStrings); override;
procedure ReadSections(Strings: TTntStrings); override;
procedure ReadSectionValues(const Section: WideString; Strings: TTntStrings); override;
procedure DeleteKey(const Section, Ident: WideString); override;
procedure EraseSection(const Section: WideString); override;
procedure UpdateFile; override;
end;
implementation
uses
SysUtils, TntSysUtils;
{ TTntMemIniFileEx }
function TTntMemIniFileEx.FileRealLastAccessedTime: Integer;
var
H: Integer; // file handle
begin
Result := 0;
H := WideFileOpen(FileName, fmOpenWrite); //fmOpenRead (?)
if H <> -1 then
try
Result := FileGetDate(H);
finally
FileClose(H);
end;
end;
procedure TTntMemIniFileEx.GetLatestVersion;
begin
if FLastAccessed = FileRealLastAccessedTime then
Exit;
LoadValues;
// FLastAccess will be updated in LoadValues(...)
end;
procedure TTntMemIniFileEx.LoadValues; // Copied from TntIniFiles.pas
var
List: TTntStringList;
begin
if (FileName <> '') and WideFileExists(FileName) then
begin
List := TTntStringList.Create;
try
List.LoadFromFile(FileName);
FLastAccessed := FileRealLastAccessedTime; // Extra
FModified := False; //
SetStrings(List);
finally
List.Free;
end;
end else
Clear;
end;
constructor TTntMemIniFileEx.Create(const FileName: WideString);
begin
inherited Create(FileName);
FUpdateCount := 0;
end;
procedure TTntMemIniFileEx.BeginUpdate;
begin
Inc(FUpdateCount);
end;
procedure TTntMemIniFileEx.EndUpdate;
begin
Dec(FUpdateCount);
end;
function TTntMemIniFileEx.ReadString(const Section, Ident, Default: WideString): WideString;
begin
GetLatestVersion;
Result := inherited ReadString(Section, Ident, Default);
end;
procedure TTntMemIniFileEx.WriteString(const Section, Ident, Value: WideString);
begin
GetLatestVersion;
inherited WriteString(Section, Ident, Value);
FModified := True;
UpdateFile; // Flush changes to disk
end;
procedure TTntMemIniFileEx.ReadSection(const Section: WideString; Strings: TTntStrings);
begin
GetLatestVersion;
inherited ReadSection(Section, Strings);
end;
procedure TTntMemIniFileEx.ReadSections(Strings: TTntStrings);
begin
GetLatestVersion;
inherited ReadSections(Strings);
end;
procedure TTntMemIniFileEx.ReadSectionValues(const Section: WideString; Strings: TTntStrings);
begin
GetLatestVersion;
inherited ReadSectionValues(Section, Strings);
end;
procedure TTntMemIniFileEx.DeleteKey(const Section, Ident: WideString);
begin
GetLatestVersion;
inherited DeleteKey(Section, Ident);
FModified := True;
UpdateFile; // Flush changes to disk
end;
procedure TTntMemIniFileEx.EraseSection(const Section: WideString);
begin
GetLatestVersion;
inherited EraseSection(Section);
FModified := True;
UpdateFile; // Flush changes to disk
end;
procedure TTntMemIniFileEx.UpdateFile;
begin
if not FModified or (FUpdateCount > 0) then
Exit;
inherited;
end;
end.
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