我正在使用 Delphi 2007，并且有一个应用程序可以通过内部网络从多个地方读取日志文件并显示异常。这些目录有时包含数千个日志文件。应用程序可以选择仅读取最近 n 天的日志文件，它也可以在任何日期时间范围内。
问题是第一次读取日志目录时可能会非常慢（几分钟）。第二次速度要快得多。
我想知道如何优化我的代码以尽可能快地读取日志文件？我正在使用 vCurrentFile: TStringList 将文件存储在内存中。这是从 FileStream 更新的，因为我认为这更快。
这是一些代码：
Refresh : 读取日志文件的主循环
// In this function the logfiles are searched for exceptions. If a exception is found it is stored in a object.
// The exceptions are then shown in the grid
procedure TfrmMain.Refresh;
var
FileData : TSearchRec; // Used for the file searching. Contains data of the file
vPos, i, PathIndex : Integer;
vCurrentFile: TStringList;
vDate: TDateTime;
vFileStream: TFileStream;
begin
tvMain.DataController.RecordCount := 0;
vCurrentFile := TStringList.Create;
memCallStack.Clear;
try
for PathIndex := 0 to fPathList.Count - 1 do // Loop 0. This loops until all directories are searched through
begin
if (FindFirst (fPathList[PathIndex] + '\*.log', faAnyFile, FileData) = 0) then
repeat // Loop 1. This loops while there are .log files in Folder (CurrentPath)
vDate := FileDateToDateTime(FileData.Time);
if chkLogNames.Items[PathIndex].Checked and FileDateInInterval(vDate) then
begin
tvMain.BeginUpdate; // To speed up the grid - delays the guichange until EndUpdate
fPathPlusFile := fPathList[PathIndex] + '\' + FileData.Name;
vFileStream := TFileStream.Create(fPathPlusFile, fmShareDenyNone);
vCurrentFile.LoadFromStream(vFileStream);
fUser := FindDataInRow(vCurrentFile[0], 'User'); // FindData Returns the string after 'User' until ' '
fComputer := FindDataInRow(vCurrentFile[0], 'Computer'); // FindData Returns the string after 'Computer' until ' '
Application.ProcessMessages; // Give some priority to the User Interface
if not CancelForm.IsCanceled then
begin
if rdException.Checked then
for i := 0 to vCurrentFile.Count - 1 do
begin
vPos := AnsiPos(MainExceptionToFind, vCurrentFile[i]);
if vPos > 0 then
UpdateView(vCurrentFile[i], i, MainException);
vPos := AnsiPos(ExceptionHintToFind, vCurrentFile[i]);
if vPos > 0 then
UpdateView(vCurrentFile[i], i, HintException);
end
else if rdOtherText.Checked then
for i := 0 to vCurrentFile.Count - 1 do
begin
vPos := AnsiPos(txtTextToSearch.Text, vCurrentFile[i]);
if vPos > 0 then
UpdateView(vCurrentFile[i], i, TextSearch)
end
end;
vFileStream.Destroy;
tvMain.EndUpdate; // Now the Gui can be updated
end;
until(FindNext(FileData) <> 0) or (CancelForm.IsCanceled); // End Loop 1
end; // End Loop 0
finally
FreeAndNil(vCurrentFile);
end;
end;
UpdateView 方法：向 displaygrid 添加一行
{: Update the grid with one exception}
procedure TfrmMain.UpdateView(aLine: string; const aIndex, aType: Integer);
var
vExceptionText: String;
vDate: TDateTime;
begin
if ExceptionDateInInterval(aLine, vDate) then // Parse the date from the beginning of date
begin
if aType = MainException then
vExceptionText := 'Exception'
else if aType = HintException then
vExceptionText := 'Exception Hint'
else if aType = TextSearch then
vExceptionText := 'Text Search';
SetRow(aIndex, vDate, ExtractFilePath(fPathPlusFile), ExtractFileName(fPathPlusFile), fUser, fComputer, aLine, vExceptionText);
end;
end;
确定行是否在日期范围内的方法：
{: This compare exact exception time against the filters
@desc 2 cases: 1. Last n days
2. From - to range}
function TfrmMain.ExceptionDateInInterval(var aTestLine: String; out aDateTime: TDateTime): Boolean;
var
vtmpDate, vTmpTime: String;
vDate, vTime: TDateTime;
vIndex: Integer;
begin
aDateTime := 0;
vtmpDate := Copy(aTestLine, 0, 8);
vTmpTime := Copy(aTestLine, 10, 9);
Insert(DateSeparator, vtmpDate, 5);
Insert(DateSeparator, vtmpDate, 8);
if TryStrToDate(vtmpDate, vDate, fFormatSetting) and TryStrToTime(vTmpTime, vTime) then
aDateTime := vDate + vTime;
Result := (rdLatest.Checked and (aDateTime >= (Now - spnDateLast.Value))) or
(rdInterval.Checked and (aDateTime>= dtpDateFrom.Date) and (aDateTime <= dtpDateTo.Date));
if Result then
begin
vIndex := AnsiPos(']', aTestLine);
if vIndex > 0 then
Delete(aTestLine, 1, vIndex + 1);
end;
end;
测试文件日期是否在范围内：
{: Returns true if the logtime is within filters range
@desc Purpose is to sort out logfiles that are no idea to parse (wrong day)}
function TfrmMain.FileDateInInterval(aFileTimeStamp: TDate): Boolean;
begin
Result := (rdLatest.Checked and (Int(aFileTimeStamp) >= Int(Now - spnDateLast.Value))) or
(rdInterval.Checked and (Int(aFileTimeStamp) >= Int(dtpDateFrom.Date)) and (Int(aFileTimeStamp) <= Int(dtpDateTo.Date)));
end;