mORMot Open Source

  with TMyLog.Family do
  begin
    Level := [sllInfo, sllError, sllServer];
    DestinationPath := ExtractFilePath(Application.ExeName) + 'logs\';
  end;

  TMyLog.Add.Log(sllInfo, 'Testing');

program TestLogger;

{$APPTYPE CONSOLE}

{$R *.res}

uses
  SynCommons,
  System.SysUtils;

type
  TTestLogger = class(TSynLog)
    procedure ComputeFileName; override;
  end;

  TSynLogFileEcho = class(TSynLogFile)
  public
    function LogEcho(Sender: TTextWriter; Level: TSynLogInfo; const Text: RawUTF8): boolean;
  end;

var
  LogFile: TSynLogFileEcho;
  FEventCaption: array[TSynLogInfo] of string;
  E: TSynLogInfo;

{ TTestLogger }

procedure TTestLogger.ComputeFileName;
begin
  inherited;
  fFileName := 'abc.log';
end;

{ TSynLogFileEcho }

function TSynLogFileEcho.LogEcho(Sender: TTextWriter; Level: TSynLogInfo;
  const Text: RawUTF8): boolean;
var
  P: PUTF8Char;
  Line: RawUTF8;
begin
  P := Pointer(Text);
  repeat
    Line := GetNextLine(P, P);
    if Length(Line) < 24 then
      Continue;
    Self.AddInMemoryLine(Line);
  until P = nil;
  Result := True;
end;

procedure ShowLogContent;
var
  index: Integer;
begin
  for index := LogFile.Count - 1 downto 0 do
    WriteLn('Level: ', FEventCaption[LogFile.EventLevel[index]], ' Text: ', LogFile.EventText[index]);
end;

procedure WaitForEnter(const Msg: string);
begin
  WriteLn(Msg);
  Write('Press ENTER to continue...');
  ReadLn;
end;

begin
  try
    with TTestLogger.Family do
    begin
      Level := LOG_VERBOSE;
      FileExistsAction := acAppend;
    end;

    for E := succ(sllNone) to high(E) do
      FEventCaption[E] := GetCaptionFromEnum(TypeInfo(TSynLogInfo),ord(E));

    if FileExists('abc.log') then
      LogFile := TSynLogFileEcho.Create('abc.log')
    else LogFile := TSynLogFileEcho.Create;

    WaitForEnter('Listing initial content');
    ShowLogContent;

    TTestLogger.Add.Log(sllNewRun, 'Starting Up!');
    TTestLogger.Family.EchoRemoteStart(nil, LogFile.LogEcho, False);

    WaitForEnter('After first log');
    ShowLogContent;

    TTestLogger.Add.Log(sllInfo, 'Information, information, information');
    TTestLogger.Add.Log(sllDebug, 'Debug, debug, debug');
    TTestLogger.Add.Log(sllWarning, 'Warning, warning, warning');

    WaitForEnter('After sample logs');
    ShowLogContent;

    WaitForEnter('The End');

    LogFile.Free;
  except
    on E: Exception do
      Writeln(E.ClassName, ': ', E.Message);
  end;
end.

    if (fFileRotationSize>0) or (fFamily.FileExistsAction <> acOverwrite) then

var
  Entries: TEntryDB;

Entries := TEntryDB.CreateAndFillPrepare(FDatabase, yourQueryHere);
while Entries.FillOne do
begin
  Display(Entries.SomeProperty);
end;

 SynCommons.pas | 95 +++++++++++++++++++++++++++++++++++-----------------------
 1 file changed, 57 insertions(+), 38 deletions(-)

diff --git a/SynCommons.pas b/SynCommons.pas
index d673641..3fec809 100644
--- a/SynCommons.pas
+++ b/SynCommons.pas
@@ -10705,6 +10705,7 @@ type
 
   /// how stack trace shall be computed
   TSynLogStackTraceUse = (stManualAndAPI,stOnlyAPI,stOnlyManual);
+  TSynLogExistsAction = (acOverwrite, acAppend, acAppendWithHeader);
 
   {/ regroup several logs under an unique family name
    - you should usualy use one family per application or per architectural
@@ -10762,6 +10763,7 @@ type
     fRotateFileCount: cardinal;
     fRotateFileSize: cardinal;
     fRotateFileAtHour: integer;
+    fLogExistsAction: TSynLogExistsAction;
     function CreateSynLog: TSynLog;
     {$ifdef MSWINDOWS}
     procedure SetAutoFlush(TimeOut: cardinal);
@@ -10945,6 +10947,8 @@ type
     // be appended instead
     // - TSynLogFile class and our LogView tool will handle both patterns
     property EndOfLineCRLF: boolean read fEndOfLineCRLF write fEndOfLineCRLF;
+    // action to take if log file already exists. Defaults to append with header
+    property LogExistsAction: TSynLogExistsAction read fLogExistsAction write fLogExistsAction;
   end;
 
   /// thread-specific internal context used during logging
@@ -11025,12 +11029,12 @@ type
     procedure CreateLogWriter; virtual;
 {$ifndef DELPHI5OROLDER}
     procedure LogInternal(Level: TSynLogInfo; TextFmt: PWinAnsiChar;
-      const TextArgs: array of const; Instance: TObject); overload; 
+      const TextArgs: array of const; Instance: TObject); overload;
 {$endif}
     procedure LogInternal(Level: TSynLogInfo; const Text: RawUTF8;
       Instance: TObject; TextTruncateAtLength: integer); overload;
     procedure LogInternal(Level: TSynLogInfo; aName: PWinAnsiChar;
-     aTypeInfo: pointer; var aValue; Instance: TObject=nil); overload; 
+     aTypeInfo: pointer; var aValue; Instance: TObject=nil); overload;
     // any call to this method MUST call UnLock
     function LogHeaderLock(Level: TSynLogInfo): boolean;
     procedure LogTrailerUnLock(Level: TSynLogInfo); {$ifdef HASINLINE}inline;{$endif}
@@ -11048,6 +11052,7 @@ type
     function Instance: TSynLog;
     function ConsoleEcho(Sender: TTextWriter; Level: TSynLogInfo;
       const Text: RawUTF8): boolean; virtual;
+    procedure GenerateFileName; virtual;
   public
     /// intialize for a TSynLog class instance
     // - WARNING: not to be called directly! Use Enter or Add class function instead
@@ -41663,6 +41668,7 @@ begin
   fExceptionIgnore := TList.Create;
   fLevelStackTrace :=
     [sllError,sllException,sllExceptionOS,sllFail,sllLastError,sllStackTrace];
+  fLogExistsAction := acAppendWithHeader;
 end;
 
 function TSynLogFamily.CreateSynLog: TSynLog;
@@ -42644,48 +42650,61 @@ begin
   end;
 end;
 
-procedure TSynLog.CreateLogWriter;
+procedure TSynLog.GenerateFileName;
 {$ifndef MSWINDOWS}
 var i: integer;
 {$endif}
-var timeNow,hourRotate,timeBeforeRotate: TDateTime;
+var timeNow, hourRotate, timeBeforeRotate: TDateTime;
+begin
+  {$ifdef MSWINDOWS}
+  ExeVersionRetrieve;
+  fFileName := Ansi7ToString(ExeVersion.ProgramName);
+  if fFamily.IncludeComputerNameInFileName then
+    fFileName := fFileName+' ('+Ansi7ToString(ExeVersion.Host)+')';
+  {$else}
+  fFileName := ExtractFileName(ParamStr(0));
+  i := Pos('.',fFileName);
+  if i>0 then
+    SetLength(fFileName,i-1);
+  {$endif}
+  fFileRotationSize := 0;
+  if fFamily.fRotateFileCount>0 then begin
+    if fFamily.fRotateFileSize>0 then
+      fFileRotationSize := fFamily.fRotateFileSize shl 10; // size KB -> B
+    if fFamily.fRotateFileAtHour in [0..23] then begin
+      hourRotate := EncodeTime(fFamily.fRotateFileAtHour,0,0,0);
+      timeNow := Time;
+      if hourRotate<timeNow then
+        hourRotate := hourRotate+1; // trigger will be tomorrow
+      timeBeforeRotate := hourRotate-timeNow;
+      fFileRotationNextHour := GetTickCount64+trunc(timeBeforeRotate*MSecsPerDay);
+    end;
+  end;
+  if (fFileRotationSize=0) and (fFileRotationNextHour=0) then
+    fFileName := fFileName+' '+Ansi7ToString(NowToString(false));
+   {$ifdef MSWINDOWS}
+  if IsLibrary then
+    fFileName := fFileName+' '+ExtractFileName(GetModuleName(HInstance));
+  {$endif}
+  if fFamily.fPerThreadLog=ptOneFilePerThread then
+    fFileName := fFileName+' '+IntToString(GetCurrentThreadId);
+  fFileName := fFamily.fDestinationPath+fFileName+fFamily.fDefaultExtension;
+end;
+
+procedure TSynLog.CreateLogWriter;
 begin
   if fWriterStream=nil then begin
-    {$ifdef MSWINDOWS}
-    ExeVersionRetrieve;
-    fFileName := Ansi7ToString(ExeVersion.ProgramName);
-    if fFamily.IncludeComputerNameInFileName then
-      fFileName := fFileName+' ('+Ansi7ToString(ExeVersion.Host)+')';
-    {$else}
-    fFileName := ExtractFileName(ParamStr(0));
-    i := Pos('.',fFileName);
-    if i>0 then
-      SetLength(fFileName,i-1);
-    {$endif}
-    fFileRotationSize := 0;
-    if fFamily.fRotateFileCount>0 then begin
-      if fFamily.fRotateFileSize>0 then
-        fFileRotationSize := fFamily.fRotateFileSize shl 10; // size KB -> B
-      if fFamily.fRotateFileAtHour in [0..23] then begin
-        hourRotate := EncodeTime(fFamily.fRotateFileAtHour,0,0,0);
-        timeNow := Time;
-        if hourRotate<timeNow then
-          hourRotate := hourRotate+1; // trigger will be tomorrow
-        timeBeforeRotate := hourRotate-timeNow;
-        fFileRotationNextHour := GetTickCount64+trunc(timeBeforeRotate*MSecsPerDay);
-      end;
-    end;
-    if (fFileRotationSize=0) and (fFileRotationNextHour=0) then
-      fFileName := fFileName+' '+Ansi7ToString(NowToString(false));
-     {$ifdef MSWINDOWS}
-    if IsLibrary then
-      fFileName := fFileName+' '+ExtractFileName(GetModuleName(HInstance));
-    {$endif}
-    if fFamily.fPerThreadLog=ptOneFilePerThread then
-      fFileName := fFileName+' '+IntToString(GetCurrentThreadId);
-    fFileName := fFamily.fDestinationPath+fFileName+fFamily.fDefaultExtension;
+    GenerateFileName;
     if fFamily.NoFile then
-      fWriterStream := TFakeWriterStream.Create else begin
+      fWriterStream := TFakeWriterStream.Create else
+    begin
+      if FileExists(fFileName) then
+      begin
+        if fFamily.fLogExistsAction = acOverwrite then
+          DeleteFile(fFileName)
+        else if fFamily.fLogExistsAction = acAppend then
+          Include(fInternalFlags,logHeaderWritten);
+      end;
       if (fFileRotationSize=0) or not FileExists(fFileName) then
         TFileStream.Create(fFileName,fmCreate).Free;   // create a void file
       fWriterStream := TFileStream.Create(fFileName, // open with read sharing

  IAdminServer = interface(IInvokable)
    ['{E3097205-9424-427E-B6B4-D61E044CC6C3}']
    function IsRunning: Boolean;
  end;

  TAdminServer = class(TInterfacedObject, IAdminServer)
  public
    function IsRunning: Boolean;
  end;

  function TAdminServer.IsRunning: Boolean;
  begin
    Result := True;
  end;

// ---- snip ----

  AdminModel := TSQLModel.Create([TSQLUser], 'admin');
  AdminDB := TSQLRestServerDB.Create(AdminModel, 'admin.db', False);
  AdminServer := TSQLHttpServer.Create('8080', [AdminDB], '+', useHttpApiRegisteringURI, 32, secNone);
  AdminServer.AccessControlAllowOrigin := '*';
  AdminDB.ServiceRegister(TAdminServer, [TypeInfo(IAdminServer)], sicShared);

    if (Par<>nil) and ((Par^='[') or IdemPChar(Par,'%5B')) then