Alog

with Alog.Logger;
with Alog.Facilities.File_Descriptor;

use Alog;

--  Alog logger example.
procedure Logger_Example1 is
   --  Initialize logger instance with default file descriptor facility
   --  (logs to stdout).
   Log : Logger.Instance (Init => True);
begin
   --  Write a message with loglevel 'Info' to stdout.
   Log.Log_Message
     (Level => Info,
      Msg   => "This is a testmessage from Alog logger");

   Attach_FD_Facility :
   declare
      FD : constant Facilities.File_Descriptor.Handle :=
        new Facilities.File_Descriptor.Instance;
   begin
      FD.Set_Logfile (Path => "/tmp/alog.log");
      Log.Attach_Facility (Facility => Facilities.Handle (FD));

      --  Log a message to file and stdout.
      Log.Log_Message (Source => "Example",
                       Level  => Warning,
                       Msg    => "Another testmessage");
   end Attach_FD_Facility;
end Logger_Example1;

with Alog.Log_Request;
with Alog.Facilities.File_Descriptor;

use Alog;

--  Alog file descriptor facility example.
procedure Facility_Example1 is
   Facility : Facilities.File_Descriptor.Instance;
begin
   --  Enable writing of loglevels.
   Facility.Toggle_Write_Loglevel (State => True);

   --  Use '/tmp/alog.log' as logfile, overwrite existing file.
   Facility.Set_Logfile (Path   => "/tmp/alog.log",
                         Append => False);

   --  Let the facility process a log request with loglevel 'Warning'.
   Facility.Process
     (Request => Log_Request.Create
        (Level   => Warning,
         Message => "This is a testmessage from Alog FD facility"));

   --  Teardown the facility.
   Facility.Teardown;
end Facility_Example1;

with Alog.Dst_Filter;
with Alog.Logger;
with Alog.Facilities.File_Descriptor;

use Alog;

--  Alog destination loglevel policy example.
procedure Policy_Example1 is
   Log : Logger.Instance (Init => True);

   Facility_Name : constant String := "Application_Errors";
   Errors        : constant Facilities.File_Descriptor.Handle
     := new Facilities.File_Descriptor.Instance;
begin
   --  Write all error messages to '/tmp/errors.log'.
   Errors.Set_Logfile (Path => "/tmp/errors.log");
   Errors.Set_Name (Name => Facility_Name);
   Errors.Toggle_Write_Loglevel (State => True);

   --  Set loglevel policy to 'Error' for destination 'Application_Errors'.
   Dst_Filter.Set_Loglevel (Name  => Facility_Name,
                            Level => Error);

   Log.Attach_Facility (Facility => Facilities.Handle (Errors));

   --  This message will appear on stdout, but not in the error logfile.
   Log.Log_Message (Level  => Info,
                    Msg    => "This is not an error");
   --  This message will also be written to the error logfile.
   Log.Log_Message (Level  => Error,
                    Msg    => "This is an error");

   --  Set global loglevel to only log messages with level higher than Warning
   --  if no facility-specific level is set.
   Dst_Filter.Set_Default_Level (Level => Warning);
   --  This message will be filtered out.
   Log.Log_Message (Level  => Info,
                    Msg    => "This message will be filtered");
   --  This message will appear on stdout, but not in the error logfile.
   Log.Log_Message (Level  => Warning,
                    Msg    => "This is a warning message");
end Policy_Example1;

with Alog.Policy_DB;
with Alog.Logger;

use Alog;

--  Alog source loglevel policy example.
procedure Policy_Example2 is
   Src_Filter : Policy_DB.Protected_Policy_DB;
   Log        : Logger.Instance (Init => True);
begin
   --  Set default loglevel to 'Info'.
   Src_Filter.Set_Default_Loglevel (Level => Info);
   --  Set source specific loglevel for all 'Example' sources to 'Debug'.
   Src_Filter.Set_Loglevel (Identifier => "Example.*",
                            Level      => Debug);

   --  This message will be logged because it matches a source specific
   --  loglevel (Example.*).
   if Src_Filter.Accept_ID (Identifier => "Example.Source1",
                            Level      => Debug)
   then
      Log.Log_Message (Source => "Example.Source1",
                       Level  => Debug,
                       Msg    => "This is a test message");
   end if;

   --  This message will not be logged because of the configured default 'Info'
   --  loglevel. There's no configured source loglevel for 'Source2'.
   if Src_Filter.Accept_ID (Identifier => "Source2",
                            Level      => Debug)
   then
      Log.Log_Message (Source => "Source2",
                       Level  => Debug,
                       Msg    => "This will not be logged");
   end if;

   --  This message will be logged because of the configured default 'Info'
   --  loglevel. There's no configured source loglevel for 'Source2'.
   if Src_Filter.Accept_ID (Identifier => "Source2",
                            Level      => Info)
   then
      Log.Log_Message (Source => "Source2",
                       Level  => Info,
                       Msg    => "This is another test message");
   end if;
end Policy_Example2;