log4cplus-devel

[Log4cplus-devel] log4cplus question

[Semyon K. <skl...@in...>]

Hi,

 

I have a some difficulties in creating of custom layout.

 

I have derived base log4cplus::Layout class:

 

class LogLayout : public Layout

{

public:

      LogLayout(void);

      ~LogLayout(void);

 

      virtual void formatAndAppend(log4cplus::tostream& output, const
log4cplus::spi::InternalLoggingEvent& event);

};

 

The problem is that in formatAndAppend function parameters there is an
InternalLoggingEvent object only and I have no way to put my parameters
there.

 

The only way I found is to format the message before I send it to
logger:

 

void LogLayout::formatAndAppend(log4cplus::tostream& output,

const log4cplus::spi::InternalLoggingEvent& event)

{

      output << event.getMessage();

}

 

 

Could you please explain me what  is the right way to create a custom
layout?

 

Thank you,

Semyon

Re: [Log4cplus-devel] log4cplus question

[Václav H. <v.h...@sh...>]

Semyon Kleinerman wrote, On 23.4.2009 16:10:
> Hi,
> I have a some difficulties in creating of custom layout.
> 
> I have derived base log4cplus::Layout class:
> 
> class LogLayout : public Layout
> {
> public:
>       LogLayout(void);
>       ~LogLayout(void);
> 
>       virtual void formatAndAppend(log4cplus::tostream& output, const
> log4cplus::spi::InternalLoggingEvent& event);
> };
> 
> The problem is that in formatAndAppend function parameters there is an
> InternalLoggingEvent object only and I have no way to put *my
> parameters* there.
What kind of parameters do you have in mind?

> 
> The only way I found is to format the message before I send it to logger:
> 
> void LogLayout::formatAndAppend(log4cplus::tostream& output,
> const log4cplus::spi::InternalLoggingEvent& event)
> {
>       output << event.getMessage();
> }
I think the idea is that formatting depends only on what you can get from the
 InternalLoggingEvent instance and the state of the layout. For that the
signature of the function is adequate.

> 
> Could you please explain me what  is the right way to create a custom
> layout?
> 

Plese, don't send HTML emails.

--
VH

Re: [Log4cplus-devel] log4cplus question

[Václav H. <v.h...@sh...>]

Semyon Kleinerman wrote, On 26.4.2009 11:49:
> Hi Vaclav,
> 
> I have a separate thread using log4cplus. There is a stack of log messages
> and my thread executing them one by one. Now the parameters I have to
> pass:
> 
> 1)	Original thread ID
> 2)	Original Time of log event
> 
> TCCLayout is not friendly for me because it will print a wrong thread id
> and a later time.
> 
> By creating a custom layout I don't reach the target as the
> InternalLoggingEvent doesn't let me to put any user data. The only way is
> to format the whole message before sending it to log.
> 
> Maybe the solution is to extend the InternalLoggingEvent members with some
> pointer "m_pUserData" and to add one more parameter to the function
> LOG4CPLUS_ERROR?
All this sounds like are trying to do logging asynchronously in separate
thread (speed concerns?). If you want to do such thing, then custom layout is
not the way. Either implement a custom appender, that will push the logging
work to separate thread (This is something that AsyncAppender on the 1.1
branch does.) or implement a custom logging layer using InternalLoggingEvent
directly, filling in the thread ID before you give it to another thread.

--
VH

Re: [Log4cplus-devel] log4cplus question

[Václav H. <v.h...@sh...>]

Semyon Kleinerman wrote, On 27.4.2009 17:49:
> Hi Vaclav,
> 
> I have another question about log4cplus implementation… I am using class
> RollingFileAppender. This class creates a set of log files like
> "filename.log", "filename.log.1", "filename.log.2" etc… I need to create
> files with a different format of file names: "filename1.log",
> "filename2.log" etc…
> 
> Is there some way to implement this?
> 
> p.s. I can derive RollingFileAppender class and implement append function,
> but it forces me to write a lot of cloned code, such as rollover function
> (it's not virtual) and  static function rolloverFiles.. This solution
> doesn't seems to be efficient….
No, this is not currently possible. Foo.N is the traditional format of
rotating log files.

--
VH