On 17 May 2012, at 15:43, Stéphane Ducasse wrote:
> So what are the candidates?
> Does anybody has experience with toothpick since it is MIT and even have a
> documentation (I will probably write chapter on it to understand it).
It will be hard to get everybody on the same line, I'm afraid.
One more data point (every body has its own logging framework)
Zinc-HTTP-Logging
It is based on Announcements. Is is in 1.3, 1.4 and 2.0 by default.
This is a subsection from the upcoming documentation (in Markdown format):
## Logging
Log output consists of an arbitrary message preceded by a number of fixed
fields.
Here is an example of a server log.
2012-05-10 13:09:10 879179 I Starting ZnManagingMultiThreadedServer HTTP
port 1701
2012-05-10 13:09:10 580596 D Initializing server socket
2012-05-10 13:09:20 398924 D Executing request/response loop
2012-05-10 13:09:20 398924 I Read a ZnRequest(GET /)
2012-05-10 13:09:20 398924 T GET / 200 1195B 0ms
2012-05-10 13:09:20 398924 I Wrote a ZnResponse(200 OK
text/html;charset=utf-8 1195B)
The first two fields are the date and time in a fixed sized format.
The next number is a fixed sized hash of the process ID.
Note how 3 different processes are involved: the one starting the server
(probably the UI process),
the actual server listening process, and the client worker process spawned to
handle the request.
Finally, the single capital letter indicates the category.
Then the actual message is printed.
Both ZnClient and ZnServer implement logging using a similar mechanism based on
the announcements framework.
ZnLogEvents are subclasses of Announcement sent by an HTTP server or client
containing logging information.
A log event has a TimeStamp, a Process ID, a category and a message.
The following categories are used: #info (I), #debug (D) and #transaction (T).
To help in the implementation, a ZnLogSupport object is used.
A hierarchy of listeners under ZnLogListener can then be used to process log
events.
Log listeners feature a filtering mechanism.
The following concrete listeners are provided.
- ZnTranscriptLogger
- ZnFileLogger
- ZnStandardOutputLogger
- ZnMemoryLogger
To log something, send #info: #debug: or #transaction: to the log support
object of a client or server (accessible by #log).
The argument can be either a string or a block that will only be executed when
logging is actually enabled.
server log info: [ 'User ', self getUsername, ' logged in.' ].
The Zn logging mechanism using an internal lock to make it thread safe, but it
does serialize logging by multiple processes.
It is important to make the time spent inside the log block short and non
blocking.
You can customize a listener before adding it to a log support.
The following example asks the default server to log just transaction events to
a file named 'zn.log', next to your image.
| logger |
logger := ZnFileLogger onFileNamed: (FileDirectory default / 'zn.log')
pathName.
logger filter: #transaction.
ZnServer default log addListener: logger.
Sven
--
Sven Van Caekenberghe
http://stfx.eu
Smalltalk is the Red Pill
