public static class Tracer.AsyncLogger extends java.lang.Object implements Tracer.Logger
Tracer.Logger
designed to print String
s to a designated OutputStream
on a private thread.
String
s are read from a private queue and printed to a buffered PrintStream
which is periodically flushed.
When instantiated the private queue is created (an in-memory ArrayBlockingQueue
in this
implementation) and when start()
ed the private thread is created and started unless it is
already present. An Tracer.AsyncLogger
may be started many times, but only one thread is created.
When stop()
ed either the number of starts is decremented, or, if this count reaches zero,
a special element is queued which causes the private thread to end when encountered.
If the private thread is interrupted, the thread will also end, and the count set to zero,
This will cause subsequent stop()
s to be ignored, and the next start()
will create a new thread.
log(String)
never blocks unless the private queue is full; this may never un-block if the Tracer.Logger
is stopped.Constructor and Description |
---|
AsyncLogger(java.io.OutputStream os)
Same as
Tracer.AsyncLogger(OutputStream, int) with a one-second flush interval. |
AsyncLogger(java.io.OutputStream os,
int flushInterval)
Start/stoppable logger that prints to an
OutputStream with flushes every flushInterval milliseconds. |
Modifier and Type | Method and Description |
---|---|
void |
log(java.lang.String message)
Write msg to the log.
|
boolean |
start()
Start logging, that is, printing log entries written using
Tracer.Logger.log(String) . |
boolean |
stop()
Stop logging, that is, stop printing log entries written using
Tracer.Logger.log(String) . |
public AsyncLogger(java.io.OutputStream os)
Tracer.AsyncLogger(OutputStream, int)
with a one-second flush interval.os
- OutputStream to print to.public AsyncLogger(java.io.OutputStream os, int flushInterval)
OutputStream
with flushes every flushInterval
milliseconds.os
- OutputStream to print to.flushInterval
- in milliseconds, time between flushes.public void log(java.lang.String message)
Tracer.Logger
log
in interface Tracer.Logger
public boolean start()
Tracer.Logger
Tracer.Logger.log(String)
. Multiple successive starts are equivalent to a
single start.start
in interface Tracer.Logger
true
if start actually started the logger;
false
otherwise.public boolean stop()
Tracer.Logger
Tracer.Logger.log(String)
. Flush preceding writes. The logger can only be
stopped if started. Multiple successive stops are equivalent to a
single stop.stop
in interface Tracer.Logger
true
if stop actually stopped the logger;
false
otherwise.