Package com.google.gerrit.server.git

Class MultiProgressMonitor

java.lang.Object

com.google.gerrit.server.git.MultiProgressMonitor

public class MultiProgressMonitor
extends Object

Progress reporting interface that multiplexes multiple sub-tasks.

Output is of the format:

   Task: subA: 1, subB: 75% (3/4) (-)\r
   Task: subA: 2, subB: 75% (3/4), subC: 1 (\)\r
   Task: subA: 2, subB: 100% (4/4), subC: 1 (|)\r
   Task: subA: 4, subB: 100% (4/4), subC: 4, done    \n
 

Callers should try to keep task and sub-task descriptions short, since the output should fit on one terminal line. (Note that git clients do not accept terminal control characters, so true multi-line progress messages would be impossible.)

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
class	MultiProgressMonitor.Task	Handle for a sub-task.

Field Summary

Fields

Modifier and Type	Field	Description
static int	UNKNOWN	Constant indicating the total work units cannot be predicted.

Constructor Summary

Constructors

Constructor	Description
MultiProgressMonitor(OutputStream out, String taskName)	Create a new progress monitor for multiple sub-tasks.
MultiProgressMonitor(OutputStream out, String taskName, long maxIntervalTime, TimeUnit maxIntervalUnit)	Create a new progress monitor for multiple sub-tasks.

Method Summary

Modifier and Type	Method	Description
MultiProgressMonitor.Task	beginSubTask(String subTask, int subTaskWork)	Begin a sub-task.
void	end()	End the overall task.
void	waitFor(Future<?> workerFuture)	Wait for a task managed by a Future, with no timeout.
void	waitFor(Future<?> workerFuture, long timeoutTime, TimeUnit timeoutUnit)	Wait for a task managed by a Future.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

UNKNOWN

public static final int UNKNOWN

Constant indicating the total work units cannot be predicted.

See Also:

Constant Field Values

Constructor Detail

MultiProgressMonitor

public MultiProgressMonitor(OutputStream out,
                            String taskName)

Create a new progress monitor for multiple sub-tasks.

Parameters:

out - stream for writing progress messages.

taskName - name of the overall task.

MultiProgressMonitor

public MultiProgressMonitor(OutputStream out,
                            String taskName,
                            long maxIntervalTime,
                            TimeUnit maxIntervalUnit)

Create a new progress monitor for multiple sub-tasks.

Parameters:

out - stream for writing progress messages.

taskName - name of the overall task.

maxIntervalTime - maximum interval between progress messages.

maxIntervalUnit - time unit for progress interval.

Method Detail

waitFor

public void waitFor(Future<?> workerFuture)
             throws ExecutionException

Wait for a task managed by a Future, with no timeout.

Throws:

ExecutionException

See Also:

waitFor(Future, long, TimeUnit)

waitFor

public void waitFor(Future<?> workerFuture,
                    long timeoutTime,
                    TimeUnit timeoutUnit)
             throws ExecutionException

Wait for a task managed by a Future.

Must be called from the main thread, not a worker thread. Once a worker thread calls end(), the future has an additional maxInterval to finish before it is forcefully cancelled and ExecutionException is thrown.

Parameters:

workerFuture - a future that returns when worker threads are finished.

timeoutTime - overall timeout for the task; the future is forcefully cancelled if the task exceeds the timeout. Non-positive values indicate no timeout.

timeoutUnit - unit for overall task timeout.

Throws:

ExecutionException - if this thread or a worker thread was interrupted, the worker was cancelled, or timed out waiting for a worker to call end().

beginSubTask

public MultiProgressMonitor.Task beginSubTask(String subTask,
                                              int subTaskWork)

Begin a sub-task.

Parameters:

subTask - sub-task name.

subTaskWork - total work units in sub-task, or UNKNOWN.

Returns:

sub-task handle.

end

public void end()

End the overall task.

Must be called from a worker thread.