com.yahoo.messagebus

Class Trace

java.lang.Object

com.yahoo.messagebus.Trace

public class Trace
extends Object

A Trace object contains ad-hoc string notes organized in a strict-loose tree. A Trace object consists of a trace level indicating which trace notes should be included and a TraceTree object containing the tree structure and collecting the trace information. Tracing is used to collect debug information about a Routable traveling through the system. The trace level is in the range [0,9]. 0 means no tracing, and 9 means all tracing is enabled. A client that has the ability to trace information will have a predefined level attached to that information. If the level on the information is lower or equal to the level set in the Trace object, the information will be traced.

Author:

Simon Thoresen Hult

Constructor Summary

Constructors

Constructor and Description
Trace() Create an empty trace with level set to 0 (no tracing)
Trace(int level) Create an empty trace with given level.

Method Summary

Modifier and Type	Method and Description
Trace	clear() Remove all trace information and set the trace level to 0.
int	getLevel() Returns the trace level.
TraceNode	getRoot() Returns the root of the trace tree.
Trace	setLevel(int level) Set the trace level.
boolean	shouldTrace(int level) Check if information with the given level should be traced.
Trace	swap(Trace other) Swap the internals of this with another.
String	toString()
boolean	trace(int level, String note) Add the given note to the trace information if tracing is enabled for the given level.
boolean	trace(int level, String note, boolean addTime) Add the given note to the trace information if tracing is enabled for the given level.

Methods inherited from class java.lang.Object

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

Constructor Detail

Trace

public Trace()

Create an empty trace with level set to 0 (no tracing)

Trace

public Trace(int level)

Create an empty trace with given level.

Parameters:

level - Level to set.

Method Detail

clear

public Trace clear()

Remove all trace information and set the trace level to 0.

Returns:

This, to allow chaining.

swap

public Trace swap(Trace other)

Swap the internals of this with another.

Parameters:

other - The trace to swap internals with.

Returns:

This, to allow chaining.

setLevel

public Trace setLevel(int level)

Set the trace level. 0 means no tracing, 9 means enable all tracing.

Parameters:

level - The level to set.

Returns:

This, to allow chaining.

getLevel

public int getLevel()

Returns the trace level.

Returns:

The trace level.

shouldTrace

public boolean shouldTrace(int level)

Check if information with the given level should be traced. This method is added to allow clients to check if something should be traced before spending time building up the trace information itself.

Parameters:

level - The trace level to test.

Returns:

True if tracing is enabled for the given level, false otherwise.

trace

public boolean trace(int level,
                     String note)

Add the given note to the trace information if tracing is enabled for the given level.

Parameters:

level - The trace level of the note.

note - The note to add.

Returns:

True if the note was added to the trace information, false otherwise.

trace

public boolean trace(int level,
                     String note,
                     boolean addTime)

Add the given note to the trace information if tracing is enabled for the given level. If the addTime parameter is true, then the note is prefixed with the current time. This is the default behaviour when ommiting this parameter.

Parameters:

level - The trace level of the note.

note - The note to add.

addTime - Whether or not to prefix note with a timestamp.

Returns:

True if the note was added to the trace information, false otherwise.

getRoot

public TraceNode getRoot()

Returns the root of the trace tree.

Returns:

The root.

toString

public String toString()

Overrides:

toString in class Object