org.eclipse.linuxtools.tmf.core/src/org/eclipse/linuxtools/tmf/core/statesystem/ITmfStateProvider.java

   1 /*******************************************************************************
   2  * Copyright (c) 2012, 2013 Ericsson
   3  * Copyright (c) 2010, 2011 École Polytechnique de Montréal
   4  * Copyright (c) 2010, 2011 Alexandre Montplaisir <alexandre.montplaisir@gmail.com>
   5  *
   6  * All rights reserved. This program and the accompanying materials are
   7  * made available under the terms of the Eclipse Public License v1.0 which
   8  * accompanies this distribution, and is available at
   9  * http://www.eclipse.org/legal/epl-v10.html
  10  *
  11  *******************************************************************************/
  12
  13 package org.eclipse.linuxtools.tmf.core.statesystem;
  14
  15 import org.eclipse.linuxtools.statesystem.core.ITmfStateSystem;
  16 import org.eclipse.linuxtools.statesystem.core.ITmfStateSystemBuilder;
  17 import org.eclipse.linuxtools.tmf.core.event.ITmfEvent;
  18 import org.eclipse.linuxtools.tmf.core.trace.ITmfTrace;
  19
  20 /**
  21  * This is the interface used to define the "state change input", which is the
  22  * main type of input that goes in the state system.
  23  *
  24  * Usually a state change input, also called "state provider" is the piece of
  25  * the pipeline which converts trace events to state changes.
  26  *
  27  * @author Alexandre Montplaisir
  28  * @since 2.0
  29  */
  30 public interface ITmfStateProvider {
  31
  32     /**
  33      * Event handler plugins should provide a version number. This is used to
  34      * determine if a potential existing file can be re-opened later (if the
  35      * versions in the file and in the viewer match), or if the file should be
  36      * rebuilt from scratch (if the versions don't match).
  37      *
  38      * @return The version number of the input plugin
  39      * @since 2.0
  40      */
  41     int getVersion();
  42
  43     /**
  44      * Get the trace with which this state input plugin is associated.
  45      *
  46      * @return The associated trace
  47      */
  48     ITmfTrace getTrace();
  49
  50     /**
  51      * Return the start time of this "state change input", which is normally the
  52      * start time of the originating trace (or it can be the time of the first
  53      * state-changing event).
  54      *
  55      * @return The start time
  56      */
  57     long getStartTime();
  58
  59     /**
  60      * Method for the input plugin to specify which type of events it expects.
  61      * This will guarantee that all events it receives via processEvent() are
  62      * indeed of the given type, so it should be safe to cast to that type.
  63      *
  64      * @return The expected Class of the event. Only events of this class (and
  65      *         valid subclasses) will be handled.
  66      * @since 2.0
  67      */
  68     Class<? extends ITmfEvent> getExpectedEventType();
  69
  70     /**
  71      * Assign the target state system where this SCI will insert its state
  72      * changes. Because of dependencies issues, this can normally not be done at
  73      * the constructor.
  74      *
  75      * This needs to be called before .run()!
  76      *
  77      * @param ssb
  78      *            Target state system for the state changes generated by this
  79      *            input plugin
  80      * @since 3.0
  81      */
  82     void assignTargetStateSystem(ITmfStateSystemBuilder ssb);
  83
  84     /**
  85      * Return the currently assigned target state system.
  86      *
  87      * @return Reference to the currently assigned state system, or null if no
  88      *         SS is assigned yet
  89      * @since 3.0
  90      */
  91     ITmfStateSystem getAssignedStateSystem();
  92
  93     /**
  94      * Send an event to this input plugin for processing. The implementation
  95      * should check the contents, and call the state-modifying methods of its
  96      * IStateSystemBuilder object accordingly.
  97      *
  98      * @param event
  99      *            The event (which should be safe to cast to the
 100      *            expectedEventType) that has to be processed.
 101      */
 102     void processEvent(ITmfEvent event);
 103
 104     /**
 105      * Provide a non-initialized copy of this state input plugin. You will need
 106      * to call {@link #assignTargetStateSystem} on it to assign its target.
 107      *
 108      * @return A new state change input object, of the same type, but without an
 109      *         assigned target state system
 110      * @since 2.0
 111      */
 112     ITmfStateProvider getNewInstance();
 113
 114     /**
 115      * Indicate to the state history building process that we are done (for now),
 116      * and that it should close its current history.
 117      */
 118     void dispose();
 119 }