| 1 | /******************************************************************************* |
| 2 | * Copyright (c) 2012 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 java.io.File; |
| 16 | import java.io.IOException; |
| 17 | |
| 18 | import org.eclipse.linuxtools.internal.tmf.core.statesystem.HistoryBuilder; |
| 19 | import org.eclipse.linuxtools.internal.tmf.core.statesystem.IStateHistoryBackend; |
| 20 | import org.eclipse.linuxtools.internal.tmf.core.statesystem.historytree.HistoryTreeBackend; |
| 21 | import org.eclipse.linuxtools.internal.tmf.core.statesystem.historytree.ThreadedHistoryTreeBackend; |
| 22 | import org.eclipse.linuxtools.tmf.core.component.TmfComponent; |
| 23 | import org.eclipse.linuxtools.tmf.core.exceptions.TmfTraceException; |
| 24 | |
| 25 | /** |
| 26 | * This abstract manager class handles loading or creating state history files |
| 27 | * for use in TMF's generic state system. |
| 28 | * |
| 29 | * @version 1.0 |
| 30 | * @author Alexandre Montplaisir |
| 31 | */ |
| 32 | public abstract class StateSystemManager extends TmfComponent { |
| 33 | |
| 34 | /** Size of the blocking queue to use when building a state history */ |
| 35 | private final static int QUEUE_SIZE = 10000; |
| 36 | |
| 37 | /** |
| 38 | * Load the history file matching the target trace. If the file already |
| 39 | * exists, it will be opened directly. If not, it will be created from |
| 40 | * scratch. In the case the history has to be built, it's possible to block |
| 41 | * the calling thread until construction is complete. |
| 42 | * |
| 43 | * @param htFile |
| 44 | * The target name of the history file we want to use. If it |
| 45 | * exists it will be opened. If it doesn't, a new file will be |
| 46 | * created with this name/path. |
| 47 | * @param htInput |
| 48 | * The IStateChangeInput to use for building the history file. It |
| 49 | * may be required even if we are opening an already-existing |
| 50 | * history (ie, for partial histories). |
| 51 | * @param buildManually |
| 52 | * If false, the construction will wait for a signal before |
| 53 | * starting. If true, it will build everything right now and |
| 54 | * block the caller. It has no effect if the file already exists. |
| 55 | * @return A IStateSystemQuerier handler to the state system, with which you |
| 56 | * can then run queries on the history. |
| 57 | * @throws TmfTraceException |
| 58 | * If there was a problem reading or writing one of the files. |
| 59 | * See the contents of this exception for more info. |
| 60 | * @since 2.0 |
| 61 | */ |
| 62 | public static ITmfStateSystem loadStateHistory(File htFile, |
| 63 | IStateChangeInput htInput, boolean buildManually) |
| 64 | throws TmfTraceException { |
| 65 | ITmfStateSystem ss; |
| 66 | IStateHistoryBackend htBackend; |
| 67 | |
| 68 | /* If the target file already exists, do not rebuild it uselessly */ |
| 69 | // TODO for now we assume it's complete. Might be a good idea to check |
| 70 | // at least if its range matches the trace's range. |
| 71 | if (htFile.exists()) { |
| 72 | /* Load an existing history */ |
| 73 | try { |
| 74 | htBackend = new HistoryTreeBackend(htFile); |
| 75 | ss = HistoryBuilder.openExistingHistory(htBackend); |
| 76 | return ss; |
| 77 | } catch (IOException e) { |
| 78 | /* |
| 79 | * There was an error opening the existing file. Perhaps it was |
| 80 | * corrupted, perhaps it's an old version? We'll just |
| 81 | * fall-through and try to build a new one from scratch instead. |
| 82 | */ |
| 83 | } |
| 84 | } |
| 85 | |
| 86 | /* Create a new state history from scratch */ |
| 87 | HistoryBuilder builder; |
| 88 | |
| 89 | if (htInput == null) { |
| 90 | return null; |
| 91 | } |
| 92 | try { |
| 93 | htBackend = new ThreadedHistoryTreeBackend(htFile, |
| 94 | htInput.getStartTime(), QUEUE_SIZE); |
| 95 | builder = new HistoryBuilder(htInput, htBackend, buildManually); |
| 96 | } catch (IOException e) { |
| 97 | /* |
| 98 | * If it fails here however, it means there was a problem writing to |
| 99 | * the disk, so throw a real exception this time. |
| 100 | */ |
| 101 | throw new TmfTraceException(e.toString(), e); |
| 102 | } |
| 103 | return builder.getStateSystemQuerier(); |
| 104 | } |
| 105 | } |