statesystem/org.eclipse.tracecompass.datastore.core/src/org/eclipse/tracecompass/internal/provisional/datastore/core/historytree/overlapping/OverlappingHistoryTree.java

   1 /*******************************************************************************
   2  * Copyright (c) 2017 École Polytechnique de Montréal
   3  *
   4  * All rights reserved. This program and the accompanying materials are
   5  * made available under the terms of the Eclipse Public License v1.0 which
   6  * accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *******************************************************************************/
   9
  10 package org.eclipse.tracecompass.internal.provisional.datastore.core.historytree.overlapping;
  11
  12 import java.io.File;
  13 import java.io.IOException;
  14
  15 import org.eclipse.tracecompass.internal.provisional.datastore.core.interval.IHTInterval;
  16 import org.eclipse.tracecompass.internal.provisional.datastore.core.interval.IHTIntervalReader;
  17
  18 /**
  19  * Basic implementation of {@link AbstractOverlappingHistoryTree} that can
  20  * be used directly by clients.
  21  *
  22  * @author Loic Prieur-Drevon
  23  * @author Geneviève Bastien
  24  * @param <E>
  25  *            The type of objects that will be saved in the tree
  26  */
  27 public class OverlappingHistoryTree<E extends IHTInterval>
  28         extends AbstractOverlappingHistoryTree<E, OverlappingNode<E>> {
  29
  30     /**
  31      * The magic number for this file format.
  32      */
  33     public static final int HISTORY_FILE_MAGIC_NUMBER = 0x05FFA800;
  34
  35     /** File format version. Increment when breaking compatibility. */
  36     private static final int FILE_VERSION = 1;
  37
  38     private final IHTNodeFactory<E, OverlappingNode<E>> fNodeFactory =
  39             (t, b, m, seq, p, start) -> new OverlappingNode<>(t, b, m, seq, p, start);
  40
  41     // ------------------------------------------------------------------------
  42     // Constructors/"Destructors"
  43     // ------------------------------------------------------------------------
  44
  45     /**
  46      * Create a new Overlapping History Tree from scratch, specifying all
  47      * configuration parameters.
  48      *
  49      * @param stateHistoryFile
  50      *            The name of the history file
  51      * @param blockSize
  52      *            The size of each "block" on disk in bytes. One node will
  53      *            always fit in one block. It should be at least 4096.
  54      * @param maxChildren
  55      *            The maximum number of children allowed per core (non-leaf)
  56      *            node.
  57      * @param providerVersion
  58      *            The version of the state provider. If a file already exists,
  59      *            and their versions match, the history file will not be rebuilt
  60      *            uselessly.
  61      * @param treeStart
  62      *            The start time of the history
  63      * @param intervalReader
  64      *            The factory to create new tree data elements when reading from
  65      *            the disk
  66      * @throws IOException
  67      *             If an error happens trying to open/write to the file
  68      *             specified in the config
  69      */
  70     public OverlappingHistoryTree(File stateHistoryFile,
  71             int blockSize,
  72             int maxChildren,
  73             int providerVersion,
  74             long treeStart,
  75             IHTIntervalReader<E> intervalReader) throws IOException {
  76
  77         super(stateHistoryFile,
  78                 blockSize,
  79                 maxChildren,
  80                 providerVersion,
  81                 treeStart,
  82                 intervalReader);
  83     }
  84
  85     /**
  86      * "Reader" constructor : instantiate a SHTree from an existing tree file on
  87      * disk
  88      *
  89      * @param existingStateFile
  90      *            Path/filename of the history-file we are to open
  91      * @param expectedProviderVersion
  92      *            The expected version of the state provider
  93      * @param objectReader
  94      *            The factory used to read segments from the history tree
  95      * @throws IOException
  96      *             If an error happens reading the file
  97      */
  98     public OverlappingHistoryTree(File existingStateFile,
  99             int expectedProviderVersion,
 100             IHTIntervalReader<E> objectReader) throws IOException {
 101         super(existingStateFile, expectedProviderVersion, objectReader);
 102     }
 103
 104     @Override
 105     protected int getMagicNumber() {
 106         return HISTORY_FILE_MAGIC_NUMBER;
 107     }
 108
 109     @Override
 110     protected int getFileVersion() {
 111         return FILE_VERSION;
 112     }
 113
 114     @Override
 115     protected IHTNodeFactory<E, OverlappingNode<E>> getNodeFactory() {
 116         return fNodeFactory;
 117     }
 118
 119 }