| /******************************************************************************* |
| * Copyright (c) 2008, 2009 IBM Corporation and others. |
| * |
| * This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License 2.0 |
| * which accompanies this distribution, and is available at |
| * https://www.eclipse.org/legal/epl-2.0/ |
| * |
| * SPDX-License-Identifier: EPL-2.0 |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.core.internal.registry; |
| |
| import java.io.*; |
| |
| /** |
| * This table stores file offsets for cached registry objects. |
| * Entries are never added when this table resides in memory. Entries could be removed. |
| */ |
| public final class OffsetTable { |
| |
| private static final float GROWTH_FACTOR = 1.33f; |
| |
| private int[] valueTable; |
| |
| public OffsetTable(int size) { |
| this.valueTable = new int[size]; |
| } |
| |
| public int get(int key) { |
| if (key < valueTable.length) |
| return valueTable[key]; |
| return Integer.MIN_VALUE; // should not happen; will be converted to exception higher in the call stack |
| } |
| |
| public void removeKey(int key) { |
| if (key < valueTable.length) // registry elements added in the running session will have IDs outside of the valid offset range |
| valueTable[key] = Integer.MIN_VALUE; |
| } |
| |
| public void put(int key, int value) { |
| if (key >= valueTable.length) { // this should not happen in the expected use cases as we know the max size in advance |
| int[] newTable = new int[(int) (key * GROWTH_FACTOR)]; |
| System.arraycopy(valueTable, 0, newTable, 0, valueTable.length); |
| valueTable = newTable; |
| } |
| valueTable[key] = value; |
| } |
| |
| public void save(DataOutputStream out) throws IOException { |
| int tableSize = valueTable.length; |
| out.writeInt(tableSize); |
| for (int i = 0; i < tableSize; i++) { |
| out.writeInt(valueTable[i]); |
| } |
| } |
| |
| static public OffsetTable load(DataInputStream in) throws IOException { |
| int tableSize = in.readInt(); |
| OffsetTable result = new OffsetTable(tableSize); |
| result.valueTable = new int[tableSize]; |
| for (int i = 0; i < tableSize; i++) |
| result.valueTable[i] = in.readInt(); |
| return result; |
| } |
| |
| } |