| /* Copyright 2015 Google Inc. All Rights Reserved. |
| |
| Distributed under MIT license. |
| See file LICENSE for detail or copy at https://opensource.org/licenses/MIT |
| */ |
| |
| package org.brotli.dec; |
| |
| import java.nio.ByteBuffer; |
| |
| /** |
| * Collection of static dictionary words. |
| * |
| * <p>Dictionary content is loaded from binary resource when {@link #getData()} is executed for the |
| * first time. Consequently, it saves memory and CPU in case dictionary is not required. |
| * |
| * <p>One possible drawback is that multiple threads that need dictionary data may be blocked (only |
| * once in each classworld). To avoid this, it is enough to call {@link #getData()} proactively. |
| */ |
| public final class Dictionary { |
| private static volatile ByteBuffer data; |
| |
| private static class DataLoader { |
| static final boolean OK; |
| |
| static { |
| boolean ok = true; |
| try { |
| Class.forName(Dictionary.class.getPackage().getName() + ".DictionaryData"); |
| } catch (Throwable ex) { |
| ok = false; |
| } |
| OK = ok; |
| } |
| } |
| |
| public static void setData(ByteBuffer data) { |
| if (!data.isDirect() || !data.isReadOnly()) { |
| throw new BrotliRuntimeException("data must be a direct read-only byte buffer"); |
| } |
| Dictionary.data = data; |
| } |
| |
| public static ByteBuffer getData() { |
| if (data != null) { |
| return data; |
| } |
| if (!DataLoader.OK) { |
| throw new BrotliRuntimeException("brotli dictionary is not set"); |
| } |
| /* Might have been set when {@link DictionaryData} was loaded.*/ |
| return data; |
| } |
| } |