| /* 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.io.IOException; |
| import java.io.InputStream; |
| |
| /** |
| * A set of utility methods. |
| */ |
| final class Utils { |
| |
| private static final byte[] BYTE_ZEROES = new byte[1024]; |
| |
| private static final int[] INT_ZEROES = new int[1024]; |
| |
| /** |
| * Fills byte array with zeroes. |
| * |
| * <p> Current implementation uses {@link System#arraycopy}, so it should be used for length not |
| * less than 16. |
| * |
| * @param dest array to fill with zeroes |
| * @param offset the first byte to fill |
| * @param length number of bytes to change |
| */ |
| static void fillBytesWithZeroes(byte[] dest, int start, int end) { |
| int cursor = start; |
| while (cursor < end) { |
| int step = Math.min(cursor + 1024, end) - cursor; |
| System.arraycopy(BYTE_ZEROES, 0, dest, cursor, step); |
| cursor += step; |
| } |
| } |
| |
| /** |
| * Fills int array with zeroes. |
| * |
| * <p> Current implementation uses {@link System#arraycopy}, so it should be used for length not |
| * less than 16. |
| * |
| * @param dest array to fill with zeroes |
| * @param offset the first item to fill |
| * @param length number of item to change |
| */ |
| static void fillIntsWithZeroes(int[] dest, int start, int end) { |
| int cursor = start; |
| while (cursor < end) { |
| int step = Math.min(cursor + 1024, end) - cursor; |
| System.arraycopy(INT_ZEROES, 0, dest, cursor, step); |
| cursor += step; |
| } |
| } |
| |
| static void copyBytesWithin(byte[] bytes, int target, int start, int end) { |
| System.arraycopy(bytes, start, bytes, target, end - start); |
| } |
| |
| static int readInput(InputStream src, byte[] dst, int offset, int length) { |
| try { |
| return src.read(dst, offset, length); |
| } catch (IOException e) { |
| throw new BrotliRuntimeException("Failed to read input", e); |
| } |
| } |
| |
| static void closeInput(InputStream src) throws IOException { |
| src.close(); |
| } |
| } |