| /* |
| * Copyright (C) 2009 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.android.server; |
| |
| import android.util.Log; |
| |
| import java.io.Closeable; |
| import java.io.EOFException; |
| import java.io.FileInputStream; |
| import java.io.FileOutputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.OutputStream; |
| |
| /** |
| * A 4k block of random {@code byte}s. |
| */ |
| class RandomBlock { |
| |
| private static final String TAG = "RandomBlock"; |
| private static final int BLOCK_SIZE = 4096; |
| private byte[] block = new byte[BLOCK_SIZE]; |
| |
| private RandomBlock() { } |
| |
| static RandomBlock fromFile(String filename) throws IOException { |
| Log.v(TAG, "reading from file " + filename); |
| InputStream stream = null; |
| try { |
| stream = new FileInputStream(filename); |
| return fromStream(stream); |
| } finally { |
| close(stream); |
| } |
| } |
| |
| private static RandomBlock fromStream(InputStream in) throws IOException { |
| RandomBlock retval = new RandomBlock(); |
| int total = 0; |
| while(total < BLOCK_SIZE) { |
| int result = in.read(retval.block, total, BLOCK_SIZE - total); |
| if (result == -1) { |
| throw new EOFException(); |
| } |
| total += result; |
| } |
| return retval; |
| } |
| |
| void toFile(String filename) throws IOException { |
| Log.v(TAG, "writing to file " + filename); |
| OutputStream out = null; |
| try { |
| // TODO: Investigate using RandomAccessFile |
| out = new FileOutputStream(filename); |
| toStream(out); |
| } finally { |
| close(out); |
| } |
| } |
| |
| private void toStream(OutputStream out) throws IOException { |
| out.write(block); |
| } |
| |
| private static void close(Closeable c) { |
| try { |
| if (c == null) { |
| return; |
| } |
| c.close(); |
| } catch (IOException e) { |
| Log.w(TAG, "IOException thrown while closing Closeable", e); |
| } |
| } |
| } |