| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 org.apache.hadoop.fs.aliyun.oss; |
| |
| import java.io.EOFException; |
| import java.io.IOException; |
| import java.util.ArrayDeque; |
| import java.util.Queue; |
| import java.util.concurrent.ExecutorService; |
| |
| import org.apache.hadoop.thirdparty.com.google.common.util.concurrent.MoreExecutors; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.fs.FSExceptionMessages; |
| import org.apache.hadoop.fs.FSInputStream; |
| import org.apache.hadoop.fs.FileSystem.Statistics; |
| |
| import static org.apache.hadoop.fs.aliyun.oss.Constants.*; |
| |
| /** |
| * The input stream for OSS blob system. |
| * The class uses multi-part downloading to read data from the object content |
| * stream. |
| */ |
| public class AliyunOSSInputStream extends FSInputStream { |
| public static final Logger LOG = LoggerFactory.getLogger(AliyunOSSInputStream.class); |
| private final long downloadPartSize; |
| private AliyunOSSFileSystemStore store; |
| private final String key; |
| private Statistics statistics; |
| private boolean closed; |
| private long contentLength; |
| private long position; |
| private long partRemaining; |
| private byte[] buffer; |
| private int maxReadAheadPartNumber; |
| private long expectNextPos; |
| private long lastByteStart; |
| |
| private ExecutorService readAheadExecutorService; |
| private Queue<ReadBuffer> readBufferQueue = new ArrayDeque<>(); |
| |
| public AliyunOSSInputStream(Configuration conf, |
| ExecutorService readAheadExecutorService, int maxReadAheadPartNumber, |
| AliyunOSSFileSystemStore store, String key, Long contentLength, |
| Statistics statistics) throws IOException { |
| this.readAheadExecutorService = |
| MoreExecutors.listeningDecorator(readAheadExecutorService); |
| this.store = store; |
| this.key = key; |
| this.statistics = statistics; |
| this.contentLength = contentLength; |
| downloadPartSize = conf.getLong(MULTIPART_DOWNLOAD_SIZE_KEY, |
| MULTIPART_DOWNLOAD_SIZE_DEFAULT); |
| this.maxReadAheadPartNumber = maxReadAheadPartNumber; |
| |
| this.expectNextPos = 0; |
| this.lastByteStart = -1; |
| reopen(0); |
| closed = false; |
| } |
| |
| /** |
| * Reopen the wrapped stream at give position, by seeking for |
| * data of a part length from object content stream. |
| * |
| * @param pos position from start of a file |
| * @throws IOException if failed to reopen |
| */ |
| private synchronized void reopen(long pos) throws IOException { |
| long partSize; |
| |
| if (pos < 0) { |
| throw new EOFException("Cannot seek at negative position:" + pos); |
| } else if (pos > contentLength) { |
| throw new EOFException("Cannot seek after EOF, contentLength:" + |
| contentLength + " position:" + pos); |
| } else if (pos + downloadPartSize > contentLength) { |
| partSize = contentLength - pos; |
| } else { |
| partSize = downloadPartSize; |
| } |
| |
| if (this.buffer != null) { |
| if (LOG.isDebugEnabled()) { |
| LOG.debug("Aborting old stream to open at pos " + pos); |
| } |
| this.buffer = null; |
| } |
| |
| boolean isRandomIO = true; |
| if (pos == this.expectNextPos) { |
| isRandomIO = false; |
| } else { |
| //new seek, remove cache buffers if its byteStart is not equal to pos |
| while (readBufferQueue.size() != 0) { |
| if (readBufferQueue.element().getByteStart() != pos) { |
| readBufferQueue.poll(); |
| } else { |
| break; |
| } |
| } |
| } |
| |
| this.expectNextPos = pos + partSize; |
| |
| int currentSize = readBufferQueue.size(); |
| if (currentSize == 0) { |
| //init lastByteStart to pos - partSize, used by for loop below |
| lastByteStart = pos - partSize; |
| } else { |
| ReadBuffer[] readBuffers = readBufferQueue.toArray( |
| new ReadBuffer[currentSize]); |
| lastByteStart = readBuffers[currentSize - 1].getByteStart(); |
| } |
| |
| int maxLen = this.maxReadAheadPartNumber - currentSize; |
| for (int i = 0; i < maxLen && i < (currentSize + 1) * 2; i++) { |
| if (lastByteStart + partSize * (i + 1) > contentLength) { |
| break; |
| } |
| |
| long byteStart = lastByteStart + partSize * (i + 1); |
| long byteEnd = byteStart + partSize -1; |
| if (byteEnd >= contentLength) { |
| byteEnd = contentLength - 1; |
| } |
| |
| ReadBuffer readBuffer = new ReadBuffer(byteStart, byteEnd); |
| if (readBuffer.getBuffer().length == 0) { |
| //EOF |
| readBuffer.setStatus(ReadBuffer.STATUS.SUCCESS); |
| } else { |
| this.readAheadExecutorService.execute( |
| new AliyunOSSFileReaderTask(key, store, readBuffer)); |
| } |
| readBufferQueue.add(readBuffer); |
| if (isRandomIO) { |
| break; |
| } |
| } |
| |
| ReadBuffer readBuffer = readBufferQueue.poll(); |
| readBuffer.lock(); |
| try { |
| readBuffer.await(ReadBuffer.STATUS.INIT); |
| if (readBuffer.getStatus() == ReadBuffer.STATUS.ERROR) { |
| this.buffer = null; |
| } else { |
| this.buffer = readBuffer.getBuffer(); |
| } |
| } catch (InterruptedException e) { |
| LOG.warn("interrupted when wait a read buffer"); |
| } finally { |
| readBuffer.unlock(); |
| } |
| |
| if (this.buffer == null) { |
| throw new IOException("Null IO stream"); |
| } |
| position = pos; |
| partRemaining = partSize; |
| } |
| |
| @Override |
| public synchronized int read() throws IOException { |
| checkNotClosed(); |
| |
| if (partRemaining <= 0 && position < contentLength) { |
| reopen(position); |
| } |
| |
| int byteRead = -1; |
| if (partRemaining != 0) { |
| byteRead = this.buffer[this.buffer.length - (int)partRemaining] & 0xFF; |
| } |
| if (byteRead >= 0) { |
| position++; |
| partRemaining--; |
| } |
| |
| if (statistics != null && byteRead >= 0) { |
| statistics.incrementBytesRead(byteRead); |
| } |
| return byteRead; |
| } |
| |
| |
| /** |
| * Verify that the input stream is open. Non blocking; this gives |
| * the last state of the volatile {@link #closed} field. |
| * |
| * @throws IOException if the connection is closed. |
| */ |
| private void checkNotClosed() throws IOException { |
| if (closed) { |
| throw new IOException(FSExceptionMessages.STREAM_IS_CLOSED); |
| } |
| } |
| |
| @Override |
| public synchronized int read(byte[] buf, int off, int len) |
| throws IOException { |
| checkNotClosed(); |
| |
| if (buf == null) { |
| throw new NullPointerException(); |
| } else if (off < 0 || len < 0 || len > buf.length - off) { |
| throw new IndexOutOfBoundsException(); |
| } else if (len == 0) { |
| return 0; |
| } |
| |
| int bytesRead = 0; |
| // Not EOF, and read not done |
| while (position < contentLength && bytesRead < len) { |
| if (partRemaining == 0) { |
| reopen(position); |
| } |
| |
| int bytes = 0; |
| for (int i = this.buffer.length - (int)partRemaining; |
| i < this.buffer.length; i++) { |
| buf[off + bytesRead] = this.buffer[i]; |
| bytes++; |
| bytesRead++; |
| if (off + bytesRead >= len) { |
| break; |
| } |
| } |
| |
| if (bytes > 0) { |
| position += bytes; |
| partRemaining -= bytes; |
| } else if (partRemaining != 0) { |
| throw new IOException("Failed to read from stream. Remaining:" + |
| partRemaining); |
| } |
| } |
| |
| if (statistics != null && bytesRead > 0) { |
| statistics.incrementBytesRead(bytesRead); |
| } |
| |
| // Read nothing, but attempt to read something |
| if (bytesRead == 0 && len > 0) { |
| return -1; |
| } else { |
| return bytesRead; |
| } |
| } |
| |
| @Override |
| public synchronized void close() throws IOException { |
| if (closed) { |
| return; |
| } |
| closed = true; |
| this.buffer = null; |
| } |
| |
| @Override |
| public synchronized int available() throws IOException { |
| checkNotClosed(); |
| |
| long remaining = contentLength - position; |
| if (remaining > Integer.MAX_VALUE) { |
| return Integer.MAX_VALUE; |
| } |
| return (int)remaining; |
| } |
| |
| @Override |
| public synchronized void seek(long pos) throws IOException { |
| checkNotClosed(); |
| if (position == pos) { |
| return; |
| } else if (pos > position && pos < position + partRemaining) { |
| long len = pos - position; |
| position = pos; |
| partRemaining -= len; |
| } else { |
| reopen(pos); |
| } |
| } |
| |
| @Override |
| public synchronized long getPos() throws IOException { |
| checkNotClosed(); |
| return position; |
| } |
| |
| @Override |
| public boolean seekToNewSource(long targetPos) throws IOException { |
| checkNotClosed(); |
| return false; |
| } |
| |
| public long getExpectNextPos() { |
| return this.expectNextPos; |
| } |
| } |