| /* |
| * |
| * 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.bookkeeper.streaming; |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.nio.ByteBuffer; |
| import java.util.Enumeration; |
| |
| import org.apache.bookkeeper.client.BKException; |
| import org.apache.bookkeeper.client.LedgerEntry; |
| import org.apache.bookkeeper.client.LedgerHandle; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| public class LedgerInputStream extends InputStream { |
| private final static Logger LOG = LoggerFactory.getLogger(LedgerInputStream.class); |
| private LedgerHandle lh; |
| private ByteBuffer bytebuff; |
| byte[] bbytes; |
| long lastEntry = 0; |
| int increment = 50; |
| int defaultSize = 1024 * 1024; // 1MB default size |
| Enumeration<LedgerEntry> ledgerSeq = null; |
| |
| /** |
| * construct a outputstream from a ledger handle |
| * |
| * @param lh |
| * ledger handle |
| * @throws {@link BKException}, {@link InterruptedException} |
| */ |
| public LedgerInputStream(LedgerHandle lh) throws BKException, InterruptedException { |
| this.lh = lh; |
| bbytes = new byte[defaultSize]; |
| this.bytebuff = ByteBuffer.wrap(bbytes); |
| this.bytebuff.position(this.bytebuff.limit()); |
| lastEntry = Math.min(lh.getLastAddConfirmed(), increment); |
| ledgerSeq = lh.readEntries(0, lastEntry); |
| } |
| |
| /** |
| * construct a outputstream from a ledger handle |
| * |
| * @param lh |
| * the ledger handle |
| * @param size |
| * the size of the buffer |
| * @throws {@link BKException}, {@link InterruptedException} |
| */ |
| public LedgerInputStream(LedgerHandle lh, int size) throws BKException, InterruptedException { |
| this.lh = lh; |
| bbytes = new byte[size]; |
| this.bytebuff = ByteBuffer.wrap(bbytes); |
| this.bytebuff.position(this.bytebuff.limit()); |
| lastEntry = Math.min(lh.getLastAddConfirmed(), increment); |
| ledgerSeq = lh.readEntries(0, lastEntry); |
| } |
| |
| /** |
| * Method close currently doesn't do anything. The application |
| * is supposed to open and close the ledger handle backing up |
| * a stream ({@link LedgerHandle}). |
| */ |
| @Override |
| public void close() { |
| // do nothing |
| // let the application |
| // close the ledger |
| } |
| |
| /** |
| * refill the buffer, we need to read more bytes |
| * |
| * @return if we can refill or not |
| */ |
| private synchronized boolean refill() throws IOException { |
| bytebuff.clear(); |
| if (!ledgerSeq.hasMoreElements() && lastEntry >= lh.getLastAddConfirmed()) { |
| return false; |
| } |
| if (!ledgerSeq.hasMoreElements()) { |
| // do refill |
| long last = Math.min(lastEntry + increment, lh.getLastAddConfirmed()); |
| try { |
| ledgerSeq = lh.readEntries(lastEntry + 1, last); |
| } catch (BKException bk) { |
| IOException ie = new IOException(bk.getMessage()); |
| ie.initCause(bk); |
| throw ie; |
| } catch (InterruptedException ie) { |
| Thread.currentThread().interrupt(); |
| } |
| lastEntry = last; |
| } |
| LedgerEntry le = ledgerSeq.nextElement(); |
| bbytes = le.getEntry(); |
| bytebuff = ByteBuffer.wrap(bbytes); |
| return true; |
| } |
| |
| @Override |
| public synchronized int read() throws IOException { |
| boolean toread = true; |
| if (bytebuff.remaining() == 0) { |
| // their are no remaining bytes |
| toread = refill(); |
| } |
| if (toread) { |
| int ret = 0xFF & bytebuff.get(); |
| return ret; |
| } |
| return -1; |
| } |
| |
| @Override |
| public synchronized int read(byte[] b) throws IOException { |
| // be smart ... just copy the bytes |
| // once and return the size |
| // user will call it again |
| boolean toread = true; |
| if (bytebuff.remaining() == 0) { |
| toread = refill(); |
| } |
| if (toread) { |
| int bcopied = bytebuff.remaining(); |
| int tocopy = Math.min(bcopied, b.length); |
| // cannot used gets because of |
| // the underflow/overflow exceptions |
| System.arraycopy(bbytes, bytebuff.position(), b, 0, tocopy); |
| bytebuff.position(bytebuff.position() + tocopy); |
| return tocopy; |
| } |
| return -1; |
| } |
| |
| @Override |
| public synchronized int read(byte[] b, int off, int len) throws IOException { |
| // again dont need ot fully |
| // fill b, just return |
| // what we have and let the application call read |
| // again |
| boolean toread = true; |
| if (bytebuff.remaining() == 0) { |
| toread = refill(); |
| } |
| if (toread) { |
| int bcopied = bytebuff.remaining(); |
| int tocopy = Math.min(bcopied, len); |
| System.arraycopy(bbytes, bytebuff.position(), b, off, tocopy); |
| bytebuff.position(bytebuff.position() + tocopy); |
| return tocopy; |
| } |
| return -1; |
| } |
| } |