ivankelly commented on a change in pull request #227: DLFS - A FileSystem API wrapper over dlog API URL: https://github.com/apache/distributedlog/pull/227#discussion_r146754363
########## File path: distributedlog-io/dlfs/src/main/java/org/apache/distributedlog/fs/DLOutputStream.java ########## @@ -0,0 +1,141 @@ +/* + * 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.distributedlog.fs; + +import static com.google.common.base.Charsets.UTF_8; + +import io.netty.buffer.ByteBuf; +import io.netty.buffer.Unpooled; +import java.io.IOException; +import java.io.OutputStream; +import java.util.concurrent.CompletableFuture; +import java.util.concurrent.atomic.AtomicReference; +import lombok.extern.slf4j.Slf4j; +import org.apache.bookkeeper.common.concurrent.FutureUtils; +import org.apache.distributedlog.DLSN; +import org.apache.distributedlog.LogRecord; +import org.apache.distributedlog.api.AsyncLogWriter; +import org.apache.distributedlog.api.DistributedLogManager; +import org.apache.distributedlog.common.concurrent.FutureEventListener; +import org.apache.distributedlog.exceptions.UnexpectedException; +import org.apache.distributedlog.util.Utils; + +/** + * DistributedLog Output Stream. + */ +@Slf4j +class DLOutputStream extends OutputStream { + + private static final byte[] CONTROL_RECORD_CONTENT = "control".getBytes(UTF_8); + + private final DistributedLogManager dlm; + private final AsyncLogWriter writer; + + // positions + private final long[] syncPos = new long[1]; + private long writePos = 0L; + + // state + private final AtomicReference<Throwable> exception = new AtomicReference<>(null); + + DLOutputStream(DistributedLogManager dlm, + AsyncLogWriter writer) { + this.dlm = dlm; + this.writer = writer; + this.writePos = writer.getLastTxId() < 0L ? 0L : writer.getLastTxId(); + this.syncPos[0] = writePos; + } + + public synchronized long position() { + return syncPos[0]; + } + + @Override + public void write(int b) throws IOException { + byte[] data = new byte[] { (byte) b }; + write(data); + } + + @Override + public void write(byte[] b) throws IOException { + write(Unpooled.wrappedBuffer(b)); + } + + @Override + public void write(byte[] b, int off, int len) throws IOException { + write(Unpooled.wrappedBuffer(b, off, len)); + } + + private synchronized void write(ByteBuf buf) throws IOException { + Throwable cause = exception.get(); + if (null != cause) { + if (cause instanceof IOException) { + throw (IOException) cause; + } else { + throw new UnexpectedException("Encountered unknown issue", cause); + } + } + + writePos += buf.readableBytes(); + LogRecord record = new LogRecord(writePos, buf); + writer.write(record).whenComplete(new FutureEventListener<DLSN>() { + @Override + public void onSuccess(DLSN value) { + synchronized (syncPos) { + syncPos[0] = record.getTransactionId(); + } + } + + @Override + public void onFailure(Throwable cause) { + exception.compareAndSet(null, cause); + } + }); + } + + private CompletableFuture<DLSN> writeControlRecord() { + LogRecord record; + synchronized (this) { + record = new LogRecord(writePos, Unpooled.wrappedBuffer(CONTROL_RECORD_CONTENT)); + record.setControl(); + } + return writer.write(record); + } + + @Override + public void flush() throws IOException { + try { + Review comment: empty line looks like you wanted to say more here. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
