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_r146754052
########## File path: distributedlog-io/dlfs/src/main/java/org/apache/distributedlog/fs/DLFileSystem.java ########## @@ -0,0 +1,330 @@ +/* + * 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 com.google.common.collect.Lists; +import java.io.BufferedOutputStream; +import java.io.File; +import java.io.FileNotFoundException; +import java.io.IOException; +import java.net.InetAddress; +import java.net.URI; +import java.util.Collections; +import java.util.Comparator; +import java.util.Iterator; +import java.util.List; +import java.util.Optional; +import lombok.extern.slf4j.Slf4j; +import org.apache.commons.configuration.ConfigurationException; +import org.apache.distributedlog.DLSN; +import org.apache.distributedlog.DistributedLogConfiguration; +import org.apache.distributedlog.DistributedLogConstants; +import org.apache.distributedlog.api.AsyncLogWriter; +import org.apache.distributedlog.api.DistributedLogManager; +import org.apache.distributedlog.api.LogReader; +import org.apache.distributedlog.api.namespace.Namespace; +import org.apache.distributedlog.api.namespace.NamespaceBuilder; +import org.apache.distributedlog.exceptions.LogEmptyException; +import org.apache.distributedlog.exceptions.LogNotFoundException; +import org.apache.distributedlog.util.Utils; +import org.apache.hadoop.conf.Configuration; +import org.apache.hadoop.fs.BufferedFSInputStream; +import org.apache.hadoop.fs.FSDataInputStream; +import org.apache.hadoop.fs.FSDataOutputStream; +import org.apache.hadoop.fs.FileStatus; +import org.apache.hadoop.fs.FileSystem; +import org.apache.hadoop.fs.Path; +import org.apache.hadoop.fs.permission.FsPermission; +import org.apache.hadoop.util.Progressable; + +/** + * A FileSystem Implementation powered by replicated logs. + */ +@Slf4j +public class DLFileSystem extends FileSystem { + + // + // Settings + // + + public static final String DLFS_CONF_FILE = "dlog.configuration.file"; + + + private URI rootUri; + private Namespace namespace; + private final DistributedLogConfiguration dlConf; + private Path workingDir; + + public DLFileSystem() { + this.dlConf = new DistributedLogConfiguration(); + setWorkingDirectory(new Path(System.getProperty("user.dir", ""))); + } + + @Override + public URI getUri() { + return rootUri; + } + + // + // Initialization + // + + @Override + public void initialize(URI name, Configuration conf) throws IOException { + super.initialize(name, conf); + setConf(conf); + + // initialize + + this.rootUri = name; + // load the configuration + String dlConfLocation = conf.get(DLFS_CONF_FILE); + if (null != dlConfLocation) { + try { + this.dlConf.loadConf(new File(dlConfLocation).toURI().toURL()); + log.info("Loaded the distributedlog configuration from {}", dlConfLocation); + } catch (ConfigurationException e) { + log.error("Failed to load the distributedlog configuration from " + dlConfLocation, e); + throw new IOException("Failed to load distributedlog configuration from " + dlConfLocation); + } + } + log.info("Initializing the filesystem at {}", name); + // initialize the namespace + this.namespace = NamespaceBuilder.newBuilder() + .clientId("dlfs-client-" + InetAddress.getLocalHost().getHostName()) + .conf(dlConf) + .regionId(DistributedLogConstants.LOCAL_REGION_ID) + .uri(name) + .build(); + log.info("Initialized the filesystem at {}", name); + } + + @Override + public void close() throws IOException { + // clean up the resource + namespace.close(); + super.close(); + } + + // + // Util Functions + // + + private Path makeAbsolute(Path f) { + if (f.isAbsolute()) { + return f; + } else { + return new Path(workingDir, f); + } + } + + private String getStreamName(Path relativePath) { + return makeAbsolute(relativePath).toUri().getPath().substring(1); + } + + // + // Home & Working Directory + // + + @Override + public Path getHomeDirectory() { + return this.makeQualified(new Path(System.getProperty("user.home", ""))); + } + + protected Path getInitialWorkingDirectory() { + return this.makeQualified(new Path(System.getProperty("user.dir", ""))); + } + + @Override + public void setWorkingDirectory(Path path) { + workingDir = makeAbsolute(path); + checkPath(workingDir); + } + + @Override + public Path getWorkingDirectory() { + return workingDir; + } + + + @Override + public FSDataInputStream open(Path path, int bufferSize) + throws IOException { + try { + DistributedLogManager dlm = namespace.openLog(getStreamName(path)); + LogReader reader; + try { + reader = dlm.openLogReader(DLSN.InitialDLSN); + } catch (LogNotFoundException lnfe) { + throw new FileNotFoundException(path.toString()); + } catch (LogEmptyException lee) { + throw new FileNotFoundException(path.toString()); + } + return new FSDataInputStream( + new BufferedFSInputStream( + new DLInputStream(dlm, reader, 0L), + bufferSize)); + } catch (LogNotFoundException e) { + throw new FileNotFoundException(path.toString()); + } + } + + @Override + public FSDataOutputStream create(Path path, + FsPermission fsPermission, + boolean overwrite, + int bufferSize, + short replication, + long blockSize, + Progressable progressable) throws IOException { + // for overwrite, delete the existing file first. + if (overwrite) { + delete(path, false); + } + + DistributedLogConfiguration confLocal = new DistributedLogConfiguration(); + confLocal.addConfiguration(dlConf); + confLocal.setEnsembleSize(replication); + confLocal.setWriteQuorumSize(replication); + confLocal.setAckQuorumSize(replication); Review comment: ack quorum == write quorum? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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