| /** |
| * 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; |
| |
| import com.google.common.base.Preconditions; |
| import org.apache.hadoop.HadoopIllegalArgumentException; |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.fs.Options.ChecksumOpt; |
| import org.apache.hadoop.fs.permission.FsPermission; |
| import org.apache.hadoop.util.Progressable; |
| |
| import javax.annotation.Nonnull; |
| import java.io.IOException; |
| import java.util.EnumSet; |
| |
| import static org.apache.hadoop.fs.CommonConfigurationKeysPublic.IO_FILE_BUFFER_SIZE_DEFAULT; |
| import static org.apache.hadoop.fs.CommonConfigurationKeysPublic.IO_FILE_BUFFER_SIZE_KEY; |
| |
| /** |
| * Builder for {@link FSDataOutputStream} and its subclasses. |
| * |
| * It is used to create {@link FSDataOutputStream} when creating a new file or |
| * appending an existing file on {@link FileSystem}. |
| * |
| * By default, it does not create parent directory that do not exist. |
| * {@link FileSystem#createNonRecursive(Path, boolean, int, short, long, |
| * Progressable)}. |
| * |
| * To create missing parent directory, use {@link #recursive()}. |
| */ |
| @InterfaceAudience.Public |
| @InterfaceStability.Evolving |
| public abstract class FSDataOutputStreamBuilder |
| <S extends FSDataOutputStream, B extends FSDataOutputStreamBuilder<S, B>> { |
| private final FileSystem fs; |
| private final Path path; |
| private FsPermission permission = null; |
| private int bufferSize; |
| private short replication; |
| private long blockSize; |
| /** set to true to create missing directory. */ |
| private boolean recursive = false; |
| private final EnumSet<CreateFlag> flags = EnumSet.noneOf(CreateFlag.class); |
| private Progressable progress = null; |
| private ChecksumOpt checksumOpt = null; |
| |
| /** |
| * Return the concrete implementation of the builder instance. |
| */ |
| protected abstract B getThisBuilder(); |
| |
| /** |
| * Constructor. |
| */ |
| protected FSDataOutputStreamBuilder(@Nonnull FileSystem fileSystem, |
| @Nonnull Path p) { |
| Preconditions.checkNotNull(fileSystem); |
| Preconditions.checkNotNull(p); |
| fs = fileSystem; |
| path = p; |
| bufferSize = fs.getConf().getInt(IO_FILE_BUFFER_SIZE_KEY, |
| IO_FILE_BUFFER_SIZE_DEFAULT); |
| replication = fs.getDefaultReplication(path); |
| blockSize = fs.getDefaultBlockSize(p); |
| } |
| |
| protected FileSystem getFS() { |
| return fs; |
| } |
| |
| protected Path getPath() { |
| return path; |
| } |
| |
| protected FsPermission getPermission() { |
| if (permission == null) { |
| permission = FsPermission.getFileDefault(); |
| } |
| return permission; |
| } |
| |
| /** |
| * Set permission for the file. |
| */ |
| public B permission(@Nonnull final FsPermission perm) { |
| Preconditions.checkNotNull(perm); |
| permission = perm; |
| return getThisBuilder(); |
| } |
| |
| protected int getBufferSize() { |
| return bufferSize; |
| } |
| |
| /** |
| * Set the size of the buffer to be used. |
| */ |
| public B bufferSize(int bufSize) { |
| bufferSize = bufSize; |
| return getThisBuilder(); |
| } |
| |
| protected short getReplication() { |
| return replication; |
| } |
| |
| /** |
| * Set replication factor. |
| */ |
| public B replication(short replica) { |
| replication = replica; |
| return getThisBuilder(); |
| } |
| |
| protected long getBlockSize() { |
| return blockSize; |
| } |
| |
| /** |
| * Set block size. |
| */ |
| public B blockSize(long blkSize) { |
| blockSize = blkSize; |
| return getThisBuilder(); |
| } |
| |
| /** |
| * Return true to create the parent directories if they do not exist. |
| */ |
| protected boolean isRecursive() { |
| return recursive; |
| } |
| |
| /** |
| * Create the parent directory if they do not exist. |
| */ |
| public B recursive() { |
| recursive = true; |
| return getThisBuilder(); |
| } |
| |
| protected Progressable getProgress() { |
| return progress; |
| } |
| |
| /** |
| * Set the facility of reporting progress. |
| */ |
| public B progress(@Nonnull final Progressable prog) { |
| Preconditions.checkNotNull(prog); |
| progress = prog; |
| return getThisBuilder(); |
| } |
| |
| protected EnumSet<CreateFlag> getFlags() { |
| return flags; |
| } |
| |
| /** |
| * Create an FSDataOutputStream at the specified path. |
| */ |
| public B create() { |
| flags.add(CreateFlag.CREATE); |
| return getThisBuilder(); |
| } |
| |
| /** |
| * Set to true to overwrite the existing file. |
| * Set it to false, an exception will be thrown when calling {@link #build()} |
| * if the file exists. |
| */ |
| public B overwrite(boolean overwrite) { |
| if (overwrite) { |
| flags.add(CreateFlag.OVERWRITE); |
| } else { |
| flags.remove(CreateFlag.OVERWRITE); |
| } |
| return getThisBuilder(); |
| } |
| |
| /** |
| * Append to an existing file (optional operation). |
| */ |
| public B append() { |
| flags.add(CreateFlag.APPEND); |
| return getThisBuilder(); |
| } |
| |
| protected ChecksumOpt getChecksumOpt() { |
| return checksumOpt; |
| } |
| |
| /** |
| * Set checksum opt. |
| */ |
| public B checksumOpt(@Nonnull final ChecksumOpt chksumOpt) { |
| Preconditions.checkNotNull(chksumOpt); |
| checksumOpt = chksumOpt; |
| return getThisBuilder(); |
| } |
| |
| /** |
| * Create the FSDataOutputStream to write on the file system. |
| * |
| * @throws HadoopIllegalArgumentException if the parameters are not valid. |
| * @throws IOException on errors when file system creates or appends the file. |
| */ |
| public abstract S build() throws IOException; |
| } |