Java tutorial
/* * 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 gobblin.data.management.copy.writer; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.net.URI; import java.util.Collections; import java.util.Iterator; import java.util.List; import java.util.Map; import java.util.concurrent.atomic.AtomicLong; import org.apache.hadoop.fs.FSDataInputStream; import org.apache.hadoop.fs.FileStatus; import org.apache.hadoop.fs.FileSystem; import org.apache.hadoop.fs.Path; import org.apache.hadoop.fs.permission.FsAction; import org.apache.hadoop.fs.permission.FsPermission; import com.codahale.metrics.Meter; import com.google.common.base.Optional; import com.google.common.base.Predicate; import com.google.common.base.Strings; import com.google.common.collect.Iterators; import com.google.common.io.Closer; import lombok.extern.slf4j.Slf4j; import gobblin.broker.EmptyKey; import gobblin.broker.gobblin_scopes.GobblinScopeTypes; import gobblin.broker.iface.NotConfiguredException; import gobblin.broker.iface.SharedResourcesBroker; import gobblin.commit.SpeculativeAttemptAwareConstruct; import gobblin.configuration.ConfigurationKeys; import gobblin.configuration.State; import gobblin.configuration.WorkUnitState; import gobblin.crypto.EncryptionConfigParser; import gobblin.crypto.EncryptionFactory; import gobblin.data.management.copy.CopyConfiguration; import gobblin.data.management.copy.CopyEntity; import gobblin.data.management.copy.CopySource; import gobblin.data.management.copy.CopyableDatasetMetadata; import gobblin.data.management.copy.CopyableFile; import gobblin.data.management.copy.FileAwareInputStream; import gobblin.data.management.copy.OwnerAndPermission; import gobblin.data.management.copy.PreserveAttributes; import gobblin.data.management.copy.recovery.RecoveryHelper; import gobblin.instrumented.writer.InstrumentedDataWriter; import gobblin.state.ConstructState; import gobblin.util.FileListUtils; import gobblin.util.FinalState; import gobblin.util.ForkOperatorUtils; import gobblin.util.PathUtils; import gobblin.util.WriterUtils; import gobblin.util.io.StreamCopier; import gobblin.util.io.StreamThrottler; import gobblin.util.io.ThrottledInputStream; import gobblin.writer.DataWriter; /** * A {@link DataWriter} to write {@link FileAwareInputStream} */ @Slf4j public class FileAwareInputStreamDataWriter extends InstrumentedDataWriter<FileAwareInputStream> implements FinalState, SpeculativeAttemptAwareConstruct { public static final String GOBBLIN_COPY_BYTES_COPIED_METER = "gobblin.copy.bytesCopiedMeter"; protected final AtomicLong bytesWritten = new AtomicLong(); protected final AtomicLong filesWritten = new AtomicLong(); protected final WorkUnitState state; protected final FileSystem fs; protected final Path stagingDir; protected final Path outputDir; private final Map<String, Object> encryptionConfig; protected CopyableDatasetMetadata copyableDatasetMetadata; protected final RecoveryHelper recoveryHelper; protected final SharedResourcesBroker<GobblinScopeTypes> taskBroker; protected final int bufferSize; protected final Meter copySpeedMeter; protected final Optional<String> writerAttemptIdOptional; /** * The copyable file in the WorkUnit might be modified by converters (e.g. output extensions added / removed). * This field is set when {@link #write} is called, and points to the actual, possibly modified {@link gobblin.data.management.copy.CopyEntity} * that was written by this writer. */ protected Optional<CopyableFile> actualProcessedCopyableFile; public FileAwareInputStreamDataWriter(State state, int numBranches, int branchId, String writerAttemptId) throws IOException { super(state); if (numBranches > 1) { throw new IOException("Distcp can only operate with one branch."); } if (!(state instanceof WorkUnitState)) { throw new RuntimeException( String.format("Distcp requires a %s on construction.", WorkUnitState.class.getSimpleName())); } this.state = (WorkUnitState) state; this.taskBroker = this.state.getTaskBroker(); this.writerAttemptIdOptional = Optional.fromNullable(writerAttemptId); String uri = this.state.getProp(ForkOperatorUtils.getPropertyNameForBranch( ConfigurationKeys.WRITER_FILE_SYSTEM_URI, numBranches, branchId), ConfigurationKeys.LOCAL_FS_URI); this.fs = FileSystem.get(URI.create(uri), WriterUtils.getFsConfiguration(state)); this.stagingDir = this.writerAttemptIdOptional.isPresent() ? WriterUtils.getWriterStagingDir(state, numBranches, branchId, this.writerAttemptIdOptional.get()) : WriterUtils.getWriterStagingDir(state, numBranches, branchId); this.outputDir = getOutputDir(state); this.copyableDatasetMetadata = CopyableDatasetMetadata .deserialize(state.getProp(CopySource.SERIALIZED_COPYABLE_DATASET)); this.recoveryHelper = new RecoveryHelper(this.fs, state); this.actualProcessedCopyableFile = Optional.absent(); this.copySpeedMeter = getMetricContext().meter(GOBBLIN_COPY_BYTES_COPIED_METER); this.bufferSize = state.getPropAsInt(CopyConfiguration.BUFFER_SIZE, StreamCopier.DEFAULT_BUFFER_SIZE); this.encryptionConfig = EncryptionConfigParser.getConfigForBranch(EncryptionConfigParser.EntityType.WRITER, this.state, numBranches, branchId); } public FileAwareInputStreamDataWriter(State state, int numBranches, int branchId) throws IOException { this(state, numBranches, branchId, null); } @Override public final void writeImpl(FileAwareInputStream fileAwareInputStream) throws IOException { CopyableFile copyableFile = fileAwareInputStream.getFile(); if (encryptionConfig != null) { copyableFile.setDestination(PathUtils.addExtension(copyableFile.getDestination(), "." + EncryptionConfigParser.getEncryptionType(encryptionConfig))); } Path stagingFile = getStagingFilePath(copyableFile); if (this.actualProcessedCopyableFile.isPresent()) { throw new IOException(this.getClass().getCanonicalName() + " can only process one file."); } this.actualProcessedCopyableFile = Optional.of(copyableFile); this.fs.mkdirs(stagingFile.getParent()); writeImpl(fileAwareInputStream.getInputStream(), stagingFile, copyableFile); this.filesWritten.incrementAndGet(); } /** * Write the contents of input stream into staging path. * * <p> * WriteAt indicates the path where the contents of the input stream should be written. When this method is called, * the path writeAt.getParent() will exist already, but the path writeAt will not exist. When this method is returned, * the path writeAt must exist. Any data written to any location other than writeAt or a descendant of writeAt * will be ignored. * </p> * * @param inputStream {@link FSDataInputStream} whose contents should be written to staging path. * @param writeAt {@link Path} at which contents should be written. * @param copyableFile {@link gobblin.data.management.copy.CopyEntity} that generated this copy operation. * @throws IOException */ protected void writeImpl(InputStream inputStream, Path writeAt, CopyableFile copyableFile) throws IOException { final short replication = copyableFile.getPreserve().preserve(PreserveAttributes.Option.REPLICATION) ? copyableFile.getOrigin().getReplication() : this.fs.getDefaultReplication(writeAt); final long blockSize = copyableFile.getPreserve().preserve(PreserveAttributes.Option.BLOCK_SIZE) ? copyableFile.getOrigin().getBlockSize() : this.fs.getDefaultBlockSize(writeAt); Predicate<FileStatus> fileStatusAttributesFilter = new Predicate<FileStatus>() { @Override public boolean apply(FileStatus input) { return input.getReplication() == replication && input.getBlockSize() == blockSize; } }; Optional<FileStatus> persistedFile = this.recoveryHelper.findPersistedFile(this.state, copyableFile, fileStatusAttributesFilter); if (persistedFile.isPresent()) { log.info(String.format("Recovering persisted file %s to %s.", persistedFile.get().getPath(), writeAt)); this.fs.rename(persistedFile.get().getPath(), writeAt); } else { OutputStream os = this.fs.create(writeAt, true, this.fs.getConf().getInt("io.file.buffer.size", 4096), replication, blockSize); if (encryptionConfig != null) { os = EncryptionFactory.buildStreamCryptoProvider(encryptionConfig).encodeOutputStream(os); } try { StreamThrottler<GobblinScopeTypes> throttler = this.taskBroker .getSharedResource(new StreamThrottler.Factory<GobblinScopeTypes>(), new EmptyKey()); ThrottledInputStream throttledInputStream = throttler.throttleInputStream().inputStream(inputStream) .sourceURI(copyableFile.getOrigin().getPath().toUri()) .targetURI(this.fs.makeQualified(writeAt).toUri()).build(); StreamCopier copier = new StreamCopier(throttledInputStream, os).withBufferSize(this.bufferSize); if (isInstrumentationEnabled()) { copier.withCopySpeedMeter(this.copySpeedMeter); } this.bytesWritten.addAndGet(copier.copy()); if (isInstrumentationEnabled()) { log.info("File {}: copied {} bytes, average rate: {} B/s", copyableFile.getOrigin().getPath(), this.copySpeedMeter.getCount(), this.copySpeedMeter.getMeanRate()); } else { log.info("File {} copied.", copyableFile.getOrigin().getPath()); } } catch (NotConfiguredException nce) { log.warn("Broker error. Some features of stream copier may not be available.", nce); } finally { os.close(); inputStream.close(); } } } /** * Sets the owner/group and permission for the file in the task staging directory */ protected void setFilePermissions(CopyableFile file) throws IOException { setRecursivePermission(getStagingFilePath(file), file.getDestinationOwnerAndPermission()); } protected Path getStagingFilePath(CopyableFile file) { return new Path(this.stagingDir, file.getDestination().getName()); } protected static Path getPartitionOutputRoot(Path outputDir, CopyEntity.DatasetAndPartition datasetAndPartition) { return new Path(outputDir, datasetAndPartition.identifier()); } public static Path getOutputFilePath(CopyableFile file, Path outputDir, CopyEntity.DatasetAndPartition datasetAndPartition) { Path destinationWithoutSchemeAndAuthority = PathUtils .getPathWithoutSchemeAndAuthority(file.getDestination()); return new Path(getPartitionOutputRoot(outputDir, datasetAndPartition), PathUtils.withoutLeadingSeparator(destinationWithoutSchemeAndAuthority)); } public static Path getOutputDir(State state) { return new Path(state .getProp(ForkOperatorUtils.getPropertyNameForBranch(ConfigurationKeys.WRITER_OUTPUT_DIR, 1, 0))); } /** * Sets the {@link FsPermission}, owner, group for the path passed. It will not throw exceptions, if operations * cannot be executed, will warn and continue. */ private void safeSetPathPermission(Path path, OwnerAndPermission ownerAndPermission) { try { if (ownerAndPermission.getFsPermission() != null) { this.fs.setPermission(path, ownerAndPermission.getFsPermission()); } } catch (IOException ioe) { log.warn("Failed to set permission for directory " + path, ioe); } String owner = Strings.isNullOrEmpty(ownerAndPermission.getOwner()) ? null : ownerAndPermission.getOwner(); String group = Strings.isNullOrEmpty(ownerAndPermission.getGroup()) ? null : ownerAndPermission.getGroup(); try { if (owner != null || group != null) { this.fs.setOwner(path, owner, group); } } catch (IOException ioe) { log.warn("Failed to set owner and/or group for path " + path, ioe); } } /** * Sets the {@link FsPermission}, owner, group for the path passed. And recursively to all directories and files under * it. */ private void setRecursivePermission(Path path, OwnerAndPermission ownerAndPermission) throws IOException { List<FileStatus> files = FileListUtils.listPathsRecursively(this.fs, path, FileListUtils.NO_OP_PATH_FILTER); // Set permissions bottom up. Permissions are set to files first and then directories Collections.reverse(files); for (FileStatus file : files) { safeSetPathPermission(file.getPath(), addExecutePermissionsIfRequired(file, ownerAndPermission)); } } /** * The method makes sure it always grants execute permissions for an owner if the <code>file</code> passed is a * directory. The publisher needs it to publish it to the final directory and list files under this directory. */ private static OwnerAndPermission addExecutePermissionsIfRequired(FileStatus file, OwnerAndPermission ownerAndPermission) { if (ownerAndPermission.getFsPermission() == null) { return ownerAndPermission; } if (!file.isDir()) { return ownerAndPermission; } return new OwnerAndPermission(ownerAndPermission.getOwner(), ownerAndPermission.getGroup(), addExecutePermissionToOwner(ownerAndPermission.getFsPermission())); } static FsPermission addExecutePermissionToOwner(FsPermission fsPermission) { FsAction newOwnerAction = fsPermission.getUserAction().or(FsAction.EXECUTE); return new FsPermission(newOwnerAction, fsPermission.getGroupAction(), fsPermission.getOtherAction()); } @Override public long recordsWritten() { return this.filesWritten.get(); } @Override public long bytesWritten() throws IOException { return this.bytesWritten.get(); } /** * Moves the file from task staging to task output. Each task has its own staging directory but all the tasks share * the same task output directory. * * {@inheritDoc} * * @see gobblin.writer.DataWriter#commit() */ @Override public void commit() throws IOException { if (!this.actualProcessedCopyableFile.isPresent()) { return; } CopyableFile copyableFile = this.actualProcessedCopyableFile.get(); Path stagingFilePath = getStagingFilePath(copyableFile); Path outputFilePath = getOutputFilePath(copyableFile, this.outputDir, copyableFile.getDatasetAndPartition(this.copyableDatasetMetadata)); log.info(String.format("Committing data from %s to %s", stagingFilePath, outputFilePath)); try { setFilePermissions(copyableFile); Iterator<OwnerAndPermission> ancestorOwnerAndPermissionIt = copyableFile .getAncestorsOwnerAndPermission() == null ? Iterators.<OwnerAndPermission>emptyIterator() : copyableFile.getAncestorsOwnerAndPermission().iterator(); ensureDirectoryExists(this.fs, outputFilePath.getParent(), ancestorOwnerAndPermissionIt); if (!this.fs.rename(stagingFilePath, outputFilePath)) { // target exists throw new IOException(String.format("Could not commit file %s.", outputFilePath)); } } catch (IOException ioe) { // persist file this.recoveryHelper.persistFile(this.state, copyableFile, stagingFilePath); throw ioe; } finally { try { this.fs.delete(this.stagingDir, true); } catch (IOException ioe) { log.warn("Failed to delete staging path at " + this.stagingDir); } } } private void ensureDirectoryExists(FileSystem fs, Path path, Iterator<OwnerAndPermission> ownerAndPermissionIterator) throws IOException { if (fs.exists(path)) { return; } if (ownerAndPermissionIterator.hasNext()) { OwnerAndPermission ownerAndPermission = ownerAndPermissionIterator.next(); if (path.getParent() != null) { ensureDirectoryExists(fs, path.getParent(), ownerAndPermissionIterator); } if (!fs.mkdirs(path)) { // fs.mkdirs returns false if path already existed. Do not overwrite permissions return; } if (ownerAndPermission.getFsPermission() != null) { log.debug("Applying permissions %s to path %s.", ownerAndPermission.getFsPermission(), path); fs.setPermission(path, addExecutePermissionToOwner(ownerAndPermission.getFsPermission())); } String group = ownerAndPermission.getGroup(); String owner = ownerAndPermission.getOwner(); if (group != null || owner != null) { log.debug("Applying owner %s and group %s to path %s.", owner, group, path); fs.setOwner(path, owner, group); } } else { fs.mkdirs(path); } } @Override public void cleanup() throws IOException { // Do nothing } @Override public State getFinalState() { State state = new State(); if (this.actualProcessedCopyableFile.isPresent()) { CopySource.serializeCopyEntity(state, this.actualProcessedCopyableFile.get()); } ConstructState constructState = new ConstructState(); constructState.addOverwriteProperties(state); return constructState; } @Override public boolean isSpeculativeAttemptSafe() { return this.writerAttemptIdOptional.isPresent() && this.getClass() == FileAwareInputStreamDataWriter.class; } }