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io.cdap.plugin.batch.source.XMLReaderBatchSource Maven / Gradle / Ivy
/*
* Copyright © 2016-2019 Cask Data, Inc.
*
* Licensed 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 io.cdap.plugin.batch.source;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Strings;
import com.google.common.collect.Iterators;
import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;
import io.cdap.cdap.api.annotation.Description;
import io.cdap.cdap.api.annotation.Macro;
import io.cdap.cdap.api.annotation.Name;
import io.cdap.cdap.api.annotation.Plugin;
import io.cdap.cdap.api.common.Bytes;
import io.cdap.cdap.api.data.batch.Input;
import io.cdap.cdap.api.data.format.StructuredRecord;
import io.cdap.cdap.api.data.schema.Schema;
import io.cdap.cdap.api.dataset.DatasetProperties;
import io.cdap.cdap.api.dataset.lib.CloseableIterator;
import io.cdap.cdap.api.dataset.lib.KeyValue;
import io.cdap.cdap.api.dataset.lib.KeyValueTable;
import io.cdap.cdap.etl.api.Emitter;
import io.cdap.cdap.etl.api.FailureCollector;
import io.cdap.cdap.etl.api.PipelineConfigurer;
import io.cdap.cdap.etl.api.batch.BatchSource;
import io.cdap.cdap.etl.api.batch.BatchSourceContext;
import io.cdap.plugin.common.BatchXMLFileFilter;
import io.cdap.plugin.common.LineageRecorder;
import io.cdap.plugin.common.ReferenceBatchSource;
import io.cdap.plugin.common.ReferencePluginConfig;
import io.cdap.plugin.common.SourceInputFormatProvider;
import io.cdap.plugin.common.TransformLineageRecorderUtils;
import io.cdap.plugin.common.batch.JobUtils;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.FileUtil;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.mapreduce.Job;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.regex.Pattern;
import javax.annotation.Nullable;
/**
* XML Reader Batch Source Plugin
* It is used to read XML files from HDFS with specified file properties and filters.
* This reader emits XML event, specified by the node path property, for each file read.
*/
@Plugin(type = BatchSource.PLUGIN_TYPE)
@Name("XMLReader")
@Description("Batch source for XML read from HDFS")
public class XMLReaderBatchSource extends ReferenceBatchSource {
private static final Logger LOG = LoggerFactory.getLogger(XMLReaderBatchSource.class);
private static final Gson GSON = new Gson();
private static final Type ARRAYLIST_PREPROCESSED_FILES = new TypeToken>() { }.getType();
public static final Schema DEFAULT_XML_SCHEMA = Schema.recordOf(
"xmlSchema",
Schema.Field.of("offset", Schema.of(Schema.Type.LONG)),
Schema.Field.of("filename", Schema.of(Schema.Type.STRING)),
Schema.Field.of("record", Schema.of(Schema.Type.STRING))
);
private final XMLReaderConfig config;
private KeyValueTable processedFileTrackingTable;
private FileSystem fileSystem;
private Path tempDirectoryPath;
public XMLReaderBatchSource(XMLReaderConfig config) {
super(config);
this.config = config;
}
@VisibleForTesting
XMLReaderConfig getConfig() {
return config;
}
@Override
public void configurePipeline(PipelineConfigurer pipelineConfigurer) {
super.configurePipeline(pipelineConfigurer);
FailureCollector collector = pipelineConfigurer.getStageConfigurer().getFailureCollector();
config.validate(collector);
collector.getOrThrowException();
pipelineConfigurer.getStageConfigurer().setOutputSchema(DEFAULT_XML_SCHEMA);
if (!config.containsMacro("tableName") && !Strings.isNullOrEmpty(config.tableName)) {
pipelineConfigurer.createDataset(config.tableName, KeyValueTable.class.getName());
}
}
@Override
public void prepareRun(BatchSourceContext context) throws Exception {
FailureCollector collector = context.getFailureCollector();
config.validate(collector);
collector.getOrThrowException();
// Create dataset if macros were provided at configure time
if (!Strings.isNullOrEmpty(config.tableName) && !context.datasetExists(config.tableName)) {
context.createDataset(config.tableName, KeyValueTable.class.getName(), DatasetProperties.EMPTY);
}
Job job = JobUtils.createInstance();
Configuration conf = job.getConfiguration();
conf.set(XMLInputFormat.XML_INPUTFORMAT_PATH_NAME, config.path);
conf.set(XMLInputFormat.XML_INPUTFORMAT_NODE_PATH, config.nodePath);
if (!Strings.isNullOrEmpty(config.pattern)) {
conf.set(XMLInputFormat.XML_INPUTFORMAT_PATTERN, config.pattern);
}
conf.set(XMLInputFormat.XML_INPUTFORMAT_FILE_ACTION, config.actionAfterProcess);
if (!Strings.isNullOrEmpty(config.targetFolder)) {
conf.set(XMLInputFormat.XML_INPUTFORMAT_TARGET_FOLDER, config.targetFolder);
}
if (!config.containsMacro("tableName") && !Strings.isNullOrEmpty(config.tableName)) {
setFileTrackingInfo(context, conf);
//Create a temporary directory, in which XMLRecordReader will add file tracking information.
fileSystem = FileSystem.get(conf);
long startTime = context.getLogicalStartTime();
//Create temp file name using start time to make it unique.
String tempDirectory = config.tableName + startTime;
tempDirectoryPath = new Path(config.temporaryFolder, tempDirectory);
fileSystem.mkdirs(tempDirectoryPath);
fileSystem.deleteOnExit(tempDirectoryPath);
conf.set(XMLInputFormat.XML_INPUTFORMAT_PROCESSED_DATA_TEMP_FOLDER, tempDirectoryPath.toUri().toString());
}
XMLInputFormat.setInputPathFilter(job, BatchXMLFileFilter.class);
XMLInputFormat.addInputPath(job, new Path(config.path));
// create the external dataset with the given schema
LineageRecorder lineageRecorder = new LineageRecorder(context, config.referenceName);
lineageRecorder.createExternalDataset(DEFAULT_XML_SCHEMA);
Schema schema = context.getOutputSchema();
if (schema != null && schema.getFields() != null) {
lineageRecorder.recordRead("Read", "Read from XML.", TransformLineageRecorderUtils.getFields(schema));
}
context.setInput(Input.of(config.referenceName, new SourceInputFormatProvider(XMLInputFormat.class, conf)));
}
/**
* Method to set file tracking information in to configuration.
*/
private void setFileTrackingInfo(BatchSourceContext context, Configuration conf) {
//For reprocessing not required, set processed file name to configuration.
processedFileTrackingTable = context.getDataset(config.tableName);
if (processedFileTrackingTable != null && !config.isReprocessingRequired()) {
List processedFiles = new ArrayList();
Date expiryDate = null;
if (config.tableExpiryPeriod != null && config.tableExpiryPeriod > 0) {
Calendar cal = Calendar.getInstance();
cal.add(Calendar.DATE, -Integer.valueOf(config.tableExpiryPeriod));
expiryDate = cal.getTime();
}
try (CloseableIterator> iterator = processedFileTrackingTable.scan(null, null)) {
while (iterator.hasNext()) {
KeyValue keyValue = iterator.next();
//Delete record before expiry time period
Long time = Bytes.toLong(keyValue.getValue());
Date processedDate = new Date(time);
if (config.tableExpiryPeriod != null && config.tableExpiryPeriod > 0 && expiryDate != null &&
processedDate.before(expiryDate)) {
processedFileTrackingTable.delete(keyValue.getKey());
} else {
processedFiles.add(Bytes.toString(keyValue.getKey()));
}
}
}
//File name use by BatchXMLFileFilter to filter already processed files.
conf.set(XMLInputFormat.XML_INPUTFORMAT_PROCESSED_FILES,
GSON.toJson(processedFiles, ARRAYLIST_PREPROCESSED_FILES));
}
}
@Override
public void transform(KeyValue input, Emitter emitter) throws Exception {
Map xmlRecord = (Map) input.getValue();
Set keySet = xmlRecord.keySet();
Iterator itr = keySet.iterator();
String fileName = Iterators.getOnlyElement(itr);
String record = xmlRecord.get(fileName);
StructuredRecord output = StructuredRecord.builder(DEFAULT_XML_SCHEMA)
.set("offset", input.getKey().get())
.set("filename", fileName)
.set("record", record)
.build();
emitter.emit(output);
}
@Override
public void onRunFinish(boolean succeeded, BatchSourceContext context) {
super.onRunFinish(succeeded, context);
if (!Strings.isNullOrEmpty(config.tableName)) {
try {
FileStatus[] status = fileSystem.listStatus(tempDirectoryPath);
long processingTime = new Date().getTime();
Path[] paths = FileUtil.stat2Paths(status);
if (paths != null && paths.length > 0) {
for (Path path : paths) {
try (FSDataInputStream input = fileSystem.open(path)) {
String key = input.readUTF();
processedFileTrackingTable.write(Bytes.toBytes(key), Bytes.toBytes(processingTime));
}
}
}
} catch (IOException exception) {
LOG.error("IOException occurred while reading temp directory path : " + exception.getMessage());
}
}
}
/**
* Config class that contains all the properties needed for the XML Reader.
*/
public static class XMLReaderConfig extends ReferencePluginConfig {
public static final String PATH = "path";
public static final String PATTERN = "pattern";
public static final String NODE_PATH = "nodePath";
public static final String TABLE_EXPIRY_PERIOD = "tableExpiryPeriod";
public static final String TARGET_FOLDER = "targetFolder";
public static final String TEMPORARY_FOLDER = "temporaryFolder";
public static final String ACTION_AFTER_PROCESS = "actionAfterProcess";
public static final String REPROCESSING_REQUIRED = "reprocessingRequired";
@Description("Path to file(s) to be read. If a directory is specified, terminate the path name with a \'/\'.")
@Macro
private final String path;
@Nullable
@Description("Pattern to select specific file(s)." +
"Examples: " +
"1. Use '^' to select files with names starting with 'catalog', such as '^catalog'. " +
"2. Use '$' to select files with names ending with 'catalog.xml', such as 'catalog.xml$'. " +
"3. Use '*' to select file with name contains 'catalogBook', such as 'catalogBook*'.")
@Macro
private final String pattern;
@Description("Node path to emit as an individual event from the XML schema. " +
"Example: '/book/price' to read only price under the book node")
@Macro
private final String nodePath;
@Description("Action to be taken after processing of the XML file. " +
"Possible actions are: " +
"1. Delete from the HDFS; " +
"2. Archived to the target location; and " +
"3. Moved to the target location.")
private final String actionAfterProcess;
@Nullable
@Description("Target folder path if user select action after process, either ARCHIVE or MOVE. " +
"Target folder must be an existing directory.")
@Macro
private final String targetFolder;
@Description("Specifies whether the file(s) should be reprocessed.")
private final String reprocessingRequired;
@Nullable
@Macro
private final String tableName;
@Nullable
@Macro
private final Integer tableExpiryPeriod;
@Description("An existing HDFS folder path with read and write access for the current user; required for storing " +
"temporary files containing paths of the processed XML files. These temporary files will be read at the end of " +
"the job to update the file track table. Default to /tmp.")
@Macro
private final String temporaryFolder;
@VisibleForTesting
XMLReaderConfig(String referenceName, String path, @Nullable String pattern, String nodePath,
String actionAfterProcess, @Nullable String targetFolder, String reprocessingRequired,
@Nullable String tableName, @Nullable Integer tableExpiryPeriod, String temporaryFolder) {
super(referenceName);
this.path = path;
this.pattern = pattern;
this.nodePath = nodePath;
this.actionAfterProcess = actionAfterProcess;
this.targetFolder = targetFolder;
this.reprocessingRequired = reprocessingRequired;
this.tableName = tableName;
this.tableExpiryPeriod = tableExpiryPeriod;
this.temporaryFolder = temporaryFolder;
}
@VisibleForTesting
String getTableName() {
return tableName;
}
boolean isReprocessingRequired() {
return reprocessingRequired.equalsIgnoreCase("YES") ? true : false;
}
@VisibleForTesting
String getPath() {
return path;
}
@VisibleForTesting
String getNodePath() {
return nodePath;
}
void validate(FailureCollector collector) {
if (!containsMacro(PATH) && Strings.isNullOrEmpty(path)) {
collector.addFailure("Path cannot be empty.", null).withConfigProperty(PATH);
}
if (!containsMacro(NODE_PATH) && Strings.isNullOrEmpty(nodePath)) {
collector.addFailure("Node path cannot be empty.", null).withConfigProperty(NODE_PATH);
}
if (!containsMacro(TABLE_EXPIRY_PERIOD) && tableExpiryPeriod != null && tableExpiryPeriod < 0) {
collector.addFailure(String.format("Invalid value: %d.", tableExpiryPeriod),
"Value for 'Table Expiry Period' should either be empty or greater than 0")
.withConfigProperty(TABLE_EXPIRY_PERIOD);
}
if (!containsMacro(TEMPORARY_FOLDER) && Strings.isNullOrEmpty(temporaryFolder)) {
collector.addFailure("Temporary folder cannot be empty.", null)
.withConfigProperty(TEMPORARY_FOLDER);
}
boolean onlyOneActionRequired = !Strings.isNullOrEmpty(actionAfterProcess)
&& !actionAfterProcess.equalsIgnoreCase("NONE")
&& isReprocessingRequired();
if (onlyOneActionRequired) {
collector.addFailure("Only one of 'After Processing Action' or 'Reprocessing Required' " +
"may be selected at a time.", null)
.withConfigProperty(ACTION_AFTER_PROCESS).withConfigProperty(REPROCESSING_REQUIRED);
}
boolean targetFolderEmpty = Strings.isNullOrEmpty(targetFolder)
&& (!Strings.isNullOrEmpty(actionAfterProcess)
&& (actionAfterProcess.equalsIgnoreCase("ARCHIVE")
|| actionAfterProcess.equalsIgnoreCase("MOVE")));
if (targetFolderEmpty) {
collector.addFailure(
String.format("Target folder cannot be empty for Action = '%s'.", actionAfterProcess), null)
.withConfigProperty(TARGET_FOLDER);
}
if (!Strings.isNullOrEmpty(pattern)) {
try {
Pattern.compile(pattern);
} catch (Exception e) {
collector.addFailure(
String.format("Invalid regular expression: '%s'.", pattern), null)
.withConfigProperty(PATTERN);
}
// By default, the Hadoop FileInputFormat won't return any files when using a regex pattern unless the path
// has globs in it. Checking for that scenario.
if (path.endsWith("/") ||
!(path.contains("*") || path.contains("?") || path.contains("{") || path.contains("["))) {
collector.addFailure("When filtering with regular expressions, the path must " +
"be a directory and leverage glob syntax.",
"Usually the folder path needs to end with '/*'.")
.withConfigProperty(PATH).withConfigProperty(PATTERN);
}
}
}
}
}
