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/**
* 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.util;
import java.io.*;
import java.nio.charset.StandardCharsets;
import java.util.Collections;
import java.util.Set;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.concurrent.atomic.AtomicReference;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceAudience.Private;
import org.apache.hadoop.classification.InterfaceStability;
import io.prestosql.hadoop.$internal.org.slf4j.Logger;
import io.prestosql.hadoop.$internal.org.slf4j.LoggerFactory;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;
// Keeps track of which datanodes/nodemanagers are allowed to connect to the
// namenode/resourcemanager.
@InterfaceAudience.LimitedPrivate({"HDFS", "MapReduce"})
@InterfaceStability.Unstable
public class HostsFileReader {
private static final Logger LOG = LoggerFactory.getLogger(HostsFileReader
.class);
private final AtomicReference current;
public HostsFileReader(String inFile,
String exFile) throws IOException {
HostDetails hostDetails = new HostDetails(
inFile, Collections.emptySet(),
exFile, Collections.emptyMap());
current = new AtomicReference<>(hostDetails);
refresh(inFile, exFile);
}
@Private
public HostsFileReader(String includesFile, InputStream inFileInputStream,
String excludesFile, InputStream exFileInputStream) throws IOException {
HostDetails hostDetails = new HostDetails(
includesFile, Collections.emptySet(),
excludesFile, Collections.emptyMap());
current = new AtomicReference<>(hostDetails);
refresh(inFileInputStream, exFileInputStream);
}
public static void readFileToSet(String type,
String filename, Set set) throws IOException {
File file = new File(filename);
FileInputStream fis = new FileInputStream(file);
readFileToSetWithFileInputStream(type, filename, fis, set);
}
@Private
public static void readFileToSetWithFileInputStream(String type,
String filename, InputStream fileInputStream, Set set)
throws IOException {
BufferedReader reader = null;
try {
reader = new BufferedReader(
new InputStreamReader(fileInputStream, StandardCharsets.UTF_8));
String line;
while ((line = reader.readLine()) != null) {
String[] nodes = line.split("[ \t\n\f\r]+");
if (nodes != null) {
for (int i = 0; i < nodes.length; i++) {
nodes[i] = nodes[i].trim();
if (nodes[i].startsWith("#")) {
// Everything from now on is a comment
break;
}
if (!nodes[i].isEmpty()) {
LOG.info("Adding a node \"" + nodes[i] + "\" to the list of "
+ type + " hosts from " + filename);
set.add(nodes[i]);
}
}
}
}
} finally {
if (reader != null) {
reader.close();
}
fileInputStream.close();
}
}
public void refresh() throws IOException {
HostDetails hostDetails = current.get();
refresh(hostDetails.includesFile, hostDetails.excludesFile);
}
public static void readFileToMap(String type,
String filename, Map map) throws IOException {
File file = new File(filename);
FileInputStream fis = new FileInputStream(file);
readFileToMapWithFileInputStream(type, filename, fis, map);
}
public static void readFileToMapWithFileInputStream(String type,
String filename, InputStream inputStream, Map map)
throws IOException {
// The input file could be either simple text or XML.
boolean xmlInput = filename.toLowerCase().endsWith(".xml");
if (xmlInput) {
readXmlFileToMapWithFileInputStream(type, filename, inputStream, map);
} else {
HashSet nodes = new HashSet();
readFileToSetWithFileInputStream(type, filename, inputStream, nodes);
for (String node : nodes) {
map.put(node, null);
}
}
}
public static void readXmlFileToMapWithFileInputStream(String type,
String filename, InputStream fileInputStream, Map map)
throws IOException {
Document dom;
DocumentBuilderFactory builder = DocumentBuilderFactory.newInstance();
try {
DocumentBuilder db = builder.newDocumentBuilder();
dom = db.parse(fileInputStream);
// Examples:
// host1
// host2 123
// host3 -1
// host4, host5,host6 1800
Element doc = dom.getDocumentElement();
NodeList nodes = doc.getElementsByTagName("host");
for (int i = 0; i < nodes.getLength(); i++) {
Node node = nodes.item(i);
if (node.getNodeType() == Node.ELEMENT_NODE) {
Element e= (Element) node;
// Support both single host and comma-separated list of hosts.
String v = readFirstTagValue(e, "name");
String[] hosts = StringUtils.getTrimmedStrings(v);
String str = readFirstTagValue(e, "timeout");
Integer timeout = (str == null)? null : Integer.parseInt(str);
for (String host : hosts) {
map.put(host, timeout);
LOG.info("Adding a node \"" + host + "\" to the list of "
+ type + " hosts from " + filename);
}
}
}
} catch (IOException|SAXException|ParserConfigurationException e) {
LOG.error("error parsing " + filename, e);
throw new RuntimeException(e);
} finally {
fileInputStream.close();
}
}
static String readFirstTagValue(Element e, String tag) {
NodeList nodes = e.getElementsByTagName(tag);
return (nodes.getLength() == 0)? null : nodes.item(0).getTextContent();
}
public void refresh(String includesFile, String excludesFile)
throws IOException {
LOG.info("Refreshing hosts (include/exclude) list");
HostDetails oldDetails = current.get();
Set newIncludes = oldDetails.includes;
Map newExcludes = oldDetails.excludes;
if (includesFile != null && !includesFile.isEmpty()) {
newIncludes = new HashSet<>();
readFileToSet("included", includesFile, newIncludes);
newIncludes = Collections.unmodifiableSet(newIncludes);
}
if (excludesFile != null && !excludesFile.isEmpty()) {
newExcludes = new HashMap<>();
readFileToMap("excluded", excludesFile, newExcludes);
newExcludes = Collections.unmodifiableMap(newExcludes);
}
HostDetails newDetails = new HostDetails(includesFile, newIncludes,
excludesFile, newExcludes);
current.set(newDetails);
}
@Private
public void refresh(InputStream inFileInputStream,
InputStream exFileInputStream) throws IOException {
LOG.info("Refreshing hosts (include/exclude) list");
HostDetails oldDetails = current.get();
Set newIncludes = oldDetails.includes;
Map newExcludes = oldDetails.excludes;
if (inFileInputStream != null) {
newIncludes = new HashSet<>();
readFileToSetWithFileInputStream("included", oldDetails.includesFile,
inFileInputStream, newIncludes);
newIncludes = Collections.unmodifiableSet(newIncludes);
}
if (exFileInputStream != null) {
newExcludes = new HashMap<>();
readFileToMapWithFileInputStream("excluded", oldDetails.excludesFile,
exFileInputStream, newExcludes);
newExcludes = Collections.unmodifiableMap(newExcludes);
}
HostDetails newDetails = new HostDetails(
oldDetails.includesFile, newIncludes,
oldDetails.excludesFile, newExcludes);
current.set(newDetails);
}
public Set getHosts() {
HostDetails hostDetails = current.get();
return hostDetails.getIncludedHosts();
}
public Set getExcludedHosts() {
HostDetails hostDetails = current.get();
return hostDetails.getExcludedHosts();
}
/**
* Retrieve an atomic view of the included and excluded hosts.
*
* @param includes set to populate with included hosts
* @param excludes set to populate with excluded hosts
* @deprecated use {@link #getHostDetails() instead}
*/
@Deprecated
public void getHostDetails(Set includes, Set excludes) {
HostDetails hostDetails = current.get();
includes.addAll(hostDetails.getIncludedHosts());
excludes.addAll(hostDetails.getExcludedHosts());
}
/**
* Retrieve an atomic view of the included and excluded hosts.
*
* @param includeHosts set to populate with included hosts
* @param excludeHosts map to populate with excluded hosts
* @deprecated use {@link #getHostDetails() instead}
*/
@Deprecated
public void getHostDetails(Set includeHosts,
Map excludeHosts) {
HostDetails hostDetails = current.get();
includeHosts.addAll(hostDetails.getIncludedHosts());
excludeHosts.putAll(hostDetails.getExcludedMap());
}
/**
* Retrieve an atomic view of the included and excluded hosts.
*
* @return the included and excluded hosts
*/
public HostDetails getHostDetails() {
return current.get();
}
public void setIncludesFile(String includesFile) {
LOG.info("Setting the includes file to " + includesFile);
HostDetails oldDetails = current.get();
HostDetails newDetails = new HostDetails(includesFile, oldDetails.includes,
oldDetails.excludesFile, oldDetails.excludes);
current.set(newDetails);
}
public void setExcludesFile(String excludesFile) {
LOG.info("Setting the excludes file to " + excludesFile);
HostDetails oldDetails = current.get();
HostDetails newDetails = new HostDetails(
oldDetails.includesFile, oldDetails.includes,
excludesFile, oldDetails.excludes);
current.set(newDetails);
}
public void updateFileNames(String includesFile, String excludesFile) {
LOG.info("Setting the includes file to " + includesFile);
LOG.info("Setting the excludes file to " + excludesFile);
HostDetails oldDetails = current.get();
HostDetails newDetails = new HostDetails(includesFile, oldDetails.includes,
excludesFile, oldDetails.excludes);
current.set(newDetails);
}
/**
* An atomic view of the included and excluded hosts
*/
public static class HostDetails {
private final String includesFile;
private final Set includes;
private final String excludesFile;
// exclude host list with optional timeout.
// If the value is null, it indicates default timeout.
private final Map excludes;
HostDetails(String includesFile, Set includes,
String excludesFile, Map excludes) {
this.includesFile = includesFile;
this.includes = includes;
this.excludesFile = excludesFile;
this.excludes = excludes;
}
public String getIncludesFile() {
return includesFile;
}
public Set getIncludedHosts() {
return includes;
}
public String getExcludesFile() {
return excludesFile;
}
public Set getExcludedHosts() {
return excludes.keySet();
}
public Map getExcludedMap() {
return excludes;
}
}
}