TzdbZoneRulesProvider.java
/*
* Copyright (c) 2007-present, Stephen Colebourne & Michael Nascimento Santos
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* * Neither the name of JSR-310 nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.threeten.bp.zone;
import java.io.ByteArrayInputStream;
import java.io.DataInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.StreamCorruptedException;
import java.net.URL;
import java.util.Arrays;
import java.util.Enumeration;
import java.util.HashSet;
import java.util.List;
import java.util.NavigableMap;
import java.util.Set;
import java.util.TreeMap;
import java.util.concurrent.ConcurrentNavigableMap;
import java.util.concurrent.ConcurrentSkipListMap;
import java.util.concurrent.CopyOnWriteArraySet;
import java.util.concurrent.atomic.AtomicReferenceArray;
import org.threeten.bp.jdk8.Jdk8Methods;
/**
* Loads time-zone rules for 'TZDB'.
* <p>
* This class is public for the service loader to access.
*
* <h3>Specification for implementors</h3>
* This class is immutable and thread-safe.
*/
public final class TzdbZoneRulesProvider extends ZoneRulesProvider {
// TODO: can this be private/hidden in any way?
// service loader seems to need it to be public
/**
* All the regions that are available.
*/
private List<String> regionIds;
/**
* All the versions that are available.
*/
private final ConcurrentNavigableMap<String, Version> versions = new ConcurrentSkipListMap<String, Version>();
/**
* All the URLs that have been loaded.
* Uses String to avoid equals() on URL.
*/
private Set<String> loadedUrls = new CopyOnWriteArraySet<String>();
/**
* Creates an instance.
* Created by the {@code ServiceLoader}.
*
* @throws ZoneRulesException if unable to load
*/
public TzdbZoneRulesProvider() {
super();
if (load(ZoneRulesProvider.class.getClassLoader()) == false) {
throw new ZoneRulesException("No time-zone rules found for 'TZDB'");
}
}
/**
* Creates an instance and loads the specified URL.
* <p>
* This could be used to wrap this provider in another instance.
*
* @param url the URL to load, not null
* @throws ZoneRulesException if unable to load
*/
public TzdbZoneRulesProvider(URL url) {
super();
try {
if (load(url) == false) {
throw new ZoneRulesException("No time-zone rules found: " + url);
}
} catch (Exception ex) {
throw new ZoneRulesException("Unable to load TZDB time-zone rules: " + url, ex);
}
}
/**
* Creates an instance and loads the specified input stream.
* <p>
* This could be used to wrap this provider in another instance.
*
* @param stream the stream to load, not null, not closed after use
* @throws ZoneRulesException if unable to load
*/
public TzdbZoneRulesProvider(InputStream stream) {
super();
try {
load(stream);
} catch (Exception ex) {
throw new ZoneRulesException("Unable to load TZDB time-zone rules", ex);
}
}
//-----------------------------------------------------------------------
@Override
protected Set<String> provideZoneIds() {
return new HashSet<String>(regionIds);
}
@Override
protected ZoneRules provideRules(String zoneId, boolean forCaching) {
Jdk8Methods.requireNonNull(zoneId, "zoneId");
ZoneRules rules = versions.lastEntry().getValue().getRules(zoneId);
if (rules == null) {
throw new ZoneRulesException("Unknown time-zone ID: " + zoneId);
}
return rules;
}
@Override
protected NavigableMap<String, ZoneRules> provideVersions(String zoneId) {
TreeMap<String, ZoneRules> map = new TreeMap<String, ZoneRules>();
for (Version version : versions.values()) {
ZoneRules rules = version.getRules(zoneId);
if (rules != null) {
map.put(version.versionId, rules);
}
}
return map;
}
//-------------------------------------------------------------------------
/**
* Loads the rules.
*
* @param classLoader the class loader to use, not null
* @return true if updated
* @throws ZoneRulesException if unable to load
*/
private boolean load(ClassLoader classLoader) {
boolean updated = false;
URL url = null;
try {
Enumeration<URL> en = classLoader.getResources("org/threeten/bp/TZDB.dat");
while (en.hasMoreElements()) {
url = en.nextElement();
updated |= load(url);
}
} catch (Exception ex) {
throw new ZoneRulesException("Unable to load TZDB time-zone rules: " + url, ex);
}
return updated;
}
/**
* Loads the rules from a URL, often in a jar file.
*
* @param url the jar file to load, not null
* @return true if updated
* @throws ClassNotFoundException if a classpath error occurs
* @throws IOException if an IO error occurs
* @throws ZoneRulesException if the data is already loaded for the version
*/
private boolean load(URL url) throws ClassNotFoundException, IOException, ZoneRulesException {
boolean updated = false;
if (loadedUrls.add(url.toExternalForm())) {
InputStream in = null;
try {
in = url.openStream();
updated |= load(in);
} finally {
if (in != null) {
in.close();
}
}
}
return updated;
}
/**
* Loads the rules from an input stream.
*
* @param in the stream to load, not null, not closed after use
* @throws Exception if an error occurs
*/
private boolean load(InputStream in) throws IOException, StreamCorruptedException {
boolean updated = false;
Iterable<Version> loadedVersions = loadData(in);
for (Version loadedVersion : loadedVersions) {
// see https://github.com/ThreeTen/threetenbp/pull/28 for issue wrt
// multiple versions of lib on classpath
Version existing = versions.putIfAbsent(loadedVersion.versionId, loadedVersion);
if (existing != null && !existing.versionId.equals(loadedVersion.versionId)) {
throw new ZoneRulesException("Data already loaded for TZDB time-zone rules version: " + loadedVersion.versionId);
}
updated = true;
}
return updated;
}
/**
* Loads the rules from an input stream.
*
* @param in the stream to load, not null, not closed after use
* @throws Exception if an error occurs
*/
private Iterable<Version> loadData(InputStream in) throws IOException, StreamCorruptedException {
DataInputStream dis = new DataInputStream(in);
if (dis.readByte() != 1) {
throw new StreamCorruptedException("File format not recognised");
}
// group
String groupId = dis.readUTF();
if ("TZDB".equals(groupId) == false) {
throw new StreamCorruptedException("File format not recognised");
}
// versions
int versionCount = dis.readShort();
String[] versionArray = new String[versionCount];
for (int i = 0; i < versionCount; i++) {
versionArray[i] = dis.readUTF();
}
// regions
int regionCount = dis.readShort();
String[] regionArray = new String[regionCount];
for (int i = 0; i < regionCount; i++) {
regionArray[i] = dis.readUTF();
}
regionIds = Arrays.asList(regionArray);
// rules
int ruleCount = dis.readShort();
Object[] ruleArray = new Object[ruleCount];
for (int i = 0; i < ruleCount; i++) {
byte[] bytes = new byte[dis.readShort()];
dis.readFully(bytes);
ruleArray[i] = bytes;
}
AtomicReferenceArray<Object> ruleData = new AtomicReferenceArray<Object>(ruleArray);
// link version-region-rules
Set<Version> versionSet = new HashSet<Version>(versionCount);
for (int i = 0; i < versionCount; i++) {
int versionRegionCount = dis.readShort();
String[] versionRegionArray = new String[versionRegionCount];
short[] versionRulesArray = new short[versionRegionCount];
for (int j = 0; j < versionRegionCount; j++) {
versionRegionArray[j] = regionArray[dis.readShort()];
versionRulesArray[j] = dis.readShort();
}
versionSet.add(new Version(versionArray[i], versionRegionArray, versionRulesArray, ruleData));
}
return versionSet;
}
@Override
public String toString() {
return "TZDB";
}
//-----------------------------------------------------------------------
/**
* A version of the TZDB rules.
*/
static class Version {
private final String versionId;
private final String[] regionArray;
private final short[] ruleIndices;
private final AtomicReferenceArray<Object> ruleData;
Version(String versionId, String[] regionIds, short[] ruleIndices, AtomicReferenceArray<Object> ruleData) {
this.ruleData = ruleData;
this.versionId = versionId;
this.regionArray = regionIds;
this.ruleIndices = ruleIndices;
}
ZoneRules getRules(String regionId) {
int regionIndex = Arrays.binarySearch(regionArray, regionId);
if (regionIndex < 0) {
return null;
}
try {
return createRule(ruleIndices[regionIndex]);
} catch (Exception ex) {
throw new ZoneRulesException("Invalid binary time-zone data: TZDB:" + regionId + ", version: " + versionId, ex);
}
}
ZoneRules createRule(short index) throws Exception {
Object obj = ruleData.get(index);
if (obj instanceof byte[]) {
byte[] bytes = (byte[]) obj;
DataInputStream dis = new DataInputStream(new ByteArrayInputStream(bytes));
obj = Ser.read(dis);
ruleData.set(index, obj);
}
return (ZoneRules) obj;
}
@Override
public String toString() {
return versionId;
}
}
}