/**
* Copyright 2007 The Apache Software Foundation
*
* 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.hbase;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.util.Arrays;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hbase.KeyValue.KVComparator;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.util.JenkinsHash;
import org.apache.hadoop.hbase.util.MD5Hash;
import org.apache.hadoop.io.VersionedWritable;
import org.apache.hadoop.io.WritableComparable;
/**
* HRegion information.
* Contains HRegion id, start and end keys, a reference to this
* HRegions' table descriptor, etc.
*/
public class HRegionInfo extends VersionedWritable implements WritableComparable<HRegionInfo>{
private static final byte VERSION = 0;
private static final Log LOG = LogFactory.getLog(HRegionInfo.class);
/**
* The new format for a region name contains its encodedName at the end.
* The encoded name also serves as the directory name for the region
* in the filesystem.
*
* New region name format:
* <tablename>,,<startkey>,<regionIdTimestamp>.<encodedName>.
* where,
* <encodedName> is a hex version of the MD5 hash of
* <tablename>,<startkey>,<regionIdTimestamp>
*
* The old region name format:
* <tablename>,<startkey>,<regionIdTimestamp>
* For region names in the old format, the encoded name is a 32-bit
* JenkinsHash integer value (in its decimal notation, string form).
*<p>
* **NOTE**
*
* ROOT, the first META region, and regions created by an older
* version of HBase (0.20 or prior) will continue to use the
* old region name format.
*/
/** Separator used to demarcate the encodedName in a region name
* in the new format. See description on new format above.
*/
private static final int ENC_SEPARATOR = '.';
public static final int MD5_HEX_LENGTH = 32;
/**
* Does region name contain its encoded name?
* @param regionName region name
* @return boolean indicating if this a new format region
* name which contains its encoded name.
*/
private static boolean hasEncodedName(final byte[] regionName) {
// check if region name ends in ENC_SEPARATOR
if ((regionName.length >= 1)
&& (regionName[regionName.length - 1] == ENC_SEPARATOR)) {
// region name is new format. it contains the encoded name.
return true;
}
return false;
}
/**
* @param regionName
* @return the encodedName
*/
public static String encodeRegionName(final byte [] regionName) {
String encodedName;
if (hasEncodedName(regionName)) {
// region is in new format:
// <tableName>,<startKey>,<regionIdTimeStamp>/encodedName/
encodedName = Bytes.toString(regionName,
regionName.length - MD5_HEX_LENGTH - 1,
MD5_HEX_LENGTH);
} else {
// old format region name. ROOT and first META region also
// use this format.EncodedName is the JenkinsHash value.
int hashVal = Math.abs(JenkinsHash.getInstance().hash(regionName,
regionName.length, 0));
encodedName = String.valueOf(hashVal);
}
return encodedName;
}
/**
* Use logging.
* @param encodedRegionName The encoded regionname.
* @return <code>-ROOT-</code> if passed <code>70236052</code> or
* <code>.META.</code> if passed </code>1028785192</code> else returns
* <code>encodedRegionName</code>
*/
public static String prettyPrint(final String encodedRegionName) {
if (encodedRegionName.equals("70236052")) {
return encodedRegionName + "/-ROOT-";
} else if (encodedRegionName.equals("1028785192")) {
return encodedRegionName + "/.META.";
}
return encodedRegionName;
}
/** delimiter used between portions of a region name */
public static final int DELIMITER = ',';
/** HRegionInfo for root region */
public static final HRegionInfo ROOT_REGIONINFO =
new HRegionInfo(0L, HTableDescriptor.ROOT_TABLEDESC);
/** HRegionInfo for first meta region */
public static final HRegionInfo FIRST_META_REGIONINFO =
new HRegionInfo(1L, HTableDescriptor.META_TABLEDESC);
private byte [] endKey = HConstants.EMPTY_BYTE_ARRAY;
// This flag is in the parent of a split while the parent is still referenced
// by daughter regions. We USED to set this flag when we disabled a table
// but now table state is kept up in zookeeper as of 0.90.0 HBase.
private boolean offLine = false;
private long regionId = -1;
private transient byte [] regionName = HConstants.EMPTY_BYTE_ARRAY;
private String regionNameStr = "";
private boolean split = false;
private byte [] startKey = HConstants.EMPTY_BYTE_ARRAY;
protected HTableDescriptor tableDesc = null;
private int hashCode = -1;
//TODO: Move NO_HASH to HStoreFile which is really the only place it is used.
public static final String NO_HASH = null;
private volatile String encodedName = NO_HASH;
private byte [] encodedNameAsBytes = null;
private void setHashCode() {
int result = Arrays.hashCode(this.regionName);
result ^= this.regionId;
result ^= Arrays.hashCode(this.startKey);
result ^= Arrays.hashCode(this.endKey);
result ^= Boolean.valueOf(this.offLine).hashCode();
result ^= this.tableDesc.hashCode();
this.hashCode = result;
}
/**
* Private constructor used constructing HRegionInfo for the catalog root and
* first meta regions
*/
private HRegionInfo(long regionId, HTableDescriptor tableDesc) {
super();
this.regionId = regionId;
this.tableDesc = tableDesc;
// Note: Root & First Meta regions names are still in old format
this.regionName = createRegionName(tableDesc.getName(), null,
regionId, false);
this.regionNameStr = Bytes.toStringBinary(this.regionName);
setHashCode();
}
/** Default constructor - creates empty object */
public HRegionInfo() {
super();
this.tableDesc = new HTableDescriptor();
}
/**
* Construct HRegionInfo with explicit parameters
*
* @param tableDesc the table descriptor
* @param startKey first key in region
* @param endKey end of key range
* @throws IllegalArgumentException
*/
public HRegionInfo(final HTableDescriptor tableDesc, final byte [] startKey,
final byte [] endKey)
throws IllegalArgumentException {
this(tableDesc, startKey, endKey, false);
}
/**
* Construct HRegionInfo with explicit parameters
*
* @param tableDesc the table descriptor
* @param startKey first key in region
* @param endKey end of key range
* @param split true if this region has split and we have daughter regions
* regions that may or may not hold references to this region.
* @throws IllegalArgumentException
*/
public HRegionInfo(HTableDescriptor tableDesc, final byte [] startKey,
final byte [] endKey, final boolean split)
throws IllegalArgumentException {
this(tableDesc, startKey, endKey, split, System.currentTimeMillis());
}
/**
* Construct HRegionInfo with explicit parameters
*
* @param tableDesc the table descriptor
* @param startKey first key in region
* @param endKey end of key range
* @param split true if this region has split and we have daughter regions
* regions that may or may not hold references to this region.
* @param regionid Region id to use.
* @throws IllegalArgumentException
*/
public HRegionInfo(HTableDescriptor tableDesc, final byte [] startKey,
final byte [] endKey, final boolean split, final long regionid)
throws IllegalArgumentException {
super();
if (tableDesc == null) {
throw new IllegalArgumentException("tableDesc cannot be null");
}
this.offLine = false;
this.regionId = regionid;
this.regionName = createRegionName(tableDesc.getName(), startKey, regionId, true);
this.regionNameStr = Bytes.toStringBinary(this.regionName);
this.split = split;
this.endKey = endKey == null? HConstants.EMPTY_END_ROW: endKey.clone();
this.startKey = startKey == null?
HConstants.EMPTY_START_ROW: startKey.clone();
this.tableDesc = tableDesc;
setHashCode();
}
/**
* Costruct a copy of another HRegionInfo
*
* @param other
*/
public HRegionInfo(HRegionInfo other) {
super();
this.endKey = other.getEndKey();
this.offLine = other.isOffline();
this.regionId = other.getRegionId();
this.regionName = other.getRegionName();
this.regionNameStr = Bytes.toStringBinary(this.regionName);
this.split = other.isSplit();
this.startKey = other.getStartKey();
this.tableDesc = other.getTableDesc();
this.hashCode = other.hashCode();
this.encodedName = other.getEncodedName();
}
/**
* Make a region name of passed parameters.
* @param tableName
* @param startKey Can be null
* @param regionid Region id (Usually timestamp from when region was created).
* @param newFormat should we create the region name in the new format
* (such that it contains its encoded name?).
* @return Region name made of passed tableName, startKey and id
*/
public static byte [] createRegionName(final byte [] tableName,
final byte [] startKey, final long regionid, boolean newFormat) {
return createRegionName(tableName, startKey, Long.toString(regionid), newFormat);
}
/**
* Make a region name of passed parameters.
* @param tableName
* @param startKey Can be null
* @param id Region id (Usually timestamp from when region was created).
* @param newFormat should we create the region name in the new format
* (such that it contains its encoded name?).
* @return Region name made of passed tableName, startKey and id
*/
public static byte [] createRegionName(final byte [] tableName,
final byte [] startKey, final String id, boolean newFormat) {
return createRegionName(tableName, startKey, Bytes.toBytes(id), newFormat);
}
/**
* Make a region name of passed parameters.
* @param tableName
* @param startKey Can be null
* @param id Region id (Usually timestamp from when region was created).
* @param newFormat should we create the region name in the new format
* (such that it contains its encoded name?).
* @return Region name made of passed tableName, startKey and id
*/
public static byte [] createRegionName(final byte [] tableName,
final byte [] startKey, final byte [] id, boolean newFormat) {
byte [] b = new byte [tableName.length + 2 + id.length +
(startKey == null? 0: startKey.length) +
(newFormat ? (MD5_HEX_LENGTH + 2) : 0)];
int offset = tableName.length;
System.arraycopy(tableName, 0, b, 0, offset);
b[offset++] = DELIMITER;
if (startKey != null && startKey.length > 0) {
System.arraycopy(startKey, 0, b, offset, startKey.length);
offset += startKey.length;
}
b[offset++] = DELIMITER;
System.arraycopy(id, 0, b, offset, id.length);
offset += id.length;
if (newFormat) {
//
// Encoded name should be built into the region name.
//
// Use the region name thus far (namely, <tablename>,<startKey>,<id>)
// to compute a MD5 hash to be used as the encoded name, and append
// it to the byte buffer.
//
String md5Hash = MD5Hash.getMD5AsHex(b, 0, offset);
byte [] md5HashBytes = Bytes.toBytes(md5Hash);
if (md5HashBytes.length != MD5_HEX_LENGTH) {
LOG.error("MD5-hash length mismatch: Expected=" + MD5_HEX_LENGTH +
"; Got=" + md5HashBytes.length);
}
// now append the bytes '.<encodedName>.' to the end
b[offset++] = ENC_SEPARATOR;
System.arraycopy(md5HashBytes, 0, b, offset, MD5_HEX_LENGTH);
offset += MD5_HEX_LENGTH;
b[offset++] = ENC_SEPARATOR;
}
return b;
}
/**
* Gets the table name from the specified region name.
* @param regionName
* @return Table name.
*/
public static byte [] getTableName(byte [] regionName) {
int offset = -1;
for (int i = 0; i < regionName.length; i++) {
if (regionName[i] == DELIMITER) {
offset = i;
break;
}
}
byte [] tableName = new byte[offset];
System.arraycopy(regionName, 0, tableName, 0, offset);
return tableName;
}
/**
* Separate elements of a regionName.
* @param regionName
* @return Array of byte[] containing tableName, startKey and id
* @throws IOException
*/
public static byte [][] parseRegionName(final byte [] regionName)
throws IOException {
int offset = -1;
for (int i = 0; i < regionName.length; i++) {
if (regionName[i] == DELIMITER) {
offset = i;
break;
}
}
if(offset == -1) throw new IOException("Invalid regionName format");
byte [] tableName = new byte[offset];
System.arraycopy(regionName, 0, tableName, 0, offset);
offset = -1;
for (int i = regionName.length - 1; i > 0; i--) {
if(regionName[i] == DELIMITER) {
offset = i;
break;
}
}
if(offset == -1) throw new IOException("Invalid regionName format");
byte [] startKey = HConstants.EMPTY_BYTE_ARRAY;
if(offset != tableName.length + 1) {
startKey = new byte[offset - tableName.length - 1];
System.arraycopy(regionName, tableName.length + 1, startKey, 0,
offset - tableName.length - 1);
}
byte [] id = new byte[regionName.length - offset - 1];
System.arraycopy(regionName, offset + 1, id, 0,
regionName.length - offset - 1);
byte [][] elements = new byte[3][];
elements[0] = tableName;
elements[1] = startKey;
elements[2] = id;
return elements;
}
/** @return the regionId */
public long getRegionId(){
return regionId;
}
/**
* @return the regionName as an array of bytes.
* @see #getRegionNameAsString()
*/
public byte [] getRegionName(){
return regionName;
}
/**
* @return Region name as a String for use in logging, etc.
*/
public String getRegionNameAsString() {
if (hasEncodedName(this.regionName)) {
// new format region names already have their encoded name.
return this.regionNameStr;
}
// old format. regionNameStr doesn't have the region name.
//
//
return this.regionNameStr + "." + this.getEncodedName();
}
/** @return the encoded region name */
public synchronized String getEncodedName() {
if (this.encodedName == NO_HASH) {
this.encodedName = encodeRegionName(this.regionName);
}
return this.encodedName;
}
public synchronized byte [] getEncodedNameAsBytes() {
if (this.encodedNameAsBytes == null) {
this.encodedNameAsBytes = Bytes.toBytes(getEncodedName());
}
return this.encodedNameAsBytes;
}
/** @return the startKey */
public byte [] getStartKey(){
return startKey;
}
/** @return the endKey */
public byte [] getEndKey(){
return endKey;
}
/**
* Returns true if the given inclusive range of rows is fully contained
* by this region. For example, if the region is foo,a,g and this is
* passed ["b","c"] or ["a","c"] it will return true, but if this is passed
* ["b","z"] it will return false.
* @throws IllegalArgumentException if the range passed is invalid (ie end < start)
*/
public boolean containsRange(byte[] rangeStartKey, byte[] rangeEndKey) {
if (Bytes.compareTo(rangeStartKey, rangeEndKey) > 0) {
throw new IllegalArgumentException(
"Invalid range: " + Bytes.toStringBinary(rangeStartKey) +
" > " + Bytes.toStringBinary(rangeEndKey));
}
boolean firstKeyInRange = Bytes.compareTo(rangeStartKey, startKey) >= 0;
boolean lastKeyInRange =
Bytes.compareTo(rangeEndKey, endKey) < 0 ||
Bytes.equals(endKey, HConstants.EMPTY_BYTE_ARRAY);
return firstKeyInRange && lastKeyInRange;
}
/**
* Return true if the given row falls in this region.
*/
public boolean containsRow(byte[] row) {
return Bytes.compareTo(row, startKey) >= 0 &&
(Bytes.compareTo(row, endKey) < 0 ||
Bytes.equals(endKey, HConstants.EMPTY_BYTE_ARRAY));
}
/** @return the tableDesc */
public HTableDescriptor getTableDesc(){
return tableDesc;
}
/**
* @param newDesc new table descriptor to use
*/
public void setTableDesc(HTableDescriptor newDesc) {
this.tableDesc = newDesc;
}
/** @return true if this is the root region */
public boolean isRootRegion() {
return this.tableDesc.isRootRegion();
}
/** @return true if this is the meta table */
public boolean isMetaTable() {
return this.tableDesc.isMetaTable();
}
/** @return true if this region is a meta region */
public boolean isMetaRegion() {
return this.tableDesc.isMetaRegion();
}
/**
* @return True if has been split and has daughters.
*/
public boolean isSplit() {
return this.split;
}
/**
* @param split set split status
*/
public void setSplit(boolean split) {
this.split = split;
}
/**
* @return True if this region is offline.
*/
public boolean isOffline() {
return this.offLine;
}
/**
* The parent of a region split is offline while split daughters hold
* references to the parent. Offlined regions are closed.
* @param offLine Set online/offline status.
*/
public void setOffline(boolean offLine) {
this.offLine = offLine;
}
/**
* @return True if this is a split parent region.
*/
public boolean isSplitParent() {
if (!isSplit()) return false;
if (!isOffline()) {
LOG.warn("Region is split but NOT offline: " + getRegionNameAsString());
}
return true;
}
/**
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
return "REGION => {" + HConstants.NAME + " => '" +
this.regionNameStr +
"', STARTKEY => '" +
Bytes.toStringBinary(this.startKey) + "', ENDKEY => '" +
Bytes.toStringBinary(this.endKey) +
"', ENCODED => " + getEncodedName() + "," +
(isOffline()? " OFFLINE => true,": "") +
(isSplit()? " SPLIT => true,": "") +
" TABLE => {" + this.tableDesc.toString() + "}";
}
/**
* @see java.lang.Object#equals(java.lang.Object)
*/
@Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
if (o == null) {
return false;
}
if (!(o instanceof HRegionInfo)) {
return false;
}
return this.compareTo((HRegionInfo)o) == 0;
}
/**
* @see java.lang.Object#hashCode()
*/
@Override
public int hashCode() {
return this.hashCode;
}
/** @return the object version number */
@Override
public byte getVersion() {
return VERSION;
}
//
// Writable
//
@Override
public void write(DataOutput out) throws IOException {
super.write(out);
Bytes.writeByteArray(out, endKey);
out.writeBoolean(offLine);
out.writeLong(regionId);
Bytes.writeByteArray(out, regionName);
out.writeBoolean(split);
Bytes.writeByteArray(out, startKey);
tableDesc.write(out);
out.writeInt(hashCode);
}
@Override
public void readFields(DataInput in) throws IOException {
super.readFields(in);
this.endKey = Bytes.readByteArray(in);
this.offLine = in.readBoolean();
this.regionId = in.readLong();
this.regionName = Bytes.readByteArray(in);
this.regionNameStr = Bytes.toStringBinary(this.regionName);
this.split = in.readBoolean();
this.startKey = Bytes.readByteArray(in);
this.tableDesc.readFields(in);
this.hashCode = in.readInt();
}
//
// Comparable
//
public int compareTo(HRegionInfo o) {
if (o == null) {
return 1;
}
// Are regions of same table?
int result = Bytes.compareTo(this.tableDesc.getName(), o.tableDesc.getName());
if (result != 0) {
return result;
}
// Compare start keys.
result = Bytes.compareTo(this.startKey, o.startKey);
if (result != 0) {
return result;
}
// Compare end keys.
return Bytes.compareTo(this.endKey, o.endKey);
}
/**
* @return Comparator to use comparing {@link KeyValue}s.
*/
public KVComparator getComparator() {
return isRootRegion()? KeyValue.ROOT_COMPARATOR: isMetaRegion()?
KeyValue.META_COMPARATOR: KeyValue.COMPARATOR;
}
}