/**
* Copyright 2010 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.client;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.DoNotRetryIOException;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.HRegionInfo;
import org.apache.hadoop.hbase.HRegionLocation;
import org.apache.hadoop.hbase.HServerAddress;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.NotServingRegionException;
import org.apache.hadoop.hbase.UnknownScannerException;
import org.apache.hadoop.hbase.client.MetaScanner.MetaScannerVisitor;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.util.Pair;
import org.apache.hadoop.hbase.util.Writables;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.TreeMap;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import java.io.DataInput;
import java.io.DataOutput;
/**
* Used to communicate with a single HBase table.
* <p>
* This class is not thread safe for writes.
* Gets, puts, and deletes take out a row lock for the duration
* of their operation. Scans (currently) do not respect
* row locking.
*/
public class HTable implements HTableInterface {
private final HConnection connection;
private final byte [] tableName;
protected final int scannerTimeout;
private volatile Configuration configuration;
private final ArrayList<Put> writeBuffer = new ArrayList<Put>();
private long writeBufferSize;
private boolean autoFlush;
private long currentWriteBufferSize;
protected int scannerCaching;
private int maxKeyValueSize;
private long maxScannerResultSize;
/**
* Creates an object to access a HBase table.
*
* @param tableName Name of the table.
* @throws IOException if a remote or network exception occurs
*/
public HTable(final String tableName)
throws IOException {
this(HBaseConfiguration.create(), Bytes.toBytes(tableName));
}
/**
* Creates an object to access a HBase table.
*
* @param tableName Name of the table.
* @throws IOException if a remote or network exception occurs
*/
public HTable(final byte [] tableName)
throws IOException {
this(HBaseConfiguration.create(), tableName);
}
/**
* Creates an object to access a HBase table.
*
* @param conf Configuration object to use.
* @param tableName Name of the table.
* @throws IOException if a remote or network exception occurs
*/
public HTable(Configuration conf, final String tableName)
throws IOException {
this(conf, Bytes.toBytes(tableName));
}
/**
* Creates an object to access a HBase table.
*
* @param conf Configuration object to use.
* @param tableName Name of the table.
* @throws IOException if a remote or network exception occurs
*/
public HTable(Configuration conf, final byte [] tableName)
throws IOException {
this.tableName = tableName;
if (conf == null) {
this.scannerTimeout = 0;
this.connection = null;
return;
}
this.connection = HConnectionManager.getConnection(conf);
this.scannerTimeout =
(int) conf.getLong(HConstants.HBASE_REGIONSERVER_LEASE_PERIOD_KEY, HConstants.DEFAULT_HBASE_REGIONSERVER_LEASE_PERIOD);
this.configuration = conf;
this.connection.locateRegion(tableName, HConstants.EMPTY_START_ROW);
this.writeBufferSize = conf.getLong("hbase.client.write.buffer", 2097152);
this.autoFlush = true;
this.currentWriteBufferSize = 0;
this.scannerCaching = conf.getInt("hbase.client.scanner.caching", 1);
this.maxScannerResultSize = conf.getLong(
HConstants.HBASE_CLIENT_SCANNER_MAX_RESULT_SIZE_KEY,
HConstants.DEFAULT_HBASE_CLIENT_SCANNER_MAX_RESULT_SIZE);
this.maxKeyValueSize = conf.getInt("hbase.client.keyvalue.maxsize", -1);
int nrHRS = getCurrentNrHRS();
if (nrHRS == 0) {
// No servers running -- set default of 10 threads.
nrHRS = 10;
}
int nrThreads = conf.getInt("hbase.htable.threads.max", nrHRS);
// Unfortunately Executors.newCachedThreadPool does not allow us to
// set the maximum size of the pool, so we have to do it ourselves.
this.pool = new ThreadPoolExecutor(0, nrThreads,
60, TimeUnit.SECONDS,
new LinkedBlockingQueue<Runnable>(),
new DaemonThreadFactory());
}
public Configuration getConfiguration() {
return configuration;
}
/**
* TODO Might want to change this to public, would be nice if the number
* of threads would automatically change when servers were added and removed
* @return the number of region servers that are currently running
* @throws IOException if a remote or network exception occurs
*/
private int getCurrentNrHRS() throws IOException {
HBaseAdmin admin = new HBaseAdmin(this.configuration);
return admin.getClusterStatus().getServers();
}
// For multiput
private ExecutorService pool;
/**
* Tells whether or not a table is enabled or not.
* @param tableName Name of table to check.
* @return {@code true} if table is online.
* @throws IOException if a remote or network exception occurs
*/
public static boolean isTableEnabled(String tableName) throws IOException {
return isTableEnabled(Bytes.toBytes(tableName));
}
/**
* Tells whether or not a table is enabled or not.
* @param tableName Name of table to check.
* @return {@code true} if table is online.
* @throws IOException if a remote or network exception occurs
*/
public static boolean isTableEnabled(byte[] tableName) throws IOException {
return isTableEnabled(HBaseConfiguration.create(), tableName);
}
/**
* Tells whether or not a table is enabled or not.
* @param conf The Configuration object to use.
* @param tableName Name of table to check.
* @return {@code true} if table is online.
* @throws IOException if a remote or network exception occurs
*/
public static boolean isTableEnabled(Configuration conf, String tableName)
throws IOException {
return isTableEnabled(conf, Bytes.toBytes(tableName));
}
/**
* Tells whether or not a table is enabled or not.
* @param conf The Configuration object to use.
* @param tableName Name of table to check.
* @return {@code true} if table is online.
* @throws IOException if a remote or network exception occurs
*/
public static boolean isTableEnabled(Configuration conf, byte[] tableName)
throws IOException {
return HConnectionManager.getConnection(conf).isTableEnabled(tableName);
}
/**
* Find region location hosting passed row using cached info
* @param row Row to find.
* @return The location of the given row.
* @throws IOException if a remote or network exception occurs
*/
public HRegionLocation getRegionLocation(final String row)
throws IOException {
return connection.getRegionLocation(tableName, Bytes.toBytes(row), false);
}
/**
* Finds the region on which the given row is being served.
* @param row Row to find.
* @return Location of the row.
* @throws IOException if a remote or network exception occurs
*/
public HRegionLocation getRegionLocation(final byte [] row)
throws IOException {
return connection.getRegionLocation(tableName, row, false);
}
public byte [] getTableName() {
return this.tableName;
}
/**
* <em>INTERNAL</em> Used by unit tests and tools to do low-level
* manipulations.
* @return An HConnection instance.
*/
// TODO(tsuna): Remove this. Unit tests shouldn't require public helpers.
public HConnection getConnection() {
return this.connection;
}
/**
* Gets the number of rows that a scanner will fetch at once.
* <p>
* The default value comes from {@code hbase.client.scanner.caching}.
*/
public int getScannerCaching() {
return scannerCaching;
}
/**
* Sets the number of rows that a scanner will fetch at once.
* <p>
* This will override the value specified by
* {@code hbase.client.scanner.caching}.
* Increasing this value will reduce the amount of work needed each time
* {@code next()} is called on a scanner, at the expense of memory use
* (since more rows will need to be maintained in memory by the scanners).
* @param scannerCaching the number of rows a scanner will fetch at once.
*/
public void setScannerCaching(int scannerCaching) {
this.scannerCaching = scannerCaching;
}
public HTableDescriptor getTableDescriptor() throws IOException {
return new UnmodifyableHTableDescriptor(
this.connection.getHTableDescriptor(this.tableName));
}
/**
* Gets the starting row key for every region in the currently open table.
* <p>
* This is mainly useful for the MapReduce integration.
* @return Array of region starting row keys
* @throws IOException if a remote or network exception occurs
*/
public byte [][] getStartKeys() throws IOException {
return getStartEndKeys().getFirst();
}
/**
* Gets the ending row key for every region in the currently open table.
* <p>
* This is mainly useful for the MapReduce integration.
* @return Array of region ending row keys
* @throws IOException if a remote or network exception occurs
*/
public byte[][] getEndKeys() throws IOException {
return getStartEndKeys().getSecond();
}
/**
* Gets the starting and ending row keys for every region in the currently
* open table.
* <p>
* This is mainly useful for the MapReduce integration.
* @return Pair of arrays of region starting and ending row keys
* @throws IOException if a remote or network exception occurs
*/
@SuppressWarnings("unchecked")
public Pair<byte[][],byte[][]> getStartEndKeys() throws IOException {
final List<byte[]> startKeyList = new ArrayList<byte[]>();
final List<byte[]> endKeyList = new ArrayList<byte[]>();
MetaScannerVisitor visitor = new MetaScannerVisitor() {
public boolean processRow(Result rowResult) throws IOException {
HRegionInfo info = Writables.getHRegionInfo(
rowResult.getValue(HConstants.CATALOG_FAMILY,
HConstants.REGIONINFO_QUALIFIER));
if (Bytes.equals(info.getTableDesc().getName(), getTableName())) {
if (!(info.isOffline() || info.isSplit())) {
startKeyList.add(info.getStartKey());
endKeyList.add(info.getEndKey());
}
}
return true;
}
};
MetaScanner.metaScan(configuration, visitor, this.tableName);
return new Pair(startKeyList.toArray(new byte[startKeyList.size()][]),
endKeyList.toArray(new byte[endKeyList.size()][]));
}
/**
* Gets all the regions and their address for this table.
* <p>
* This is mainly useful for the MapReduce integration.
* @return A map of HRegionInfo with it's server address
* @throws IOException if a remote or network exception occurs
*/
public Map<HRegionInfo, HServerAddress> getRegionsInfo() throws IOException {
final Map<HRegionInfo, HServerAddress> regionMap =
new TreeMap<HRegionInfo, HServerAddress>();
MetaScannerVisitor visitor = new MetaScannerVisitor() {
public boolean processRow(Result rowResult) throws IOException {
HRegionInfo info = Writables.getHRegionInfo(
rowResult.getValue(HConstants.CATALOG_FAMILY,
HConstants.REGIONINFO_QUALIFIER));
if (!(Bytes.equals(info.getTableDesc().getName(), getTableName()))) {
return false;
}
HServerAddress server = new HServerAddress();
byte [] value = rowResult.getValue(HConstants.CATALOG_FAMILY,
HConstants.SERVER_QUALIFIER);
if (value != null && value.length > 0) {
String address = Bytes.toString(value);
server = new HServerAddress(address);
}
if (!(info.isOffline() || info.isSplit())) {
regionMap.put(new UnmodifyableHRegionInfo(info), server);
}
return true;
}
};
MetaScanner.metaScan(configuration, visitor, tableName);
return regionMap;
}
/**
* Save the passed region information and the table's regions
* cache.
* <p>
* This is mainly useful for the MapReduce integration. You can call
* {@link #deserializeRegionInfo deserializeRegionInfo}
* to deserialize regions information from a
* {@link DataInput}, then call this method to load them to cache.
*
* <pre>
* {@code
* HTable t1 = new HTable("foo");
* FileInputStream fis = new FileInputStream("regions.dat");
* DataInputStream dis = new DataInputStream(fis);
*
* Map<HRegionInfo, HServerAddress> hm = t1.deserializeRegionInfo(dis);
* t1.prewarmRegionCache(hm);
* }
* </pre>
* @param regionMap This piece of regions information will be loaded
* to region cache.
*/
public void prewarmRegionCache(Map<HRegionInfo, HServerAddress> regionMap) {
this.connection.prewarmRegionCache(this.getTableName(), regionMap);
}
/**
* Serialize the regions information of this table and output
* to <code>out</code>.
* <p>
* This is mainly useful for the MapReduce integration. A client could
* perform a large scan for all the regions for the table, serialize the
* region info to a file. MR job can ship a copy of the meta for the table in
* the DistributedCache.
* <pre>
* {@code
* FileOutputStream fos = new FileOutputStream("regions.dat");
* DataOutputStream dos = new DataOutputStream(fos);
* table.serializeRegionInfo(dos);
* dos.flush();
* dos.close();
* }
* </pre>
* @param out {@link DataOutput} to serialize this object into.
* @throws IOException if a remote or network exception occurs
*/
public void serializeRegionInfo(DataOutput out) throws IOException {
Map<HRegionInfo, HServerAddress> allRegions = this.getRegionsInfo();
// first, write number of regions
out.writeInt(allRegions.size());
for (Map.Entry<HRegionInfo, HServerAddress> es : allRegions.entrySet()) {
es.getKey().write(out);
es.getValue().write(out);
}
}
/**
* Read from <code>in</code> and deserialize the regions information.
*
* <p>It behaves similarly as {@link #getRegionsInfo getRegionsInfo}, except
* that it loads the region map from a {@link DataInput} object.
*
* <p>It is supposed to be followed immediately by {@link
* #prewarmRegionCache prewarmRegionCache}.
*
* <p>
* Please refer to {@link #prewarmRegionCache prewarmRegionCache} for usage.
*
* @param in {@link DataInput} object.
* @return A map of HRegionInfo with its server address.
* @throws IOException if an I/O exception occurs.
*/
public Map<HRegionInfo, HServerAddress> deserializeRegionInfo(DataInput in)
throws IOException {
final Map<HRegionInfo, HServerAddress> allRegions =
new TreeMap<HRegionInfo, HServerAddress>();
// the first integer is expected to be the size of records
int regionsCount = in.readInt();
for (int i = 0; i < regionsCount; ++i) {
HRegionInfo hri = new HRegionInfo();
hri.readFields(in);
HServerAddress hsa = new HServerAddress();
hsa.readFields(in);
allRegions.put(hri, hsa);
}
return allRegions;
}
public Result getRowOrBefore(final byte[] row, final byte[] family)
throws IOException {
return connection.getRegionServerWithRetries(
new ServerCallable<Result>(connection, tableName, row) {
public Result call() throws IOException {
return server.getClosestRowBefore(location.getRegionInfo().getRegionName(),
row, family);
}
});
}
public ResultScanner getScanner(final Scan scan) throws IOException {
ClientScanner s = new ClientScanner(scan);
s.initialize();
return s;
}
public ResultScanner getScanner(byte [] family) throws IOException {
Scan scan = new Scan();
scan.addFamily(family);
return getScanner(scan);
}
public ResultScanner getScanner(byte [] family, byte [] qualifier)
throws IOException {
Scan scan = new Scan();
scan.addColumn(family, qualifier);
return getScanner(scan);
}
public Result get(final Get get) throws IOException {
return connection.getRegionServerWithRetries(
new ServerCallable<Result>(connection, tableName, get.getRow()) {
public Result call() throws IOException {
return server.get(location.getRegionInfo().getRegionName(), get);
}
}
);
}
public void delete(final Delete delete)
throws IOException {
connection.getRegionServerWithRetries(
new ServerCallable<Boolean>(connection, tableName, delete.getRow()) {
public Boolean call() throws IOException {
server.delete(location.getRegionInfo().getRegionName(), delete);
return null; // FindBugs NP_BOOLEAN_RETURN_NULL
}
}
);
}
public void delete(final List<Delete> deletes)
throws IOException {
int last = 0;
try {
last = connection.processBatchOfDeletes(deletes, this.tableName);
} finally {
deletes.subList(0, last).clear();
}
}
public void put(final Put put) throws IOException {
doPut(Arrays.asList(put));
}
public void put(final List<Put> puts) throws IOException {
doPut(puts);
}
private void doPut(final List<Put> puts) throws IOException {
for (Put put : puts) {
validatePut(put);
writeBuffer.add(put);
currentWriteBufferSize += put.heapSize();
}
if (autoFlush || currentWriteBufferSize > writeBufferSize) {
flushCommits();
}
}
public long incrementColumnValue(final byte [] row, final byte [] family,
final byte [] qualifier, final long amount)
throws IOException {
return incrementColumnValue(row, family, qualifier, amount, true);
}
@SuppressWarnings({"ThrowableInstanceNeverThrown"})
public long incrementColumnValue(final byte [] row, final byte [] family,
final byte [] qualifier, final long amount, final boolean writeToWAL)
throws IOException {
NullPointerException npe = null;
if (row == null) {
npe = new NullPointerException("row is null");
} else if (family == null) {
npe = new NullPointerException("column is null");
}
if (npe != null) {
throw new IOException(
"Invalid arguments to incrementColumnValue", npe);
}
return connection.getRegionServerWithRetries(
new ServerCallable<Long>(connection, tableName, row) {
public Long call() throws IOException {
return server.incrementColumnValue(
location.getRegionInfo().getRegionName(), row, family,
qualifier, amount, writeToWAL);
}
}
);
}
/**
* Atomically checks if a row/family/qualifier value match the expectedValue.
* If it does, it adds the put. If value == null, checks for non-existence
* of the value.
*
* @param row to check
* @param family column family
* @param qualifier column qualifier
* @param value the expected value
* @param put put to execute if value matches.
* @throws IOException
* @return true if the new put was execute, false otherwise
*/
public boolean checkAndPut(final byte [] row,
final byte [] family, final byte [] qualifier, final byte [] value,
final Put put)
throws IOException {
return connection.getRegionServerWithRetries(
new ServerCallable<Boolean>(connection, tableName, row) {
public Boolean call() throws IOException {
return server.checkAndPut(location.getRegionInfo().getRegionName(),
row, family, qualifier, value, put) ? Boolean.TRUE : Boolean.FALSE;
}
}
);
}
/**
* Atomically checks if a row/family/qualifier value match the expectedValue.
* If it does, it adds the delete. If value == null, checks for non-existence
* of the value.
*
* @param row to check
* @param family column family
* @param qualifier column qualifier
* @param value the expected value
* @param delete delete to execute if value matches.
* @throws IOException
* @return true if the new delete was executed, false otherwise
*/
public boolean checkAndDelete(final byte [] row,
final byte [] family, final byte [] qualifier, final byte [] value,
final Delete delete)
throws IOException {
return connection.getRegionServerWithRetries(
new ServerCallable<Boolean>(connection, tableName, row) {
public Boolean call() throws IOException {
return server.checkAndDelete(
location.getRegionInfo().getRegionName(),
row, family, qualifier, value, delete)
? Boolean.TRUE : Boolean.FALSE;
}
}
);
}
/**
* Test for the existence of columns in the table, as specified in the Get.<p>
*
* This will return true if the Get matches one or more keys, false if not.<p>
*
* This is a server-side call so it prevents any data from being transfered
* to the client.
* @param get param to check for
* @return true if the specified Get matches one or more keys, false if not
* @throws IOException
*/
public boolean exists(final Get get) throws IOException {
return connection.getRegionServerWithRetries(
new ServerCallable<Boolean>(connection, tableName, get.getRow()) {
public Boolean call() throws IOException {
return server.
exists(location.getRegionInfo().getRegionName(), get);
}
}
);
}
public void flushCommits() throws IOException {
try {
connection.processBatchOfPuts(writeBuffer,
tableName, pool);
} finally {
// the write buffer was adjusted by processBatchOfPuts
currentWriteBufferSize = 0;
for (Put aPut : writeBuffer) {
currentWriteBufferSize += aPut.heapSize();
}
}
}
public void close() throws IOException{
flushCommits();
}
// validate for well-formedness
private void validatePut(final Put put) throws IllegalArgumentException{
if (put.isEmpty()) {
throw new IllegalArgumentException("No columns to insert");
}
if (maxKeyValueSize > 0) {
for (List<KeyValue> list : put.getFamilyMap().values()) {
for (KeyValue kv : list) {
if (kv.getLength() > maxKeyValueSize) {
throw new IllegalArgumentException("KeyValue size too large");
}
}
}
}
}
public RowLock lockRow(final byte [] row)
throws IOException {
return connection.getRegionServerWithRetries(
new ServerCallable<RowLock>(connection, tableName, row) {
public RowLock call() throws IOException {
long lockId =
server.lockRow(location.getRegionInfo().getRegionName(), row);
return new RowLock(row,lockId);
}
}
);
}
public void unlockRow(final RowLock rl)
throws IOException {
connection.getRegionServerWithRetries(
new ServerCallable<Boolean>(connection, tableName, rl.getRow()) {
public Boolean call() throws IOException {
server.unlockRow(location.getRegionInfo().getRegionName(),
rl.getLockId());
return null; // FindBugs NP_BOOLEAN_RETURN_NULL
}
}
);
}
public boolean isAutoFlush() {
return autoFlush;
}
/**
* Turns 'auto-flush' on or off.
* <p>
* When enabled (default), {@link Put} operations don't get buffered/delayed
* and are immediately executed. This is slower but safer.
* <p>
* Turning this off means that multiple {@link Put}s will be accepted before
* any RPC is actually sent to do the write operations. If the application
* dies before pending writes get flushed to HBase, data will be lost.
* Other side effects may include the fact that the application thinks a
* {@link Put} was executed successfully whereas it was in fact only
* buffered and the operation may fail when attempting to flush all pending
* writes. In that case though, the code will retry the failed {@link Put}
* upon its next attempt to flush the buffer.
*
* @param autoFlush Whether or not to enable 'auto-flush'.
* @see #flushCommits
*/
public void setAutoFlush(boolean autoFlush) {
this.autoFlush = autoFlush;
}
/**
* Returns the maximum size in bytes of the write buffer for this HTable.
* <p>
* The default value comes from the configuration parameter
* {@code hbase.client.write.buffer}.
* @return The size of the write buffer in bytes.
*/
public long getWriteBufferSize() {
return writeBufferSize;
}
/**
* Sets the size of the buffer in bytes.
* <p>
* If the new size is less than the current amount of data in the
* write buffer, the buffer gets flushed.
* @param writeBufferSize The new write buffer size, in bytes.
* @throws IOException if a remote or network exception occurs.
*/
public void setWriteBufferSize(long writeBufferSize) throws IOException {
this.writeBufferSize = writeBufferSize;
if(currentWriteBufferSize > writeBufferSize) {
flushCommits();
}
}
/**
* Returns the write buffer.
* @return The current write buffer.
*/
public ArrayList<Put> getWriteBuffer() {
return writeBuffer;
}
/**
* Implements the scanner interface for the HBase client.
* If there are multiple regions in a table, this scanner will iterate
* through them all.
*/
protected class ClientScanner implements ResultScanner {
private final Log CLIENT_LOG = LogFactory.getLog(this.getClass());
// HEADSUP: The scan internal start row can change as we move through table.
private Scan scan;
private boolean closed = false;
// Current region scanner is against. Gets cleared if current region goes
// wonky: e.g. if it splits on us.
private HRegionInfo currentRegion = null;
private ScannerCallable callable = null;
private final LinkedList<Result> cache = new LinkedList<Result>();
private final int caching;
private long lastNext;
// Keep lastResult returned successfully in case we have to reset scanner.
private Result lastResult = null;
protected ClientScanner(final Scan scan) {
if (CLIENT_LOG.isDebugEnabled()) {
CLIENT_LOG.debug("Creating scanner over "
+ Bytes.toString(getTableName())
+ " starting at key '" + Bytes.toStringBinary(scan.getStartRow()) + "'");
}
this.scan = scan;
this.lastNext = System.currentTimeMillis();
// Use the caching from the Scan. If not set, use the default cache setting for this table.
if (this.scan.getCaching() > 0) {
this.caching = this.scan.getCaching();
} else {
this.caching = HTable.this.scannerCaching;
}
// Removed filter validation. We have a new format now, only one of all
// the current filters has a validate() method. We can add it back,
// need to decide on what we're going to do re: filter redesign.
// Need, at the least, to break up family from qualifier as separate
// checks, I think it's important server-side filters are optimal in that
// respect.
}
public void initialize() throws IOException {
nextScanner(this.caching, false);
}
protected Scan getScan() {
return scan;
}
protected long getTimestamp() {
return lastNext;
}
// returns true if the passed region endKey
private boolean checkScanStopRow(final byte [] endKey) {
if (this.scan.getStopRow().length > 0) {
// there is a stop row, check to see if we are past it.
byte [] stopRow = scan.getStopRow();
int cmp = Bytes.compareTo(stopRow, 0, stopRow.length,
endKey, 0, endKey.length);
if (cmp <= 0) {
// stopRow <= endKey (endKey is equals to or larger than stopRow)
// This is a stop.
return true;
}
}
return false; //unlikely.
}
/*
* Gets a scanner for the next region. If this.currentRegion != null, then
* we will move to the endrow of this.currentRegion. Else we will get
* scanner at the scan.getStartRow(). We will go no further, just tidy
* up outstanding scanners, if <code>currentRegion != null</code> and
* <code>done</code> is true.
* @param nbRows
* @param done Server-side says we're done scanning.
*/
private boolean nextScanner(int nbRows, final boolean done)
throws IOException {
// Close the previous scanner if it's open
if (this.callable != null) {
this.callable.setClose();
getConnection().getRegionServerWithRetries(callable);
this.callable = null;
}
// Where to start the next scanner
byte [] localStartKey;
// if we're at end of table, close and return false to stop iterating
if (this.currentRegion != null) {
byte [] endKey = this.currentRegion.getEndKey();
if (endKey == null ||
Bytes.equals(endKey, HConstants.EMPTY_BYTE_ARRAY) ||
checkScanStopRow(endKey) ||
done) {
close();
if (CLIENT_LOG.isDebugEnabled()) {
CLIENT_LOG.debug("Finished with scanning at " + this.currentRegion);
}
return false;
}
localStartKey = endKey;
if (CLIENT_LOG.isDebugEnabled()) {
CLIENT_LOG.debug("Finished with region " + this.currentRegion);
}
} else {
localStartKey = this.scan.getStartRow();
}
if (CLIENT_LOG.isDebugEnabled()) {
CLIENT_LOG.debug("Advancing internal scanner to startKey at '" +
Bytes.toStringBinary(localStartKey) + "'");
}
try {
callable = getScannerCallable(localStartKey, nbRows);
// Open a scanner on the region server starting at the
// beginning of the region
getConnection().getRegionServerWithRetries(callable);
this.currentRegion = callable.getHRegionInfo();
} catch (IOException e) {
close();
throw e;
}
return true;
}
protected ScannerCallable getScannerCallable(byte [] localStartKey,
int nbRows) {
scan.setStartRow(localStartKey);
ScannerCallable s = new ScannerCallable(getConnection(),
getTableName(), scan);
s.setCaching(nbRows);
return s;
}
public Result next() throws IOException {
// If the scanner is closed but there is some rows left in the cache,
// it will first empty it before returning null
if (cache.size() == 0 && this.closed) {
return null;
}
if (cache.size() == 0) {
Result [] values = null;
long remainingResultSize = maxScannerResultSize;
int countdown = this.caching;
// We need to reset it if it's a new callable that was created
// with a countdown in nextScanner
callable.setCaching(this.caching);
// This flag is set when we want to skip the result returned. We do
// this when we reset scanner because it split under us.
boolean skipFirst = false;
do {
try {
// Server returns a null values if scanning is to stop. Else,
// returns an empty array if scanning is to go on and we've just
// exhausted current region.
values = getConnection().getRegionServerWithRetries(callable);
if (skipFirst) {
skipFirst = false;
// Reget.
values = getConnection().getRegionServerWithRetries(callable);
}
} catch (DoNotRetryIOException e) {
if (e instanceof UnknownScannerException) {
long timeout = lastNext + scannerTimeout;
// If we are over the timeout, throw this exception to the client
// Else, it's because the region moved and we used the old id
// against the new region server; reset the scanner.
if (timeout < System.currentTimeMillis()) {
long elapsed = System.currentTimeMillis() - lastNext;
ScannerTimeoutException ex = new ScannerTimeoutException(
elapsed + "ms passed since the last invocation, " +
"timeout is currently set to " + scannerTimeout);
ex.initCause(e);
throw ex;
}
} else {
Throwable cause = e.getCause();
if (cause == null || !(cause instanceof NotServingRegionException)) {
throw e;
}
}
// Else, its signal from depths of ScannerCallable that we got an
// NSRE on a next and that we need to reset the scanner.
if (this.lastResult != null) {
this.scan.setStartRow(this.lastResult.getRow());
// Skip first row returned. We already let it out on previous
// invocation.
skipFirst = true;
}
// Clear region
this.currentRegion = null;
continue;
}
lastNext = System.currentTimeMillis();
if (values != null && values.length > 0) {
for (Result rs : values) {
cache.add(rs);
for (KeyValue kv : rs.raw()) {
remainingResultSize -= kv.heapSize();
}
countdown--;
this.lastResult = rs;
}
}
// Values == null means server-side filter has determined we must STOP
} while (remainingResultSize > 0 && countdown > 0 && nextScanner(countdown, values == null));
}
if (cache.size() > 0) {
return cache.poll();
}
return null;
}
/**
* Get <param>nbRows</param> rows.
* How many RPCs are made is determined by the {@link Scan#setCaching(int)}
* setting (or hbase.client.scanner.caching in hbase-site.xml).
* @param nbRows number of rows to return
* @return Between zero and <param>nbRows</param> RowResults. Scan is done
* if returned array is of zero-length (We never return null).
* @throws IOException
*/
public Result [] next(int nbRows) throws IOException {
// Collect values to be returned here
ArrayList<Result> resultSets = new ArrayList<Result>(nbRows);
for(int i = 0; i < nbRows; i++) {
Result next = next();
if (next != null) {
resultSets.add(next);
} else {
break;
}
}
return resultSets.toArray(new Result[resultSets.size()]);
}
public void close() {
if (callable != null) {
callable.setClose();
try {
getConnection().getRegionServerWithRetries(callable);
} catch (IOException e) {
// We used to catch this error, interpret, and rethrow. However, we
// have since decided that it's not nice for a scanner's close to
// throw exceptions. Chances are it was just an UnknownScanner
// exception due to lease time out.
}
callable = null;
}
closed = true;
}
public Iterator<Result> iterator() {
return new Iterator<Result>() {
// The next RowResult, possibly pre-read
Result next = null;
// return true if there is another item pending, false if there isn't.
// this method is where the actual advancing takes place, but you need
// to call next() to consume it. hasNext() will only advance if there
// isn't a pending next().
public boolean hasNext() {
if (next == null) {
try {
next = ClientScanner.this.next();
return next != null;
} catch (IOException e) {
throw new RuntimeException(e);
}
}
return true;
}
// get the pending next item and advance the iterator. returns null if
// there is no next item.
public Result next() {
// since hasNext() does the real advancing, we call this to determine
// if there is a next before proceeding.
if (!hasNext()) {
return null;
}
// if we get to here, then hasNext() has given us an item to return.
// we want to return the item and then null out the next pointer, so
// we use a temporary variable.
Result temp = next;
next = null;
return temp;
}
public void remove() {
throw new UnsupportedOperationException();
}
};
}
}
static class DaemonThreadFactory implements ThreadFactory {
static final AtomicInteger poolNumber = new AtomicInteger(1);
final ThreadGroup group;
final AtomicInteger threadNumber = new AtomicInteger(1);
final String namePrefix;
DaemonThreadFactory() {
SecurityManager s = System.getSecurityManager();
group = (s != null)? s.getThreadGroup() :
Thread.currentThread().getThreadGroup();
namePrefix = "pool-" +
poolNumber.getAndIncrement() +
"-thread-";
}
public Thread newThread(Runnable r) {
Thread t = new Thread(group, r,
namePrefix + threadNumber.getAndIncrement(),
0);
if (!t.isDaemon())
t.setDaemon(true);
if (t.getPriority() != Thread.NORM_PRIORITY)
t.setPriority(Thread.NORM_PRIORITY);
return t;
}
}
/**
* Enable or disable region cache prefetch for the table. It will be
* applied for the given table's all HTable instances who share the same
* connection. By default, the cache prefetch is enabled.
* @param tableName name of table to configure.
* @param enable Set to true to enable region cache prefetch. Or set to
* false to disable it.
*/
public static void setRegionCachePrefetch(final byte[] tableName,
boolean enable) {
HConnectionManager.getConnection(HBaseConfiguration.create()).
setRegionCachePrefetch(tableName, enable);
}
/**
* Enable or disable region cache prefetch for the table. It will be
* applied for the given table's all HTable instances who share the same
* connection. By default, the cache prefetch is enabled.
* @param conf The Configuration object to use.
* @param tableName name of table to configure.
* @param enable Set to true to enable region cache prefetch. Or set to
* false to disable it.
*/
public static void setRegionCachePrefetch(final Configuration conf,
final byte[] tableName, boolean enable) {
HConnectionManager.getConnection(conf).setRegionCachePrefetch(
tableName, enable);
}
/**
* Check whether region cache prefetch is enabled or not for the table.
* @param conf The Configuration object to use.
* @param tableName name of table to check
* @return true if table's region cache prefecth is enabled. Otherwise
* it is disabled.
*/
public static boolean getRegionCachePrefetch(final Configuration conf,
final byte[] tableName) {
return HConnectionManager.getConnection(conf).getRegionCachePrefetch(
tableName);
}
/**
* Check whether region cache prefetch is enabled or not for the table.
* @param tableName name of table to check
* @return true if table's region cache prefecth is enabled. Otherwise
* it is disabled.
*/
public static boolean getRegionCachePrefetch(final byte[] tableName) {
return HConnectionManager.getConnection(HBaseConfiguration.create()).
getRegionCachePrefetch(tableName);
}
}