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HBASE-532 Odd interaction between HRegion.get, HRegion.deleteAll and compactions 

git-svn-id: https://svn.apache.org/repos/asf/hadoop/hbase/trunk@648850 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Michael Stack 2008-04-16 21:07:32 +00:00
parent dbd74f2f9a
commit 373761483f
7 changed files with 416 additions and 339 deletions
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1
CHANGES.txt
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@ -9,6 +9,7 @@ Hbase Change Log
HBASE-575 master dies with stack overflow error if rootdir isn't qualified
HBASE-582 HBase 554 forgot to clear results on each iteration caused by a filter
(Clint Morgan via Stack)
HBASE-532 Odd interaction between HRegion.get, HRegion.deleteAll and compactions
IMPROVEMENTS
HBASE-559 MR example job to count table rows

116
src/java/org/apache/hadoop/hbase/regionserver/HAbstractScanner.java
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@ -34,7 +34,6 @@ import org.apache.hadoop.io.Text;
/**
* Abstract base class that implements the InternalScanner.
* Used by the concrete HMemcacheScanner and HStoreScanners
*/
public abstract class HAbstractScanner implements InternalScanner {
final Log LOG = LogFactory.getLog(this.getClass().getName());
@ -111,12 +110,6 @@ public abstract class HAbstractScanner implements InternalScanner {
protected TreeMap<Text, Vector<ColumnMatcher>> okCols; // Holds matchers for each column family
protected boolean scannerClosed = false; // True when scanning is done
// Keys retrieved from the sources
protected HStoreKey keys[];
// Values that correspond to those keys
protected byte [][] vals;
protected long timestamp; // The timestamp to match entries against
private boolean wildcardMatch;
private boolean multipleMatchers;
@ -138,6 +131,10 @@ public abstract class HAbstractScanner implements InternalScanner {
this.wildcardMatch = true;
}
matchers.add(matcher);
// TODO: Does this multipleMatchers matter any more now that scanners
// are done at the store level? It might have mattered when scanners
// could have been done at the region level when memcache was at the
// region level rather than down here at store level.
if (matchers.size() > 1) {
this.multipleMatchers = true;
}
@ -146,20 +143,19 @@ public abstract class HAbstractScanner implements InternalScanner {
}
/**
* For a particular column i, find all the matchers defined for the column.
* For a particular column, find all the matchers defined for the column.
* Compare the column family and column key using the matchers. The first one
* that matches returns true. If no matchers are successful, return false.
*
* @param i index into the keys array
* @return true - if any of the matchers for the column match the column family
* @param column Column to test
* @return true if any of the matchers for the column match the column family
* and the column key.
*
* @throws IOException
*/
boolean columnMatch(int i) throws IOException {
Text column = keys[i].getColumn();
protected boolean columnMatch(final Text column) throws IOException {
Vector<ColumnMatcher> matchers =
okCols.get(HStoreKey.extractFamily(column));
this.okCols.get(HStoreKey.extractFamily(column));
if (matchers == null) {
return false;
}
@ -171,18 +167,6 @@ public abstract class HAbstractScanner implements InternalScanner {
return false;
}
/**
* If the user didn't want to start scanning at the first row, this method
* seeks to the requested row.
*/
abstract boolean findFirstRow(int i, Text firstRow) throws IOException;
/** The concrete implementations provide a mechanism to find the next set of values */
abstract boolean getNext(int i) throws IOException;
/** Mechanism used by concrete implementation to shut down a particular scanner */
abstract void closeSubScanner(int i);
/** {@inheritDoc} */
public boolean isWildcardScanner() {
return this.wildcardMatch;
@ -193,87 +177,9 @@ public abstract class HAbstractScanner implements InternalScanner {
return this.multipleMatchers;
}
/**
* Get the next set of values for this scanner.
*
* @param key The key that matched
* @param results All the results for <code>key</code>
* @return true if a match was found
* @throws IOException
*
* @see org.apache.hadoop.hbase.InternalScanner#next(org.apache.hadoop.hbase.HStoreKey, java.util.SortedMap)
*/
public boolean next(HStoreKey key, SortedMap<Text, byte []> results)
throws IOException {
if (scannerClosed) {
return false;
}
// Find the next row label (and timestamp)
Text chosenRow = null;
long chosenTimestamp = -1;
for(int i = 0; i < keys.length; i++) {
if((keys[i] != null)
&& (columnMatch(i))
&& (keys[i].getTimestamp() <= this.timestamp)
&& ((chosenRow == null)
|| (keys[i].getRow().compareTo(chosenRow) < 0)
|| ((keys[i].getRow().compareTo(chosenRow) == 0)
&& (keys[i].getTimestamp() > chosenTimestamp)))) {
chosenRow = new Text(keys[i].getRow());
chosenTimestamp = keys[i].getTimestamp();
}
}
public abstract boolean next(HStoreKey key, SortedMap<Text, byte []> results)
throws IOException;
// Grab all the values that match this row/timestamp
boolean insertedItem = false;
if(chosenRow != null) {
key.setRow(chosenRow);
key.setVersion(chosenTimestamp);
key.setColumn(new Text(""));
for(int i = 0; i < keys.length; i++) {
// Fetch the data
while((keys[i] != null)
&& (keys[i].getRow().compareTo(chosenRow) == 0)) {
// If we are doing a wild card match or there are multiple matchers
// per column, we need to scan all the older versions of this row
// to pick up the rest of the family members
if(!wildcardMatch
&& !multipleMatchers
&& (keys[i].getTimestamp() != chosenTimestamp)) {
break;
}
if(columnMatch(i)) {
// We only want the first result for any specific family member
if(!results.containsKey(keys[i].getColumn())) {
results.put(new Text(keys[i].getColumn()), vals[i]);
insertedItem = true;
}
}
if(!getNext(i)) {
closeSubScanner(i);
}
}
// Advance the current scanner beyond the chosen row, to
// a valid timestamp, so we're ready next time.
while((keys[i] != null)
&& ((keys[i].getRow().compareTo(chosenRow) <= 0)
|| (keys[i].getTimestamp() > this.timestamp)
|| (! columnMatch(i)))) {
getNext(i);
}
}
}
return insertedItem;
}
/** {@inheritDoc} */
public Iterator<Entry<HStoreKey, SortedMap<Text, byte[]>>> iterator() {
throw new UnsupportedOperationException("Unimplemented serverside. " +
"next(HStoreKey, StortedMap(...) is more efficient");

34
src/java/org/apache/hadoop/hbase/regionserver/HStore.java
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@ -611,22 +611,28 @@ public class HStore implements HConstants {
* @throws IOException
*/
void flushCache(final long logCacheFlushId) throws IOException {
internalFlushCache(memcache.getSnapshot(), logCacheFlushId);
SortedMap<HStoreKey, byte []> cache = this.memcache.snapshot();
internalFlushCache(cache, logCacheFlushId);
// If an exception happens flushing, we let it out without clearing
// the memcache snapshot. The old snapshot will be returned when we say
// 'snapshot', the next time flush comes around.
this.memcache.clearSnapshot(cache);
}
private void internalFlushCache(SortedMap<HStoreKey, byte []> cache,
long logCacheFlushId) throws IOException {
// Don't flush if there are no entries.
if (cache.size() == 0) {
return;
}
// TODO: We can fail in the below block before we complete adding this
// flush to list of store files. Add cleanup of anything put on filesystem
// if we fail.
synchronized(flushLock) {
// A. Write the Maps out to the disk
HStoreFile flushedFile = new HStoreFile(conf, fs, basedir,
info.getEncodedName(), family.getFamilyName(), -1L, null);
String name = flushedFile.toString();
MapFile.Writer out = flushedFile.getWriter(this.fs, this.compression,
this.bloomFilter);
@ -678,7 +684,7 @@ public class HStore implements HConstants {
flushedFile.getReader(this.fs, this.bloomFilter));
this.storefiles.put(flushid, flushedFile);
if(LOG.isDebugEnabled()) {
LOG.debug("Added " + name + " with " + entries +
LOG.debug("Added " + flushedFile.toString() + " with " + entries +
" entries, sequence id " + logCacheFlushId + ", data size " +
StringUtils.humanReadableInt(cacheSize) + ", file size " +
StringUtils.humanReadableInt(newStoreSize) + " for " +
@ -1360,31 +1366,27 @@ public class HStore implements HConstants {
*/
Text getRowKeyAtOrBefore(final Text row)
throws IOException{
// map of HStoreKeys that are candidates for holding the row key that
// most closely matches what we're looking for. we'll have to update it
// Map of HStoreKeys that are candidates for holding the row key that
// most closely matches what we're looking for. We'll have to update it
// deletes found all over the place as we go along before finally reading
// the best key out of it at the end.
SortedMap<HStoreKey, Long> candidateKeys = new TreeMap<HStoreKey, Long>();
// obtain read lock
// Obtain read lock
this.lock.readLock().lock();
try {
// Process each store file
MapFile.Reader[] maparray = getReaders();
// process each store file
for (int i = maparray.length - 1; i >= 0; i--) {
// update the candidate keys from the current map file
rowAtOrBeforeFromMapFile(maparray[i], row, candidateKeys);
}
// finally, check the memcache
memcache.getRowKeyAtOrBefore(row, candidateKeys);
// Finally, check the memcache
this.memcache.getRowKeyAtOrBefore(row, candidateKeys);
// return the best key from candidateKeys
if (!candidateKeys.isEmpty()) {
return candidateKeys.lastKey().getRow();
}
return null;
// Return the best key from candidateKeys
return candidateKeys.isEmpty()? null: candidateKeys.lastKey().getRow();
} finally {
this.lock.readLock().unlock();
}

13
src/java/org/apache/hadoop/hbase/regionserver/InternalScanner.java
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@ -30,13 +30,14 @@ import org.apache.hadoop.hbase.HStoreKey;
* HStoreKeys and byte[] instead of RowResults. This is because they are
* actually close to how the data is physically stored, and therefore it is more
* convenient to interact with them that way. It is also much easier to merge
* the results across SortedMaps that RowResults.
* the results across SortedMaps than RowResults.
*
* Additionally, we need to be able to determine if the scanner is doing wildcard
* column matches (when only a column family is specified or if a column regex
* is specified) or if multiple members of the same column family were
* specified. If so, we need to ignore the timestamp to ensure that we get all
* the family members, as they may have been last updated at different times.
* <p>Additionally, we need to be able to determine if the scanner is doing
* wildcard column matches (when only a column family is specified or if a
* column regex is specified) or if multiple members of the same column family
* were specified. If so, we need to ignore the timestamp to ensure that we get
* all the family members, as they may have been last updated at different
* times.
*/
public interface InternalScanner extends Closeable {
/**

354
src/java/org/apache/hadoop/hbase/regionserver/Memcache.java
View File

@ -21,92 +21,129 @@
package org.apache.hadoop.hbase.regionserver;
import java.io.IOException;
import java.rmi.UnexpectedException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.SortedMap;
import java.util.TreeMap;
import java.util.Collections;
import java.util.Map;
import java.util.List;
import java.util.ArrayList;
import java.util.Set;
import java.util.Iterator;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.HStoreKey;
import org.apache.hadoop.hbase.io.Cell;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.io.WritableComparable;
/**
* The Memcache holds in-memory modifications to the HRegion. This is really a
* wrapper around a TreeMap that helps us when staging the Memcache out to disk.
* The Memcache holds in-memory modifications to the HRegion.
* Keeps a current map. When asked to flush the map, current map is moved
* to snapshot and is cleared. We continue to serve edits out of new map
* and backing snapshot until flusher reports in that the flush succeeded. At
* this point we let the snapshot go.
*/
class Memcache {
private final Log LOG = LogFactory.getLog(this.getClass().getName());
// Note that since these structures are always accessed with a lock held,
// no additional synchronization is required.
// so no additional synchronization is required.
@SuppressWarnings("hiding")
private final SortedMap<HStoreKey, byte[]> memcache =
Collections.synchronizedSortedMap(new TreeMap<HStoreKey, byte []>());
// The currently active sorted map of edits.
private volatile SortedMap<HStoreKey, byte[]> memcache =
createSynchronizedSortedMap();
volatile SortedMap<HStoreKey, byte[]> snapshot;
// Snapshot of memcache. Made for flusher.
private volatile SortedMap<HStoreKey, byte[]> snapshot =
createSynchronizedSortedMap();
@SuppressWarnings("hiding")
private final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
/**
* Constructor
/*
* Utility method.
* @return sycnhronized sorted map of HStoreKey to byte arrays.
*/
public Memcache() {
snapshot =
Collections.synchronizedSortedMap(new TreeMap<HStoreKey, byte []>());
private static SortedMap<HStoreKey, byte[]> createSynchronizedSortedMap() {
return Collections.synchronizedSortedMap(new TreeMap<HStoreKey, byte []>());
}
/**
* Creates a snapshot of the current Memcache
* Must be followed by a call to {@link #clearSnapshot(SortedMap)}
* @return Snapshot. Never null. May have no entries.
*/
void snapshot() {
SortedMap<HStoreKey, byte[]> snapshot() {
this.lock.writeLock().lock();
try {
synchronized (memcache) {
if (memcache.size() != 0) {
snapshot.putAll(memcache);
memcache.clear();
// If snapshot has entries, then flusher failed or didn't call cleanup.
if (this.snapshot.size() > 0) {
LOG.warn("Returning extant snapshot. Is there another ongoing " +
"flush or did last attempt fail?");
return this.snapshot;
}
// We used to synchronize on the memcache here but we're inside a
// write lock so removed it. Comment is left in case removal was a
// mistake. St.Ack
if (this.memcache.size() != 0) {
this.snapshot = this.memcache;
this.memcache = createSynchronizedSortedMap();
}
return this.snapshot;
} finally {
this.lock.writeLock().unlock();
}
}
/**
* @return memcache snapshot
* Return the current snapshot.
* @return Return snapshot.
* @see {@link #snapshot()}
* @see {@link #clearSnapshot(SortedMap)}
*/
SortedMap<HStoreKey, byte[]> getSnapshot() {
return this.snapshot;
}
/**
* The passed snapshot was successfully persisted; it can be let go.
* @param ss The snapshot to clean out.
* @throws UnexpectedException
* @see {@link #snapshot()}
*/
void clearSnapshot(final SortedMap<HStoreKey, byte []> ss)
throws UnexpectedException {
this.lock.writeLock().lock();
try {
SortedMap<HStoreKey, byte[]> currentSnapshot = snapshot;
snapshot =
Collections.synchronizedSortedMap(new TreeMap<HStoreKey, byte []>());
return currentSnapshot;
if (this.snapshot != ss) {
throw new UnexpectedException("Current snapshot is " +
this.snapshot + ", was passed " + ss);
}
// OK. Passed in snapshot is same as current snapshot. If not-empty,
// create a new snapshot and let the old one go.
if (ss.size() != 0) {
this.snapshot = createSynchronizedSortedMap();
}
} finally {
this.lock.writeLock().unlock();
}
}
/**
* Store a value.
* Write an update
* @param key
* @param value
*/
void add(final HStoreKey key, final byte[] value) {
this.lock.readLock().lock();
try {
memcache.put(key, value);
this.memcache.put(key, value);
} finally {
this.lock.readLock().unlock();
}
@ -122,20 +159,80 @@ class Memcache {
this.lock.readLock().lock();
try {
List<Cell> results;
synchronized (memcache) {
results = internalGet(memcache, key, numVersions);
// The synchronizations here are because internalGet iterates
synchronized (this.memcache) {
results = internalGet(this.memcache, key, numVersions);
}
synchronized (snapshot) {
synchronized (this.snapshot) {
results.addAll(results.size(),
internalGet(snapshot, key, numVersions - results.size()));
internalGet(this.snapshot, key, numVersions - results.size()));
}
return results;
} finally {
this.lock.readLock().unlock();
}
}
/**
* @param a
* @param b
* @return Return lowest of a or b or null if both a and b are null
*/
@SuppressWarnings("unchecked")
private WritableComparable getLowest(final WritableComparable a,
final WritableComparable b) {
if (a == null) {
return b;
}
if (b == null) {
return a;
}
return a.compareTo(b) <= 0? a: b;
}
/**
* @param row Find the row that comes after this one.
* @return Next row or null if none found
*/
Text getNextRow(final Text row) {
this.lock.readLock().lock();
try {
return (Text)getLowest(getNextRow(row, this.memcache),
getNextRow(row, this.snapshot));
} finally {
this.lock.readLock().unlock();
}
}
/*
* @param row Find row that follows this one.
* @param map Map to look in for a row beyond <code>row</code>.
* This method synchronizes on passed map while iterating it.
* @return Next row or null if none found.
*/
private Text getNextRow(final Text row,
final SortedMap<HStoreKey, byte []> map) {
Text result = null;
// Synchronize on the map to make the tailMap making 'safe'.
synchronized (map) {
// Make an HSK with maximum timestamp so we get past most of the current
// rows cell entries.
HStoreKey hsk = new HStoreKey(row, HConstants.LATEST_TIMESTAMP);
SortedMap<HStoreKey, byte []> tailMap = map.tailMap(hsk);
// Iterate until we fall into the next row; i.e. move off current row
for (Map.Entry<HStoreKey, byte []> es: tailMap.entrySet()) {
HStoreKey itKey = es.getKey();
if (itKey.getRow().compareTo(row) <= 0) {
continue;
}
// Note: Not suppressing deletes.
result = itKey.getRow();
break;
}
}
return result;
}
/**
* Return all the available columns for the given key. The key indicates a
* row and timestamp, but not a column name.
@ -148,13 +245,13 @@ class Memcache {
Map<Text, Cell> results) {
this.lock.readLock().lock();
try {
synchronized (memcache) {
internalGetFull(memcache, key, columns, deletes, results);
// The synchronizations here are because internalGet iterates
synchronized (this.memcache) {
internalGetFull(this.memcache, key, columns, deletes, results);
}
synchronized (snapshot) {
internalGetFull(snapshot, key, columns, deletes, results);
synchronized (this.snapshot) {
internalGetFull(this.snapshot, key, columns, deletes, results);
}
} finally {
this.lock.readLock().unlock();
}
@ -178,7 +275,7 @@ class Memcache {
if (HLogEdit.isDeleted(val)) {
if (!deletes.containsKey(itCol)
|| deletes.get(itCol).longValue() < itKey.getTimestamp()) {
deletes.put(new Text(itCol), itKey.getTimestamp());
deletes.put(new Text(itCol), Long.valueOf(itKey.getTimestamp()));
}
} else if (!(deletes.containsKey(itCol)
&& deletes.get(itCol).longValue() >= itKey.getTimestamp())) {
@ -192,13 +289,13 @@ class Memcache {
}
/**
* @param row
* @param timestamp
* @param row Row to look for.
* @param candidateKeys Map of candidate keys (Accumulation over lots of
* lookup over stores and memcaches)
*/
void getRowKeyAtOrBefore(final Text row,
SortedMap<HStoreKey, Long> candidateKeys) {
this.lock.readLock().lock();
try {
synchronized (memcache) {
internalGetRowKeyAtOrBefore(memcache, row, candidateKeys);
@ -313,7 +410,7 @@ class Memcache {
}
} else {
candidateKeys.put(stripTimestamp(found_key),
found_key.getTimestamp());
Long.valueOf(found_key.getTimestamp()));
}
} while (key_iterator.hasNext());
}
@ -451,22 +548,11 @@ class Memcache {
* @return a scanner over the keys in the Memcache
*/
InternalScanner getScanner(long timestamp,
Text targetCols[], Text firstRow) throws IOException {
// Here we rely on ReentrantReadWriteLock's ability to acquire multiple
// locks by the same thread and to be able to downgrade a write lock to
// a read lock. We need to hold a lock throughout this method, but only
// need the write lock while creating the memcache snapshot
this.lock.writeLock().lock(); // hold write lock during memcache snapshot
snapshot(); // snapshot memcache
this.lock.readLock().lock(); // acquire read lock
this.lock.writeLock().unlock(); // downgrade to read lock
Text targetCols[], Text firstRow)
throws IOException {
this.lock.readLock().lock();
try {
// Prevent a cache flush while we are constructing the scanner
return new MemcacheScanner(timestamp, targetCols, firstRow);
} finally {
this.lock.readLock().unlock();
}
@ -477,112 +563,66 @@ class Memcache {
// It lets the caller scan the contents of the Memcache.
//////////////////////////////////////////////////////////////////////////////
class MemcacheScanner extends HAbstractScanner {
SortedMap<HStoreKey, byte []> backingMap;
Iterator<HStoreKey> keyIterator;
private class MemcacheScanner extends HAbstractScanner {
private Text currentRow;
private final Set<Text> columns;
@SuppressWarnings("unchecked")
MemcacheScanner(final long timestamp, final Text targetCols[],
final Text firstRow) throws IOException {
final Text firstRow)
throws IOException {
// Call to super will create ColumnMatchers and whether this is a regex
// scanner or not. Will also save away timestamp. Also sorts rows.
super(timestamp, targetCols);
try {
this.backingMap = new TreeMap<HStoreKey, byte[]>();
this.backingMap.putAll(snapshot);
this.keys = new HStoreKey[1];
this.vals = new byte[1][];
// Generate list of iterators
HStoreKey firstKey = new HStoreKey(firstRow);
if (firstRow != null && firstRow.getLength() != 0) {
keyIterator =
backingMap.tailMap(firstKey).keySet().iterator();
} else {
keyIterator = backingMap.keySet().iterator();
this.currentRow = firstRow;
// If we're being asked to scan explicit columns rather than all in
// a family or columns that match regexes, cache the sorted array of
// columns.
this.columns = this.isWildcardScanner()? this.okCols.keySet(): null;
}
while (getNext(0)) {
if (!findFirstRow(0, firstRow)) {
@Override
public boolean next(HStoreKey key, SortedMap<Text, byte []> results)
throws IOException {
if (this.scannerClosed) {
return false;
}
Map<Text, Long> deletes = new HashMap<Text, Long>();
// Catch all row results in here. These results are ten filtered to
// ensure they match column name regexes, or if none, added to results.
Map<Text, Cell> rowResults = new HashMap<Text, Cell>();
if (results.size() > 0) {
results.clear();
}
while (results.size() <= 0 &&
(this.currentRow = getNextRow(this.currentRow)) != null) {
if (deletes.size() > 0) {
deletes.clear();
}
if (rowResults.size() > 0) {
rowResults.clear();
}
key.setRow(this.currentRow);
key.setVersion(this.timestamp);
getFull(key, isWildcardScanner()? null: this.columns, deletes, rowResults);
for (Map.Entry<Text, Cell> e: rowResults.entrySet()) {
Text column = e.getKey();
Cell c = e.getValue();
if (isWildcardScanner()) {
// Check the results match. We only check columns, not timestamps.
// We presume that timestamps have been handled properly when we
// called getFull.
if (!columnMatch(column)) {
continue;
}
if (columnMatch(0)) {
break;
}
results.put(column, c.getValue());
}
}
} catch (RuntimeException ex) {
LOG.error("error initializing Memcache scanner: ", ex);
close();
IOException e = new IOException("error initializing Memcache scanner");
e.initCause(ex);
throw e;
} catch(IOException ex) {
LOG.error("error initializing Memcache scanner: ", ex);
close();
throw ex;
}
return results.size() > 0;
}
/**
* The user didn't want to start scanning at the first row. This method
* seeks to the requested row.
*
* @param i which iterator to advance
* @param firstRow seek to this row
* @return true if this is the first row
*/
@Override
boolean findFirstRow(int i, Text firstRow) {
return firstRow.getLength() == 0 ||
keys[i].getRow().compareTo(firstRow) >= 0;
}
/**
* Get the next value from the specified iterator.
*
* @param i Which iterator to fetch next value from
* @return true if there is more data available
*/
@Override
boolean getNext(int i) {
boolean result = false;
while (true) {
if (!keyIterator.hasNext()) {
closeSubScanner(i);
break;
}
// Check key is < than passed timestamp for this scanner.
HStoreKey hsk = keyIterator.next();
if (hsk == null) {
throw new NullPointerException("Unexpected null key");
}
if (hsk.getTimestamp() <= this.timestamp) {
this.keys[i] = hsk;
this.vals[i] = backingMap.get(keys[i]);
result = true;
break;
}
}
return result;
}
/** Shut down an individual map iterator. */
@Override
void closeSubScanner(int i) {
keyIterator = null;
keys[i] = null;
vals[i] = null;
backingMap = null;
}
/** Shut down map iterators */
public void close() {
if (!scannerClosed) {
if(keyIterator != null) {
closeSubScanner(0);
}
scannerClosed = true;
}
}

122
src/java/org/apache/hadoop/hbase/regionserver/StoreFileScanner.java
View File

@ -21,6 +21,7 @@
package org.apache.hadoop.hbase.regionserver;
import java.io.IOException;
import java.util.SortedMap;
import org.apache.hadoop.io.MapFile;
import org.apache.hadoop.io.Text;
@ -28,14 +29,19 @@ import org.apache.hadoop.hbase.HStoreKey;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
/**
* A scanner that iterates through the HStore files
* A scanner that iterates through HStore files
*/
class StoreFileScanner extends HAbstractScanner {
@SuppressWarnings("hiding")
// Keys retrieved from the sources
private HStoreKey keys[];
// Values that correspond to those keys
private byte [][] vals;
private MapFile.Reader[] readers;
private HStore store;
public StoreFileScanner(HStore store, long timestamp, Text[] targetCols, Text firstRow)
public StoreFileScanner(final HStore store, final long timestamp,
final Text[] targetCols, final Text firstRow)
throws IOException {
super(timestamp, targetCols);
this.store = store;
@ -54,13 +60,11 @@ class StoreFileScanner extends HAbstractScanner {
// Advance the readers to the first pos.
for(i = 0; i < readers.length; i++) {
keys[i] = new HStoreKey();
if(firstRow.getLength() != 0) {
if(findFirstRow(i, firstRow)) {
continue;
}
}
while(getNext(i)) {
if(columnMatch(i)) {
break;
@ -76,15 +80,109 @@ class StoreFileScanner extends HAbstractScanner {
}
}
/**
* For a particular column i, find all the matchers defined for the column.
* Compare the column family and column key using the matchers. The first one
* that matches returns true. If no matchers are successful, return false.
*
* @param i index into the keys array
* @return true if any of the matchers for the column match the column family
* and the column key.
* @throws IOException
*/
boolean columnMatch(int i) throws IOException {
return columnMatch(keys[i].getColumn());
}
/**
* Get the next set of values for this scanner.
*
* @param key The key that matched
* @param results All the results for <code>key</code>
* @return true if a match was found
* @throws IOException
*
* @see org.apache.hadoop.hbase.regionserver.InternalScanner#next(org.apache.hadoop.hbase.HStoreKey, java.util.SortedMap)
*/
@Override
public boolean next(HStoreKey key, SortedMap<Text, byte []> results)
throws IOException {
if (scannerClosed) {
return false;
}
// Find the next row label (and timestamp)
Text chosenRow = null;
long chosenTimestamp = -1;
for(int i = 0; i < keys.length; i++) {
if((keys[i] != null)
&& (columnMatch(i))
&& (keys[i].getTimestamp() <= this.timestamp)
&& ((chosenRow == null)
|| (keys[i].getRow().compareTo(chosenRow) < 0)
|| ((keys[i].getRow().compareTo(chosenRow) == 0)
&& (keys[i].getTimestamp() > chosenTimestamp)))) {
chosenRow = new Text(keys[i].getRow());
chosenTimestamp = keys[i].getTimestamp();
}
}
// Grab all the values that match this row/timestamp
boolean insertedItem = false;
if(chosenRow != null) {
key.setRow(chosenRow);
key.setVersion(chosenTimestamp);
key.setColumn(new Text(""));
for(int i = 0; i < keys.length; i++) {
// Fetch the data
while((keys[i] != null)
&& (keys[i].getRow().compareTo(chosenRow) == 0)) {
// If we are doing a wild card match or there are multiple matchers
// per column, we need to scan all the older versions of this row
// to pick up the rest of the family members
if(!isWildcardScanner()
&& !isMultipleMatchScanner()
&& (keys[i].getTimestamp() != chosenTimestamp)) {
break;
}
if(columnMatch(i)) {
// We only want the first result for any specific family member
if(!results.containsKey(keys[i].getColumn())) {
results.put(new Text(keys[i].getColumn()), vals[i]);
insertedItem = true;
}
}
if(!getNext(i)) {
closeSubScanner(i);
}
}
// Advance the current scanner beyond the chosen row, to
// a valid timestamp, so we're ready next time.
while((keys[i] != null)
&& ((keys[i].getRow().compareTo(chosenRow) <= 0)
|| (keys[i].getTimestamp() > this.timestamp)
|| (! columnMatch(i)))) {
getNext(i);
}
}
}
return insertedItem;
}
/**
* The user didn't want to start scanning at the first row. This method
* seeks to the requested row.
*
* @param i - which iterator to advance
* @param firstRow - seek to this row
* @return - true if this is the first row or if the row was not found
* @param i which iterator to advance
* @param firstRow seek to this row
* @return true if this is the first row or if the row was not found
*/
@Override
boolean findFirstRow(int i, Text firstRow) throws IOException {
ImmutableBytesWritable ibw = new ImmutableBytesWritable();
HStoreKey firstKey
@ -104,10 +202,9 @@ class StoreFileScanner extends HAbstractScanner {
/**
* Get the next value from the specified reader.
*
* @param i - which reader to fetch next value from
* @return - true if there is more data available
* @param i which reader to fetch next value from
* @return true if there is more data available
*/
@Override
boolean getNext(int i) throws IOException {
boolean result = false;
ImmutableBytesWritable ibw = new ImmutableBytesWritable();
@ -126,7 +223,6 @@ class StoreFileScanner extends HAbstractScanner {
}
/** Close down the indicated reader. */
@Override
void closeSubScanner(int i) {
try {
if(readers[i] != null) {

53
src/test/org/apache/hadoop/hbase/regionserver/TestHMemcache.java
View File

@ -21,6 +21,7 @@ package org.apache.hadoop.hbase.regionserver;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.rmi.UnexpectedException;
import java.util.List;
import java.util.Map;
import java.util.SortedMap;
@ -129,13 +130,13 @@ public class TestHMemcache extends TestCase {
}
}
private void runSnapshot(final Memcache hmc) {
private void runSnapshot(final Memcache hmc) throws UnexpectedException {
// Save off old state.
int oldHistorySize = hmc.snapshot.size();
hmc.snapshot();
int oldHistorySize = hmc.getSnapshot().size();
SortedMap<HStoreKey, byte[]> ss = hmc.snapshot();
// Make some assertions about what just happened.
assertTrue("History size has not increased",
oldHistorySize < hmc.snapshot.size());
assertTrue("History size has not increased", oldHistorySize < ss.size());
hmc.clearSnapshot(ss);
}
/**
@ -148,9 +149,8 @@ public class TestHMemcache extends TestCase {
for (int i = 0; i < snapshotCount; i++) {
addRows(this.hmemcache);
runSnapshot(this.hmemcache);
this.hmemcache.getSnapshot();
assertEquals("History not being cleared", 0,
this.hmemcache.snapshot.size());
SortedMap<HStoreKey, byte[]> ss = this.hmemcache.getSnapshot();
assertEquals("History not being cleared", 0, ss.size());
}
}
@ -195,6 +195,40 @@ public class TestHMemcache extends TestCase {
}
}
/** Test getNextRow from memcache
* @throws UnsupportedEncodingException
*/
public void testGetNextRow() throws UnsupportedEncodingException {
addRows(this.hmemcache);
Text closestToEmpty = this.hmemcache.getNextRow(HConstants.EMPTY_TEXT);
assertEquals(closestToEmpty, getRowName(0));
for (int i = 0; i < ROW_COUNT; i++) {
Text nr = this.hmemcache.getNextRow(getRowName(i));
if (i + 1 == ROW_COUNT) {
assertEquals(nr, null);
} else {
assertEquals(nr, getRowName(i + 1));
}
}
}
/** Test getClosest from memcache
* @throws UnsupportedEncodingException
*/
public void testGetClosest() throws UnsupportedEncodingException {
addRows(this.hmemcache);
Text closestToEmpty = this.hmemcache.getNextRow(HConstants.EMPTY_TEXT);
assertEquals(closestToEmpty, getRowName(0));
for (int i = 0; i < ROW_COUNT; i++) {
Text nr = this.hmemcache.getNextRow(getRowName(i));
if (i + 1 == ROW_COUNT) {
assertEquals(nr, null);
} else {
assertEquals(nr, getRowName(i + 1));
}
}
}
/**
* Test memcache scanner
* @throws IOException
@ -272,7 +306,4 @@ public class TestHMemcache extends TestCase {
private HStoreKey getHSKForRow(Text row) {
return new HStoreKey(row, new Text("test_col:"), HConstants.LATEST_TIMESTAMP);
}
}