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HBASE-2496 Less ArrayList churn on the scan path

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git-svn-id: https://svn.apache.org/repos/asf/hadoop/hbase/trunk@939030 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Jean-Daniel Cryans 2010-04-28 17:52:43 +00:00
parent 0c50c92879
commit 369056d691
4 changed files with 30 additions and 14 deletions
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1
CHANGES.txt
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@ -537,6 +537,7 @@ Release 0.21.0 - Unreleased
(Todd Lipcon via Stack) (Todd Lipcon via Stack)
HBASE-2393 ThriftServer instantiates a new HTable per request HBASE-2393 ThriftServer instantiates a new HTable per request
(Bogdan DRAGU via Stack) (Bogdan DRAGU via Stack)
HBASE-2496 Less ArrayList churn on the scan path
NEW FEATURES NEW FEATURES
HBASE-1961 HBase EC2 scripts HBASE-1961 HBase EC2 scripts

15
core/src/main/java/org/apache/hadoop/hbase/regionserver/ColumnCount.java
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@ -25,9 +25,9 @@ package org.apache.hadoop.hbase.regionserver;
* NOT thread-safe because it is not used in a multi-threaded context, yet. * NOT thread-safe because it is not used in a multi-threaded context, yet.
*/ */
public class ColumnCount { public class ColumnCount {
private byte [] bytes; private final byte [] bytes;
private int offset; private final int offset;
private int length; private final int length;
private int count; private int count;
/** /**
@ -97,6 +97,15 @@ public class ColumnCount {
public int increment() { public int increment() {
return ++count; return ++count;
} }
/**
* Set the current count to a new count
* @param count new count to set
*/
public void setCount(int count) {
this.count = count;
}
/** /**
* Check to see if needed to fetch more versions * Check to see if needed to fetch more versions

23
core/src/main/java/org/apache/hadoop/hbase/regionserver/ExplicitColumnTracker.java
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@ -46,11 +46,11 @@ import org.apache.hadoop.hbase.util.Bytes;
*/ */
public class ExplicitColumnTracker implements ColumnTracker { public class ExplicitColumnTracker implements ColumnTracker {
private int maxVersions; private final int maxVersions;
private List<ColumnCount> columns; private final List<ColumnCount> columns;
private final List<ColumnCount> columnsToReuse;
private int index; private int index;
private ColumnCount column; private ColumnCount column;
private NavigableSet<byte[]> origColumns;
/** /**
* Default constructor. * Default constructor.
@ -59,7 +59,11 @@ public class ExplicitColumnTracker implements ColumnTracker {
*/ */
public ExplicitColumnTracker(NavigableSet<byte[]> columns, int maxVersions) { public ExplicitColumnTracker(NavigableSet<byte[]> columns, int maxVersions) {
this.maxVersions = maxVersions; this.maxVersions = maxVersions;
this.origColumns = columns; this.columns = new ArrayList<ColumnCount>(columns.size());
this.columnsToReuse = new ArrayList<ColumnCount>(columns.size());
for(byte [] column : columns) {
this.columnsToReuse.add(new ColumnCount(column,maxVersions));
}
reset(); reset();
} }
@ -147,15 +151,16 @@ public class ExplicitColumnTracker implements ColumnTracker {
// Called between every row. // Called between every row.
public void reset() { public void reset() {
buildColumnList(this.origColumns); buildColumnList();
this.index = 0; this.index = 0;
this.column = this.columns.get(this.index); this.column = this.columns.get(this.index);
} }
private void buildColumnList(NavigableSet<byte[]> columns) { private void buildColumnList() {
this.columns = new ArrayList<ColumnCount>(columns.size()); this.columns.clear();
for(byte [] column : columns) { this.columns.addAll(this.columnsToReuse);
this.columns.add(new ColumnCount(column,maxVersions)); for(ColumnCount col : this.columns) {
col.setCount(this.maxVersions);
} }
} }
} }

5
core/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java
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@ -1815,12 +1815,12 @@ public class HRegionServer implements HConstants, HRegionInterface,
throw e; throw e;
} }
this.leases.renewLease(scannerName); this.leases.renewLease(scannerName);
List<Result> results = new ArrayList<Result>(); List<Result> results = new ArrayList<Result>(nbRows);
long currentScanResultSize = 0; long currentScanResultSize = 0;
List<KeyValue> values = new ArrayList<KeyValue>();
for (int i = 0; i < nbRows && currentScanResultSize < maxScannerResultSize; i++) { for (int i = 0; i < nbRows && currentScanResultSize < maxScannerResultSize; i++) {
requestCount.incrementAndGet(); requestCount.incrementAndGet();
// Collect values to be returned here // Collect values to be returned here
List<KeyValue> values = new ArrayList<KeyValue>();
boolean moreRows = s.next(values); boolean moreRows = s.next(values);
if (!values.isEmpty()) { if (!values.isEmpty()) {
for (KeyValue kv : values) { for (KeyValue kv : values) {
@ -1831,6 +1831,7 @@ public class HRegionServer implements HConstants, HRegionInterface,
if (!moreRows) { if (!moreRows) {
break; break;
} }
values.clear();
} }
// Below is an ugly hack where we cast the InternalScanner to be a // Below is an ugly hack where we cast the InternalScanner to be a
// HRegion.RegionScanner. The alternative is to change InternalScanner // HRegion.RegionScanner. The alternative is to change InternalScanner