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Merged
merged 1 commit into from
Nov 8, 2017
Merged

Simplify the logic of compute added and removed addresses in routing table #1

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28 changes: 20 additions & 8 deletions driver/src/main/java/org/neo4j/driver/internal/cluster/ClusterRoutingTable.java
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Original file line number Diff line number Diff line change
Expand Up @@ -43,8 +43,7 @@ public class ClusterRoutingTable implements RoutingTable
public ClusterRoutingTable( Clock clock, BoltServerAddress... routingAddresses )
{
this( clock );
routers.update( new LinkedHashSet<>( asList( routingAddresses ) ), new HashSet<BoltServerAddress>(),
new HashSet<BoltServerAddress>() );
routers.update( new LinkedHashSet<>( asList( routingAddresses ) ));
}

private ClusterRoutingTable( Clock clock )
Expand All @@ -66,16 +65,29 @@ public boolean isStaleFor( AccessMode mode )
mode == AccessMode.WRITE && writers.size() == 0;
}

private Set<BoltServerAddress> servers()
{
Set<BoltServerAddress> servers = new HashSet<>();
servers.addAll( readers.servers() );
servers.addAll( writers.servers() );
servers.addAll( routers.servers() );
return servers;
}

@Override
public synchronized RoutingTableChange update( ClusterComposition cluster )
{
expirationTimeout = cluster.expirationTimestamp();
// todo: what if server is added as reader and removed as writer? we should not treat it as removed
Set<BoltServerAddress> added = new HashSet<>();
Set<BoltServerAddress> removed = new HashSet<>();
readers.update( cluster.readers(), added, removed );
writers.update( cluster.writers(), added, removed );
routers.update( cluster.routers(), added, removed );
Set<BoltServerAddress> pre = servers();
readers.update( cluster.readers() );
writers.update( cluster.writers() );
routers.update( cluster.routers() );
Set<BoltServerAddress> cur = servers();

Set<BoltServerAddress> added = new HashSet<>( cur );
Set<BoltServerAddress> removed = new HashSet<>( pre );
added.removeAll( pre );
removed.removeAll( cur );
return new RoutingTableChange( added, removed );
}

Expand Down
60 changes: 8 additions & 52 deletions driver/src/main/java/org/neo4j/driver/internal/cluster/RoundRobinAddressSet.java
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Original file line number Diff line number Diff line change
Expand Up @@ -19,7 +19,7 @@
package org.neo4j.driver.internal.cluster;

import java.util.Arrays;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;
import java.util.concurrent.atomic.AtomicInteger;

Expand All @@ -46,6 +46,11 @@ public BoltServerAddress next()
return addresses[next( addresses.length )];
}

public Set<BoltServerAddress> servers()
{
return new HashSet<>( Arrays.asList( addresses ) );
}

int next( int divisor )
{
int index = offset.getAndIncrement();
Expand All @@ -56,58 +61,9 @@ int next( int divisor )
return index % divisor;
}

public synchronized void update( Set<BoltServerAddress> addresses, Set<BoltServerAddress> added,
Set<BoltServerAddress> removed )
public synchronized void update( Set<BoltServerAddress> addresses )
{
BoltServerAddress[] prev = this.addresses;
if ( addresses.isEmpty() )
{
this.addresses = NONE;
Collections.addAll( removed, prev );
return;
}
if ( prev.length == 0 )
{
this.addresses = addresses.toArray( NONE );
Collections.addAll( added, this.addresses );
return;
}
BoltServerAddress[] copy = null;
if ( addresses.size() != prev.length )
{
copy = new BoltServerAddress[addresses.size()];
}
int j = 0;
for ( int i = 0; i < prev.length; i++ )
{
if ( addresses.remove( prev[i] ) )
{
if ( copy != null )
{
copy[j++] = prev[i];
}
}
else
{
removed.add( prev[i] );
if ( copy == null )
{
copy = new BoltServerAddress[prev.length];
System.arraycopy( prev, 0, copy, 0, i );
j = i;
}
}
}
if ( copy == null )
{
return;
}
for ( BoltServerAddress address : addresses )
{
copy[j++] = address;
added.add( address );
}
this.addresses = copy;
this.addresses = addresses.toArray( NONE );
}

public synchronized void remove( BoltServerAddress address )
Expand Down
16 changes: 16 additions & 0 deletions driver/src/test/java/org/neo4j/driver/internal/cluster/ClusterRoutingTableTest.java
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Original file line number Diff line number Diff line change
Expand Up @@ -215,4 +215,20 @@ public void shouldReturnCorrectChangeWhenUpdated()
assertEquals( 2, change.removed().size() );
assertThat( change.removed(), containsInAnyOrder( A, D ) );
}

@Test
public void shouldNotRemoveServerIfPreWriterNowReader()
{
ClusterRoutingTable routingTable = new ClusterRoutingTable( new FakeClock() );
routingTable.update( createClusterComposition( singletonList( A ), singletonList( B ), singletonList( C ) ) );

ClusterComposition newComposition =
createClusterComposition( singletonList( D ), singletonList( E ), singletonList( B ) );
RoutingTableChange change = routingTable.update( newComposition );

assertEquals( 2, change.added().size() );
assertThat( change.added(), containsInAnyOrder( D, E ) );
assertEquals( 2, change.removed().size() );
assertThat( change.removed(), containsInAnyOrder( A, C ) );
}
}
3 changes: 1 addition & 2 deletions driver/src/test/java/org/neo4j/driver/internal/cluster/LoadBalancerTest.java
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Original file line number Diff line number Diff line change
Expand Up @@ -341,8 +341,7 @@ private static RoutingTable newStaleRoutingTableMock( AccessMode mode )
when( routingTable.update( any( ClusterComposition.class ) ) ).thenReturn( RoutingTableChange.EMPTY );

RoundRobinAddressSet addresses = new RoundRobinAddressSet();
addresses.update( new HashSet<>( singletonList( LOCAL_DEFAULT ) ), new HashSet<BoltServerAddress>(),
new HashSet<BoltServerAddress>() );
addresses.update( new HashSet<>( singletonList( LOCAL_DEFAULT ) ));
when( routingTable.readers() ).thenReturn( addresses );
when( routingTable.writers() ).thenReturn( addresses );

Expand Down
113 changes: 6 additions & 107 deletions driver/src/test/java/org/neo4j/driver/internal/cluster/RoundRobinAddressSetTest.java
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Expand Up @@ -21,15 +21,13 @@
import org.junit.Test;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import org.neo4j.driver.internal.net.BoltServerAddress;

import static java.util.Arrays.asList;
import static java.util.Collections.singleton;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotEquals;
import static org.junit.Assert.assertNull;
Expand Down Expand Up @@ -57,7 +55,7 @@ public void shouldReturnRoundRobin() throws Exception
new BoltServerAddress( "two" ),
new BoltServerAddress( "tre" ) ) );

set.update( addresses, new HashSet<BoltServerAddress>(), new HashSet<BoltServerAddress>() );
set.update( addresses );

// when
BoltServerAddress a = set.next();
Expand Down Expand Up @@ -85,7 +83,7 @@ public void shouldPreserveOrderWhenAdding() throws Exception
new BoltServerAddress( "two" ),
new BoltServerAddress( "tre" ) ) );
RoundRobinAddressSet set = new RoundRobinAddressSet();
set.update( servers, new HashSet<BoltServerAddress>(), new HashSet<BoltServerAddress>() );
set.update( servers );

List<BoltServerAddress> order = new ArrayList<>();
for ( int i = 3 * 4 + 1; i-- > 0; )
Expand All @@ -100,7 +98,7 @@ public void shouldPreserveOrderWhenAdding() throws Exception

// when
servers.add( new BoltServerAddress( "fyr" ) );
set.update( servers, new HashSet<BoltServerAddress>(), new HashSet<BoltServerAddress>() );
set.update( servers );

// then
assertEquals( order.get( 1 ), set.next() );
Expand All @@ -126,7 +124,7 @@ public void shouldPreserveOrderWhenRemoving() throws Exception
new BoltServerAddress( "two" ),
new BoltServerAddress( "tre" ) ) );
RoundRobinAddressSet set = new RoundRobinAddressSet();
set.update( servers, new HashSet<BoltServerAddress>(), new HashSet<BoltServerAddress>() );
set.update( servers );

List<BoltServerAddress> order = new ArrayList<>();
for ( int i = 3 * 2 + 1; i-- > 0; )
Expand Down Expand Up @@ -158,7 +156,7 @@ public void shouldPreserveOrderWhenRemovingThroughUpdate() throws Exception
new BoltServerAddress( "two" ),
new BoltServerAddress( "tre" ) ) );
RoundRobinAddressSet set = new RoundRobinAddressSet();
set.update( servers, new HashSet<BoltServerAddress>(), new HashSet<BoltServerAddress>() );
set.update( servers );

List<BoltServerAddress> order = new ArrayList<>();
for ( int i = 3 * 2 + 1; i-- > 0; )
Expand All @@ -173,7 +171,7 @@ public void shouldPreserveOrderWhenRemovingThroughUpdate() throws Exception

// when
servers.remove( order.get( 1 ) );
set.update( servers, new HashSet<BoltServerAddress>(), new HashSet<BoltServerAddress>() );
set.update( servers );

// then
assertEquals( order.get( 2 ), set.next() );
Expand All @@ -182,106 +180,7 @@ public void shouldPreserveOrderWhenRemovingThroughUpdate() throws Exception
assertEquals( order.get( 0 ), set.next() );
}

@Test
public void shouldRecordRemovedAddressesWhenUpdating() throws Exception
{
// given
RoundRobinAddressSet set = new RoundRobinAddressSet();
Set<BoltServerAddress> addresses = new HashSet<>( asList(
new BoltServerAddress( "one" ),
new BoltServerAddress( "two" ),
new BoltServerAddress( "tre" ) ) );
set.update( addresses, new HashSet<BoltServerAddress>(), new HashSet<BoltServerAddress>() );

// when
Set<BoltServerAddress> removed = new HashSet<>();
Set<BoltServerAddress> newAddresses = new HashSet<>( asList(
new BoltServerAddress( "one" ),
new BoltServerAddress( "two" ),
new BoltServerAddress( "fyr" ) ) );
set.update( newAddresses, new HashSet<BoltServerAddress>(), removed );

// then
assertEquals( singleton( new BoltServerAddress( "tre" ) ), removed );
}

@Test
public void shouldRecordRemovedAddressesWhenUpdateIsEmpty()
{
RoundRobinAddressSet set = new RoundRobinAddressSet();
Set<BoltServerAddress> addresses = new HashSet<>( asList(
new BoltServerAddress( "one" ),
new BoltServerAddress( "two" ) ) );
set.update( addresses, new HashSet<BoltServerAddress>(), new HashSet<BoltServerAddress>() );

Set<BoltServerAddress> update = Collections.emptySet();
Set<BoltServerAddress> removed = new HashSet<>();
set.update( update, new HashSet<BoltServerAddress>(), removed );

assertEquals( addresses, removed );
}

@Test
public void shouldRecordAddedAddressesWhenUpdatingAnEmptySet()
{
RoundRobinAddressSet set = new RoundRobinAddressSet();

Set<BoltServerAddress> added1 = new HashSet<>();
Set<BoltServerAddress> addresses1 = new HashSet<>( asList(
new BoltServerAddress( "one" ),
new BoltServerAddress( "two" ),
new BoltServerAddress( "tre" ) ) );
set.update( addresses1, added1, new HashSet<BoltServerAddress>() );

assertEquals( addresses1, added1 );
}

@Test
public void shouldRecordAddedAddressesWhenUpdating()
{
RoundRobinAddressSet set = new RoundRobinAddressSet();

Set<BoltServerAddress> addresses1 = new HashSet<>( asList(
new BoltServerAddress( "one" ),
new BoltServerAddress( "two" ),
new BoltServerAddress( "tre" ) ) );
set.update( addresses1, new HashSet<BoltServerAddress>(), new HashSet<BoltServerAddress>() );

Set<BoltServerAddress> added = new HashSet<>();
Set<BoltServerAddress> newAddresses = new HashSet<>( asList(
new BoltServerAddress( "one" ),
new BoltServerAddress( "tre" ),
new BoltServerAddress( "four" ) ) );
set.update( newAddresses, added, new HashSet<BoltServerAddress>() );

assertEquals( singleton( new BoltServerAddress( "four" ) ), added );
}

@Test
public void shouldRecordBothAddedAndRemovedAddressesWhenUpdating()
{
RoundRobinAddressSet set = new RoundRobinAddressSet();

Set<BoltServerAddress> addresses1 = new HashSet<>( asList(
new BoltServerAddress( "one" ),
new BoltServerAddress( "two" ),
new BoltServerAddress( "three" ) ) );
set.update( addresses1, new HashSet<BoltServerAddress>(), new HashSet<BoltServerAddress>() );

Set<BoltServerAddress> newAddresses = new HashSet<>( asList(
new BoltServerAddress( "two" ),
new BoltServerAddress( "four" ),
new BoltServerAddress( "five" ) ) );

Set<BoltServerAddress> added = new HashSet<>();
Set<BoltServerAddress> removed = new HashSet<>();
set.update( newAddresses, added, removed );

assertEquals(
new HashSet<>( asList( new BoltServerAddress( "four" ), new BoltServerAddress( "five" ) ) ), added );
assertEquals(
new HashSet<>( asList( new BoltServerAddress( "one" ), new BoltServerAddress( "three" ) ) ), removed );
}

@Test
public void shouldPreserveOrderEvenWhenIntegerOverflows() throws Exception
Expand Down