Add support for ReadableByteChannel views to AdversarialPagedFile

neo4j · May 16, 2016 · 843e141 · 843e141
1 parent f9a287c
commit 843e141
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Showing 4 changed files with 28 additions and 6 deletions.
diff --git a/...impl/muninn/PagedReadableByteChannel.java → ...ecache/impl/PagedReadableByteChannel.java b/...impl/muninn/PagedReadableByteChannel.java → ...ecache/impl/PagedReadableByteChannel.java
@@ -17,7 +17,7 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-package org.neo4j.io.pagecache.impl.muninn;
+package org.neo4j.io.pagecache.impl;
 
 import java.io.IOException;
 import java.nio.ByteBuffer;
@@ -27,7 +27,7 @@
 import org.neo4j.io.pagecache.PageCursor;
 import org.neo4j.io.pagecache.PagedFile;
 
-final class PagedReadableByteChannel implements ReadableByteChannel
+public final class PagedReadableByteChannel implements ReadableByteChannel
 {
     private final PageCursor cursor;
     private boolean open = true;

diff --git a/community/io/src/main/java/org/neo4j/io/pagecache/impl/muninn/MuninnPagedFile.java b/community/io/src/main/java/org/neo4j/io/pagecache/impl/muninn/MuninnPagedFile.java
@@ -30,6 +30,7 @@
 import org.neo4j.io.pagecache.PageSwapper;
 import org.neo4j.io.pagecache.PageSwapperFactory;
 import org.neo4j.io.pagecache.PagedFile;
+import org.neo4j.io.pagecache.impl.PagedReadableByteChannel;
 import org.neo4j.io.pagecache.tracing.FlushEvent;
 import org.neo4j.io.pagecache.tracing.FlushEventOpportunity;
 import org.neo4j.io.pagecache.tracing.MajorFlushEvent;

diff --git a/community/io/src/test/java/org/neo4j/adversaries/pagecache/AdversarialPagedFile.java b/community/io/src/test/java/org/neo4j/adversaries/pagecache/AdversarialPagedFile.java
@@ -28,6 +28,7 @@
 import org.neo4j.io.pagecache.IOLimiter;
 import org.neo4j.io.pagecache.PageCursor;
 import org.neo4j.io.pagecache.PagedFile;
+import org.neo4j.io.pagecache.impl.PagedReadableByteChannel;
 
 /**
  * A {@linkplain PagedFile paged file} that wraps another paged file and an {@linkplain Adversary adversary} to provide
@@ -37,12 +38,12 @@
  * or {@link IOException} like {@link FileNotFoundException}.
  */
 @SuppressWarnings( "unchecked" )
-class AdversarialPagedFile implements PagedFile
+public class AdversarialPagedFile implements PagedFile
 {
     private final PagedFile delegate;
     private final Adversary adversary;
 
-    AdversarialPagedFile( PagedFile delegate, Adversary adversary )
+    public AdversarialPagedFile( PagedFile delegate, Adversary adversary )
     {
         this.delegate = Objects.requireNonNull( delegate );
         this.adversary = Objects.requireNonNull( adversary );
@@ -95,8 +96,8 @@ public void close() throws IOException
     }
 
     @Override
-    public ReadableByteChannel openReadableByteChannel()
+    public ReadableByteChannel openReadableByteChannel() throws IOException
     {
-        throw new UnsupportedOperationException( "Not implemented for AdversarialPagedFile" );
+        return new PagedReadableByteChannel( this );
     }
 }
diff --git a/community/io/src/test/java/org/neo4j/io/pagecache/PageCacheTest.java b/community/io/src/test/java/org/neo4j/io/pagecache/PageCacheTest.java
@@ -48,6 +48,8 @@
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicReference;
 
+import org.neo4j.adversaries.RandomAdversary;
+import org.neo4j.adversaries.pagecache.AdversarialPagedFile;
 import org.neo4j.concurrent.BinaryLatch;
 import org.neo4j.function.ThrowingConsumer;
 import org.neo4j.graphdb.mockfs.DelegatingFileSystemAbstraction;
@@ -4029,6 +4031,24 @@ public void readableByteChannelMustReadAllBytesInFile() throws Exception
         }
     }
 
+    @RepeatRule.Repeat( times = 20 )
+    @Test
+    public void readableByteChannelMustReadAllBytesInFileConsistently() throws Exception
+    {
+        File file = file( "a" );
+        generateFileWithRecords( file, recordCount, recordSize );
+        getPageCache( fs, maxPages, pageCachePageSize, PageCacheTracer.NULL );
+        try ( PagedFile pf = pageCache.map( file, filePageSize ) )
+        {
+            RandomAdversary adversary = new RandomAdversary( 0.9, 0, 0 );
+            AdversarialPagedFile apf = new AdversarialPagedFile( pf, adversary );
+            try ( ReadableByteChannel channel = apf.openReadableByteChannel() )
+            {
+                verifyRecordsInFile( channel, recordCount );
+            }
+        }
+    }
+
     @Test( expected = ClosedChannelException.class )
     public void readingFromClosedReadableByteChannelMustThrow() throws Exception
     {