Improve scan speed by avoiding division and modulus

neo4j · May 25, 2018 · 83874f8 · 83874f8
1 parent 571a740
commit 83874f8
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Showing 9 changed files with 114 additions and 13 deletions.
diff --git a/community/kernel/src/main/java/org/neo4j/kernel/impl/newapi/AllStoreHolder.java b/community/kernel/src/main/java/org/neo4j/kernel/impl/newapi/AllStoreHolder.java
@@ -706,6 +706,12 @@ void node( NodeRecord record, long reference, PageCursor pageCursor )
         nodes.getRecordByCursor( reference, record, RecordLoad.CHECK, pageCursor );
     }
 
+    @Override
+    void nodeAdvance( NodeRecord record, PageCursor pageCursor )
+    {
+        nodes.nextRecordByCursor( record, RecordLoad.CHECK, pageCursor );
+    }
+
     @Override
     void relationship( RelationshipRecord record, long reference, PageCursor pageCursor )
     {

diff --git a/community/kernel/src/main/java/org/neo4j/kernel/impl/newapi/DefaultNodeCursor.java b/community/kernel/src/main/java/org/neo4j/kernel/impl/newapi/DefaultNodeCursor.java
@@ -44,6 +44,7 @@ class DefaultNodeCursor extends NodeRecord implements NodeCursor
     private PageCursor pageCursor;
     private long next;
     private long highMark;
+    private long nextStoreReference;
     private HasChanges hasChanges = HasChanges.MAYBE;
     private LongSet addedNodes;
 
@@ -67,6 +68,7 @@ void scan( Read read )
         }
         this.next = 0;
         this.highMark = read.nodeHighMark();
+        this.nextStoreReference = NO_ID;
         this.read = read;
         this.hasChanges = HasChanges.MAYBE;
         this.addedNodes = LongSets.immutable.empty();
@@ -85,6 +87,7 @@ void single( long reference, Read read )
         this.next = reference;
         //This marks the cursor as a "single cursor"
         this.highMark = NO_ID;
+        this.nextStoreReference = NO_ID;
         this.read = read;
         this.hasChanges = HasChanges.MAYBE;
         this.addedNodes = LongSets.immutable.empty();
@@ -225,9 +228,16 @@ else if ( hasChanges && txs.nodeIsDeletedInThisTx( next ) )
                 next++;
                 setInUse( false );
             }
+            else if ( nextStoreReference == next )
+            {
+                read.nodeAdvance( this, pageCursor );
+                next++;
+                nextStoreReference++;
+            }
             else
             {
                 read.node( this, next++, pageCursor );
+                nextStoreReference = next;
             }
 
             if ( next > highMark )

diff --git a/community/kernel/src/main/java/org/neo4j/kernel/impl/newapi/Read.java b/community/kernel/src/main/java/org/neo4j/kernel/impl/newapi/Read.java
@@ -587,6 +587,8 @@ public final void futureRelationshipPropertyReferenceRead( long reference )
 
     abstract void node( NodeRecord record, long reference, PageCursor pageCursor );
 
+    abstract void nodeAdvance( NodeRecord record, PageCursor pageCursor );
+
     abstract void relationship( RelationshipRecord record, long reference, PageCursor pageCursor );
 
     abstract void relationshipFull( RelationshipRecord record, long reference, PageCursor pageCursor );

diff --git a/community/kernel/src/main/java/org/neo4j/kernel/impl/store/CommonAbstractStore.java b/community/kernel/src/main/java/org/neo4j/kernel/impl/store/CommonAbstractStore.java
@@ -1042,7 +1042,6 @@ public void getRecordByCursor( long id, RECORD record, RecordLoad mode, PageCurs
         {
             throw new UnderlyingStorageException( e );
         }
-
     }
 
     void readIntoRecord( long id, RECORD record, RecordLoad mode, PageCursor cursor ) throws IOException
@@ -1055,24 +1054,58 @@ void readIntoRecord( long id, RECORD record, RecordLoad mode, PageCursor cursor
         int offset = offsetForId( id );
         if ( cursor.next( pageId ) )
         {
-            // There is a page in the store that covers this record, go read it
             cursor.setOffset( offset );
-            cursor.mark();
-            do
-            {
-                prepareForReading( cursor, record );
-                recordFormat.read( record, cursor, mode, recordSize );
-            }
-            while ( cursor.shouldRetry() );
-            checkForDecodingErrors( cursor, id, mode );
-            verifyAfterReading( record, mode );
+            readRecordFromPage( id, record, mode, cursor );
         }
         else
         {
             verifyAfterNotRead( record, mode );
         }
     }
 
+    @Override
+    public void nextRecordByCursor( RECORD record, RecordLoad mode, PageCursor cursor ) throws UnderlyingStorageException
+    {
+        assert cursor.getOffset() % recordSize == 0 : "Cursor offset is record start";
+        assert cursor.getCurrentPageId() >= -1 : "Pages are assumed to be positive or -1 if not initialized";
+
+        try
+        {
+            int offset = cursor.getOffset();
+            long id = record.getId() + 1;
+            record.setId( id );
+            long pageId = cursor.getCurrentPageId();
+            if ( offset >= storeFile.pageSize() || pageId < 0 )
+            {
+                if ( !cursor.next( pageId + 1 ) )
+                {
+                    verifyAfterNotRead( record, mode );
+                    return;
+                }
+                cursor.setOffset( 0 );
+            }
+            readRecordFromPage( id, record, mode, cursor );
+        }
+        catch ( IOException e )
+        {
+            throw new UnderlyingStorageException( e );
+        }
+    }
+
+    private void readRecordFromPage( long id, RECORD record, RecordLoad mode, PageCursor cursor )
+            throws IOException
+    {
+        cursor.mark();
+        do
+        {
+            prepareForReading( cursor, record );
+            recordFormat.read( record, cursor, mode, recordSize );
+        }
+        while ( cursor.shouldRetry() );
+        checkForDecodingErrors( cursor, id, mode );
+        verifyAfterReading( record, mode );
+    }
+
     @Override
     public void updateRecord( RECORD record )
     {

diff --git a/community/kernel/src/main/java/org/neo4j/kernel/impl/store/RecordStore.java b/community/kernel/src/main/java/org/neo4j/kernel/impl/store/RecordStore.java
@@ -130,6 +130,21 @@ public interface RecordStore<RECORD extends AbstractBaseRecord> extends IdSequen
      */
     void getRecordByCursor( long id, RECORD target, RecordLoad mode, PageCursor cursor ) throws InvalidRecordException;
 
+    /**
+     * Reads a record from the store into {@code target}, see
+     * {@link RecordStore#getRecord(long, AbstractBaseRecord, RecordLoad)}.
+     * <p>
+     * This method requires that the cursor page and offset point to the first byte of the record in target on calling.
+     * The provided page cursor will be used to get the record, and in doing this it will be redirected to the
+     * next page if the input record was the last on it's page.
+     *
+     * @param target the record to fill.
+     * @param mode loading behaviour, read more in {@link RecordStore#getRecord(long, AbstractBaseRecord, RecordLoad)}.
+     * @param cursor the PageCursor to use for record loading.
+     * @throws InvalidRecordException if record not in use and the {@code mode} allows for throwing.
+     */
+    void nextRecordByCursor( RECORD target, RecordLoad mode, PageCursor cursor ) throws InvalidRecordException;
+
     /**
      * For stores that have other stores coupled underneath, the "top level" record will have a flag
      * saying whether or not it's light. Light means that no records from the coupled store have been loaded yet.
@@ -295,6 +310,12 @@ public void getRecordByCursor( long id, R target, RecordLoad mode, PageCursor cu
             actual.getRecordByCursor( id, target, mode, cursor );
         }
 
+        @Override
+        public void nextRecordByCursor( R target, RecordLoad mode, PageCursor cursor ) throws InvalidRecordException
+        {
+            actual.nextRecordByCursor( target, mode, cursor );
+        }
+
         @Override
         public Collection<R> getRecords( long firstId, RecordLoad mode ) throws InvalidRecordException
         {

diff --git a/...ty/kernel/src/main/java/org/neo4j/kernel/impl/store/format/standard/NodeRecordFormat.java b/...ty/kernel/src/main/java/org/neo4j/kernel/impl/store/format/standard/NodeRecordFormat.java
@@ -19,8 +19,6 @@
  */
 package org.neo4j.kernel.impl.store.format.standard;
 
-import java.io.IOException;
-
 import org.neo4j.io.pagecache.PageCursor;
 import org.neo4j.kernel.impl.store.format.BaseOneByteHeaderRecordFormat;
 import org.neo4j.kernel.impl.store.format.BaseRecordFormat;
@@ -32,6 +30,7 @@ public class NodeRecordFormat extends BaseOneByteHeaderRecordFormat<NodeRecord>
 {
     // in_use(byte)+next_rel_id(int)+next_prop_id(int)+labels(5)+extra(byte)
     public static final int RECORD_SIZE = 15;
+    private static final int HEADER_SIZE = 1;
 
     public NodeRecordFormat()
     {
@@ -68,6 +67,11 @@ public void read( NodeRecord record, PageCursor cursor, RecordLoad mode, int rec
                     BaseRecordFormat.longFromIntAndMod( nextProp, propModifier ), dense,
                     BaseRecordFormat.longFromIntAndMod( nextRel, relModifier ), labels );
         }
+        else
+        {
+            int nextOffset = cursor.getOffset() + recordSize - HEADER_SIZE;
+            cursor.setOffset( nextOffset );
+        }
     }
 
     @Override

diff --git a/community/kernel/src/main/java/org/neo4j/storageengine/api/StorageReader.java b/community/kernel/src/main/java/org/neo4j/storageengine/api/StorageReader.java
@@ -602,6 +602,22 @@ interface RecordReads<RECORD>
         void getRecordByCursor( long reference, RECORD record, RecordLoad mode, PageCursor cursor )
                 throws InvalidRecordException;
 
+        /**
+         * Reads a record from the store into {@code target}, see
+         * {@link RecordStore#getRecord(long, AbstractBaseRecord, RecordLoad)}.
+         * <p>
+         * This method requires that the cursor page and offset point to the first byte of the record in target on calling.
+         * The provided page cursor will be used to get the record, and in doing this it will be redirected to the
+         * next page if the input record was the last on it's page.
+         *
+         * @param record the record to fill.
+         * @param mode loading behaviour, read more in {@link RecordStore#getRecord(long, AbstractBaseRecord, RecordLoad)}.
+         * @param cursor the PageCursor to use for record loading.
+         * @throws InvalidRecordException if record not in use and the {@code mode} allows for throwing.
+         */
+        void nextRecordByCursor( RECORD record, RecordLoad mode, PageCursor cursor )
+                throws InvalidRecordException;
+
         long getHighestPossibleIdInUse();
     }
 

diff --git a/community/kernel/src/test/java/org/neo4j/kernel/impl/newapi/MockStore.java b/community/kernel/src/test/java/org/neo4j/kernel/impl/newapi/MockStore.java
@@ -579,6 +579,12 @@ void node( NodeRecord record, long reference, PageCursor pageCursor )
         initialize( record, reference, nodes );
     }
 
+    @Override
+    void nodeAdvance( NodeRecord record, PageCursor pageCursor )
+    {
+        initialize( record, record.getId() + 1, nodes );
+    }
+
     @Override
     void relationship( RelationshipRecord record, long reference, PageCursor pageCursor )
     {

diff --git a/...src/main/java/org/neo4j/kernel/impl/store/format/highlimit/BaseHighLimitRecordFormat.java b/...src/main/java/org/neo4j/kernel/impl/store/format/highlimit/BaseHighLimitRecordFormat.java
@@ -160,6 +160,9 @@ public void read( RECORD record, PageCursor primaryCursor, RecordLoad mode, int
             record.setUseFixedReferences( isUseFixedReferences( headerByte ) );
             doReadInternal( record, primaryCursor, recordSize, headerByte, inUse );
         }
+
+        // Set cursor offset to next record to prepare next read in case of scanning.
+        primaryCursor.setOffset( primaryStartOffset + recordSize );
     }
 
     private boolean isUseFixedReferences( byte headerByte )