Differentiate between entry index and work address

neo4j · Dec 1, 2017 · fad926b · fad926b
1 parent 9614a29
commit fad926b
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Showing 6 changed files with 29 additions and 26 deletions.
diff --git a/...ections/src/main/java/org/neo4j/collection/primitive/hopscotch/IntArrayBasedKeyTable.java b/...ections/src/main/java/org/neo4j/collection/primitive/hopscotch/IntArrayBasedKeyTable.java
@@ -27,12 +27,15 @@
  * Table implementation for handling primitive int/long keys and hop bits. The quantized unit is int so a
  * multiple of ints will be used for every entry.
  *
+ * In this class, <code>index</code> refers to the index of an entry (key + value + hop bits), while
+ * <code>address</code> refers to the position of an int word in the internal <code>table</code>.
+ *
  * @param <VALUE> essentially ignored, since no values are stored in this table. Although subclasses can.
  */
 public abstract class IntArrayBasedKeyTable<VALUE> extends PowerOfTwoQuantizedTable<VALUE>
 {
     protected int[] table;
-    protected final VALUE singleValue;
+    protected final VALUE singleValue; // used as a pointer to pass around a primitive value in concrete subclasses
     private final int itemsPerEntry;
 
     protected IntArrayBasedKeyTable( int capacity, int itemsPerEntry, int h, VALUE singleValue )
@@ -72,17 +75,17 @@ protected long getLong( int actualIndex )
     @Override
     public void put( int index, long key, VALUE value )
     {
-        int actualIndex = index( index );
-        internalPut( actualIndex, key, value );
+        int address = address( index );
+        internalPut( address, key, value );
         size++;
     }
 
     @Override
     public VALUE remove( int index )
     {
-        int actualIndex = index( index );
+        int address = address( index );
         VALUE value = value( index );
-        internalRemove( actualIndex );
+        internalRemove( address );
         size--;
         return value;
     }
@@ -91,13 +94,13 @@ public VALUE remove( int index )
     public long move( int fromIndex, int toIndex )
     {
         long key = key( fromIndex );
-        int actualFromIndex = index( fromIndex );
-        int actualToIndex = index( toIndex );
+        int fromAddress = address( fromIndex );
+        int toAddress = address( toIndex );
         for ( int i = 0; i < itemsPerEntry - 1; i++ )
         {
-            int tempValue = table[actualFromIndex + i];
-            table[actualFromIndex + i] = table[actualToIndex + i];
-            table[actualToIndex + i] = tempValue;
+            int tempValue = table[fromAddress + i];
+            table[fromAddress + i] = table[toAddress + i];
+            table[toAddress + i] = tempValue;
         }
         return key;
     }
@@ -124,7 +127,7 @@ public VALUE putValue( int index, VALUE value )
     @Override
     public long hopBits( int index )
     {
-        return ~(table[index( index ) + itemsPerEntry - 1] | 0xFFFFFFFF00000000L);
+        return ~(table[address( index ) + itemsPerEntry - 1] | 0xFFFFFFFF00000000L);
     }
 
     private int hopBit( int hd )
@@ -135,22 +138,22 @@ private int hopBit( int hd )
     @Override
     public void putHopBit( int index, int hd )
     {
-        table[index( index ) + itemsPerEntry - 1] &= ~hopBit( hd );
+        table[address( index ) + itemsPerEntry - 1] &= ~hopBit( hd );
     }
 
     @Override
     public void moveHopBit( int index, int hd, int delta )
     {
-        table[index( index ) + itemsPerEntry - 1] ^= hopBit( hd ) | hopBit( hd + delta );
+        table[address( index ) + itemsPerEntry - 1] ^= hopBit( hd ) | hopBit( hd + delta );
     }
 
     @Override
     public void removeHopBit( int index, int hd )
     {
-        table[index( index ) + itemsPerEntry - 1] |= hopBit( hd );
+        table[address( index ) + itemsPerEntry - 1] |= hopBit( hd );
     }
 
-    protected int index( int index )
+    protected int address( int index )
     {
         return index * itemsPerEntry;
     }

diff --git a/...lections/src/main/java/org/neo4j/collection/primitive/hopscotch/IntKeyLongValueTable.java b/...lections/src/main/java/org/neo4j/collection/primitive/hopscotch/IntKeyLongValueTable.java
@@ -31,7 +31,7 @@ public IntKeyLongValueTable( int capacity )
     @Override
     public long key( int index )
     {
-        return table[index( index )];
+        return table[address( index )];
     }
 
     @Override
@@ -44,14 +44,14 @@ protected void internalPut( int actualIndex, long key, long[] valueHolder )
     @Override
     public long[] value( int index )
     {
-        singleValue[0] = getLong( index( index ) + 1 );
+        singleValue[0] = getLong( address( index ) + 1 );
         return singleValue;
     }
 
     @Override
     public long[] putValue( int index, long[] value )
     {
-        singleValue[0] = putLong( index( index ) + 1, value[0] );
+        singleValue[0] = putLong( address( index ) + 1, value[0] );
         return singleValue;
     }
 

diff --git a/...itive-collections/src/main/java/org/neo4j/collection/primitive/hopscotch/IntKeyTable.java b/...itive-collections/src/main/java/org/neo4j/collection/primitive/hopscotch/IntKeyTable.java
@@ -29,7 +29,7 @@ public IntKeyTable( int capacity, VALUE singleValue )
     @Override
     public long key( int index )
     {
-        return table[index( index )];
+        return table[address( index )];
     }
 
     @Override

diff --git a/...lections/src/main/java/org/neo4j/collection/primitive/hopscotch/LongKeyIntValueTable.java b/...lections/src/main/java/org/neo4j/collection/primitive/hopscotch/LongKeyIntValueTable.java
@@ -31,7 +31,7 @@ public LongKeyIntValueTable( int capacity )
     @Override
     public long key( int index )
     {
-        return getLong( index( index ) );
+        return getLong( address( index ) );
     }
 
     @Override
@@ -44,7 +44,7 @@ protected void internalPut( int actualIndex, long key, int[] value )
     @Override
     public int[] putValue( int index, int[] value )
     {
-        int actualIndex = index( index ) + 2;
+        int actualIndex = address( index ) + 2;
         int previous = table[actualIndex];
         table[actualIndex] = value[0];
         return pack( previous );
@@ -53,7 +53,7 @@ public int[] putValue( int index, int[] value )
     @Override
     public int[] value( int index )
     {
-        return pack( table[index( index ) + 2] );
+        return pack( table[address( index ) + 2] );
     }
 
     @Override

diff --git a/...ections/src/main/java/org/neo4j/collection/primitive/hopscotch/LongKeyLongValueTable.java b/...ections/src/main/java/org/neo4j/collection/primitive/hopscotch/LongKeyLongValueTable.java
@@ -32,7 +32,7 @@ public LongKeyLongValueTable( int capacity )
     @Override
     public long key( int index )
     {
-        return getLong( index( index ) );
+        return getLong( address( index ) );
     }
 
     @Override
@@ -45,7 +45,7 @@ protected void internalPut( int actualIndex, long key, long[] value )
     @Override
     public long[] putValue( int index, long[] value )
     {
-        int actualValueIndex = index( index ) + 2;
+        int actualValueIndex = address( index ) + 2;
         long previous = getLong( actualValueIndex );
         putLong( actualValueIndex, value[0] );
         return pack( previous );
@@ -54,7 +54,7 @@ public long[] putValue( int index, long[] value )
     @Override
     public long[] value( int index )
     {
-        return pack( getLong( index( index ) + 2 ) );
+        return pack( getLong( address( index ) + 2 ) );
     }
 
     @Override

diff --git a/...tive-collections/src/main/java/org/neo4j/collection/primitive/hopscotch/LongKeyTable.java b/...tive-collections/src/main/java/org/neo4j/collection/primitive/hopscotch/LongKeyTable.java
@@ -30,7 +30,7 @@ public LongKeyTable( int capacity, VALUE singleValue )
     @Override
     public long key( int index )
     {
-        return getLong( index( index ) );
+        return getLong( address( index ) );
     }
 
     @Override