More tests and docs about ByteArray

community/kernel/src/main/java/org/neo4j/unsafe/impl/batchimport/cache/ByteArray.java

@@ -22,36 +22,135 @@
 /**
  * Abstraction of a {@code byte[]} so that different implementations can be plugged in, for example
  * off-heap, dynamically growing, or other implementations. This interface is slightly different than
- * {@link IntArray} and {@link LongArray} in that one item in the array isn't necessarily just a byte,
- * instead item size can be set to any number and the bytes in an item can be read and written as other
+ * {@link IntArray} and {@link LongArray} in that one index in the array isn't necessarily just a byte,
+ * instead item size can be set to any number and the bytes in an index can be read and written as other
  * number representations like {@link #setInt(long, int, int) int} or {@link #setLong(long, int, long) long},
- * even a special {@link #set6BLong(long, int, long) 6B long}. More can easily be added on demand.
+ * even a special {@link #set6ByteLong(long, int, long) 6B long}. More can easily be added on demand.
+ *
+ * Each index in the array can hold multiple values, each at its own offset (starting from 0 at each index), e.g.
+ * an array could have items holding values <pre>byte, int, short, long</pre>, where:
+ * - the byte would be accessed using offset=0
+ * - the int would be accessed using offset=1
+ * - the short would be accessed using offset=5
+ * - the long would be accessed using offset=7
  *
  * @see NumberArrayFactory
  */
 public interface ByteArray extends NumberArray<ByteArray>
 {
+    /**
+     * Gets the data at the given {@code index}. The data is read into the given byte array.
+     *
+     * @param index array index to get.
+     * @param into byte[] to read into.
+     */
     void get( long index, byte[] into );
 
+    /**
+     * Gets a part of an item, at the given {@code index}. An item in this array can consist of
+     * multiple values. This call will get a byte at the given {@code offset}.
+     *
+     * @param index array index to get.
+     * @param offset offset into this index to get the value from.
+     * @return the byte at the given offset at the given array index.
+     */
     byte getByte( long index, int offset );
 
+    /**
+     * Gets a part of an item, at the given {@code index}. An item in this array can consist of
+     * multiple values. This call will get a short at the given {@code offset}.
+     *
+     * @param index array index to get.
+     * @param offset offset into this index to get the value from.
+     * @return the short at the given offset at the given array index.
+     */
     short getShort( long index, int offset );
 
+    /**
+     * Gets a part of an item, at the given {@code index}. An item in this array can consist of
+     * multiple values. This call will get a int at the given {@code offset}.
+     *
+     * @param index array index to get.
+     * @param offset offset into this index to get the value from.
+     * @return the int at the given offset at the given array index.
+     */
     int getInt( long index, int offset );
 
-    long get6BLong( long index, int offset );
+    /**
+     * Gets a part of an item, at the given {@code index}. An item in this array can consist of
+     * multiple values. This call will get a 6-byte long at the given {@code offset}.
+     *
+     * @param index array index to get.
+     * @param offset offset into this index to get the value from.
+     * @return the 6-byte long at the given offset at the given array index.
+     */
+    long get6ByteLong( long index, int offset );
 
+    /**
+     * Gets a part of an item, at the given {@code index}. An item in this array can consist of
+     * multiple values. This call will get a long at the given {@code offset}.
+     *
+     * @param index array index to get.
+     * @param offset offset into this index to get the value from.
+     * @return the long at the given offset at the given array index.
+     */
     long getLong( long index, int offset );
 
+    /**
+     * Sets the given {@code data} at the given {@code index}, overwriting all the values in it.
+     *
+     * @param index array index to get.
+     * @param value the byte[] to copy into the given offset at the given array index.
+     */
     void set( long index, byte[] value );
 
+    /**
+     * Sets a part of an item, at the given {@code index}. An item in this array can consist of
+     * multiple values. This call will set a byte at the given {@code offset}.
+     *
+     * @param index array index to get.
+     * @param offset offset into this index to set the value for.
+     * @param value the byte value to set at the given offset at the given array index.
+     */
     void setByte( long index, int offset, byte value );
 
+    /**
+     * Sets a part of an item, at the given {@code index}. An item in this array can consist of
+     * multiple values. This call will set a short at the given {@code offset}.
+     *
+     * @param index array index to get.
+     * @param offset offset into this index to set the value for.
+     * @param value the short value to set at the given offset at the given array index.
+     */
     void setShort( long index, int offset, short value );
 
+    /**
+     * Sets a part of an item, at the given {@code index}. An item in this array can consist of
+     * multiple values. This call will set a int at the given {@code offset}.
+     *
+     * @param index array index to get.
+     * @param offset offset into this index to set the value for.
+     * @param value the int value to set at the given offset at the given array index.
+     */
     void setInt( long index, int offset, int value );
 
-    void set6BLong( long index, int offset, long value );
+    /**
+     * Sets a part of an item, at the given {@code index}. An item in this array can consist of
+     * multiple values. This call will set a 6-byte long at the given {@code offset}.
+     *
+     * @param index array index to get.
+     * @param offset offset into this index to set the value for.
+     * @param value the 6-byte long value to set at the given offset at the given array index.
+     */
+    void set6ByteLong( long index, int offset, long value );
 
+    /**
+     * Sets a part of an item, at the given {@code index}. An item in this array can consist of
+     * multiple values. This call will set a long at the given {@code offset}.
+     *
+     * @param index array index to get.
+     * @param offset offset into this index to set the value for.
+     * @param value the long value to set at the given offset at the given array index.
+     */
     void setLong( long index, int offset, long value );
 }

community/kernel/src/main/java/org/neo4j/unsafe/impl/batchimport/cache/DynamicByteArray.java

@@ -86,10 +86,10 @@ public int getInt( long index, int offset )
     }
 
     @Override
-    public long get6BLong( long index, int offset )
+    public long get6ByteLong( long index, int offset )
     {
         ByteArray chunk = chunkOrNullAt( index );
-        return chunk != null ? chunk.get6BLong( index, offset ) :
+        return chunk != null ? chunk.get6ByteLong( index, offset ) :
             get6BLongFromByteBuffer( defaultValueConvenienceBuffer, offset );
     }
 
@@ -125,9 +125,9 @@ public void setInt( long index, int offset, int value )
     }
 
     @Override
-    public void set6BLong( long index, int offset, long value )
+    public void set6ByteLong( long index, int offset, long value )
     {
-        at( index ).set6BLong( index, offset, value );
+        at( index ).set6ByteLong( index, offset, value );
     }
 
     @Override

community/kernel/src/main/java/org/neo4j/unsafe/impl/batchimport/cache/DynamicNumberArray.java

@@ -88,19 +88,16 @@ public N at( long index )
         return chunks[chunkIndex];
     }
 
-    private void synchronizedAddChunk( long index )
+    private synchronized void synchronizedAddChunk( long index )
     {
-        synchronized ( this )
+        if ( index >= length() )
         {
-            if ( index >= length() )
+            N[] newChunks = Arrays.copyOf( chunks, chunkIndex( index )+1 );
+            for ( int i = chunks.length; i < newChunks.length; i++ )
             {
-                N[] newChunks = Arrays.copyOf( chunks, chunkIndex( index )+1 );
-                for ( int i = chunks.length; i < newChunks.length; i++ )
-                {
-                    newChunks[i] = addChunk( chunkSize, chunkSize * i );
-                }
-                chunks = newChunks;
+                newChunks[i] = addChunk( chunkSize, chunkSize * i );
             }
+            chunks = newChunks;
         }
     }
 

community/kernel/src/main/java/org/neo4j/unsafe/impl/batchimport/cache/HeapByteArray.java

@@ -89,7 +89,7 @@ public int getInt( long index, int offset )
     }
 
     @Override
-    public long get6BLong( long index, int offset )
+    public long get6ByteLong( long index, int offset )
     {
         return get6BLongFromByteBuffer( buffer, index( index, offset ) );
     }
@@ -132,7 +132,7 @@ public void setInt( long index, int offset, int value )
     }
 
     @Override
-    public void set6BLong( long index, int offset, long value )
+    public void set6ByteLong( long index, int offset, long value )
     {
         int absIndex = index( index, offset );
         buffer.putInt( absIndex, (int) value );