hollow/src/main/java/com/netflix/hollow/core/memory/encoding/VarInt.java
public static int readVInt(ByteData arr, long position) {
        byte b = arr.get(position++);

        if(b == (byte) 0x80)
            throw new RuntimeException("Attempting to read null value as int");

        int value = b & 0x7F;
        while ((b & 0x80) != 0) {
          b = arr.get(position++);
          value <<= 7;
          value |= (b & 0x7F);
        }

        return value;
    }
public static int readVInt(ByteData arr, long position) {
        byte b = arr.get(position++);

        if(b == (byte) 0x80)
            throw new RuntimeException("Attempting to read null value as int");

        int value = b & 0x7F;
        while ((b & 0x80) != 0) {
          b = arr.get(position++);
          value <<= 7;
          value |= (b & 0x7F);
        }

        return value;
    }
Read a variable length integer from the supplied {@link ByteData} starting at the specified position.
@param arr the byte data to read from
@param position the position in the byte data to read from
@return the int value