content: package com.ankurdave.part;
  
  class ArtNode256 extends ArtNode {
      public static int count;
  
      public ArtNode256() {
          super();
          count++;
      }
  
      public ArtNode256(final ArtNode256 other) {
          super(other);
          for (int i = 0; i < 256; i++) {
              children[i] = other.children[i];
              if (children[i] != null) {
                  children[i].refcount++;
              }
          }
          count++;
      }
  
      public ArtNode256(final ArtNode48 other) {
          this();
          // ArtNode
          this.num_children = other.num_children;
          this.partial_len = other.partial_len;
          System.arraycopy(other.partial, 0, this.partial, 0, Math.min(MAX_PREFIX_LEN, this.partial_len));
          // ArtNode256 from ArtNode48
          for (int i = 0; i < 256; i++) {
              if (other.keys[i] != 0) {
                  children[i] = other.children[to_uint(other.keys[i]) - 1];
                  children[i].refcount++;
              }
          }
      }
  
      @Override public Node n_clone() {
          return new ArtNode256(this);
      }
  
      @Override public ChildPtr find_child(byte c) {
          if (children[to_uint(c)] != null) return new ArrayChildPtr(children, to_uint(c));
          return null;
      }
  
      @Override public Leaf minimum() {
          int idx = 0;
          while (children[idx] == null) idx++;
          return Node.minimum(children[idx]);
       }
  
      @Override public void add_child(ChildPtr ref, byte c, Node child) {
          assert(refcount <= 1);
  
          this.num_children++;
          this.children[to_uint(c)] = child;
          child.refcount++;
      }
  
      @Override public void remove_child(ChildPtr ref, byte c) {
          assert(refcount <= 1);
  
          children[to_uint(c)].decrement_refcount();
          children[to_uint(c)] = null;
          num_children--;
  
          if (num_children == 37) {
              ArtNode48 result = new ArtNode48(this);
              ref.change(result);
          }
      }
  
      @Override public boolean exhausted(int c) {
          for (int i = c; i < 256; i++) {
              if (children[i] != null) {
                  return false;
              }
          }
          return true;
      }
  
      @Override public int nextChildAtOrAfter(int c) {
          int pos = c;
          for (; pos < 256; pos++) {
              if (children[pos] != null) {
                  break;
              }
          }
          return pos;
      }
  
      @Override public Node childAt(int pos) {
          return children[pos];
      }
  
      @Override public int decrement_refcount() {
          if (--this.refcount <= 0) {
              int freed = 0;
              for (int i = 0; i < 256; i++) {
                  if (children[i] != null) {
                      freed += children[i].decrement_refcount();
                  }
              }
              count--;
              // delete this;
              return freed + 2120;
              // object size (8) + refcount (4) +
              // num_children int (4) + partial_len int (4) +
              // pointer to partial array (8) + partial array size (8+4+1*MAX_PREFIX_LEN)
              // pointer to children array (8) + children array size (8+4+8*256) +
              // padding (4)
          }
          return 0;
      }
  
      Node[] children = new Node[256];
  }
  