lego1: MxVariableTable (#87)

* MxStringVariable -> MxVariable

* cursor test

* GetVariable to 100

* meh

* node insert inline

* move to header file

* use reference to match available code

* variable table init in mxomni, some reshuffling

LEGO1/mxhashtable.h

@@ -0,0 +1,241 @@
+#ifndef MXHASHTABLE_H
+#define MXHASHTABLE_H
+
+#include "mxtypes.h"
+#include "mxcore.h"
+
+#define HASH_TABLE_INIT_SIZE              128
+#define HASH_TABLE_OPT_NO_EXPAND          0
+#define HASH_TABLE_OPT_EXPAND_ADD         1
+#define HASH_TABLE_OPT_EXPAND_MULTIPLY    2
+
+template <class T>
+class MxHashTableNode
+{
+public:
+  MxHashTableNode<T>() {}
+  MxHashTableNode<T>(T *p_obj, MxU32 p_hash)
+  {
+    m_obj = p_obj;
+    m_hash = p_hash;
+    m_prev = NULL;
+    m_next = NULL;
+  }
+
+//private:
+  T* m_obj;
+  MxU32 m_hash;
+  MxHashTableNode *m_prev;
+  MxHashTableNode *m_next;
+};
+
+// See MxOmni::Create
+// VTABLE 0x100dc1b0
+template <class T>
+class HashTableParent : public MxCore
+{
+public:
+  HashTableParent() {
+    m_numKeys = 0;
+    m_customDestructor = Destroy;
+  }
+
+  // OFFSET: LEGO1 0x100afd30
+  static void Destroy(T*) {};
+
+  // OFFSET: LEGO1 0x100afcd0
+  virtual MxS8 Compare(T*, T*) = 0;
+
+protected:
+  MxU32 m_numKeys; // +0x8
+  void (*m_customDestructor)(T*); // +0xc
+};
+
+// VTABLE 0x100dc1e8
+template <class T>
+class MxHashTable : protected HashTableParent<T>
+{
+public:
+  MxHashTable()
+  {
+    m_numSlots = HASH_TABLE_INIT_SIZE;
+    m_slots = new MxHashTableNode<T>*[HASH_TABLE_INIT_SIZE];
+    memset(m_slots, 0, sizeof(MxHashTableNode<T> *) * m_numSlots);
+    m_resizeOption = HASH_TABLE_OPT_NO_EXPAND;
+  }
+
+  virtual ~MxHashTable();
+
+  void Resize();
+  void MxHashTable::Add(T* );
+
+  virtual MxS8 Compare(T*, T*) = 0;
+
+  // OFFSET: LEGO1 0x100afdc0
+  virtual MxU32 Hash(T*) = 0;
+
+  // FIXME: use of friend here?
+  friend class MxHashTableCursor<T>;
+
+protected:
+  void _NodeInsert(MxHashTableNode<T> *);
+
+  MxHashTableNode<T> **m_slots; // +0x10
+  MxU32 m_numSlots; // +0x14
+  MxU32 m_autoResizeRatio;
+  int m_resizeOption; // +0x1c
+  // FIXME: or FIXME? This qword is used as an integer or double depending
+  // on the value of m_resizeOption. Hard to say whether this is how the devs
+  // did it, but a simple cast in either direction doesn't match.
+  union {
+    MxU32 m_increaseAmount;
+    double m_increaseFactor;
+  };
+};
+
+template <class T>
+class MxHashTableCursor : public MxCore
+{
+public:
+  MxHashTableCursor(MxHashTable<T> *p_hashTable)
+  {
+    m_table = p_hashTable;
+    m_match = NULL;
+  }
+
+  MxBool Find(T *p_obj)
+  {
+    MxU32 hash = m_table->Hash(p_obj);
+    int bucket = hash % m_table->m_numSlots;
+
+    MxHashTableNode<T> *t = m_table->m_slots[bucket];
+
+    while (t) {
+      if (t->m_hash == hash && !m_table->Compare(t->m_obj, p_obj))
+        m_match = t;
+      t = t->m_next;
+    }
+
+    return m_match != NULL;
+  }
+
+  void GetMatch(T*& p_obj)
+  {
+    if (m_match) {
+      p_obj = m_match->m_obj;
+    }
+  }
+
+  void DeleteMatch()
+  {
+    // Cut the matching node out of the linked list
+    // by updating pointer references.
+
+    if (m_match->m_prev) {
+      m_match->m_prev->m_next = m_match->m_next;
+    } else {
+      // No "prev" node, so move "next" to the head of the list.
+      int bucket = m_match->m_hash % m_table->m_numSlots;
+      m_table->m_slots[bucket] = m_match->m_next;
+    }
+
+    if (m_match->m_next)
+      m_match->m_next->m_prev = m_match->m_prev;
+
+    m_table->m_customDestructor(m_match->m_obj);
+    delete m_match;
+    m_table->m_numKeys--;
+  }
+
+private:
+  MxHashTable<T> *m_table;
+  MxHashTableNode<T> *m_match;
+};
+
+
+template <class T>
+// OFFSET: LEGO1 0x100b0bd0
+MxHashTable<T>::~MxHashTable()
+{
+  for (int i = 0; i < m_numSlots; i++) {
+    MxHashTableNode<T> *t = m_slots[i];
+    
+    while (t) {
+      MxHashTableNode<T> *next = t->m_next;
+      m_customDestructor(t->m_obj);
+      delete t;
+      t = next;
+    }
+  }
+
+  m_numKeys = 0;
+  memset(m_slots, 0, sizeof(MxHashTableNode<T> *) * m_numSlots);
+
+  delete[] m_slots;
+}
+
+template <class T>
+// OFFSET: LEGO1 0x100b7ab0
+inline void MxHashTable<T>::Resize()
+{
+  // Save a reference to the current table
+  // so we can walk nodes and re-insert
+  MxU32 old_size = m_numSlots;
+  MxHashTableNode<T> **old_table = m_slots;
+
+  switch (m_resizeOption) {
+    case HASH_TABLE_OPT_EXPAND_ADD:
+      m_numSlots = old_size + m_increaseAmount;
+      break;
+    case HASH_TABLE_OPT_EXPAND_MULTIPLY:
+      m_numSlots = old_size * m_increaseFactor;
+      break;
+  }
+
+  MxHashTableNode<T> **new_table = new MxHashTableNode<T>*[m_numSlots];
+  // FIXME: order? m_numKeys set after `rep stosd`
+  m_slots = new_table;
+  memset(m_slots, 0, sizeof(MxHashTableNode<T> *) * m_numSlots);
+  m_numKeys = 0;
+
+  for (int i = 0; i != old_size; i++) {
+    MxHashTableNode<T> *t = old_table[i];
+    
+    while (t) {
+      MxHashTableNode<T> *next = t->m_next;
+      _NodeInsert(t);
+      t = next;
+    }
+  }
+
+  delete[] old_table;
+}
+
+template <class T>
+// OFFSET: LEGO1 0x100b7b80
+inline void MxHashTable<T>::_NodeInsert(MxHashTableNode<T> *p_node)
+{
+  int bucket = p_node->m_hash % m_numSlots;
+  
+  p_node->m_next = m_slots[bucket];
+  
+  if (m_slots[bucket])
+    m_slots[bucket]->m_prev = p_node;
+
+  m_slots[bucket] = p_node;
+  m_numKeys++;
+}
+
+template <class T>
+inline void MxHashTable<T>::Add(T* p_newobj)
+{
+  if (m_resizeOption && ((m_numKeys + 1) / m_numSlots) > m_autoResizeRatio)
+    MxHashTable<T>::Resize();
+
+  MxU32 hash = Hash(p_newobj);
+  MxHashTableNode<T> *node = new MxHashTableNode<T>(p_newobj, hash);
+
+  MxHashTable<T>::_NodeInsert(node);
+}
+
+#endif // MXHASHTABLE_H