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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

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#ifndef SHARE_VM_LIBADT_DICT_HPP

#define SHARE_VM_LIBADT_DICT_HPP

// Dictionaries - An Abstract Data Type

#include "memory/resourceArea.hpp"

#include "runtime/thread.hpp"

class Dict;

// These dictionaries define a key-value mapping.  They can be inserted to,

// searched or deleted from.  They grow and shrink as needed.  The key is a

// pointer to something (or anything which can be stored in a pointer).  A

// key comparison routine determines if two keys are equal or not.  A hash

// function can be provided; if it's not provided the key itself is used

// instead.  A nice string hash function is included.

typedef int32_t (*CmpKey)(const void *key1, const void *key2);

typedef int  (*Hash)(const void *key);

typedef void (*FuncDict)(const void *key, const void *val, Dict *d);

class Dict : public ResourceObj { // Dictionary structure

 private:

  class Arena *_arena;          // Where to draw storage from

  class bucket *_bin;           // Hash table is array of buckets

  uint _size;                   // Size (# of slots) in hash table

  uint32_t _cnt;                // Number of key-value pairs in hash table

  const Hash _hash;             // Hashing function

  const CmpKey _cmp;            // Key comparison function

  void doubhash( void );        // Double hash table size

 public:

  friend class DictI;            // Friendly iterator function

  // cmp is a key comparision routine.  hash is a routine to hash a key.

  Dict( CmpKey cmp, Hash hash );

  Dict( CmpKey cmp, Hash hash, Arena *arena, int size=16 );

  ~Dict();

  Dict( const Dict & );         // Deep-copy guts

  Dict &operator =( const Dict & );

  // Zap to empty; ready for re-use

  void Clear();

  // Return # of key-value pairs in dict

  uint32_t Size(void) const { return _cnt; }

  // Insert inserts the given key-value pair into the dictionary.  The prior

  // value of the key is returned; NULL if the key was not previously defined.

  void *Insert(void *key, void *val, bool replace = true); // A new key-value

  void *Delete(void *key);        // Delete & return old

  // Find finds the value of a given key; or NULL if not found.

  // The dictionary is NOT changed.

  void *operator [](const void *key) const;  // Do a lookup

  // == compares two dictionaries; they must have the same keys (their keys

  // must match using CmpKey) and they must have the same values (pointer

  // comparison).  If so 1 is returned, if not 0 is returned.

  int32_t operator ==(const Dict &d) const;   // Compare dictionaries for equal

  // Print out the dictionary contents as key-value pairs

  void print();

};

// Hashing functions

int hashstr(const void *s);        // Nice string hash

// Slimey cheap hash function; no guaranteed performance.  Better than the

// default for pointers, especially on MS-DOS machines.

int hashptr(const void *key);

// Slimey cheap hash function; no guaranteed performance.

int hashkey(const void *key);

// Key comparators

int32_t cmpstr(const void *k1, const void *k2);

// Slimey cheap key comparator.

int32_t cmpkey(const void *key1, const void *key2);

//------------------------------Iteration--------------------------------------

// The class of dictionary iterators.  Fails in the presences of modifications

// to the dictionary during iteration (including searches).

// Usage:  for( DictI i(dict); i.test(); ++i ) { body = i.key; body = i.value;}

class DictI {

 private:

  const Dict *_d;               // Dictionary being iterated over

  uint _i;                      // Counter over the bins

  uint _j;                      // Counter inside each bin

 public:

  const void *_key, *_value;    // Easy access to the key-value pair

  DictI( const Dict *d ) {reset(d);}; // Create a new iterator

  void reset( const Dict *dict );     // Reset existing iterator

  void operator ++(void);             // Increment iterator

  int test(void) { return _i<_d->_size;} // Test for end of iteration

};

#endif // SHARE_VM_LIBADT_DICT_HPP