/** 
    @file

    A reliable hashtable implementation.  The implementation makes
    use of nested top actions, and is reentrant.  Currently, all keys
    and values must be of the same length, although this restriction
    will eventually be removed.

    The implementation uses a linear hash function, allowing the
    bucket list to be resized dynamically.  Because the bucket list is
    built on top of arrayList, all operations are O(1), assuming the
    hash function behaves correctly.  Currently, linkedListNTA
    implements the bucket lists.

    @see nestedTopAction.h, linkedListNTA.h, arrayList.h

    @ingroup OPERATIONS

    $id$

*/

#ifndef __LINEAR_HASH_NTA_H
#define __LINEAR_HASH_NTA_H

typedef struct {
  recordid hashHeader;
  recordid bucket;
  int numBuckets;
  int keySize;
  int valueSize;
  lladd_linkedList_iterator * it;
} lladd_hash_iterator;

recordid ThashCreate(int xid, int keySize, int valSize);
void ThashDelete(int xid, recordid hash);
/* @return 1 if the key was defined, 0 otherwise. */
int ThashInsert(int xid, recordid hash, const byte* key, int keySize, const byte* value, int valueSize);
/* @return 1 if the key was defined, 0 otherwise. */
int ThashRemove(int xid, recordid hash, const byte* key, int keySize);

/** @return size of the value associated with key, or -1 if key not found. 
                   (a return value of zero means the key is associated with an
		   empty value.) */
int ThashLookup(int xid, recordid hash, const byte* key, int keySize, byte ** value);
lladd_hash_iterator * ThashIterator(int xid, recordid hash, int keySize, int valueSize);
int ThashNext(int xid, lladd_hash_iterator * it, byte ** key, int * keySize, byte** value, int * valueSize);

Operation getLinearHashInsert();
Operation getLinearHashRemove();

//Support 16 entries by default.
#define HASH_INIT_BITS 4
#define HASH_FILL_FACTOR 0.7

#endif // __LINEAR_HASH_NTA_H