79 lines
2.2 KiB
C
79 lines
2.2 KiB
C
/**
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* A durable, recoverable hashtable
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* Based on Peter Graf's pblhash, <http://mission.base.com/peter/source/>
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* (actually based on jbhash.c, which was based on pblhash)
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*
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*
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* $Id$
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*/
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/**
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@file
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Do not use this hashtable. Instead, use the one provided by
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linearHashNTA.h
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@deprecated This hash implementation is fundamentally flawed.
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A persistant hash, based on logical operations.
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lladdhash: /yad-hash/ n. LLADD's hash table, based on logical operations.
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@todo CORRECTNESS PROBLEM. It allows logical operations to span
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more than one record, which is incompatible with our logical
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operations. Also, Blob handling + LLADD hash's implementation
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result in poor performance when the bucket size is large, and
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transactions are short.
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@ingroup OPERATIONS
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$Id$
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*/
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#ifndef __LLADDHASH_H__
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#define __LLADDHASH_H__
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int isNullRecord(recordid x);
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typedef struct lladdHash_t lladdHash_t;
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/** Allocate a new hash */
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recordid lHtCreate(int xid, int size);
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int lHtDelete(int xid, lladdHash_t *ht);
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lladdHash_t * lHtOpen(int xid, recordid rid) ;
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void lHtClose(int xid, lladdHash_t * lht);
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int lHtValid(int xid, lladdHash_t *ht);
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recordid lHtLookup( int xid, lladdHash_t *ht, const void *key, int keylen);
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/**
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@return ZERO_RECORDID if the entry did not already exist, the
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recordid of the old value of key otherwise.
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*/
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recordid lHtInsert(int xid, lladdHash_t *ht, const void *key, int keylen, recordid dat);
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/**
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The recommended code sequence for deletion of a value is this:
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recordid old = lHtRemove(xid, ht, key, keylen);
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if(old != ZERO_RECORDID) { Tdealloc(xid, old); }
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If you are certain that the value exists in the hashtable, then it
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is safe to skip the (old != ZERO_RECORDID) check.
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@return the recordid of the entry if it existed, ZERO_RECORDID otherwise.
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*/
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recordid lHtRemove( int xid, lladdHash_t *ht, const void *key, int keylen);
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/*
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int lHtFirst( int xid, lladdHash_t *ht, void *buf );
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int lHtNext( int xid, lladdHash_t *ht, void *buf );
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int lHtCurrent( int xid, lladdHash_t *ht, void *buf);
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int lHtCurrentKey(int xid, lladdHash_t *ht, void *buf);
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int lHtPosition( int xid, lladdHash_t *ht, const void *key, int key_length );
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*/
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#endif
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