blob: cbcf70f8ee4f20c6c7ac7921177fa90c6e71ce70 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
|
#ifndef HASH_FUNCTION
#define HASH_FUNCTION
/** This represents the shell of a hash function. It must be aggregated in
* order to be used. Please read about it's two functions for specificatins
* relating to what values will be passed to them and what they should return
* for creating your own hash functions.
*@author Mike Buland.
*/
class HashFunction
{
public:
/**
* Standard Constructor.
*/
HashFunction();
/**
* Standard Deconstructor.
*/
virtual ~HashFunction();
/** Hashes the value represnted by id. This must return a fairly unique
* number in the range of 0-2^32 (or whatever the size of an unsigned long
* is on your system) based on the id given. The faster the number changes
* the better in a general sence. The return value will be the index
* (after probing takes place) to the data assosiated with an id, so this
* function should always produce the same number for any given id.
*@param id The identifier to use to create a unique numerical identifier.
*@returns A mostly unique numerical identifier generated using the given
* id.
*/
virtual unsigned long int hash( const void *id ) = 0;
/** This function must compare two ids in the format that this hashfunction
* accepts. For example, if the hash function hashes strings it should
* probably { return strcmp( id1, id2 ) == 0 }.
*@param id1 One value to use in the comparison
*@param id2 Another value to use in the comparison
*@returns True if the two values match, otherwise false.
*/
virtual bool cmpIDs( const void *id1, const void *id2 ) = 0;
// virtual void *createPersistantID( const void *id ) = 0;
// virtual void destroyPersistantID( const void *id ) = 0;
};
#endif
|
