Hash Class Reference

Implementation of a hash table. More...

#include <hash.h>

List of all members.

Public Member Functions
	Hash (int sizeHint=8)
	Object constructor; specify initial size of hash table or default to 8.
void	AddItem (int key, void *value)
	Add an item, based on key.
void *	GetItem (int key)
	Get the item associated with key.
void *	ReplaceItem (int key, void *value)
	Replace the item associated with key, returning old item.
int	Dump (OnDisk *pOnDisk)
	Dump the hash table to disk.
void	CallAll (void(*f)(int key, void *value))
	Call function (*f)(key,value) for each hash table entry.
Classes
class	CollisionNode

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Detailed Description

Implementation of a hash table.

Class Hash implements a hash table. The hash table key is a 32-bit integer, such as an Id. Note: Keys must be unique.

TODO: Probably Hash should be a template. Then instead of using void * we could use a typed parameter.

Limitations:

• Storing a key==NULL is not allowed, because, NULL indicates empty table slots.
• Storing a value==NULL is not allowed because returning NULL value indicates "not found".
• Each stored item must be unique. In other words, different items will not have the same key. As a result, custom solutions need to be coded every time multiple data items need to be associated with a key. Also, nothing enforces uniqueness, so, behavior is undefined if multiple items are inserted with the same key, or even if you insert an item that is already in the Hash table. TODO: Generalize Hash or use the STL or something.

Responsibilities:

• Store a key, value pair.
• Retrieve the value associated with a key.
• TODO: Sometime will probably need to add a 'delete' capability.

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Constructor & Destructor Documentation

Hash::Hash (  int  sizeHint = 8  )

Object constructor; specify initial size of hash table or default to 8.

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Member Function Documentation

void Hash::AddItem (  int  key, void *  value )

Add an item, based on key.

void Hash::CallAll (  void(*)(int key, void *value)  f  )

Call function (*f)(key,value) for each hash table entry.

int Hash::Dump (  OnDisk *  pOnDisk  )

Dump the hash table to disk.

void * Hash::GetItem (  int  key  )

Get the item associated with key.

void * Hash::ReplaceItem (  int  key, void *  value )

Replace the item associated with key, returning old item.

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The documentation for this class was generated from the following files:

• hash.h
• hash.c

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