NAME¶
UHashTable, UHashElem - hash table classes
SYNOPSIS¶
#include <Unidraw/uhash.h>
DESCRIPTION¶
UHashTable implements a simple open hash table. The number of slots can be
specified when the table is created. UHashTable stores UHashElem instances,
which contain the key that is hashed. Code that uses UHashTables may derive
from UHashElem to store data in addition to the key. UHashTable also provides
operations for iterating over the elements in the hash table.
UHASHELEM OPERATIONS¶
- UHashElem(void* = nil)
- Create a UHashElem with the given key value.
- void* GetKey()
- void SetKey(void*)
- Explicitly get and set the element's key value.
UHASHTABLE PUBLIC OPERATIONS¶
- UHashTable(int nslots)
- Create a new UHashTable, specifying its number of
slots.
- virtual void Register(void* key, UHashElem* =
nil)
- Make an entry into the hash table. If no UHashElem is
supplied, this function call the CreateElem function (described below) to
create one, and it will call SetKey (with key as its argument) on
the result.
- virtual void Unregister(void* key)
- Remove the element with the matching key from the hash
table and delete it.
- void First(Iterator&)
- void Next(Iterator&)
- boolean Done(Iterator)
- UHashElem* GetElem(Iterator)
- Operations for iterating over the elements in the hash
table. These operation do not guarantee a particular ordering for the
iteration. First initializes an iterator to point to the first element in
the traversal, Next increments the iterator to point to the following
element, and Done returns whether or not the iterator points beyond the
last element in the traversal. GetElem returns the element to which the
given iterator points.
- UHashElem* Find(void* key)
- Find the element with the matching key (as defined by the
Equal operation, described below) in the hash table.
UHASHTABLE PROTECTED OPERATIONS¶
- virtual UHashElem* CreateElem()
- Return a new UHashElem instance. Subclasses of UHashTable
should redefine this function if they use subclasses of UHashElem.
- virtual int Hash(void* key)
- Hash the specified key to return a slot index. This value
should be less than the value of the _nslots member variable.
- virtual boolean Equal(void* key1, void* key2)
- Return whether the specified keys are equivalent. By
default, Equal simply compares the pointers for equality. Subclasses may
redefine this operation to make more sophisticated comparisons.
SEE ALSO¶
Iterator(3U)