pl_newhashtable.rst

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PL_NewHashTable

===============

Create a new hash table.

Syntax

------

.. code::

   #include <plhash.h>

   PLHashTable *PL_NewHashTable(

     PRUint32 numBuckets,

     PLHashFunction keyHash,

     PLHashComparator keyCompare,

     PLHashComparator valueCompare,

     const PLHashAllocOps *allocOps,

     void *allocPriv

);

Parameters

~~~~~~~~~~

The function has the following parameters:

``numBuckets``

   The number of buckets in the hash table.

``keyHash``

   Hash function.

``keyCompare``

   Function used to compare keys of entries.

``valueCompare``

   Function used to compare keys of entries.

``allocOps``

   A pointer to a ``PLHashAllocOps`` structure that must exist

   throughout the lifetime of the new hash table.

``allocPriv``

   Passed as the first argument (pool).

Returns

~~~~~~~

The new hash table.

Description

-----------

:ref:`PL_NewHashTable` creates a new hash table. The table has at least 16

buckets. You can pass a value of 0 as ``numBuckets`` to create the

default number of buckets in the new table. The arguments ``keyCompare``

and ``valueCompare`` are functions of type :ref:`PLHashComparator` that the

hash table library functions use to compare the keys and the values of

entries.

The argument ``allocOps`` points to a ``PLHashAllocOps`` structure that

must exist throughout the lifetime of the new hash table. The hash table

library functions do not make a copy of this structure. When the

allocation functions in ``allocOps`` are invoked, the allocation private

data allocPriv is passed as the first argument (pool). You can specify a

``NULL`` value for ``allocOps`` to use the default allocation functions.

If ``allocOps`` is ``NULL``, ``allocPriv`` is ignored. Note that the

default ``freeEntry`` function does not free the value of the entry.