itable.h File Reference

An integer-indexed hash table. More...

#include "int_sizes.h"

Go to the source code of this file.

Functions
struct itable *	itable_create (int buckets)
	Create a new integer table. More...
void	itable_clear (struct itable *h)
	Remove all entries from an integer table. More...
void	itable_delete (struct itable *h)
	Delete an integer table. More...
int	itable_size (struct itable *h)
	Count the entries in an integer table. More...
int	itable_insert (struct itable *h, UINT64_T key, const void *value)
	Insert a key and value. More...
void *	itable_lookup (struct itable *h, UINT64_T key)
	Look up a value by key. More...
void *	itable_remove (struct itable *h, UINT64_T key)
	Remove a value by key. More...
void	itable_firstkey (struct itable *h)
	Begin iteration over all keys. More...
int	itable_nextkey (struct itable *h, UINT64_T *key, void **value)
	Continue iteration over all keys. More...

Detailed Description

An integer-indexed hash table.

This hash table module maps integers to arbitrary objects (void pointers). For example, to store a filename using the file descriptor as a key:

struct itable *t;
t = itable_create(0);

fd = open(pathname,O_RDONLY,0);

itable_insert(t,fd,pathname);
pathname = itable_remove(h,id);

To list all of the items in an itable, use itable_firstkey and itable_nextkey like this:

UINT64_T  key;
void *value;

itable_firstkey(h);

while(itable_nextkey(h,&key,&value)) {
        printf("table contains: %d\n",key);
}

Function Documentation

struct itable* itable_create

(

int

buckets

)

Create a new integer table.

Parameters

buckets

The number of buckets in the table. If zero, a default value will be used.

Returns

A pointer to a new integer table.

void itable_clear

(

struct itable *

h

)

Remove all entries from an integer table.

Note that this function will not delete all of the objects contained within the integer table.

Parameters

h	The integer table to delete.

void itable_delete

(

struct itable *

h

)

Delete an integer table.

Note that this function will not delete all of the objects contained within the integer table.

Parameters

h	The integer table to delete.

int itable_size

(

struct itable *

h

)

Count the entries in an integer table.

Returns

The number of entries in the table.

Parameters

h	A pointer to an integer table.

int itable_insert	(	struct itable *	h,
		UINT64_T	key,
		const void *	value
	)

Insert a key and value.

This call will fail if the table already contains the same key. You must call itable_remove to remove it. Also note that you cannot insert a null value into the table.

Parameters

h	A pointer to an integer table.
key	An integer key
value	A pointer to store with the key.

Returns

One if the insert succeeded, failure otherwise

void* itable_lookup	(	struct itable *	h,
		UINT64_T	key
	)

Look up a value by key.

Parameters

h	A pointer to an integer table.
key	An integer key to search for.

Returns

If found, the pointer associated with the key, otherwise null.

void* itable_remove	(	struct itable *	h,
		UINT64_T	key
	)

Remove a value by key.

Parameters

h	A pointer to an integer table.
key	An integer key to remove.

Returns

If found, the pointer associated with the key, otherwise null.

void itable_firstkey

(

struct itable *

h

)

Begin iteration over all keys.

This function begins a new iteration over an integer table, allowing you to visit every key and value in the table. Next, invoke itable_nextkey to retrieve each value in order.

Parameters

h	A pointer to an integer table.

int itable_nextkey	(	struct itable *	h,
		UINT64_T *	key,
		void **	value
	)

Continue iteration over all keys.

This function returns the next key and value in the iteration.

Parameters

h	A pointer to an integer table.
key	A pointer to a key integer.
value	A pointer to a value pointer. (can be NULL)

Returns

Zero if there are no more elements to visit, one otherwise.