relation.c File Reference

Relation implementation for the Relational Algebra Engine. More...

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "relation.h"

Include dependency graph for relation.c:

Classes
struct	FindTupleContext

Functions
Relation *	relation_create (const char *name)
	Create a new Relation.
void	relation_destroy (Relation *r)
	Destroy a Relation and free its memory.
int	relation_add_tuple (Relation *r, Tuple *t)
	Add a tuple to a relation.
void	relation_print (const Relation *r)
	Print a Relation to stdout.
Tuple *	relation_find_tuple (Relation *r, Tuple *target)
	Find a tuple in a relation matching the target.

Detailed Description

Relation implementation for the Relational Algebra Engine.

Provides creation, destruction, and manipulation of relations (for now, simply sets of tuples), adhering to the strict theoretical model of relational algebra.

Function Documentation

relation_add_tuple()

int relation_add_tuple	(	Relation *	r,
		Tuple *	t
	)

Add a tuple to a relation.

Parameters

r	Pointer to the Relation.
t	Pointer to the Tuple to add.

Returns

1 if added, 0 if already present, -1 on error.

relation_create()

Relation * relation_create

(

const char *

name

)

Create a new Relation.

Parameters

name	Name of the relation (copied).

Returns

Pointer to the new Relation, or NULL on failure.

relation_destroy()

void relation_destroy

(

Relation *

r

)

Destroy a Relation and free its memory.

Parameters

r	Pointer to the Relation to destroy. Safe to pass NULL.

relation_find_tuple()

Tuple * relation_find_tuple	(	Relation *	r,
		Tuple *	target
	)

Find a tuple in a relation matching the target.

Parameters

r	Pointer to the Relation.
target	Pointer to the Tuple to find.

Returns

Pointer to the found Tuple, or NULL if not found.

relation_print()

void relation_print

(

const Relation *

r

)

Print a Relation to stdout.

Parameters

r	Pointer to the Relation to print.