Added the vector module which is a vector implementation. I use it in the

hashmap implementation.
This commit is contained in:
Robert James Kaes 2002-04-07 21:29:23 +00:00
parent e70b98252a
commit 54f369a734
2 changed files with 276 additions and 0 deletions

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/* $Id: vector.c,v 1.1 2002-04-07 21:29:23 rjkaes Exp $
*
* A vector implementation. The vector can be of an arbritrary length, and
* the data for each entry is an lump of data (the size is stored in the
* vector.)
*
* Copyright (C) 2002 Robert James Kaes (rjkaes@flarenet.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#if defined(HAVE_CONFIG_H)
# include <config.h>
#endif
#include <sys/types.h>
#include <inttypes.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include "vector.h"
/*
* These structures are the storage for the "vector". Entries are
* stored in struct vectorentry_s (the data and the length), and the
* "vector" structure is implemented as a linked-list. The struct
* vector_s stores a pointer to the first vector (vector[0]) and a
* count of the number of enteries (or how long the vector is.)
*/
struct vectorentry_s {
void *data;
size_t len;
struct vectorentry_s *next;
};
struct vector_s {
size_t num_entries;
struct vectorentry_s *vector;
};
/*
* Create an vector. The vector initially has no elements and no
* storage has been allocated for the entries.
*
* A NULL is returned if memory could not be allocated for the
* vector.
*/
vector_t
vector_create(void)
{
vector_t vector;
vector = malloc(sizeof(struct vector_s));
if (!vector)
return NULL;
vector->num_entries = 0;
vector->vector = NULL;
return vector;
}
/*
* Deletes an vector. All the enteries when this function is run.
*
* Returns: 0 on success
* negative if a NULL vector is supplied
*/
int
vector_delete(vector_t vector)
{
struct vectorentry_s *ptr, *next;
if (!vector)
return -EINVAL;
ptr = vector->vector;
while (ptr) {
next = ptr->next;
free(ptr->data);
free(ptr);
ptr = next;
}
free(vector);
return 0;
}
/*
* Inserts an entry into the vector. The entry is an arbitrary
* collection of bytes of _len_ octets. The data is copied into the
* vector, so the original data must be freed to avoid a memory leak.
* The "data" must be non-NULL and the "len" must be greater than zero.
*
* Returns: 0 on success
* negative number if there are errors
*/
int
vector_insert(vector_t vector, void *data, ssize_t len)
{
struct vectorentry_s *entry, **ptr;
if (!vector || !data || len <= 0)
return -EINVAL;
entry = malloc(sizeof(struct vectorentry_s));
if (!entry)
return -ENOMEM;
entry->data = malloc(len);
if (!entry->data) {
free(entry);
return -ENOMEM;
}
memcpy(entry->data, data, len);
entry->len = len;
entry->next = NULL;
ptr = &vector->vector;
while (*ptr)
ptr = &((*ptr)->next);
*ptr = entry;
vector->num_entries++;
return 0;
}
/*
* A pointer to the data at position "pos" (zero based) is returned in the
* "data" pointer. If the vector is out of bound, data is set to NULL.
*
* Returns: negative upon an error
* length of data if position is valid
*/
ssize_t
vector_getentry(vector_t vector, size_t pos, void **data)
{
struct vectorentry_s *ptr;
size_t loc;
if (!vector || !data)
return -EINVAL;
if (pos < 0 || pos >= vector->num_entries)
return -ERANGE;
loc = 0;
ptr = vector->vector;
while (loc != pos) {
ptr = ptr->next;
loc++;
}
*data = ptr->data;
return ptr->len;
}
/*
* Returns the number of enteries (or the length) of the vector.
*
* Returns: negative if vector is not valid
* positive length of vector otherwise
*/
ssize_t
vector_length(vector_t vector)
{
if (!vector)
return -EINVAL;
return vector->num_entries;
}

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/* $Id: vector.h,v 1.1 2002-04-07 21:29:23 rjkaes Exp $
*
* A vector implementation. The vector can be of an arbritrary length, and
* the data for each entry is an lump of data (the size is stored in the
* vector.)
*
* Copyright (C) 2002 Robert James Kaes (rjkaes@flarenet.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef _VECTOR_H
#define _VECTOR_H
/* Allow the use in C++ code. */
#if defined(__cplusplus)
extern "C" {
#endif
/*
* We're using a typedef here to "hide" the implementation details of the
* vector. Sure, it's a pointer, but the struct is hidden in the C file.
* So, just use the vector_t like it's a cookie. :)
*/
typedef struct vector_s *vector_t;
/*
* vector_create() takes no arguments.
* vector_delete() is self explanatory.
*/
extern vector_t vector_create(void);
extern int vector_delete(vector_t vector);
/*
* When you insert a piece of data into the vector, the data will be
* duplicated, so you must free your copy if it was created on the
* heap. The data must be non-NULL and the length must be greater
* than zero.
*
* Returns: negative on error
* 0 upon successful insert.
*/
extern int vector_insert(vector_t vector, void *data, ssize_t len);
/*
* A pointer to the data at position "pos" (zero based) is returned in the
* "data" pointer. If the vector is out of bound, data is set to NULL.
*
* The pointer points to the actual data in the vector, so you have
* the power to modify the data, but do it responsibly since the
* library doesn't take any steps to prevent you from messing up the
* vector. (A better rule is, don't modify the data since you'll
* likely mess up the "length" parameter of the data.) However, DON'T
* try to realloc or free the data; doing so will break the vector.
*
* Returns: negative upon an error
* length of data if position is valid
*/
extern ssize_t vector_getentry(vector_t vector, size_t pos, void **data);
/*
* Returns the number of enteries (or the length) of the vector.
*
* Returns: negative if vector is not valid
* positive length of vector otherwise
*/
extern ssize_t vector_length(vector_t vector);
#if defined(_cplusplus)
}
#endif /* C++ */
#endif /* _VECTOR_H */