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| -rw-r--r-- | src/vector.c | 191 | ||||
| -rw-r--r-- | src/vector.h | 85 |
2 files changed, 276 insertions, 0 deletions
diff --git a/src/vector.c b/src/vector.c new file mode 100644 index 0000000..fe6a67d --- /dev/null +++ b/src/vector.c @@ -0,0 +1,191 @@ +/* $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; +} diff --git a/src/vector.h b/src/vector.h new file mode 100644 index 0000000..dadc421 --- /dev/null +++ b/src/vector.h @@ -0,0 +1,85 @@ +/* $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 */ |