dynarray.c，C语言，动态数组，动态字符串列表

#ifndef DYNARRAY_H
#define DYNARRAY_H

#include <stddef.h>

/* simple dynamic array of pointers */
typedef struct {
int count;
int capacity;
void** items;
} dynarray_t;

#define DYNARRAY_INITIALIZER  { 0, 0, NULL }

void dynarray_init( dynarray_t *a );
void dynarray_done( dynarray_t *a );

void dynarray_append( dynarray_t *a, void* item );

/* Used to iterate over a dynarray_t
* _array :: pointer to the array
* _item_type :: type of objects pointed to by the array
* _item      :: name of a local variable defined within the loop
*               with type '_item_type'
* _stmnt     :: C statement that will be executed in each iteration.
*
* You case use 'break' and 'continue' within _stmnt
*
* This macro is only intended for simple uses. I.e. do not add or
* remove items from the array during iteration.
*/
#define DYNARRAY_FOREACH_TYPE(_array,_item_type,_item,_stmnt) \
do { \
int _nn_##__LINE__ = 0; \
for (;_nn_##__LINE__ < (_array)->count; ++ _nn_##__LINE__) { \
_item_type _item = (_item_type)(_array)->items[_nn_##__LINE__]; \
_stmnt; \
} \
} while (0)

#define DYNARRAY_FOREACH(_array,_item,_stmnt) \
DYNARRAY_FOREACH_TYPE(_array,void *,_item,_stmnt)

/* Simple dynamic string arrays
*
* NOTE: A strlist_t owns the strings it references.
*/
typedef dynarray_t  strlist_t;

#define  STRLIST_INITIALIZER  DYNARRAY_INITIALIZER

/* Used to iterate over a strlist_t
* _list   :: pointer to strlist_t object
* _string :: name of local variable name defined within the loop with
*            type 'char*'
* _stmnt  :: C statement executed in each iteration
*
* This macro is only intended for simple uses. Do not add or remove items
* to/from the list during iteration.
*/
#define  STRLIST_FOREACH(_list,_string,_stmnt) \
DYNARRAY_FOREACH_TYPE(_list,char *,_string,_stmnt)

void strlist_init( strlist_t *list );

/* note: strlist_done will free all the strings owned by the list */
void strlist_done( strlist_t *list );

/* append a new string made of the first 'slen' characters from 'str'
* followed by a trailing zero.
*/
void strlist_append_b( strlist_t *list, const void* str, size_t  slen );

/* append the copy of a given input string to a strlist_t */
void strlist_append_dup( strlist_t *list, const char *str);

/* sort the strings in a given list (using strcmp) */
void strlist_sort( strlist_t *list );

#endif /* DYNARRAY_H */

#include "dynarray.h"
#include <stdlib.h>
#include <string.h>
#include <limits.h>

void dynarray_init( dynarray_t *a )
{
a->count = a->capacity = 0;
a->items = NULL;
}

static void dynarray_reserve_more( dynarray_t *a, int count )
{
int old_cap = a->capacity;
int new_cap = old_cap;
const int max_cap = INT_MAX/sizeof(void*);
void** new_items;
int new_count = a->count + count;

if (count <= 0)
return;

if (count > max_cap - a->count)
abort();

new_count = a->count + count;

while (new_cap < new_count) {
old_cap = new_cap;
new_cap += (new_cap >> 2) + 4;
if (new_cap < old_cap || new_cap > max_cap) {
new_cap = max_cap;
}
}
new_items = realloc(a->items, new_cap*sizeof(void*));
if (new_items == NULL)
abort();

a->items = new_items;
a->capacity = new_cap;
}

void dynarray_append( dynarray_t *a, void* item )
{
if (a->count >= a->capacity)
dynarray_reserve_more(a, 1);

a->items[a->count++] = item;
}

void dynarray_done( dynarray_t *a )
{
free(a->items);
a->items = NULL;
a->count = a->capacity = 0;
}

// string arrays

void strlist_init( strlist_t *list )
{
dynarray_init(list);
}

void strlist_append_b( strlist_t *list, const void* str, size_t  slen )
{
char *copy = malloc(slen+1);
memcpy(copy, str, slen);
copy[slen] = '\0';
dynarray_append(list, copy);
}

void strlist_append_dup( strlist_t *list, const char *str)
{
strlist_append_b(list, str, strlen(str));
}

void strlist_done( strlist_t *list )
{
STRLIST_FOREACH(list, string, free(string));
dynarray_done(list);
}

static int strlist_compare_strings(const void* a, const void* b)
{
const char *sa = *(const char **)a;
const char *sb = *(const char **)b;
return strcmp(sa, sb);
}

void strlist_sort( strlist_t *list )
{
if (list->count > 0) {
qsort(list->items,
(size_t)list->count,
sizeof(void*),
strlist_compare_strings);
}
}