src/libstatgrab/vector.h

#include <stdlib.h>

typedef void (*vector_init_function)(void *item);
typedef void (*vector_destroy_function)(void *item);

typedef struct {
        size_t item_size;
        int used_count;
        int alloc_count;
        int error;
        int block_size;
        vector_init_function init_fn;
        vector_destroy_function destroy_fn;
} vector_header;

#define VECTOR_HEADER(name, item_type, block_size, init_fn, destroy_fn) \
        vector_header name##_header = { \
                sizeof(item_type), \
                0, \
                0, \
                0, \
                block_size, \
                (vector_init_function) init_fn, \
                (vector_destroy_function) destroy_fn \
        }

/* Internal function to resize the vector. */
void *statgrab_vector_resize(void *vector, vector_header *h, int count);

/* Declare a vector. Specify the init/destroy functions as NULL if you don't
 * need them. The block size is how many items to allocate at once. */
#define VECTOR_DECLARE(name, item_type, block_size, init_fn, destroy_fn) \
        item_type *name = NULL; \
        VECTOR_HEADER(name, item_type, block_size, init_fn, destroy_fn)

/* As VECTOR_DECLARE, but for a static vector. */
#define VECTOR_DECLARE_STATIC(name, item_type, block_size, init_fn, destroy_fn) \
        static item_type *name = NULL; \
        static VECTOR_HEADER(name, item_type, block_size, init_fn, destroy_fn)

/* Return the current size of a vector. */
#define VECTOR_SIZE(name) \
        name##_header.used_count

/* Resize a vector. Returns 0 on success, -1 on out-of-memory. On
 * out-of-memory, the old contents of the vector will be destroyed and the old
 * vector will be freed. */
#define VECTOR_RESIZE(name, num_items) \
        (name = statgrab_vector_resize((char *) name, &name##_header, num_items), \
         name##_header.error)

/* Free a vector, destroying its contents. */
#define VECTOR_FREE(name) \
        VECTOR_RESIZE(name, 0)

Revision:	1.5
Committed:	Mon Apr 5 00:58:05 2004 UTC (20 years, 1 month ago) by ats
Content type:	text/plain
Branch:	MAIN
Changes since 1.4:	+6 -16 lines
Log Message:	Fix the strict-aliasing problem in a clean, sensible way that actually works. As a bonus, we now get a "value computed is not used" warning from GCC if we don't check the return value of VECTOR_RESIZE. (This is dubiously a bonus when it's being resized to 0, but it's not going to hurt to check even then -- we might support destructors failing in the future.)
#	Content
1	#include <stdlib.h>
2
3	typedef void (vector_init_function)(void item);
4	typedef void (vector_destroy_function)(void item);
5
6	typedef struct {
7	size_t item_size;
8	int used_count;
9	int alloc_count;
10	int error;
11	int block_size;
12	vector_init_function init_fn;
13	vector_destroy_function destroy_fn;
14	} vector_header;
15
16	#define VECTOR_HEADER(name, item_type, block_size, init_fn, destroy_fn) \
17	vector_header name##_header = { \
18	sizeof(item_type), \
19	0, \
20	0, \
21	0, \
22	block_size, \
23	(vector_init_function) init_fn, \
24	(vector_destroy_function) destroy_fn \
25	}
26
27	/* Internal function to resize the vector. */
28	void statgrab_vector_resize(void vector, vector_header *h, int count);
29
30	/* Declare a vector. Specify the init/destroy functions as NULL if you don't
31	* need them. The block size is how many items to allocate at once. */
32	#define VECTOR_DECLARE(name, item_type, block_size, init_fn, destroy_fn) \
33	item_type *name = NULL; \
34	VECTOR_HEADER(name, item_type, block_size, init_fn, destroy_fn)
35
36	/* As VECTOR_DECLARE, but for a static vector. */
37	#define VECTOR_DECLARE_STATIC(name, item_type, block_size, init_fn, destroy_fn) \
38	static item_type *name = NULL; \
39	static VECTOR_HEADER(name, item_type, block_size, init_fn, destroy_fn)
40
41	/* Return the current size of a vector. */
42	#define VECTOR_SIZE(name) \
43	name##_header.used_count
44
45	/* Resize a vector. Returns 0 on success, -1 on out-of-memory. On
46	* out-of-memory, the old contents of the vector will be destroyed and the old
47	* vector will be freed. */
48	#define VECTOR_RESIZE(name, num_items) \
49	(name = statgrab_vector_resize((char *) name, &name##_header, num_items), \
50	name##_header.error)
51
52	/* Free a vector, destroying its contents. */
53	#define VECTOR_FREE(name) \
54	VECTOR_RESIZE(name, 0)
55