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/* nbdkit
* Copyright Red Hat
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* * Neither the name of Red Hat nor the names of its contributors may be
* used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/* Simple implementation of a vector. It can be cheaply appended, and
* more expensively inserted. There are two main use-cases we
* consider: lists of strings (either with a defined length, or
* NULL-terminated), and lists of numbers. It is generic so could be
* used for lists of anything (eg. structs) where being able to append
* easily is important.
*/
#ifndef NBDKIT_VECTOR_H
#define NBDKIT_VECTOR_H
#include <stdbool.h>
#include <assert.h>
#include <string.h>
#include "compiler-macros.h"
#include "static-assert.h"
#ifdef __clang__
#pragma clang diagnostic ignored "-Wunused-function"
#pragma clang diagnostic ignored "-Wduplicate-decl-specifier"
#endif
/* Use of this macro defines a new type called ‘name’ containing an
* extensible vector of ‘type’ elements. For example:
*
* DEFINE_VECTOR_TYPE (string_vector, char *);
*
* defines a new type called ‘string_vector’ as a vector of ‘char *’.
* You can create variables of this type:
*
* string_vector names = empty_vector;
*
* or
*
* string_vector names;
* names = (string_vector)empty_vector;
*
* where ‘names.ptr[]’ will be an array of strings and ‘names.len’
* will be the number of strings. There are no get/set accessors. To
* iterate over the strings you can use the ‘.ptr’ field directly:
*
* for (size_t i = 0; i < names.len; ++i)
* printf ("%s\n", names.ptr[i]);
*
* Initializing with ‘empty_vector’, or assigning the compound literal
* ‘(string_vector)empty_vector’, sets ‘.ptr = NULL’ and ‘.len = 0’.
*
* DEFINE_VECTOR_TYPE also defines utility functions. For the full
* list see the definition below, but useful functions include:
*
* ‘name’_append (eg. ‘string_vector_append’)
* - Append a new element at the end. This operation is cheap.
*
* ‘name’_insert (eg. ‘string_vector_insert’)
* - Insert a new element at the beginning, middle or end. This
* operation is more expensive because existing elements may need
* to be copied around.
*
* Both functions extend the vector if required, and so both may fail
* (returning -1) which you must check for.
*/
#define DEFINE_VECTOR_TYPE(name, type) \
struct name { \
type *ptr; /* Pointer to array of items. */ \
size_t len; /* Number of valid items in the array. */ \
size_t cap; /* Maximum number of items. */ \
}; \
typedef struct name name; \
\
/* Reserve n elements at the end of the vector. Note space is \
* allocated and capacity is increased, but the vector length is \
* not increased and the new elements are not initialized. \
*/ \
static inline int __attribute__ ((__unused__)) \
name##_reserve (name *v, size_t n) \
{ \
return generic_vector_reserve ((struct generic_vector *)v, n, \
sizeof (type), false); \
} \
\
/* Same as _reserve, but reserve exactly this number of elements \
* without any overhead. Useful if you know ahead of time that you \
* will never need to extend the vector. \
*/ \
static inline int __attribute__ ((__unused__)) \
name##_reserve_exactly (name *v, size_t n) \
{ \
return generic_vector_reserve ((struct generic_vector *)v, \
n, sizeof (type), true); \
} \
\
/* Same as _reserve, but the allocation will be page aligned. Note \
* that the machine page size must be divisible by sizeof (type). \
*/ \
static inline int __attribute__ ((__unused__)) \
name##_reserve_page_aligned (name *v, size_t n) \
{ \
return generic_vector_reserve_page_aligned ((struct generic_vector *)v, \
n, sizeof (type)); \
} \
\
/* Insert list at i'th element. i=0 => beginning i=len => append */ \
static inline int __attribute__ ((__unused__)) \
name##_insert_array (name *v, type *elems, size_t nr_elems, size_t i) \
{ \
assert (i <= v->len); \
if (v->len+nr_elems > v->cap) { \
if (name##_reserve (v, nr_elems) == -1) return -1; \
} \
memmove (&v->ptr[i+nr_elems], &v->ptr[i], \
(v->len-i) * sizeof (elems[0])); \
memcpy (&v->ptr[i], elems, nr_elems * sizeof (elems[0])); \
v->len += nr_elems; \
return 0; \
} \
\
/* Insert at i'th element. i=0 => beginning i=len => append */ \
static inline int __attribute__ ((__unused__)) \
name##_insert (name *v, type elem, size_t i) \
{ \
return name##_insert_array (v, &elem, 1, i); \
} \
\
/* Append a new element to the end of the vector. */ \
static inline int __attribute__ ((__unused__)) \
name##_append (name *v, type elem) \
{ \
return name##_insert (v, elem, v->len); \
} \
\
/* Append list of new elements to the end of the vector. */ \
static inline int __attribute__ ((__unused__)) \
name##_append_array (name *v, type *elems, size_t nr_elems) \
{ \
return name##_insert_array (v, elems, nr_elems, v->len); \
} \
\
/* Remove [i..i+nr-1] elements. i=0 => beginning i=len-1 => end */ \
static inline void __attribute__ ((__unused__)) \
name##_remove_range (name *v, size_t nr, size_t i) \
{ \
assert (i < v->len); \
memmove (&v->ptr[i], &v->ptr[i+nr], (v->len-i-nr) * sizeof (type)); \
v->len -= nr; \
} \
\
/* Remove i'th element. i=0 => beginning i=len-1 => end */ \
static inline void __attribute__ ((__unused__)) \
name##_remove (name *v, size_t i) \
{ \
name##_remove_range (v, 1, i); \
} \
\
/* Remove all elements and deallocate the vector. */ \
static inline void __attribute__ ((__unused__)) \
name##_reset (name *v) \
{ \
free (v->ptr); \
v->ptr = NULL; \
v->len = v->cap = 0; \
} \
\
/* Iterate over the vector, calling f() on each element. */ \
static inline void __attribute__ ((__unused__)) \
name##_iter (name *v, void (*f) (type elem)) \
{ \
size_t i; \
for (i = 0; i < v->len; ++i) \
f (v->ptr[i]); \
} \
\
/* Sort the elements of the vector. */ \
static inline void __attribute__ ((__unused__)) \
name##_sort (name *v, \
int (*compare) (const type *p1, const type *p2)) \
{ \
qsort (v->ptr, v->len, sizeof (type), (void *)compare); \
} \
\
/* Remove duplicate adjacent elements (uniq). */ \
static inline void __attribute__ ((__unused__)) \
name##_uniq (name *v, \
int (*compare) (type const *p1, type const *p2)) \
{ \
size_t i; \
for (i = 0; i < v->len - 1; ++i) { \
if (compare (&v->ptr[i], &v->ptr[i+1]) == 0) { \
name##_remove (v, i); \
i--; \
} \
} \
} \
\
/* Search for an exactly matching element in the vector using a \
* binary search. Returns a pointer to the element or NULL. \
*/ \
static inline type * __attribute__ ((__unused__)) \
name##_search (const name *v, const void *key, \
int (*compare) (const void *key, const type *v)) \
{ \
return bsearch (key, v->ptr, v->len, sizeof (type), \
(void *)compare); \
} \
\
/* Make a new vector with the same elements. */ \
static inline int __attribute__ ((__unused__)) \
name##_duplicate (name *v, name *copy) \
{ \
/* Note it's allowed for v and copy to be the same pointer. */ \
type const *vptr = v->ptr; \
type *newptr; \
const size_t len = v->len * sizeof (type); \
\
newptr = malloc (len); \
if (newptr == NULL) return -1; \
memcpy (newptr, vptr, len); \
copy->ptr = newptr; \
copy->len = copy->cap = v->len; \
return 0; \
} \
\
/* End with duplicate declaration, so callers must supply ';'. */ \
struct name
#define empty_vector { .ptr = NULL, .len = 0, .cap = 0 }
/* This macro should only be used if:
* - the vector contains pointers, and
* - the pointed-to objects are:
* - neither const- nor volatile-qualified, and
* - allocated with malloc() or equivalent.
*/
#define ADD_VECTOR_EMPTY_METHOD(name) \
/* Call free() on each element of the vector, then reset the vector. \
*/ \
static inline void __attribute__ ((__unused__)) \
name##_empty (name *v) \
{ \
size_t i; \
for (i = 0; i < v->len; ++i) { \
STATIC_ASSERT (TYPE_IS_POINTER (v->ptr[i]), \
_vector_contains_pointers); \
free (v->ptr[i]); \
} \
name##_reset (v); \
} \
\
/* Force callers to supply ';'. */ \
struct name
/* Convenience macro tying together DEFINE_VECTOR_TYPE() and
* ADD_VECTOR_EMPTY_METHOD(). Inherit and forward the requirement for a
* trailing semicolon from ADD_VECTOR_EMPTY_METHOD() to the caller.
*/
#define DEFINE_POINTER_VECTOR_TYPE(name, type) \
DEFINE_VECTOR_TYPE (name, type); \
ADD_VECTOR_EMPTY_METHOD (name)
struct generic_vector {
void *ptr;
size_t len;
size_t cap;
};
extern int generic_vector_reserve (struct generic_vector *v,
size_t n, size_t itemsize,
bool exactly);
extern int generic_vector_reserve_page_aligned (struct generic_vector *v,
size_t n, size_t itemsize);
#endif /* NBDKIT_VECTOR_H */
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