/* Initializes 'b' as an empty ofpbuf that contains the 'allocated' bytes of
* memory starting at 'base'. 'base' should point to a buffer on the stack.
* (Nothing actually relies on 'base' being allocated on the stack. It could
* be static or malloc()'d memory. But stack space is the most common use
* case.)
*
* 'base' should be appropriately aligned. Using an array of uint32_t or
* uint64_t for the buffer is a reasonable way to ensure appropriate alignment
* for 32- or 64-bit data.
*
* An ofpbuf operation that requires reallocating data will copy the provided
* buffer into a malloc()'d buffer. Thus, it is wise to call ofpbuf_uninit()
* on an ofpbuf initialized by this function, so that if it expanded into the
* heap, that memory is freed. */
void
ofpbuf_use_stub(struct ofpbuf *b, void *base, size_t allocated)
{
ofpbuf_use__(b, base, allocated, OFPBUF_STUB);
}
/* Initializes 'b' as an empty ofpbuf that contains the 'allocated' bytes of
* memory starting at 'base'. 'base' should be the first byte of a region
* obtained from malloc(). It will be freed (with free()) if 'b' is resized or
* freed. */
void
ofpbuf_use(struct ofpbuf *b, void *base, size_t allocated)
{
ofpbuf_use__(b, base, allocated, OFPBUF_MALLOC);
}
/* Initializes 'b' as an empty ofpbuf that contains the 'allocated' bytes of
* memory starting at 'base'. 'base' should point to a buffer on the stack.
* (Nothing actually relies on 'base' being allocated on the stack. It could
* be static or malloc()'d memory. But stack space is the most common use
* case.)
*
* 'base' should be appropriately aligned. Using an array of uint32_t or
* uint64_t for the buffer is a reasonable way to ensure appropriate alignment
* for 32- or 64-bit data.
*
* An ofpbuf operation that requires reallocating data will assert-fail if this
* function was used to initialize it. Thus, one need not call ofpbuf_uninit()
* on an ofpbuf initialized by this function (though doing so is harmless),
* because it is guaranteed that 'b' does not own any heap-allocated memory. */
void
ofpbuf_use_stack(struct ofpbuf *b, void *base, size_t allocated)
{
ofpbuf_use__(b, base, allocated, OFPBUF_STACK);
}
/* Initializes 'b' as an ofpbuf whose data starts at 'data' and continues for
* 'size' bytes. This is appropriate for an ofpbuf that will be used to
* inspect existing data, without moving it around or reallocating it, and
* generally without modifying it at all.
*
* An ofpbuf operation that requires reallocating data will assert-fail if this
* function was used to initialize it. */
void
ofpbuf_use_const(struct ofpbuf *b, const void *data, size_t size)
{
ofpbuf_use__(b, (void *) data, size, OFPBUF_STACK);
b->size = size;
}
