diff options
Diffstat (limited to 'src/vlib')
| -rw-r--r-- | src/vlib/buffer_funcs.h | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/src/vlib/buffer_funcs.h b/src/vlib/buffer_funcs.h index 4831eb5ebac..cc56db7762c 100644 --- a/src/vlib/buffer_funcs.h +++ b/src/vlib/buffer_funcs.h @@ -1004,6 +1004,68 @@ vlib_validate_buffer_set_in_use (vlib_buffer_t * b, u32 expected) #endif } +/** minimum data size of first buffer in a buffer chain */ +#define VLIB_BUFFER_CHAIN_MIN_FIRST_DATA_SIZE (256) + +/** + * @brief compress buffer chain in a way where the first buffer is at least + * VLIB_BUFFER_CHAIN_MIN_FIRST_DATA_SIZE long + * + * @param[in] vm - vlib_main + * @param[in,out] first - first buffer in chain + * @param[in,out] discard_vector - vector of buffer indexes which were removed + * from the chain + */ +always_inline void +vlib_buffer_chain_compress (vlib_main_t * vm, + vlib_buffer_t * first, u32 ** discard_vector) +{ + if (first->current_length >= VLIB_BUFFER_CHAIN_MIN_FIRST_DATA_SIZE || + !(first->flags & VLIB_BUFFER_NEXT_PRESENT)) + { + /* this is already big enough or not a chain */ + return; + } + /* probe free list to find allocated buffer size to avoid overfill */ + u32 index; + vlib_buffer_free_list_t *free_list = + vlib_buffer_get_buffer_free_list (vm, first, &index); + + u32 want_first_size = clib_min (VLIB_BUFFER_CHAIN_MIN_FIRST_DATA_SIZE, + free_list->n_data_bytes - + first->current_data); + do + { + vlib_buffer_t *second = vlib_get_buffer (vm, first->next_buffer); + u32 need = want_first_size - first->current_length; + u32 amount_to_copy = clib_min (need, second->current_length); + clib_memcpy (((u8 *) vlib_buffer_get_current (first)) + + first->current_length, + vlib_buffer_get_current (second), amount_to_copy); + first->current_length += amount_to_copy; + vlib_buffer_advance (second, amount_to_copy); + if (first->flags & VLIB_BUFFER_TOTAL_LENGTH_VALID) + { + first->total_length_not_including_first_buffer -= amount_to_copy; + } + if (!second->current_length) + { + vec_add1 (*discard_vector, first->next_buffer); + if (second->flags & VLIB_BUFFER_NEXT_PRESENT) + { + first->next_buffer = second->next_buffer; + } + else + { + first->flags &= ~VLIB_BUFFER_NEXT_PRESENT; + } + second->flags &= ~VLIB_BUFFER_NEXT_PRESENT; + } + } + while ((first->current_length < want_first_size) && + (first->flags & VLIB_BUFFER_NEXT_PRESENT)); +} + #endif /* included_vlib_buffer_funcs_h */ /* |