| /* |
| Copyright (c) 2012 Martin Sustrik All rights reserved. |
| |
| Permission is hereby granted, free of charge, to any person obtaining a copy |
| of this software and associated documentation files (the "Software"), |
| to deal in the Software without restriction, including without limitation |
| the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| and/or sell copies of the Software, and to permit persons to whom |
| the Software is furnished to do so, subject to the following conditions: |
| |
| The above copyright notice and this permission notice shall be included |
| in all copies or substantial portions of the Software. |
| |
| THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
| IN THE SOFTWARE. |
| */ |
| |
| #include <stddef.h> |
| |
| #include "queue.h" |
| #include "err.h" |
| |
| void nn_queue_init (struct nn_queue *self) |
| { |
| self->head = NULL; |
| self->tail = NULL; |
| } |
| |
| void nn_queue_term (struct nn_queue *self) |
| { |
| self->head = NULL; |
| self->tail = NULL; |
| } |
| |
| int nn_queue_empty (struct nn_queue *self) |
| { |
| return self->head ? 0 : 1; |
| } |
| |
| void nn_queue_push (struct nn_queue *self, struct nn_queue_item *item) |
| { |
| nn_assert (item->next == NN_QUEUE_NOTINQUEUE); |
| |
| item->next = NULL; |
| if (!self->head) |
| self->head = item; |
| if (self->tail) |
| self->tail->next = item; |
| self->tail = item; |
| } |
| |
| void nn_queue_remove (struct nn_queue *self, struct nn_queue_item *item) |
| { |
| struct nn_queue_item *it; |
| struct nn_queue_item *prev; |
| |
| if (item->next == NN_QUEUE_NOTINQUEUE) |
| return; |
| |
| prev = NULL; |
| for (it = self->head; it != NULL; it = it->next) { |
| if (it == item) { |
| if (self->head == it) |
| self->head = it->next; |
| if (self->tail == it) |
| self->tail = prev; |
| if (prev) |
| prev->next = it->next; |
| item->next = NN_QUEUE_NOTINQUEUE; |
| return; |
| } |
| prev = it; |
| } |
| } |
| |
| struct nn_queue_item *nn_queue_pop (struct nn_queue *self) |
| { |
| struct nn_queue_item *result; |
| |
| if (!self->head) |
| return NULL; |
| result = self->head; |
| self->head = result->next; |
| if (!self->head) |
| self->tail = NULL; |
| result->next = NN_QUEUE_NOTINQUEUE; |
| return result; |
| } |
| |
| void nn_queue_item_init (struct nn_queue_item *self) |
| { |
| self->next = NN_QUEUE_NOTINQUEUE; |
| } |
| |
| void nn_queue_item_term (struct nn_queue_item *self) |
| { |
| nn_assert (self->next == NN_QUEUE_NOTINQUEUE); |
| } |
| |
| int nn_queue_item_isinqueue (struct nn_queue_item *self) |
| { |
| return self->next == NN_QUEUE_NOTINQUEUE ? 0 : 1; |
| } |
| |