diff options
Diffstat (limited to 'lib/libc/stdlib/qr.h')
-rw-r--r-- | lib/libc/stdlib/qr.h | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/lib/libc/stdlib/qr.h b/lib/libc/stdlib/qr.h new file mode 100644 index 0000000..6e02321 --- /dev/null +++ b/lib/libc/stdlib/qr.h @@ -0,0 +1,106 @@ +/****************************************************************************** + * + * Copyright (C) 2002 Jason Evans <jasone@FreeBSD.org>. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice(s), this list of conditions and the following disclaimer + * unmodified other than the allowable addition of one or more + * copyright notices. + * 2. Redistributions in binary form must reproduce the above copyright + * notice(s), this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``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 THE COPYRIGHT HOLDER(S) 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. + * + ******************************************************************************/ + +#ifndef QR_H_ +#define QR_H_ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +/* Ring definitions. */ +#define qr(a_type) \ +struct { \ + a_type *qre_next; \ + a_type *qre_prev; \ +} + +/* Ring functions. */ +#define qr_new(a_qr, a_field) do { \ + (a_qr)->a_field.qre_next = (a_qr); \ + (a_qr)->a_field.qre_prev = (a_qr); \ +} while (0) + +#define qr_next(a_qr, a_field) ((a_qr)->a_field.qre_next) + +#define qr_prev(a_qr, a_field) ((a_qr)->a_field.qre_prev) + +#define qr_before_insert(a_qrelm, a_qr, a_field) do { \ + (a_qr)->a_field.qre_prev = (a_qrelm)->a_field.qre_prev; \ + (a_qr)->a_field.qre_next = (a_qrelm); \ + (a_qr)->a_field.qre_prev->a_field.qre_next = (a_qr); \ + (a_qrelm)->a_field.qre_prev = (a_qr); \ +} while (0) + +#define qr_after_insert(a_qrelm, a_qr, a_field) \ + do \ + { \ + (a_qr)->a_field.qre_next = (a_qrelm)->a_field.qre_next; \ + (a_qr)->a_field.qre_prev = (a_qrelm); \ + (a_qr)->a_field.qre_next->a_field.qre_prev = (a_qr); \ + (a_qrelm)->a_field.qre_next = (a_qr); \ + } while (0) + +#define qr_meld(a_qr_a, a_qr_b, a_field) do { \ + void *t; \ + (a_qr_a)->a_field.qre_prev->a_field.qre_next = (a_qr_b); \ + (a_qr_b)->a_field.qre_prev->a_field.qre_next = (a_qr_a); \ + t = (a_qr_a)->a_field.qre_prev; \ + (a_qr_a)->a_field.qre_prev = (a_qr_b)->a_field.qre_prev; \ + (a_qr_b)->a_field.qre_prev = t; \ +} while (0) + +/* qr_meld() and qr_split() are functionally equivalent, so there's no need to + * have two copies of the code. */ +#define qr_split(a_qr_a, a_qr_b, a_field) \ + qr_meld((a_qr_a), (a_qr_b), a_field) + +#define qr_remove(a_qr, a_field) do { \ + (a_qr)->a_field.qre_prev->a_field.qre_next \ + = (a_qr)->a_field.qre_next; \ + (a_qr)->a_field.qre_next->a_field.qre_prev \ + = (a_qr)->a_field.qre_prev; \ + (a_qr)->a_field.qre_next = (a_qr); \ + (a_qr)->a_field.qre_prev = (a_qr); \ +} while (0) + +#define qr_foreach(var, a_qr, a_field) \ + for ((var) = (a_qr); \ + (var) != NULL; \ + (var) = (((var)->a_field.qre_next != (a_qr)) \ + ? (var)->a_field.qre_next : NULL)) + +#define qr_reverse_foreach(var, a_qr, a_field) \ + for ((var) = ((a_qr) != NULL) ? qr_prev(a_qr, a_field) : NULL; \ + (var) != NULL; \ + (var) = (((var) != (a_qr)) \ + ? (var)->a_field.qre_prev : NULL)) + +#endif /* QR_H_ */ |