Support graceful shutdown

[wmpus] / util.c

diff --git a/util.c b/util.c
index e69de29bb2d1d6434b8b29ae775ad8c2e48c5391..aeb766eaa01f32d65234e84261b97d63d503efe3 100644 (file)
--- a/util.c
+++ b/util.c
@@ -0,0 +1,104 @@
+/*
+ * Copyright (c) 2011, Andy Spencer <andy753421@gmail.com>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+
+#include "util.h"
+
+/* Doubly linked lists */
+list_t *list_insert(list_t *next, void *data)
+{
+       list_t *node = new0(list_t);
+       node->data = data;
+       node->next = next;
+       node->prev = next ? next->prev : NULL;
+       if (node->next) node->next->prev = node;
+       if (node->prev) node->prev->next = node;
+       return node;
+}
+
+void list_insert_after(list_t *prev, void *data)
+{
+       // prev must be valid,
+       // as we cannot return the original list head
+       list_t *node = new0(list_t);
+       node->data = data;
+       node->prev = prev;
+       node->next = prev->next;
+       prev->next = node;
+       if (node->next) node->next->prev = node;
+}
+
+list_t *list_append(list_t *head, void *data)
+{
+       list_t *last = head;
+       while (last && last->next)
+               last = last->next;
+       list_t *node = new0(list_t);
+       node->data = data;
+       node->prev = last;
+       if (last) last->next = node;
+       return last ? head : node;
+}
+
+list_t *list_remove(list_t *head, list_t *node, int freedata)
+{
+       list_t *next = node->next;
+       list_t *prev = node->prev;
+       if (next) next->prev = prev;
+       if (prev) prev->next = next;
+       if (freedata)
+               free(node->data);
+       free(node);
+       return head == node ? next : head;
+}
+
+int list_length(list_t *node)
+{
+       int len = 0;
+       for (; node; node = node->next)
+               len++;
+       return len;
+}
+
+list_t *list_last(list_t *list)
+{
+       while (list && list->next)
+               list = list->next;
+       return list;
+}
+
+list_t *list_find(list_t *list, void *data)
+{
+       for (list_t *cur = list; cur; cur = cur->next)
+               if (cur->data == data)
+                       return cur;
+       return NULL;
+}
+
+/* Misc */
+int error(char *fmt, ...)
+{
+       va_list ap;
+       va_start(ap, fmt);
+       fprintf(stderr, "Error: ");
+       vfprintf(stderr, fmt, ap);
+       fprintf(stderr, "\n");
+       va_end(ap);
+       exit(1);
+       return 0;
+}