Initial Spring 2016 commit.

kern/lib/array.c

@@ -0,0 +1,135 @@
+/*-
+ * Copyright (c) 2009 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by David A. Holland.
+ *
+ * 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, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, 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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``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 FOUNDATION OR CONTRIBUTORS
+ * 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.
+ */
+
+#define ARRAYINLINE
+
+#include <types.h>
+#include <kern/errno.h>
+#include <lib.h>
+#include <array.h>
+
+struct array *
+array_create(void)
+{
+	struct array *a;
+
+	a = kmalloc(sizeof(*a));
+	if (a != NULL) {
+		array_init(a);
+	}
+	return a;
+}
+
+void
+array_destroy(struct array *a)
+{
+	array_cleanup(a);
+	kfree(a);
+}
+
+void
+array_init(struct array *a)
+{
+	a->num = a->max = 0;
+	a->v = NULL;
+}
+
+void
+array_cleanup(struct array *a)
+{
+	/*
+	 * Require array to be empty - helps avoid memory leaks since
+	 * we don't/can't free anything any contents may be pointing
+	 * to.
+	 */
+	ARRAYASSERT(a->num == 0);
+	kfree(a->v);
+#ifdef ARRAYS_CHECKED
+	a->v = NULL;
+#endif
+}
+
+int
+array_preallocate(struct array *a, unsigned num)
+{
+	void **newptr;
+	unsigned newmax;
+
+	if (num > a->max) {
+		/* Don't touch A until the allocation succeeds. */
+		newmax = a->max;
+		while (num > newmax) {
+			newmax = newmax ? newmax*2 : 4;
+		}
+
+		/*
+		 * We don't have krealloc, and it wouldn't be
+		 * worthwhile to implement just for this. So just
+		 * allocate a new block and copy. (Exercise: what
+		 * about this and/or kmalloc makes it not worthwhile?)
+		 */
+
+		newptr = kmalloc(newmax*sizeof(*a->v));
+		if (newptr == NULL) {
+			return ENOMEM;
+		}
+		memcpy(newptr, a->v, a->num*sizeof(*a->v));
+		kfree(a->v);
+		a->v = newptr;
+		a->max = newmax;
+	}
+	return 0;
+}
+
+int
+array_setsize(struct array *a, unsigned num)
+{
+	int result;
+
+	result = array_preallocate(a, num);
+	if (result) {
+		return result;
+	}
+	a->num = num;
+
+	return 0;
+}
+
+void
+array_remove(struct array *a, unsigned index)
+{
+        unsigned num_to_move;
+
+        ARRAYASSERT(a->num <= a->max);
+        ARRAYASSERT(index < a->num);
+
+        num_to_move = a->num - (index + 1);
+        memmove(a->v + index, a->v + index+1, num_to_move*sizeof(void *));
+        a->num--;
+}