Support custom build directories and move includes

One of the neat tricks an autoconf style project is capable of
is allow configurion/building in a directory other than the
source directory.  The major advantage to this is that you can
build the project various different ways while making changes
in a single source tree.

For example, this project is designed to work on various different
Linux distributions each of which work slightly differently.  This
means that changes need to verified on each of those supported
distributions perferably before the change is committed to the
public git repo.

Using nfs and custom build directories makes this much easier.
I now have a single source tree in nfs mounted on several different
systems each running a supported distribution.  When I make a
change to the source base I suspect may break things I can
concurrently build from the same source on all the systems each
in their own subdirectory.

wget -c http://github.com/downloads/behlendorf/zfs/zfs-x.y.z.tar.gz
tar -xzf zfs-x.y.z.tar.gz
cd zfs-x-y-z

------------------------- run concurrently ----------------------
<ubuntu system>  <fedora system>  <debian system>  <rhel6 system>
mkdir ubuntu     mkdir fedora     mkdir debian     mkdir rhel6
cd ubuntu        cd fedora        cd debian        cd rhel6
../configure     ../configure     ../configure     ../configure
make             make             make             make
make check       make check       make check       make check

This change also moves many of the include headers from individual
incude/sys directories under the modules directory in to a single
top level include directory.  This has the advantage of making
the build rules cleaner and logically it makes a bit more sense.

1 files changed, 309 insertions, 0 deletions

diff --git a/include/sys/avl.h b/include/sys/avl.h
new file mode 100644
index 000000000..ba305c908
--- /dev/null
+++ b/include/sys/avl.h
@@ -0,0 +1,309 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#ifndef	_AVL_H
+#define	_AVL_H
+
+/*
+ * This is a private header file.  Applications should not directly include
+ * this file.
+ */
+
+#ifdef	__cplusplus
+extern "C" {
+#endif
+
+#include <sys/types.h>
+#include <sys/avl_impl.h>
+
+/*
+ * This is a generic implemenatation of AVL trees for use in the Solaris kernel.
+ * The interfaces provide an efficient way of implementing an ordered set of
+ * data structures.
+ *
+ * AVL trees provide an alternative to using an ordered linked list. Using AVL
+ * trees will usually be faster, however they requires more storage. An ordered
+ * linked list in general requires 2 pointers in each data structure. The
+ * AVL tree implementation uses 3 pointers. The following chart gives the
+ * approximate performance of operations with the different approaches:
+ *
+ *	Operation	 Link List	AVL tree
+ *	---------	 --------	--------
+ *	lookup		   O(n)		O(log(n))
+ *
+ *	insert 1 node	 constant	constant
+ *
+ *	delete 1 node	 constant	between constant and O(log(n))
+ *
+ *	delete all nodes   O(n)		O(n)
+ *
+ *	visit the next
+ *	or prev node	 constant	between constant and O(log(n))
+ *
+ *
+ * The data structure nodes are anchored at an "avl_tree_t" (the equivalent
+ * of a list header) and the individual nodes will have a field of
+ * type "avl_node_t" (corresponding to list pointers).
+ *
+ * The type "avl_index_t" is used to indicate a position in the list for
+ * certain calls.
+ *
+ * The usage scenario is generally:
+ *
+ * 1. Create the list/tree with: avl_create()
+ *
+ * followed by any mixture of:
+ *
+ * 2a. Insert nodes with: avl_add(), or avl_find() and avl_insert()
+ *
+ * 2b. Visited elements with:
+ *	 avl_first() - returns the lowest valued node
+ *	 avl_last() - returns the highest valued node
+ *	 AVL_NEXT() - given a node go to next higher one
+ *	 AVL_PREV() - given a node go to previous lower one
+ *
+ * 2c.  Find the node with the closest value either less than or greater
+ *	than a given value with avl_nearest().
+ *
+ * 2d. Remove individual nodes from the list/tree with avl_remove().
+ *
+ * and finally when the list is being destroyed
+ *
+ * 3. Use avl_destroy_nodes() to quickly process/free up any remaining nodes.
+ *    Note that once you use avl_destroy_nodes(), you can no longer
+ *    use any routine except avl_destroy_nodes() and avl_destoy().
+ *
+ * 4. Use avl_destroy() to destroy the AVL tree itself.
+ *
+ * Any locking for multiple thread access is up to the user to provide, just
+ * as is needed for any linked list implementation.
+ */
+
+
+/*
+ * Type used for the root of the AVL tree.
+ */
+typedef struct avl_tree avl_tree_t;
+
+/*
+ * The data nodes in the AVL tree must have a field of this type.
+ */
+typedef struct avl_node avl_node_t;
+
+/*
+ * An opaque type used to locate a position in the tree where a node
+ * would be inserted.
+ */
+typedef uintptr_t avl_index_t;
+
+
+/*
+ * Direction constants used for avl_nearest().
+ */
+#define	AVL_BEFORE	(0)
+#define	AVL_AFTER	(1)
+
+
+/*
+ * Prototypes
+ *
+ * Where not otherwise mentioned, "void *" arguments are a pointer to the
+ * user data structure which must contain a field of type avl_node_t.
+ *
+ * Also assume the user data structures looks like:
+ *	stuct my_type {
+ *		...
+ *		avl_node_t	my_link;
+ *		...
+ *	};
+ */
+
+/*
+ * Initialize an AVL tree. Arguments are:
+ *
+ * tree   - the tree to be initialized
+ * compar - function to compare two nodes, it must return exactly: -1, 0, or +1
+ *          -1 for <, 0 for ==, and +1 for >
+ * size   - the value of sizeof(struct my_type)
+ * offset - the value of OFFSETOF(struct my_type, my_link)
+ */
+extern void avl_create(avl_tree_t *tree,
+	int (*compar) (const void *, const void *), size_t size, size_t offset);
+
+
+/*
+ * Find a node with a matching value in the tree. Returns the matching node
+ * found. If not found, it returns NULL and then if "where" is not NULL it sets
+ * "where" for use with avl_insert() or avl_nearest().
+ *
+ * node   - node that has the value being looked for
+ * where  - position for use with avl_nearest() or avl_insert(), may be NULL
+ */
+extern void *avl_find(avl_tree_t *tree, const void *node, avl_index_t *where);
+
+/*
+ * Insert a node into the tree.
+ *
+ * node   - the node to insert
+ * where  - position as returned from avl_find()
+ */
+extern void avl_insert(avl_tree_t *tree, void *node, avl_index_t where);
+
+/*
+ * Insert "new_data" in "tree" in the given "direction" either after
+ * or before the data "here".
+ *
+ * This might be usefull for avl clients caching recently accessed
+ * data to avoid doing avl_find() again for insertion.
+ *
+ * new_data	- new data to insert
+ * here		- existing node in "tree"
+ * direction	- either AVL_AFTER or AVL_BEFORE the data "here".
+ */
+extern void avl_insert_here(avl_tree_t *tree, void *new_data, void *here,
+    int direction);
+
+
+/*
+ * Return the first or last valued node in the tree. Will return NULL
+ * if the tree is empty.
+ *
+ */
+extern void *avl_first(avl_tree_t *tree);
+extern void *avl_last(avl_tree_t *tree);
+
+
+/*
+ * Return the next or previous valued node in the tree.
+ * AVL_NEXT() will return NULL if at the last node.
+ * AVL_PREV() will return NULL if at the first node.
+ *
+ * node   - the node from which the next or previous node is found
+ */
+#define	AVL_NEXT(tree, node)	avl_walk(tree, node, AVL_AFTER)
+#define	AVL_PREV(tree, node)	avl_walk(tree, node, AVL_BEFORE)
+
+
+/*
+ * Find the node with the nearest value either greater or less than
+ * the value from a previous avl_find(). Returns the node or NULL if
+ * there isn't a matching one.
+ *
+ * where     - position as returned from avl_find()
+ * direction - either AVL_BEFORE or AVL_AFTER
+ *
+ * EXAMPLE get the greatest node that is less than a given value:
+ *
+ *	avl_tree_t *tree;
+ *	struct my_data look_for_value = {....};
+ *	struct my_data *node;
+ *	struct my_data *less;
+ *	avl_index_t where;
+ *
+ *	node = avl_find(tree, &look_for_value, &where);
+ *	if (node != NULL)
+ *		less = AVL_PREV(tree, node);
+ *	else
+ *		less = avl_nearest(tree, where, AVL_BEFORE);
+ */
+extern void *avl_nearest(avl_tree_t *tree, avl_index_t where, int direction);
+
+
+/*
+ * Add a single node to the tree.
+ * The node must not be in the tree, and it must not
+ * compare equal to any other node already in the tree.
+ *
+ * node   - the node to add
+ */
+extern void avl_add(avl_tree_t *tree, void *node);
+
+
+/*
+ * Remove a single node from the tree.  The node must be in the tree.
+ *
+ * node   - the node to remove
+ */
+extern void avl_remove(avl_tree_t *tree, void *node);
+
+/*
+ * Reinsert a node only if its order has changed relative to its nearest
+ * neighbors. To optimize performance avl_update_lt() checks only the previous
+ * node and avl_update_gt() checks only the next node. Use avl_update_lt() and
+ * avl_update_gt() only if you know the direction in which the order of the
+ * node may change.
+ */
+extern boolean_t avl_update(avl_tree_t *, void *);
+extern boolean_t avl_update_lt(avl_tree_t *, void *);
+extern boolean_t avl_update_gt(avl_tree_t *, void *);
+
+/*
+ * Return the number of nodes in the tree
+ */
+extern ulong_t avl_numnodes(avl_tree_t *tree);
+
+/*
+ * Return B_TRUE if there are zero nodes in the tree, B_FALSE otherwise.
+ */
+extern boolean_t avl_is_empty(avl_tree_t *tree);
+
+/*
+ * Used to destroy any remaining nodes in a tree. The cookie argument should
+ * be initialized to NULL before the first call. Returns a node that has been
+ * removed from the tree and may be free()'d. Returns NULL when the tree is
+ * empty.
+ *
+ * Once you call avl_destroy_nodes(), you can only continuing calling it and
+ * finally avl_destroy(). No other AVL routines will be valid.
+ *
+ * cookie - a "void *" used to save state between calls to avl_destroy_nodes()
+ *
+ * EXAMPLE:
+ *	avl_tree_t *tree;
+ *	struct my_data *node;
+ *	void *cookie;
+ *
+ *	cookie = NULL;
+ *	while ((node = avl_destroy_nodes(tree, &cookie)) != NULL)
+ *		free(node);
+ *	avl_destroy(tree);
+ */
+extern void *avl_destroy_nodes(avl_tree_t *tree, void **cookie);
+
+
+/*
+ * Final destroy of an AVL tree. Arguments are:
+ *
+ * tree   - the empty tree to destroy
+ */
+extern void avl_destroy(avl_tree_t *tree);
+
+
+
+#ifdef	__cplusplus
+}
+#endif
+
+#endif	/* _AVL_H */