avltree-omap: New module.

* lib/gl_avltree_omap.h: New file.
* lib/gl_avltree_omap.c: New file.
* lib/gl_avltree_ordered.h: Code moved to here from
lib/gl_avltree_oset.c. Parameterize.
* lib/gl_avltree_oset.c: Include gl_avltree_ordered.h.
* lib/gl_anytree_omap.h: New file.
* modules/avltree-omap: New file.
* modules/avltree-oset (Files): Add lib/gl_avltree_ordered.h.
(Makefile.am): Add gl_avltree_ordered.h to lib_SOURCES.

1 files changed, 15 insertions, 527 deletions

diff --git a/lib/gl_avltree_oset.c b/lib/gl_avltree_oset.c
index ead337c0e1..4bda91eaae 100644
--- a/lib/gl_avltree_oset.c
+++ b/lib/gl_avltree_oset.c
@@ -22,542 +22,30 @@
 
 #include <stdlib.h>
 
-/* An AVL tree is a binary tree where
-   1. The height of each node is calculated as
-        heightof(node) = 1 + max (heightof(node.left), heightof(node.right)).
-   2. The heights of the subtrees of each node differ by at most 1:
-        | heightof(right) - heightof(left) | <= 1.
-   3. The index of the elements in the node.left subtree are smaller than
-      the index of node.
-      The index of the elements in the node.right subtree are larger than
-      the index of node.
- */
-
 /* -------------------------- gl_oset_t Data Type -------------------------- */
 
-/* Tree node implementation, valid for this file only.  */
-struct gl_oset_node_impl
-{
-  struct gl_oset_node_impl *left;   /* left branch, or NULL */
-  struct gl_oset_node_impl *right;  /* right branch, or NULL */
-  /* Parent pointer, or NULL. The parent pointer is not needed for most
-     operations.  It is needed so that a gl_oset_node_t can be returned
-     without memory allocation, on which the functions gl_oset_remove_node,
-     gl_oset_add_before, gl_oset_add_after can be implemented.  */
-  struct gl_oset_node_impl *parent;
-  int balance;                      /* heightof(right) - heightof(left),
-                                       always = -1 or 0 or 1 */
+/* Parameterization of gl_avltree_ordered.h.  */
+#define CONTAINER_T gl_oset_t
+#define CONTAINER_IMPL gl_oset_impl
+#define CONTAINER_IMPL_BASE gl_oset_impl_base
+#define NODE_IMPL gl_oset_node_impl
+#define NODE_T gl_oset_node_t
+#define NODE_PAYLOAD_FIELDS \
   const void *value;
-};
-typedef struct gl_oset_node_impl * gl_oset_node_t;
-
-/* Concrete gl_oset_impl type, valid for this file only.  */
-struct gl_oset_impl
-{
-  struct gl_oset_impl_base base;
-  struct gl_oset_node_impl *root;   /* root node or NULL */
-  size_t count;                     /* number of nodes */
-};
-
-/* An AVL tree of height h has at least F_(h+2) - 1 [Fibonacci number] and at
-   most 2^h - 1 elements.  So, h <= 84 (because a tree of height h >= 85 would
-   have at least F_87 - 1 elements, and because even on 64-bit machines,
-     sizeof (gl_oset_node_impl) * (F_87 - 1) > 2^64
-   this would exceed the address space of the machine.  */
-#define MAXHEIGHT 83
-
-/* Ensure the tree is balanced, after an insertion or deletion operation.
-   The height of NODE is incremented by HEIGHT_DIFF (1 or -1).
-   PARENT = NODE->parent.  (NODE can also be NULL.  But PARENT is non-NULL.)
-   Rotation operations are performed starting at PARENT (not NODE itself!).  */
-static void
-rebalance (gl_oset_t set,
-           gl_oset_node_t node, int height_diff, gl_oset_node_t parent)
-{
-  for (;;)
-    {
-      gl_oset_node_t child;
-      int previous_balance;
-      int balance_diff;
-      gl_oset_node_t nodeleft;
-      gl_oset_node_t noderight;
-
-      child = node;
-      node = parent;
-
-      previous_balance = node->balance;
-
-      /* The balance of NODE is incremented by BALANCE_DIFF: +1 if the right
-         branch's height has increased by 1 or the left branch's height has
-         decreased by 1, -1 if the right branch's height has decreased by 1 or
-         the left branch's height has increased by 1, 0 if no height change.  */
-      if (node->left != NULL || node->right != NULL)
-        balance_diff = (child == node->right ? height_diff : -height_diff);
-      else
-        /* Special case where above formula doesn't work, because the caller
-           didn't tell whether node's left or right branch shrunk from height 1
-           to NULL.  */
-        balance_diff = - previous_balance;
-
-      node->balance += balance_diff;
-      if (balance_diff == previous_balance)
-        {
-          /* node->balance is outside the range [-1,1].  Must rotate.  */
-          gl_oset_node_t *nodep;
-
-          if (node->parent == NULL)
-            /* node == set->root */
-            nodep = &set->root;
-          else if (node->parent->left == node)
-            nodep = &node->parent->left;
-          else if (node->parent->right == node)
-            nodep = &node->parent->right;
-          else
-            abort ();
-
-          nodeleft = node->left;
-          noderight = node->right;
-
-          if (balance_diff < 0)
-            {
-              /* node->balance = -2.  The subtree is heavier on the left side.
-                 Rotate from left to right:
-
-                                  *
-                                /   \
-                             h+2      h
-               */
-              gl_oset_node_t nodeleftright = nodeleft->right;
-              if (nodeleft->balance <= 0)
-                {
-                  /*
-                              *                    h+2|h+3
-                            /   \                  /    \
-                         h+2      h      -->      /   h+1|h+2
-                         / \                      |    /    \
-                       h+1 h|h+1                 h+1  h|h+1  h
-                   */
-                  node->left = nodeleftright;
-                  nodeleft->right = node;
-
-                  nodeleft->parent = node->parent;
-                  node->parent = nodeleft;
-                  if (nodeleftright != NULL)
-                    nodeleftright->parent = node;
-
-                  nodeleft->balance += 1;
-                  node->balance = - nodeleft->balance;
-
-                  *nodep = nodeleft;
-                  height_diff = (height_diff < 0
-                                 ? /* noderight's height had been decremented from
-                                      h+1 to h.  The subtree's height changes from
-                                      h+3 to h+2|h+3.  */
-                                   nodeleft->balance - 1
-                                 : /* nodeleft's height had been incremented from
-                                      h+1 to h+2.  The subtree's height changes from
-                                      h+2 to h+2|h+3.  */
-                                   nodeleft->balance);
-                }
-              else
-                {
-                  /*
-                            *                     h+2
-                          /   \                 /     \
-                       h+2      h      -->    h+1     h+1
-                       / \                    / \     / \
-                      h  h+1                 h   L   R   h
-                         / \
-                        L   R
-
-                   */
-                  gl_oset_node_t L = nodeleft->right = nodeleftright->left;
-                  gl_oset_node_t R = node->left = nodeleftright->right;
-                  nodeleftright->left = nodeleft;
-                  nodeleftright->right = node;
-
-                  nodeleftright->parent = node->parent;
-                  if (L != NULL)
-                    L->parent = nodeleft;
-                  if (R != NULL)
-                    R->parent = node;
-                  nodeleft->parent = nodeleftright;
-                  node->parent = nodeleftright;
-
-                  nodeleft->balance = (nodeleftright->balance > 0 ? -1 : 0);
-                  node->balance = (nodeleftright->balance < 0 ? 1 : 0);
-                  nodeleftright->balance = 0;
+#define NODE_PAYLOAD_PARAMS \
+  const void *elt
+#define NODE_PAYLOAD_ASSIGN(node) \
+  node->value = elt;
+#define NODE_PAYLOAD_DISPOSE \
+  if (container->base.dispose_fn != NULL) \
+    container->base.dispose_fn (node->value);
 
-                  *nodep = nodeleftright;
-                  height_diff = (height_diff < 0
-                                 ? /* noderight's height had been decremented from
-                                      h+1 to h.  The subtree's height changes from
-                                      h+3 to h+2.  */
-                                   -1
-                                 : /* nodeleft's height had been incremented from
-                                      h+1 to h+2.  The subtree's height changes from
-                                      h+2 to h+2.  */
-                                   0);
-                }
-            }
-          else
-            {
-              /* node->balance = 2.  The subtree is heavier on the right side.
-                 Rotate from right to left:
-
-                                  *
-                                /   \
-                              h      h+2
-               */
-              gl_oset_node_t noderightleft = noderight->left;
-              if (noderight->balance >= 0)
-                {
-                  /*
-                              *                    h+2|h+3
-                            /   \                   /    \
-                          h      h+2     -->    h+1|h+2   \
-                                 / \            /    \    |
-                             h|h+1 h+1         h   h|h+1 h+1
-                   */
-                  node->right = noderightleft;
-                  noderight->left = node;
-
-                  noderight->parent = node->parent;
-                  node->parent = noderight;
-                  if (noderightleft != NULL)
-                    noderightleft->parent = node;
-
-                  noderight->balance -= 1;
-                  node->balance = - noderight->balance;
-
-                  *nodep = noderight;
-                  height_diff = (height_diff < 0
-                                 ? /* nodeleft's height had been decremented from
-                                      h+1 to h.  The subtree's height changes from
-                                      h+3 to h+2|h+3.  */
-                                   - noderight->balance - 1
-                                 : /* noderight's height had been incremented from
-                                      h+1 to h+2.  The subtree's height changes from
-                                      h+2 to h+2|h+3.  */
-                                   - noderight->balance);
-                }
-              else
-                {
-                  /*
-                            *                    h+2
-                          /   \                /     \
-                        h      h+2    -->    h+1     h+1
-                               / \           / \     / \
-                             h+1  h         h   L   R   h
-                             / \
-                            L   R
-
-                   */
-                  gl_oset_node_t L = node->right = noderightleft->left;
-                  gl_oset_node_t R = noderight->left = noderightleft->right;
-                  noderightleft->left = node;
-                  noderightleft->right = noderight;
-
-                  noderightleft->parent = node->parent;
-                  if (L != NULL)
-                    L->parent = node;
-                  if (R != NULL)
-                    R->parent = noderight;
-                  node->parent = noderightleft;
-                  noderight->parent = noderightleft;
-
-                  node->balance = (noderightleft->balance > 0 ? -1 : 0);
-                  noderight->balance = (noderightleft->balance < 0 ? 1 : 0);
-                  noderightleft->balance = 0;
-
-                  *nodep = noderightleft;
-                  height_diff = (height_diff < 0
-                                 ? /* nodeleft's height had been decremented from
-                                      h+1 to h.  The subtree's height changes from
-                                      h+3 to h+2.  */
-                                   -1
-                                 : /* noderight's height had been incremented from
-                                      h+1 to h+2.  The subtree's height changes from
-                                      h+2 to h+2.  */
-                                   0);
-                }
-            }
-          node = *nodep;
-        }
-      else
-        {
-          /* No rotation needed.  Only propagation of the height change to the
-             next higher level.  */
-          if (height_diff < 0)
-            height_diff = (previous_balance == 0 ? 0 : -1);
-          else
-            height_diff = (node->balance == 0 ? 0 : 1);
-        }
-
-      if (height_diff == 0)
-        break;
-
-      parent = node->parent;
-      if (parent == NULL)
-        break;
-    }
-}
-
-static gl_oset_node_t
-gl_tree_nx_add_first (gl_oset_t set, const void *elt)
-{
-  /* Create new node.  */
-  gl_oset_node_t new_node =
-    (struct gl_oset_node_impl *) malloc (sizeof (struct gl_oset_node_impl));
-
-  if (new_node == NULL)
-    return NULL;
-
-  new_node->left = NULL;
-  new_node->right = NULL;
-  new_node->balance = 0;
-  new_node->value = elt;
-
-  /* Add it to the tree.  */
-  if (set->root == NULL)
-    {
-      set->root = new_node;
-      new_node->parent = NULL;
-    }
-  else
-    {
-      gl_oset_node_t node;
-
-      for (node = set->root; node->left != NULL; )
-        node = node->left;
-
-      node->left = new_node;
-      new_node->parent = node;
-      node->balance--;
-
-      /* Rebalance.  */
-      if (node->right == NULL && node->parent != NULL)
-        rebalance (set, node, 1, node->parent);
-    }
-
-  set->count++;
-  return new_node;
-}
-
-static gl_oset_node_t
-gl_tree_nx_add_before (gl_oset_t set, gl_oset_node_t node, const void *elt)
-{
-  /* Create new node.  */
-  gl_oset_node_t new_node =
-    (struct gl_oset_node_impl *) malloc (sizeof (struct gl_oset_node_impl));
-  bool height_inc;
-
-  if (new_node == NULL)
-    return NULL;
-
-  new_node->left = NULL;
-  new_node->right = NULL;
-  new_node->balance = 0;
-  new_node->value = elt;
-
-  /* Add it to the tree.  */
-  if (node->left == NULL)
-    {
-      node->left = new_node;
-      node->balance--;
-      height_inc = (node->right == NULL);
-    }
-  else
-    {
-      for (node = node->left; node->right != NULL; )
-        node = node->right;
-      node->right = new_node;
-      node->balance++;
-      height_inc = (node->left == NULL);
-    }
-  new_node->parent = node;
-
-  /* Rebalance.  */
-  if (height_inc && node->parent != NULL)
-    rebalance (set, node, 1, node->parent);
-
-  set->count++;
-  return new_node;
-}
-
-static gl_oset_node_t
-gl_tree_nx_add_after (gl_oset_t set, gl_oset_node_t node, const void *elt)
-{
-  /* Create new node.  */
-  gl_oset_node_t new_node =
-    (struct gl_oset_node_impl *) malloc (sizeof (struct gl_oset_node_impl));
-  bool height_inc;
-
-  if (new_node == NULL)
-    return NULL;
-
-  new_node->left = NULL;
-  new_node->right = NULL;
-  new_node->balance = 0;
-  new_node->value = elt;
-
-  /* Add it to the tree.  */
-  if (node->right == NULL)
-    {
-      node->right = new_node;
-      node->balance++;
-      height_inc = (node->left == NULL);
-    }
-  else
-    {
-      for (node = node->right; node->left != NULL; )
-        node = node->left;
-      node->left = new_node;
-      node->balance--;
-      height_inc = (node->right == NULL);
-    }
-  new_node->parent = node;
-
-  /* Rebalance.  */
-  if (height_inc && node->parent != NULL)
-    rebalance (set, node, 1, node->parent);
-
-  set->count++;
-  return new_node;
-}
-
-static bool
-gl_tree_remove_node (gl_oset_t set, gl_oset_node_t node)
-{
-  gl_oset_node_t parent = node->parent;
-
-  if (node->left == NULL)
-    {
-      /* Replace node with node->right.  */
-      gl_oset_node_t child = node->right;
-
-      if (child != NULL)
-        child->parent = parent;
-      if (parent == NULL)
-        set->root = child;
-      else
-        {
-          if (parent->left == node)
-            parent->left = child;
-          else /* parent->right == node */
-            parent->right = child;
-
-          rebalance (set, child, -1, parent);
-        }
-    }
-  else if (node->right == NULL)
-    {
-      /* It is not absolutely necessary to treat this case.  But the more
-         general case below is more complicated, hence slower.  */
-      /* Replace node with node->left.  */
-      gl_oset_node_t child = node->left;
-
-      child->parent = parent;
-      if (parent == NULL)
-        set->root = child;
-      else
-        {
-          if (parent->left == node)
-            parent->left = child;
-          else /* parent->right == node */
-            parent->right = child;
-
-          rebalance (set, child, -1, parent);
-        }
-    }
-  else
-    {
-      /* Replace node with the rightmost element of the node->left subtree.  */
-      gl_oset_node_t subst;
-      gl_oset_node_t subst_parent;
-      gl_oset_node_t child;
-
-      for (subst = node->left; subst->right != NULL; )
-        subst = subst->right;
-
-      subst_parent = subst->parent;
-
-      child = subst->left;
-
-      /* The case subst_parent == node is special:  If we do nothing special,
-         we get confusion about node->left, subst->left and child->parent.
-           subst_parent == node
-           <==> The 'for' loop above terminated immediately.
-           <==> subst == subst_parent->left
-                [otherwise subst == subst_parent->right]
-         In this case, we would need to first set
-           child->parent = node; node->left = child;
-         and later - when we copy subst into node's position - again
-           child->parent = subst; subst->left = child;
-         Altogether a no-op.  */
-      if (subst_parent != node)
-        {
-          if (child != NULL)
-            child->parent = subst_parent;
-          subst_parent->right = child;
-        }
-
-      /* Copy subst into node's position.
-         (This is safer than to copy subst's value into node, keep node in
-         place, and free subst.)  */
-      if (subst_parent != node)
-        {
-          subst->left = node->left;
-          subst->left->parent = subst;
-        }
-      subst->right = node->right;
-      subst->right->parent = subst;
-      subst->balance = node->balance;
-      subst->parent = parent;
-      if (parent == NULL)
-        set->root = subst;
-      else if (parent->left == node)
-        parent->left = subst;
-      else /* parent->right == node */
-        parent->right = subst;
-
-      /* Rebalancing starts at child's parent, that is subst_parent -
-         except when subst_parent == node.  In this case, we need to use
-         its replacement, subst.  */
-      rebalance (set, child, -1, subst_parent != node ? subst_parent : subst);
-    }
-
-  set->count--;
-  if (set->base.dispose_fn != NULL)
-    set->base.dispose_fn (node->value);
-  free (node);
-  return true;
-}
+#include "gl_avltree_ordered.h"
 
 /* Generic binary tree code.  */
 #include "gl_anytree_oset.h"
 
 /* For debugging.  */
-static unsigned int
-check_invariants (gl_oset_node_t node, gl_oset_node_t parent, size_t *counterp)
-{
-  unsigned int left_height =
-    (node->left != NULL ? check_invariants (node->left, node, counterp) : 0);
-  unsigned int right_height =
-    (node->right != NULL ? check_invariants (node->right, node, counterp) : 0);
-  int balance = (int)right_height - (int)left_height;
-
-  if (!(node->parent == parent))
-    abort ();
-  if (!(balance >= -1 && balance <= 1))
-    abort ();
-  if (!(node->balance == balance))
-    abort ();
-
-  (*counterp)++;
-
-  return 1 + (left_height > right_height ? left_height : right_height);
-}
 void
 gl_avltree_oset_check_invariants (gl_oset_t set)
 {