return node->in_intree == 1;
}
-static inline __u64 interval_low(struct interval_node *node)
-{
- return node->in_extent.start;
-}
-
static inline __u64 interval_high(struct interval_node *node)
{
return node->in_extent.end;
node->in_max_high = end;
}
-/* Rules to write an interval callback.
- * - the callback returns INTERVAL_ITER_STOP when it thinks the iteration
- * should be stopped. It will then cause the iteration function to return
- * immediately with return value INTERVAL_ITER_STOP.
- * - callbacks for interval_iterate and interval_iterate_reverse: Every
- * nodes in the tree will be set to @node before the callback being called
- * - callback for interval_search: Only overlapped node will be set to @node
- * before the callback being called.
- */
-typedef enum interval_iter (*interval_callback_t)(struct interval_node *node,
- void *args);
-
struct interval_node *interval_insert(struct interval_node *node,
struct interval_node **root);
void interval_erase(struct interval_node *node, struct interval_node **root);
-/* Search the extents in the tree and call @func for each overlapped
- * extents. */
-enum interval_iter interval_search(struct interval_node *root,
- struct interval_node_extent *ex,
- interval_callback_t func, void *data);
-
-/* Iterate every node in the tree - by reverse order or regular order. */
-enum interval_iter interval_iterate(struct interval_node *root,
- interval_callback_t func, void *data);
-enum interval_iter interval_iterate_reverse(struct interval_node *root,
- interval_callback_t func, void *data);
-
-void interval_expand(struct interval_node *root,
- struct interval_node_extent *ext,
- struct interval_node_extent *limiter);
-int interval_is_overlapped(struct interval_node *root,
- struct interval_node_extent *ex);
-struct interval_node *interval_find(struct interval_node *root,
- struct interval_node_extent *ex);
#endif
return (e1->start == e2->start) && (e1->end == e2->end);
}
-static inline int extent_overlapped(struct interval_node_extent *e1,
- struct interval_node_extent *e2)
-{
- return (e1->start <= e2->end) && (e2->start <= e1->end);
-}
-
static inline int node_compare(struct interval_node *n1,
struct interval_node *n2)
{
return x > y ? x : y;
}
-static inline __u64 min_u64(__u64 x, __u64 y)
-{
- return x < y ? x : y;
-}
-
-#define interval_for_each(node, root) \
-for (node = interval_first(root); node != NULL; \
- node = interval_next(node))
-
-#define interval_for_each_reverse(node, root) \
-for (node = interval_last(root); node != NULL; \
- node = interval_prev(node))
-
static struct interval_node *interval_first(struct interval_node *node)
{
if (!node)
return node;
}
-static struct interval_node *interval_last(struct interval_node *node)
-{
- if (!node)
- return NULL;
- while (node->in_right)
- node = node->in_right;
- return node;
-}
-
static struct interval_node *interval_next(struct interval_node *node)
{
if (!node)
return node->in_parent;
}
-static struct interval_node *interval_prev(struct interval_node *node)
-{
- if (!node)
- return NULL;
-
- if (node->in_left)
- return interval_last(node->in_left);
-
- while (node->in_parent && node_is_left_child(node))
- node = node->in_parent;
-
- return node->in_parent;
-}
-
-enum interval_iter interval_iterate(struct interval_node *root,
- interval_callback_t func,
- void *data)
-{
- struct interval_node *node;
- enum interval_iter rc = INTERVAL_ITER_CONT;
-
- interval_for_each(node, root) {
- rc = func(node, data);
- if (rc == INTERVAL_ITER_STOP)
- break;
- }
-
- return rc;
-}
-EXPORT_SYMBOL(interval_iterate);
-
-enum interval_iter interval_iterate_reverse(struct interval_node *root,
- interval_callback_t func,
- void *data)
-{
- struct interval_node *node;
- enum interval_iter rc = INTERVAL_ITER_CONT;
-
- interval_for_each_reverse(node, root) {
- rc = func(node, data);
- if (rc == INTERVAL_ITER_STOP)
- break;
- }
-
- return rc;
-}
-EXPORT_SYMBOL(interval_iterate_reverse);
-
-/* try to find a node with same interval in the tree,
- * if found, return the pointer to the node, otherwise return NULL*/
-struct interval_node *interval_find(struct interval_node *root,
- struct interval_node_extent *ex)
-{
- struct interval_node *walk = root;
- int rc;
-
- while (walk) {
- rc = extent_compare(ex, &walk->in_extent);
- if (rc == 0)
- break;
- else if (rc < 0)
- walk = walk->in_left;
- else
- walk = walk->in_right;
- }
-
- return walk;
-}
-EXPORT_SYMBOL(interval_find);
-
static void __rotate_change_maxhigh(struct interval_node *node,
struct interval_node *rotate)
{
interval_erase_color(child, parent, root);
}
EXPORT_SYMBOL(interval_erase);
-
-static inline int interval_may_overlap(struct interval_node *node,
- struct interval_node_extent *ext)
-{
- return (ext->start <= node->in_max_high &&
- ext->end >= interval_low(node));
-}
-
-/*
- * This function finds all intervals that overlap interval ext,
- * and calls func to handle resulted intervals one by one.
- * in lustre, this function will find all conflicting locks in
- * the granted queue and add these locks to the ast work list.
- *
- * {
- * if (node == NULL)
- * return 0;
- * if (ext->end < interval_low(node)) {
- * interval_search(node->in_left, ext, func, data);
- * } else if (interval_may_overlap(node, ext)) {
- * if (extent_overlapped(ext, &node->in_extent))
- * func(node, data);
- * interval_search(node->in_left, ext, func, data);
- * interval_search(node->in_right, ext, func, data);
- * }
- * return 0;
- * }
- *
- */
-enum interval_iter interval_search(struct interval_node *node,
- struct interval_node_extent *ext,
- interval_callback_t func,
- void *data)
-{
- struct interval_node *parent;
- enum interval_iter rc = INTERVAL_ITER_CONT;
-
- LASSERT(ext != NULL);
- LASSERT(func != NULL);
-
- while (node) {
- if (ext->end < interval_low(node)) {
- if (node->in_left) {
- node = node->in_left;
- continue;
- }
- } else if (interval_may_overlap(node, ext)) {
- if (extent_overlapped(ext, &node->in_extent)) {
- rc = func(node, data);
- if (rc == INTERVAL_ITER_STOP)
- break;
- }
-
- if (node->in_left) {
- node = node->in_left;
- continue;
- }
- if (node->in_right) {
- node = node->in_right;
- continue;
- }
- }
-
- parent = node->in_parent;
- while (parent) {
- if (node_is_left_child(node) &&
- parent->in_right) {
- /* If we ever got the left, it means that the
- * parent met ext->end<interval_low(parent), or
- * may_overlap(parent). If the former is true,
- * we needn't go back. So stop early and check
- * may_overlap(parent) after this loop. */
- node = parent->in_right;
- break;
- }
- node = parent;
- parent = parent->in_parent;
- }
- if (parent == NULL || !interval_may_overlap(parent, ext))
- break;
- }
-
- return rc;
-}
-EXPORT_SYMBOL(interval_search);
-
-static enum interval_iter interval_overlap_cb(struct interval_node *n,
- void *args)
-{
- *(int *)args = 1;
- return INTERVAL_ITER_STOP;
-}
-
-int interval_is_overlapped(struct interval_node *root,
- struct interval_node_extent *ext)
-{
- int has = 0;
- (void)interval_search(root, ext, interval_overlap_cb, &has);
- return has;
-}
-EXPORT_SYMBOL(interval_is_overlapped);
-
-/* Don't expand to low. Expanding downwards is expensive, and meaningless to
- * some extents, because programs seldom do IO backward.
- *
- * The recursive algorithm of expanding low:
- * expand_low {
- * struct interval_node *tmp;
- * static __u64 res = 0;
- *
- * if (root == NULL)
- * return res;
- * if (root->in_max_high < low) {
- * res = max_u64(root->in_max_high + 1, res);
- * return res;
- * } else if (low < interval_low(root)) {
- * interval_expand_low(root->in_left, low);
- * return res;
- * }
- *
- * if (interval_high(root) < low)
- * res = max_u64(interval_high(root) + 1, res);
- * interval_expand_low(root->in_left, low);
- * interval_expand_low(root->in_right, low);
- *
- * return res;
- * }
- *
- * It's much easy to eliminate the recursion, see interval_search for
- * an example. -jay
- */
-static inline __u64 interval_expand_low(struct interval_node *root, __u64 low)
-{
- /* we only concern the empty tree right now. */
- if (root == NULL)
- return 0;
- return low;
-}
-
-static inline __u64 interval_expand_high(struct interval_node *node, __u64 high)
-{
- __u64 result = ~0;
-
- while (node != NULL) {
- if (node->in_max_high < high)
- break;
-
- if (interval_low(node) > high) {
- result = interval_low(node) - 1;
- node = node->in_left;
- } else {
- node = node->in_right;
- }
- }
-
- return result;
-}
-
-/* expanding the extent based on @ext. */
-void interval_expand(struct interval_node *root,
- struct interval_node_extent *ext,
- struct interval_node_extent *limiter)
-{
- /* The assertion of interval_is_overlapped is expensive because we may
- * travel many nodes to find the overlapped node. */
- LASSERT(interval_is_overlapped(root, ext) == 0);
- if (!limiter || limiter->start < ext->start)
- ext->start = interval_expand_low(root, ext->start);
- if (!limiter || limiter->end > ext->end)
- ext->end = interval_expand_high(root, ext->end);
- LASSERT(interval_is_overlapped(root, ext) == 0);
-}
-EXPORT_SYMBOL(interval_expand);
projects / openwrt / staging / blogic.git / commitdiff