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Diffstat (limited to 'vcs-svn/trp.txt')
-rw-r--r-- | vcs-svn/trp.txt | 109 |
1 files changed, 0 insertions, 109 deletions
diff --git a/vcs-svn/trp.txt b/vcs-svn/trp.txt deleted file mode 100644 index 5ca6b42edb..0000000000 --- a/vcs-svn/trp.txt +++ /dev/null @@ -1,109 +0,0 @@ -Motivation -========== - -Treaps provide a memory-efficient binary search tree structure. -Insertion/deletion/search are about as about as fast in the average -case as red-black trees and the chances of worst-case behavior are -vanishingly small, thanks to (pseudo-)randomness. The bad worst-case -behavior is a small price to pay, given that treaps are much simpler -to implement. - -API -=== - -The trp API generates a data structure and functions to handle a -large growing set of objects stored in a pool. - -The caller: - -. Specifies parameters for the generated functions with the - trp_gen(static, foo_, ...) macro. - -. Allocates a `struct trp_root` variable and sets it to {~0}. - -. Adds new nodes to the set using `foo_insert`. Any pointers - to existing nodes cannot be relied upon any more, so the caller - might retrieve them anew with `foo_pointer`. - -. Can find a specific item in the set using `foo_search`. - -. Can iterate over items in the set using `foo_first` and `foo_next`. - -. Can remove an item from the set using `foo_remove`. - -Example: - ----- -struct ex_node { - const char *s; - struct trp_node ex_link; -}; -static struct trp_root ex_base = {~0}; -obj_pool_gen(ex, struct ex_node, 4096); -trp_gen(static, ex_, struct ex_node, ex_link, ex, strcmp) -struct ex_node *item; - -item = ex_pointer(ex_alloc(1)); -item->s = "hello"; -ex_insert(&ex_base, item); -item = ex_pointer(ex_alloc(1)); -item->s = "goodbye"; -ex_insert(&ex_base, item); -for (item = ex_first(&ex_base); item; item = ex_next(&ex_base, item)) - printf("%s\n", item->s); ----- - -Functions ---------- - -trp_gen(attr, foo_, node_type, link_field, pool, cmp):: - - Generate a type-specific treap implementation. -+ -. The storage class for generated functions will be 'attr' (e.g., `static`). -. Generated function names are prefixed with 'foo_' (e.g., `treap_`). -. Treap nodes will be of type 'node_type' (e.g., `struct treap_node`). - This type must be a struct with at least one `struct trp_node` field - to point to its children. -. The field used to access child nodes will be 'link_field'. -. All treap nodes must lie in the 'pool' object pool. -. Treap nodes must be totally ordered by the 'cmp' relation, with the - following prototype: -+ -int (*cmp)(node_type \*a, node_type \*b) -+ -and returning a value less than, equal to, or greater than zero -according to the result of comparison. - -node_type {asterisk}foo_insert(struct trp_root *treap, node_type \*node):: - - Insert node into treap. If inserted multiple times, - a node will appear in the treap multiple times. -+ -The return value is the address of the node within the treap, -which might differ from `node` if `pool_alloc` had to call -`realloc` to expand the pool. - -void foo_remove(struct trp_root *treap, node_type \*node):: - - Remove node from treap. Caller must ensure node is - present in treap before using this function. - -node_type *foo_search(struct trp_root \*treap, node_type \*key):: - - Search for a node that matches key. If no match is found, - result is NULL. - -node_type *foo_nsearch(struct trp_root \*treap, node_type \*key):: - - Like `foo_search`, but if if the key is missing return what - would be key's successor, were key in treap (NULL if no - successor). - -node_type *foo_first(struct trp_root \*treap):: - - Find the first item from the treap, in sorted order. - -node_type *foo_next(struct trp_root \*treap, node_type \*node):: - - Find the next item. |