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authorJason Evans <jasone@canonware.com>2010-08-09 17:17:34 -0500
committerJunio C Hamano <gitster@pobox.com>2010-08-14 19:35:37 -0700
commit951f316470acc7c785c460a4e40735b22822349f (patch)
tree8cc846b9eead64502e00fc4064d5decfa1897320 /test-treap.c
parent4709455db3891f6cad9a96a574296b4926f70cbe (diff)
downloadgit-951f316470acc7c785c460a4e40735b22822349f.tar.gz
Add treap implementation
Provide macros to generate a type-specific treap implementation and various functions to operate on it. It uses obj_pool.h to store memory nodes in a treap. Previously committed nodes are never removed from the pool; after any *_commit operation, it is assumed (correctly, in the case of svn-fast-export) that someone else must care about them. 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. >From http://www.canonware.com/download/trp/trp_hash/trp.h [db: Altered to reference nodes by offset from a common base pointer] [db: Bob Jenkins' hashing implementation dropped for Knuth's] [db: Methods unnecessary for search and insert dropped] [rr: Squelched compiler warnings] [db: Added support for immutable treap nodes] [jn: Reintroduced treap_nsearch(); with tests] Signed-off-by: David Barr <david.barr@cordelta.com> Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'test-treap.c')
-rw-r--r--test-treap.c65
1 files changed, 65 insertions, 0 deletions
diff --git a/test-treap.c b/test-treap.c
new file mode 100644
index 0000000000..cdba5111e1
--- /dev/null
+++ b/test-treap.c
@@ -0,0 +1,65 @@
+/*
+ * test-treap.c: code to exercise the svn importer's treap structure
+ */
+
+#include "cache.h"
+#include "vcs-svn/obj_pool.h"
+#include "vcs-svn/trp.h"
+
+struct int_node {
+ uintmax_t n;
+ struct trp_node children;
+};
+
+obj_pool_gen(node, struct int_node, 3)
+
+static int node_cmp(struct int_node *a, struct int_node *b)
+{
+ return (a->n > b->n) - (a->n < b->n);
+}
+
+trp_gen(static, treap_, struct int_node, children, node, node_cmp)
+
+static void strtonode(struct int_node *item, const char *s)
+{
+ char *end;
+ item->n = strtoumax(s, &end, 10);
+ if (*s == '\0' || (*end != '\n' && *end != '\0'))
+ die("invalid integer: %s", s);
+}
+
+int main(int argc, char *argv[])
+{
+ struct strbuf sb = STRBUF_INIT;
+ struct trp_root root = { ~0 };
+ uint32_t item;
+
+ if (argc != 1)
+ usage("test-treap < ints");
+
+ while (strbuf_getline(&sb, stdin, '\n') != EOF) {
+ item = node_alloc(1);
+ strtonode(node_pointer(item), sb.buf);
+ treap_insert(&root, node_pointer(item));
+ }
+
+ item = node_offset(treap_first(&root));
+ while (~item) {
+ uint32_t next;
+ struct int_node *tmp = node_pointer(node_alloc(1));
+
+ tmp->n = node_pointer(item)->n;
+ next = node_offset(treap_next(&root, node_pointer(item)));
+
+ treap_remove(&root, node_pointer(item));
+ item = node_offset(treap_nsearch(&root, tmp));
+
+ if (item != next && (!~item || node_pointer(item)->n != tmp->n))
+ die("found %"PRIuMAX" in place of %"PRIuMAX"",
+ ~item ? node_pointer(item)->n : ~(uintmax_t) 0,
+ ~next ? node_pointer(next)->n : ~(uintmax_t) 0);
+ printf("%"PRIuMAX"\n", tmp->n);
+ }
+ node_reset();
+ return 0;
+}