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951f316470
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>
66 lines
1.5 KiB
C
66 lines
1.5 KiB
C
/*
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* test-treap.c: code to exercise the svn importer's treap structure
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*/
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#include "cache.h"
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#include "vcs-svn/obj_pool.h"
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#include "vcs-svn/trp.h"
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struct int_node {
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uintmax_t n;
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struct trp_node children;
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};
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obj_pool_gen(node, struct int_node, 3)
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static int node_cmp(struct int_node *a, struct int_node *b)
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{
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return (a->n > b->n) - (a->n < b->n);
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}
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trp_gen(static, treap_, struct int_node, children, node, node_cmp)
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static void strtonode(struct int_node *item, const char *s)
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{
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char *end;
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item->n = strtoumax(s, &end, 10);
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if (*s == '\0' || (*end != '\n' && *end != '\0'))
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die("invalid integer: %s", s);
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}
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int main(int argc, char *argv[])
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{
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struct strbuf sb = STRBUF_INIT;
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struct trp_root root = { ~0 };
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uint32_t item;
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if (argc != 1)
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usage("test-treap < ints");
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while (strbuf_getline(&sb, stdin, '\n') != EOF) {
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item = node_alloc(1);
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strtonode(node_pointer(item), sb.buf);
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treap_insert(&root, node_pointer(item));
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}
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item = node_offset(treap_first(&root));
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while (~item) {
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uint32_t next;
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struct int_node *tmp = node_pointer(node_alloc(1));
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tmp->n = node_pointer(item)->n;
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next = node_offset(treap_next(&root, node_pointer(item)));
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treap_remove(&root, node_pointer(item));
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item = node_offset(treap_nsearch(&root, tmp));
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if (item != next && (!~item || node_pointer(item)->n != tmp->n))
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die("found %"PRIuMAX" in place of %"PRIuMAX"",
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~item ? node_pointer(item)->n : ~(uintmax_t) 0,
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~next ? node_pointer(next)->n : ~(uintmax_t) 0);
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printf("%"PRIuMAX"\n", tmp->n);
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}
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node_reset();
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return 0;
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}
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