stringmap: Flipped bit order to match sorted string order and added traversal test
authorJoey Adams <joeyadams3.14159@gmail.com>
Tue, 21 Jul 2009 06:32:36 +0000 (02:32 -0400)
committerJoey Adams <joeyadams3.14159@gmail.com>
Tue, 21 Jul 2009 06:32:36 +0000 (02:32 -0400)
ccan/stringmap/stringmap.c
ccan/stringmap/test/run.c

index 7380e4e1e82b0fc0575c98ad3562bb9cd6ea1650..b3ca57afe1b8a892d67d62743f804b591209bb30 100644 (file)
@@ -39,7 +39,7 @@
 #define assert(...) do {} while(0)
 #endif
 
-#define PEEK_BIT(key, bit)             ((key[bit >> 3] >> (bit & 7)) & 1)
+#define PEEK_BIT(key, bit)             ((key[bit >> 3] >> (~bit & 7)) & 1)
 
 struct stringmap_node {
        uint32_t left_is_leaf:1, right_is_leaf:1, bitno:30;
@@ -155,8 +155,8 @@ void *stringmap_lookup_real(struct stringmap *t, const char *key, size_t len, in
                        
                        //advance cix to the first differing bit
                        ix = *m ^ *k;
-                       while ((ix & 1) == 0)
-                               ix >>= 1, cix++;
+                       while ((ix & 128) == 0)
+                               ix <<= 1, cix++;
                        
                        //choose left/right based on the differing bit
                        bit = PEEK_BIT(key, cix);
index a8099ec8ee670070be891744ec01157788f304b7..52309c2601d863deef142151c6781f116a77bec2 100644 (file)
@@ -88,13 +88,21 @@ struct test_entry {
                   this key has been entered already. */
 };
 
-static int tecmp(const struct test_entry *a, const struct test_entry *b) {
-       if (a->len < b->len)
-               return -1;
-       else if (a->len > b->len)
-               return 1;
-       else
-               return memcmp(a->str, b->str, a->len);
+static int tecmp(const struct test_entry *ap, const struct test_entry *bp) {
+       const unsigned char *a = (unsigned char*)ap->str, *ae = a+ap->len;
+       const unsigned char *b = (unsigned char*)bp->str, *be = b+bp->len;
+       
+       for (;;a++, b++) {
+               if (a >= ae) {
+                       if (b >= be)
+                               return 0; //strings are the same
+                       return -1; //a is shorter than b
+               }
+               if (b >= be)
+                       return 1; //b is shorter than a
+               if (*a != *b) //there is a differing character
+                       return (unsigned int)*a - (unsigned int)*b;
+       }
 }
 
 static int by_str(const void *a, const void *b) {
@@ -126,26 +134,116 @@ static void cull_duplicates(struct test_entry *entries, size_t *count) {
        *count = o-entries;
 }
 
+#define print(tag, fmt, ...) do { \
+               if (out) \
+                       fprintf(out, tag fmt "\n", ##__VA_ARGS__); \
+       } while(0)
+#define err(...) do { \
+               print("error: ", __VA_ARGS__); \
+               goto fail; \
+       } while(0)
+//#define debug(...) print("debug: ", __VA_ARGS__)
+#define debug(...) do {} while(0)
+#define msg(...) print("info: ", __VA_ARGS__)
+
+static int test_traverse(struct stringmap *map, struct test_entry *strings, size_t size, FILE *out) {
+       size_t sp = 0;
+       size_t stack_alloc = 16;
+       struct stringmap_node **stack = NULL;
+       struct stringmap_node *n;
+       void *leaf;
+       #define check(lri) do { \
+                       leaf = n->lr[lri]; \
+                       if (!size--) \
+                               err("Fewer items in tree than counted"); \
+                       if (tecmp(leaf, strings++)) \
+                               err("%s leaf has incorrect string", lri ? "Left" : "Right"); \
+               } while(0)
+       #define check_left() check(0)
+       #define check_right() check(1)
+       
+       if (map->count != size)
+               err("map->count != size");
+       
+       if (map->count == 0)
+               return 1;
+       
+       if (map->count == 1) {
+               leaf = (struct test_entry*)map->root;
+               if (!tecmp(leaf, &strings[0]))
+                       return 1;
+               else
+                       err("Only leaf in tree has incorrect value");
+       }
+       
+       stack = malloc(sizeof(*stack) * stack_alloc);
+       n = map->root;
+       
+       for (;;) {
+               //descend left
+               while (!n->left_is_leaf) {
+                       stack[sp++] = n;
+                       n = n->lr[0];
+                       
+                       if (sp >= stack_alloc) {
+                               stack_alloc += stack_alloc;
+                               stack = realloc(stack, sizeof(*stack) * stack_alloc);
+                       }
+               }
+               
+               check_left();
+               
+       ascend_right:
+               while (n->right_is_leaf) {
+                       check_right();
+                       
+                       if (!sp)
+                               goto done; //we finished up the last entry
+                       n = stack[--sp];
+               }
+               
+               //descend right
+               n = n->lr[1];
+               while (n->left_is_leaf) {
+                       check_left();
+                       
+                       if (n->right_is_leaf) {
+                               check_right();
+                               
+                               if (!sp)
+                                       goto done;
+                               n = stack[--sp];
+                               goto ascend_right; //sorry
+                       }
+                       n = n->lr[1];
+               }
+       }
+       
+done:
+       if (size != 0)
+               err("More items in tree than counted");
+       
+       free(stack);
+       return 1;
+       
+fail:
+       if (stack)
+               free(stack);
+       return 0;
+       
+       #undef check
+       #undef check_left
+       #undef check_right
+}
+
 static int test_stringmap(size_t count, FILE *out) {
        stringmap(char*) map = stringmap_new(NULL);
        
-       #define print(tag, fmt, ...) do { \
-                       if (out) \
-                               fprintf(out, tag fmt "\n", ##__VA_ARGS__); \
-               } while(0)
-       #define err(...) do { \
-                       print("error: ", __VA_ARGS__); \
-                       goto fail; \
-               } while(0)
-       //#define debug(...) print("debug: ", __VA_ARGS__)
-       #define debug(...) do {} while(0)
-       #define msg(...) print("info: ", __VA_ARGS__)
-       
        struct block_pool *bp = block_pool_new(NULL);
        struct test_entry *entries = block_pool_alloc(bp, sizeof(*entries) * count);
-       struct test_entry *i, *e = entries+count;
+       struct test_entry *i, *e = entries+count, *o;
        char *value_base = block_pool_alloc(bp, count), *value = value_base;
-       size_t unique_count = 0;
+       size_t unique_count;
        
        //we use value to track whether an entry has been added or not
        memset(value, 0, count);
@@ -170,7 +268,7 @@ static int test_stringmap(size_t count, FILE *out) {
        
        msg("Inserting/looking up %zu entries...", count);
        
-       for (i=entries; i<e; i++) {
+       for (i=entries, o=entries; i<e; i++) {
                char **node;
                
                debug("Looking up %s", i->str);
@@ -191,7 +289,8 @@ static int test_stringmap(size_t count, FILE *out) {
                        *node = i->value;
                        *i->value = 1; //mark that the entry is entered
                        
-                       unique_count++;
+                       //write this unique entry to the entry list to traverse later
+                       *o++ = *i;
                } else {
                        if (tecmp(i, (void*)map.last))
                                err("lookup returned incorrect string");
@@ -204,9 +303,17 @@ static int test_stringmap(size_t count, FILE *out) {
                }
        }
        
+       unique_count = o-entries;
+       
        if (map.t.count != unique_count)
                err("Map has incorrect count");
        
+       qsort(entries, unique_count, sizeof(*entries), by_str);
+       
+       msg("Traversing forward through %zu items", unique_count);      
+       if (!test_traverse(&map.t, entries, unique_count, out))
+               err("Traversal does not produce the strings in order");
+       
        printf("stringmap test passed after %zu inserts, %zu lookups (%zu total operations)\n",
                unique_count, (i-entries)-unique_count, i-entries);
        
@@ -221,13 +328,13 @@ fail:
        block_pool_free(bp);
        stringmap_free(map);
        return 0;
-       
-       #undef print
-       #undef err
-       #undef debug
-       #undef msg
 }
 
+#undef print
+#undef err
+#undef debug
+#undef msg
+
 int main(void)
 {
        plan_tests(14);