trie: Get rid of the linked list of leaves

tavianator · Nov 2, 2024 · 0c4c6b5 · 0c4c6b5
1 parent f6b3a72
commit 0c4c6b5
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Showing 3 changed files with 4 additions and 17 deletions.
diff --git a/src/trie.c b/src/trie.c
@@ -87,7 +87,6 @@
 #include "bfs.h"
 #include "bit.h"
 #include "diag.h"
-#include "list.h"
 
 #include <stdint.h>
 #include <string.h>
@@ -165,7 +164,6 @@ static uintptr_t trie_encode_leaf(const struct trie_leaf *leaf) {
 
 void trie_init(struct trie *trie) {
 	trie->root = 0;
-	LIST_INIT(trie);
 	VARENA_INIT(&trie->nodes, struct trie_node, children);
 	VARENA_INIT(&trie->leaves, struct trie_leaf, key);
 }
@@ -339,9 +337,6 @@ static struct trie_leaf *trie_leaf_alloc(struct trie *trie, const void *key, siz
 		return NULL;
 	}
 
-	LIST_ITEM_INIT(leaf);
-	LIST_APPEND(trie, leaf);
-
 	leaf->value = NULL;
 	leaf->length = length;
 	memcpy(leaf->key, key, length);
@@ -351,7 +346,6 @@ static struct trie_leaf *trie_leaf_alloc(struct trie *trie, const void *key, siz
 
 /** Free a leaf. */
 static void trie_leaf_free(struct trie *trie, struct trie_leaf *leaf) {
-	LIST_REMOVE(trie, leaf);
 	varena_free(&trie->leaves, leaf);
 }
 
@@ -736,8 +730,6 @@ void trie_remove(struct trie *trie, struct trie_leaf *leaf) {
 
 void trie_clear(struct trie *trie) {
 	trie->root = 0;
-	LIST_INIT(trie);
-
 	varena_clear(&trie->leaves);
 	varena_clear(&trie->nodes);
 }

diff --git a/src/trie.h b/src/trie.h
@@ -14,8 +14,6 @@
  * A leaf of a trie.
  */
 struct trie_leaf {
-	/** Linked list of leaves, in insertion order. */
-	struct trie_leaf *prev, *next;
 	/** An arbitrary value associated with this leaf. */
 	void *value;
 	/** The length of the key in bytes. */
@@ -30,8 +28,6 @@ struct trie_leaf {
 struct trie {
 	/** Pointer to the root node/leaf. */
 	uintptr_t root;
-	/** Linked list of leaves. */
-	struct trie_leaf *head, *tail;
 	/** Node allocator. */
 	struct varena nodes;
 	/** Leaf allocator. */
@@ -143,6 +139,6 @@ void trie_destroy(struct trie *trie);
  * Iterate over the leaves of a trie.
  */
 #define for_trie(leaf, trie) \
-	for_list (struct trie_leaf, leaf, trie)
+	for_varena (struct trie_leaf, leaf, &(trie)->leaves)
 
 #endif // BFS_TRIE_H
diff --git a/tests/trie.c b/tests/trie.c
@@ -71,15 +71,14 @@ void check_trie(void) {
 		bfs_verify(leaf);
 		bfs_check(strcmp(keys[i], leaf->key) == 0);
 		bfs_check(leaf->length == strlen(keys[i]) + 1);
+		leaf->value = (void *)keys[i];
 	}
 
 	{
 		size_t i = 0;
 		for_trie (leaf, &trie) {
-			bfs_check(leaf == trie_find_str(&trie, keys[i]));
-			bfs_check(leaf == trie_insert_str(&trie, keys[i]));
-			bfs_check(!leaf->prev || leaf->prev->next == leaf);
-			bfs_check(!leaf->next || leaf->next->prev == leaf);
+			bfs_check(strcmp(leaf->value, leaf->key) == 0);
+			leaf->value = NULL;
 			++i;
 		}
 		bfs_check(i == nkeys);