From 505520d673f9969d841d8894731d476bd30be5cf Mon Sep 17 00:00:00 2001
From: Egor <egor@patchysicp.xyz>
Date: Mon, 23 Oct 2023 00:34:09 +0300
Subject: [PATCH] trie: limit key size

---
 src/map.h      |  4 ++--
 src/map_trie.c | 15 +++------------
 2 files changed, 5 insertions(+), 14 deletions(-)

diff --git a/src/map.h b/src/map.h
index 4126273..02f62d2 100644
--- a/src/map.h
+++ b/src/map.h
@@ -41,12 +41,12 @@ struct trie_node {
 	struct trie_node *data[1];
 };
 typedef struct trie_node *map_t;
+#define TRIE_MAX_KEY 256
 struct trie_find {
 	struct trie_node *n;
 	void *value;
 	size_t len;
-	size_t cap;
-	char key[1];
+	char key[TRIE_MAX_KEY];
 };
 typedef struct trie_find *map_find_t;
 #define map_findfree(f) (free(*(f)), *(f) = 0)
diff --git a/src/map_trie.c b/src/map_trie.c
index 19723cc..5c28b20 100644
--- a/src/map_trie.c
+++ b/src/map_trie.c
@@ -44,6 +44,8 @@ void *map_get(map_t *root, const char *key)
 int map_set(map_t *root, const char *key, const void *value, void **oldvalue)
 {
 	int rv = 0;
+	if (strlen(key)+1 > TRIE_MAX_KEY)
+		return -1;
 	if (oldvalue)
 		*oldvalue = NULL;
 	struct trie_node *n = *root;
@@ -139,16 +141,6 @@ int map_findnext(map_find_t *pf) {
 	int ent = 0; // go to the first child node
 	for (;;) {
 		if (!trie_is_end(ent, f->n)) {
-			if (f->len == f->cap) {
-				f->cap *= 2;
-				void *nf = realloc(f, sizeof(*f)+f->cap);
-				if (!nf) {
-					*pf = NULL;
-					free(f);
-					return -1;
-				}
-				*pf = f = nf;
-			}
 			f->n = f->n->data[ent];
 			f->key[f->len++] = f->n->key;
 			if (f->n->value) { // found a value
@@ -176,11 +168,10 @@ int map_findfirst(map_find_t *pf, map_t *root) {
 	if (*pf) {
 		f = *pf;
 	} else {
-		f = *pf = malloc(sizeof(*f)+16);
+		f = *pf = malloc(sizeof(*f));
 		if (!f)
 			return -1;
 		f->len = 0;
-		f->cap = 16;
 	}
 	f->n = *root;
 	if (f->n->value) {
-- 
2.56.0