{
struct hmap_node node; /* Node in hash table. */
size_t ref_cnt; /* Reference count. */
+ size_t length; /* strlen(string). */
char string[1]; /* Null-terminated string. */
};
/* All interned strings. */
static struct hmap interns = HMAP_INITIALIZER (interns);
-/* Searches the table of interned string for */
+/* Searches the table of interned strings for one equal to S, which has length
+ LENGTH and hash value HASH. */
static struct interned_string *
intern_lookup__ (const char *s, size_t length, unsigned int hash)
{
struct interned_string *is;
HMAP_FOR_EACH_WITH_HASH (is, struct interned_string, node, hash, &interns)
- if (!memcmp (s, is->string, length + 1))
+ if (is->length == length && !memcmp (s, is->string, length))
return is;
return NULL;
is = xmalloc (length + sizeof *is);
hmap_insert (&interns, &is->node, hash);
is->ref_cnt = 1;
+ is->length = length;
memcpy (is->string, s, length + 1);
}
return is->string;
}
static struct interned_string *
-interned_string_from_string (const char *s)
+interned_string_from_string (const char *s_)
{
+ char (*s)[1] = (char (*)[1]) s_;
struct interned_string *is = UP_CAST (s, struct interned_string, string);
assert (is->ref_cnt > 0);
return is;
unsigned int hash = hash_bytes (s, length, 0);
return intern_lookup__ (s, length, hash) != NULL;
}
+
+/* Returns the length of S, which must be an interned string returned by
+ intern_new(). */
+size_t
+intern_strlen (const char *s)
+{
+ return interned_string_from_string (s)->length;
+}