X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=src%2Flibpspp%2Fintern.c;h=fc31acf0b439fec19c339296abe3e5fe8f5ce314;hb=02b9b37698eb0b483fe0338f3b28d8f784a7af9a;hp=258e2829af132f8548b59a00577a29c623fcbabc;hpb=993af59a283dbad8b26a390535f76cdeb00a9108;p=pspp diff --git a/src/libpspp/intern.c b/src/libpspp/intern.c index 258e2829af..fc31acf0b4 100644 --- a/src/libpspp/intern.c +++ b/src/libpspp/intern.c @@ -33,20 +33,22 @@ struct interned_string { 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; @@ -69,14 +71,16 @@ intern_new (const char *s) 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; @@ -119,3 +123,11 @@ is_interned_string (const char *s) 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; +}