Modified strtable to support length-delimited string keys. Allows for

arbitrary binary data, e.g., to support strings from other languages as
key values.

upb/bindings/lua/table.c

@@ -68,7 +68,7 @@ static void lupbtable_pushent(lua_State *L, const upb_tabent *e,
     if (inttab) {
       lua_pushnumber(L, e->key.num);
     } else {
-      lua_pushstring(L, e->key.str);
+      lua_pushlstring(L, e->key.s.str, e->key.s.length);
     }
     lua_setfield(L, -2, "key");
     lupbtable_pushval(L, e->val, ctype);

upb/table.c

@@ -36,31 +36,28 @@ int log2ceil(uint64_t v) {
 }
 
 char *upb_strdup(const char *s) {
-  size_t n = strlen(s) + 1;
+  return upb_strdup2(s, strlen(s));
+}
+
+char *upb_strdup2(const char *s, size_t len) {
+  // Always null-terminate, even if binary data; but don't rely on the input to
+  // have a null-terminating byte since it may be a raw binary buffer.
+  size_t n = len + 1;
   char *p = malloc(n);
-  if (p) memcpy(p, s, n);
+  if (p) memcpy(p, s, len);
+  p[len] = 0;
   return p;
 }
 
 // A type to represent the lookup key of either a strtable or an inttable.
-// This is like upb_tabkey, but can carry a size also to allow lookups of
-// non-NULL-terminated strings (we don't store string lengths in the table).
 typedef struct {
   upb_tabkey key;
-  uint32_t len;  // For string keys only.
 } lookupkey_t;
 
-static lookupkey_t strkey(const char *str) {
-  lookupkey_t k;
-  k.key.str = (char*)str;
-  k.len = strlen(str);
-  return k;
-}
-
 static lookupkey_t strkey2(const char *str, size_t len) {
   lookupkey_t k;
-  k.key.str = (char*)str;
-  k.len = len;
+  k.key.s.str = (char*)str;
+  k.key.s.length = len;
   return k;
 }
 
@@ -242,11 +239,12 @@ static size_t begin(const upb_table *t) {
 // A simple "subclass" of upb_table that only adds a hash function for strings.
 
 static uint32_t strhash(upb_tabkey key) {
-  return MurmurHash2(key.str, strlen(key.str), 0);
+  return MurmurHash2(key.s.str, key.s.length, 0);
 }
 
 static bool streql(upb_tabkey k1, lookupkey_t k2) {
-  return strncmp(k1.str, k2.key.str, k2.len) == 0 && k1.str[k2.len] == '\0';
+  return k1.s.length == k2.key.s.length &&
+         memcmp(k1.s.str, k2.key.s.str, k1.s.length) == 0;
 }
 
 bool upb_strtable_init(upb_strtable *t, upb_ctype_t ctype) {
@@ -255,7 +253,7 @@ bool upb_strtable_init(upb_strtable *t, upb_ctype_t ctype) {
 
 void upb_strtable_uninit(upb_strtable *t) {
   for (size_t i = 0; i < upb_table_size(&t->t); i++)
-    free((void*)t->t.entries[i].key.str);
+    free((void*)t->t.entries[i].key.s.str);
   uninit(&t->t);
 }
 
@@ -266,26 +264,30 @@ bool upb_strtable_resize(upb_strtable *t, size_t size_lg2) {
   upb_strtable_iter i;
   upb_strtable_begin(&i, t);
   for ( ; !upb_strtable_done(&i); upb_strtable_next(&i)) {
-    upb_strtable_insert(
-        &new_table, upb_strtable_iter_key(&i), upb_strtable_iter_value(&i));
+    upb_strtable_insert2(
+        &new_table,
+        upb_strtable_iter_key(&i),
+        upb_strtable_iter_keylength(&i),
+        upb_strtable_iter_value(&i));
   }
   upb_strtable_uninit(t);
   *t = new_table;
   return true;
 }
 
-bool upb_strtable_insert(upb_strtable *t, const char *k, upb_value v) {
+bool upb_strtable_insert2(upb_strtable *t, const char *k, size_t len,
+                          upb_value v) {
   if (isfull(&t->t)) {
     // Need to resize.  New table of double the size, add old elements to it.
     if (!upb_strtable_resize(t, t->t.size_lg2 + 1)) {
       return false;
     }
   }
-  if ((k = upb_strdup(k)) == NULL) return false;
+  if ((k = upb_strdup2(k, len)) == NULL) return false;
 
-  lookupkey_t key = strkey(k);
-  uint32_t hash = MurmurHash2(key.key.str, key.len, 0);
-  insert(&t->t, strkey(k), v, hash, &strhash, &streql);
+  lookupkey_t key = strkey2(k, len);
+  uint32_t hash = MurmurHash2(key.key.s.str, key.key.s.length, 0);
+  insert(&t->t, key, v, hash, &strhash, &streql);
   return true;
 }
 
@@ -295,11 +297,12 @@ bool upb_strtable_lookup2(const upb_strtable *t, const char *key, size_t len,
   return lookup(&t->t, strkey2(key, len), v, hash, &streql);
 }
 
-bool upb_strtable_remove(upb_strtable *t, const char *key, upb_value *val) {
+bool upb_strtable_remove2(upb_strtable *t, const char *key, size_t len,
+                         upb_value *val) {
   uint32_t hash = MurmurHash2(key, strlen(key), 0);
   upb_tabkey tabkey;
-  if (rm(&t->t, strkey(key), val, &tabkey, hash, &streql)) {
-    free((void*)tabkey.str);
+  if (rm(&t->t, strkey2(key, len), val, &tabkey, hash, &streql)) {
+    free((void*)tabkey.s.str);
     return true;
   } else {
     return false;
@@ -328,7 +331,12 @@ bool upb_strtable_done(const upb_strtable_iter *i) {
 
 const char *upb_strtable_iter_key(upb_strtable_iter *i) {
   assert(!upb_strtable_done(i));
-  return str_tabent(i)->key.str;
+  return str_tabent(i)->key.s.str;
+}
+
+size_t upb_strtable_iter_keylength(upb_strtable_iter *i) {
+  assert(!upb_strtable_done(i));
+  return str_tabent(i)->key.s.length;
 }
 
 upb_value upb_strtable_iter_value(const upb_strtable_iter *i) {

upb/table.int.h

@@ -97,6 +97,9 @@ typedef struct {
 
 // Like strdup(), which isn't always available since it's not ANSI C.
 char *upb_strdup(const char *s);
+// Variant that works with a length-delimited rather than NULL-delimited string,
+// as supported by strtable.
+char *upb_strdup2(const char *s, size_t len);
 
 UPB_INLINE void _upb_value_setval(upb_value *v, _upb_value val,
                                   upb_ctype_t ctype) {
@@ -151,12 +154,24 @@ FUNCS(fptr,     fptr,         upb_func*,    UPB_CTYPE_FPTR);
 
 typedef union {
   uintptr_t num;
-  const char *str;  // We own, nullz.
+  struct {
+    // We own this. NULL-terminated but may also contain binary data; see
+    // explicit length below.
+    // TODO: move the length to the start of the string in order to reduce
+    // tabkey's size (to one machine word) in a way that supports static
+    // initialization.
+    const char *str;
+    size_t length;
+  } s;
 } upb_tabkey;
 
 #define UPB_TABKEY_NUM(n) {n}
 #ifdef UPB_C99
-#define UPB_TABKEY_STR(s) {.str = s}
+// Given that |s| is a string literal, sizeof(s) gives us a
+// compile-time-constant strlen(). We must ensure that this works for static
+// data initializers.
+#define UPB_TABKEY_STR(strval) { .s = { .str = strval,                    \
+                                        .length = sizeof(strval) - 1 } }
 #endif
 // TODO(haberman): C++
 #define UPB_TABKEY_NONE {0}
@@ -262,7 +277,14 @@ UPB_INLINE size_t upb_strtable_count(const upb_strtable *t) {
 // If a table resize was required but memory allocation failed, false is
 // returned and the table is unchanged.
 bool upb_inttable_insert(upb_inttable *t, uintptr_t key, upb_value val);
-bool upb_strtable_insert(upb_strtable *t, const char *key, upb_value val);
+bool upb_strtable_insert2(upb_strtable *t, const char *key, size_t len,
+                          upb_value val);
+
+// For NULL-terminated strings.
+UPB_INLINE bool upb_strtable_insert(upb_strtable *t, const char *key,
+                                    upb_value val) {
+  return upb_strtable_insert2(t, key, strlen(key), val);
+}
 
 // Looks up key in this table, returning "true" if the key was found.
 // If v is non-NULL, copies the value for this key into *v.
@@ -279,7 +301,14 @@ UPB_INLINE bool upb_strtable_lookup(const upb_strtable *t, const char *key,
 // Removes an item from the table.  Returns true if the remove was successful,
 // and stores the removed item in *val if non-NULL.
 bool upb_inttable_remove(upb_inttable *t, uintptr_t key, upb_value *val);
-bool upb_strtable_remove(upb_strtable *t, const char *key, upb_value *val);
+bool upb_strtable_remove2(upb_strtable *t, const char *key, size_t len,
+                          upb_value *val);
+
+// For NULL-terminated strings.
+UPB_INLINE bool upb_strtable_remove(upb_strtable *t, const char *key,
+                                    upb_value *v) {
+  return upb_strtable_remove2(t, key, strlen(key), v);
+}
 
 // Updates an existing entry in an inttable.  If the entry does not exist,
 // returns false and does nothing.  Unlike insert/remove, this does not
@@ -373,6 +402,7 @@ void upb_strtable_begin(upb_strtable_iter *i, const upb_strtable *t);
 void upb_strtable_next(upb_strtable_iter *i);
 bool upb_strtable_done(const upb_strtable_iter *i);
 const char *upb_strtable_iter_key(upb_strtable_iter *i);
+size_t upb_strtable_iter_keylength(upb_strtable_iter *i);
 upb_value upb_strtable_iter_value(const upb_strtable_iter *i);
 void upb_strtable_iter_setdone(upb_strtable_iter *i);
 bool upb_strtable_iter_isequal(const upb_strtable_iter *i1,