+
+/**** Reference-counted strings. ****/
+
+/* Create and return a new reference-counted string. The reference count is
+ * initially one. The newly-returned string takes ownership of the memory
+ * pointed at by data, and will call g_free on it when the reference count
+ * drops to zero. */
+BlueSkyRCStr *bluesky_string_new(gpointer data, gsize len)
+{
+ BlueSkyRCStr *string = g_new(BlueSkyRCStr, 1);
+ string->data = data;
+ string->len = len;
+ g_atomic_int_set(&string->refcount, 1);
+ return string;
+}
+
+void bluesky_string_ref(BlueSkyRCStr *string)
+{
+ if (string == NULL)
+ return;
+
+ g_atomic_int_inc(&string->refcount);
+}
+
+void bluesky_string_unref(BlueSkyRCStr *string)
+{
+ if (string == NULL)
+ return;
+
+ if (g_atomic_int_dec_and_test(&string->refcount)) {
+ g_free(string->data);
+ g_free(string);
+ }
+}
+
+/* Duplicate and return a new reference-counted string, containing a copy of
+ * the original data, with a reference count of 1. As an optimization, if the
+ * passed-in string already has a reference count of 1, the original is
+ * returned. Can be used to make a mutable copy of a shared string. For this
+ * to truly be safe, it is probably needed that there be some type of lock
+ * protecting access to the string. */
+BlueSkyRCStr *bluesky_string_dup(BlueSkyRCStr *string)
+{
+ if (string == NULL)
+ return NULL;
+
+ if (g_atomic_int_dec_and_test(&string->refcount)) {
+ /* There are no other shared copies, so return this one. */
+ g_atomic_int_inc(&string->refcount);
+ return string;
+ } else {
+ return bluesky_string_new(g_memdup(string->data, string->len),
+ string->len);
+ }
+}
+
+/* Resize the data block used by a BlueSkyRCStr. The data pointer might change
+ * after making this call, so it should not be cached across calls to this
+ * function. To avoid confusing any other users, the caller probably ought to
+ * hold the only reference to the string (by calling bluesky_string_dup first
+ * if needed). */
+void bluesky_string_resize(BlueSkyRCStr *string, gsize len)
+{
+ if (string->len == len)
+ return;
+
+ string->data = g_realloc(string->data, len);
+}