sds.c: sdsAllocSize() function added.

src/sds.h

@@ -94,5 +94,7 @@ sds sdsmapchars(sds s, char *from, char *to, size_t setlen);
 /* Low level functions exposed to the user API */
 sds sdsMakeRoomFor(sds s, size_t addlen);
 void sdsIncrLen(sds s, int incr);
+sds sdsRemoveFreeSpace(sds s);
+size_t sdsAllocSize(sds s);
 
 #endif