final int lookup(String name) {
        int entry = hash[Math.abs(name.hashCode() % hashSize())];
        while (entry != 0) {
            final int sym = hash[entry];
            if (names[sym].equals(name)) { // found entry
                return sym;
            }
            entry = hash[entry + 1];
        }
        return INVALID;
    }
Find the id associated with a symbol name; if the
name was not in the symbol table returns the
INVALID constant instead.
vespajlib/src/main/java/com/yahoo/slime/SymbolTable.java