legacy.java

    @Override
    public String hash(final NodeInfo info, final int repetition) {
        String hostname = info.hostname().getHostAddress();
        if (hostname.startsWith("/")) {
            hostname = hostname.substring(1);
        }
        int port = info.services().get(ServiceType.BINARY);
        return hostname + ":" + port + "-" + repetition;
    }

populate.java

    private void populateKetamaNodes() {
        for (NodeInfo node : nodes()) {
            if (!node.services().containsKey(ServiceType.BINARY)) {
                continue;
            }

            for (int i = 0; i < 40; i++) {
                MessageDigest md5;
                try {
                    md5 = MessageDigest.getInstance("MD5");
                    md5.update(env.memcachedHashingStrategy().hash(node, i).getBytes(CharsetUtil.UTF_8));
                    byte[] digest = md5.digest();
                    for (int j = 0; j < 4; j++) {
                        Long key = ((long) (digest[3 + j * 4] & 0xFF) << 24)
                            | ((long) (digest[2 + j * 4] & 0xFF) << 16)
                            | ((long) (digest[1 + j * 4] & 0xFF) << 8)
                            | (digest[j * 4] & 0xFF);
                        ketamaNodes.put(key, node);
                    }
                } catch (NoSuchAlgorithmException e) {
                    throw new IllegalStateException("Could not populate ketama nodes.", e);
                }
            }
        }
    }