Method upload

app/src/extra/java/eu/faircode/email/Send.java:79–232

(InputStream is, DocumentFile dfile, int dLimit, int timeLimit, String host, IProgress intf)

    private static final int TIMEOUT = 20 * 1000; // milliseconds

    public static String upload(InputStream is, DocumentFile dfile, int dLimit, int timeLimit, String host, IProgress intf) throws Throwable {
        String result;
        SecureRandom rnd = new SecureRandom();

        byte[] secret = new byte[16];
        rnd.nextBytes(secret);

        JSONObject jupload = getMetadata(dfile, dLimit, timeLimit, secret);

        Uri uri = Uri.parse("wss://" + Uri.parse(host).getHost() + "/api/ws");

        WebSocket ws = new WebSocketFactory().createSocket(uri.toString(), TIMEOUT);
        ws.setFrameQueueSize(32); // 32 x 64KB = 2 MB

        Semaphore sem = new Semaphore(0);
        List<String> queue = Collections.synchronizedList(new ArrayList<>());

        ws.addListener(new WebSocketAdapter() {
            @Override
            public void onTextMessage(WebSocket ws, String text) {
                Log.i("Send text message=" + text);
                queue.add(text);
                sem.release();
            }
        });

        Log.i("Send connect");
        ws.connect();

        try {
            Log.i("Send upload=" + jupload);
            ws.sendText(jupload.toString());

            Log.i("Send wait reply");
            if (!sem.tryAcquire(TIMEOUT, TimeUnit.MILLISECONDS))
                throw new TimeoutException("reply");

            JSONObject jreply = new JSONObject(queue.remove(0));
            Log.i("Send reply=" + jreply);

            if (jreply.has("error")) {
                String error = jreply.getString("error");
                if ("400".equals(error))
                    error += " - try lower limits";
                throw new IOException("Error: " + error);
            }

            result = jreply.getString("url") +
                    "#" + Base64.encodeToString(secret, Base64.URL_SAFE | Base64.NO_PADDING | Base64.NO_WRAP);
            Log.i("Send url=" + result);

            // The record sequence number (SEQ) is a 96-bit unsigned integer in network byte order that starts at zero.
            // network byte order = transmitting the most significant byte first
            // Java = big endian = network byte order
            // sizeof(int) = 4 bytes
            // sizeof(long) = 8 bytes
            long seq = 0;
            byte[] buffer = new byte[65536];