Quic Class — netty Architecture

Source Code

codec-classes-quic/src/main/java/io/netty/handler/codec/quic/Quic.java lines 30–175

public final class Quic {
    @SuppressWarnings("unchecked")
    static final Map.Entry<ChannelOption<?>, Object>[] EMPTY_OPTION_ARRAY = new Map.Entry[0];
    @SuppressWarnings("unchecked")
    static final Map.Entry<AttributeKey<?>, Object>[] EMPTY_ATTRIBUTE_ARRAY = new Map.Entry[0];

    static final int MAX_DATAGRAM_SIZE = 1350;

    static final int RESET_TOKEN_LEN = 16;

    private static final Throwable UNAVAILABILITY_CAUSE;

    static {
        Throwable cause = null;

        try {
            String version = Quiche.quiche_version();
            assert version != null;
        } catch (Throwable error) {
            cause = error;
        }

        UNAVAILABILITY_CAUSE = cause;
    }

    /**
     * The maximum length of the <a href="https://www.rfc-editor.org/rfc/rfc9000.html#section-17.2">connection id</a>.
     *
     */
    public static final int MAX_CONN_ID_LEN = 20;

    /**
     * Return if the given QUIC version is supported.
     *
     * @param version   the version.
     * @return          {@code true} if supported, {@code false} otherwise.
     */
    public static boolean isVersionSupported(int version) {
        return isAvailable() && Quiche.quiche_version_is_supported(version);
    }

    /**
     * Returns {@code true} if and only if the QUIC implementation is usable on the running platform is available.
     *
     * @return {@code true} if this QUIC implementation can be used on the current platform, {@code false} otherwise.
     */
    public static boolean isAvailable() {
        return UNAVAILABILITY_CAUSE == null;
    }

    /**
     * Ensure that QUIC implementation is usable on the running platform is available.
     *
     * @throws UnsatisfiedLinkError if unavailable
     */
    public static void ensureAvailability() {
        if (UNAVAILABILITY_CAUSE != null) {
            throw (Error) new UnsatisfiedLinkError(
                    "failed to load the required native library").initCause(UNAVAILABILITY_CAUSE);
        }
    }

    /**
     * Returns the cause of unavailability.
     *
     * @return the cause if unavailable. {@code null} if available.
     */
    @Nullable
    public static Throwable unavailabilityCause() {
        return UNAVAILABILITY_CAUSE;
    }

    static Map.Entry<ChannelOption<?>, Object>[] toOptionsArray(Map<ChannelOption<?>, Object> opts) {
        return new HashMap<>(opts).entrySet().toArray(EMPTY_OPTION_ARRAY);
    }

    static Map.Entry<AttributeKey<?>, Object>[] toAttributesArray(Map<AttributeKey<?>, Object> attributes) {
        return new LinkedHashMap<>(attributes).entrySet().toArray(EMPTY_ATTRIBUTE_ARRAY);
    }

    private static void setAttributes(Channel channel, Map.Entry<AttributeKey<?>, Object>[] attrs) {