ReadOnlyHttp2Headers Class — netty Architecture

Source Code

codec-http2/src/main/java/io/netty/handler/codec/http2/ReadOnlyHttp2Headers.java lines 46–892

public final class ReadOnlyHttp2Headers implements Http2Headers {
    private static final byte PSEUDO_HEADER_TOKEN = (byte) ':';
    private final AsciiString[] pseudoHeaders;
    private final AsciiString[] otherHeaders;

    /**
     * Used to create read only object designed to represent trailers.
     * <p>
     * If this is used for a purpose other than trailers you may violate the header serialization ordering defined by
     * <a href="https://tools.ietf.org/html/rfc7540#section-8.1.2.1">RFC 7540, 8.1.2.1</a>.
     * @param validateHeaders {@code true} will run validation on each header name/value pair to ensure protocol
     *                        compliance.
     * @param otherHeaders An array of key:value pairs. Must not contain any
     *                     <a href="https://tools.ietf.org/html/rfc7540#section-8.1.2.1">pseudo headers</a>
     *                     or {@code null} names/values.
     *                     A copy will <strong>NOT</strong> be made of this array. If the contents of this array
     *                     may be modified externally you are responsible for passing in a copy.
     * @return A read only representation of the headers.
     */
    public static ReadOnlyHttp2Headers trailers(boolean validateHeaders, AsciiString... otherHeaders) {
        return new ReadOnlyHttp2Headers(validateHeaders, EMPTY_ASCII_STRINGS, otherHeaders);
    }

    /**
     * Create a new read only representation of headers used by clients.
     * @param validateHeaders {@code true} will run validation on each header name/value pair to ensure protocol
     *                        compliance.
     * @param method The value for {@link PseudoHeaderName#METHOD}.
     * @param path The value for {@link PseudoHeaderName#PATH}.
     * @param scheme The value for {@link PseudoHeaderName#SCHEME}.
     * @param authority The value for {@link PseudoHeaderName#AUTHORITY}.
     * @param otherHeaders An array of key:value pairs. Must not contain any
     *                     <a href="https://tools.ietf.org/html/rfc7540#section-8.1.2.1">pseudo headers</a>
     *                     or {@code null} names/values.
     *                     A copy will <strong>NOT</strong> be made of this array. If the contents of this array
     *                     may be modified externally you are responsible for passing in a copy.
     * @return a new read only representation of headers used by clients.
     */
    public static ReadOnlyHttp2Headers clientHeaders(boolean validateHeaders,
                                                     AsciiString method, AsciiString path,
                                                     AsciiString scheme, AsciiString authority,
                                                     AsciiString... otherHeaders) {
        return new ReadOnlyHttp2Headers(validateHeaders,
                new AsciiString[] {
                  PseudoHeaderName.METHOD.value(), method, PseudoHeaderName.PATH.value(), path,
                  PseudoHeaderName.SCHEME.value(), scheme, PseudoHeaderName.AUTHORITY.value(), authority
                },
                otherHeaders);
    }

    /**
     * Create a new read only representation of headers used by servers.
     * @param validateHeaders {@code true} will run validation on each header name/value pair to ensure protocol
     *                        compliance.
     * @param status The value for {@link PseudoHeaderName#STATUS}.
     * @param otherHeaders An array of key:value pairs. Must not contain any
     *                     <a href="https://tools.ietf.org/html/rfc7540#section-8.1.2.1">pseudo headers</a>
     *                     or {@code null} names/values.
     *                     A copy will <strong>NOT</strong> be made of this array. If the contents of this array
     *                     may be modified externally you are responsible for passing in a copy.
     * @return a new read only representation of headers used by servers.
     */
    public static ReadOnlyHttp2Headers serverHeaders(boolean validateHeaders,
                                                     AsciiString status,
                                                     AsciiString... otherHeaders) {
        return new ReadOnlyHttp2Headers(validateHeaders,
                                        new AsciiString[] { PseudoHeaderName.STATUS.value(), status },
                                        otherHeaders);
    }

    private ReadOnlyHttp2Headers(boolean validateHeaders, AsciiString[] pseudoHeaders, AsciiString... otherHeaders) {
        assert (pseudoHeaders.length & 1) == 0; // pseudoHeaders are only set internally so assert should be enough.
        if ((otherHeaders.length & 1) != 0) {
            throw newInvalidArraySizeException();
        }
        if (validateHeaders) {
            validateHeaders(pseudoHeaders, otherHeaders);
        }
        this.pseudoHeaders = pseudoHeaders;
        this.otherHeaders = otherHeaders;
    }