/** * Called by transport implementations when they receive headers. * * @param headers the parsed headers */ protected void inboundHeadersReceived(Metadata headers) { if (headers.containsKey(GrpcUtil.MESSAGE_ENCODING_KEY)) { String messageEncoding = headers.get(GrpcUtil.MESSAGE_ENCODING_KEY); try { setDecompressor(messageEncoding); } catch (IllegalArgumentException e) { Status status = Status.INVALID_ARGUMENT .withDescription("Unable to decompress encoding " + messageEncoding) .withCause(e); abortStream(status, true); return; } } // This checks to see if the client will accept any encoding. If so, a compressor is picked for // the stream, and the decision is recorded. When the Server Call Handler writes the first // headers, the negotiated encoding will be added in #writeHeaders(). It is safe to call // pickCompressor multiple times before the headers have been written to the wire, though in // practice this should never happen. There should only be one call to inboundHeadersReceived. // Alternatively, compression could be negotiated after the server handler is invoked, but that // would mean the inbound header would have to be stored until the first #writeHeaders call. if (headers.containsKey(GrpcUtil.MESSAGE_ACCEPT_ENCODING_KEY)) { Compressor c = pickCompressor( ACCEPT_ENCODING_SPLITER.split(headers.get(GrpcUtil.MESSAGE_ACCEPT_ENCODING_KEY))); if (c != null) { messageEncoding = c.getMessageEncoding(); } } inboundPhase(Phase.MESSAGE); }
@Test public void prepareHeaders_acceptedEncodingsAdded() { Metadata m = new Metadata(); DecompressorRegistry customRegistry = DecompressorRegistry.emptyInstance() .with( new Decompressor() { @Override public String getMessageEncoding() { return "a"; } @Override public InputStream decompress(InputStream is) throws IOException { return null; } }, true) .with( new Decompressor() { @Override public String getMessageEncoding() { return "b"; } @Override public InputStream decompress(InputStream is) throws IOException { return null; } }, true) .with( new Decompressor() { @Override public String getMessageEncoding() { return "c"; } @Override public InputStream decompress(InputStream is) throws IOException { return null; } }, false); // not advertised ClientCallImpl.prepareHeaders(m, customRegistry, Codec.Identity.NONE); Iterable<String> acceptedEncodings = ACCEPT_ENCODING_SPLITER.split(m.get(GrpcUtil.MESSAGE_ACCEPT_ENCODING_KEY)); // Order may be different, since decoder priorities have not yet been implemented. assertEquals(ImmutableSet.of("b", "a"), ImmutableSet.copyOf(acceptedEncodings)); }