io.grpc.Metadata#discardAll ( )源码实例Demo

public static Http2Headers convertClientHeaders(Metadata headers,
    AsciiString scheme,
    AsciiString defaultPath,
    AsciiString authority,
    AsciiString method,
    AsciiString userAgent) {
  Preconditions.checkNotNull(defaultPath, "defaultPath");
  Preconditions.checkNotNull(authority, "authority");
  Preconditions.checkNotNull(method, "method");

  // Discard any application supplied duplicates of the reserved headers
  headers.discardAll(CONTENT_TYPE_KEY);
  headers.discardAll(GrpcUtil.TE_HEADER);
  headers.discardAll(GrpcUtil.USER_AGENT_KEY);

  return GrpcHttp2OutboundHeaders.clientRequestHeaders(
      toHttp2Headers(headers),
      authority,
      defaultPath,
      method,
      scheme,
      userAgent);
}
 

@Override
public ClientStreamTracer newClientStreamTracer(CallOptions callOptions, Metadata headers) {
  ClientTracer tracer = new ClientTracer();
  // TODO(zhangkun83): Once retry or hedging is implemented, a ClientCall may start more than
  // one streams.  We will need to update this file to support them.
  if (streamTracerUpdater != null) {
    checkState(
        streamTracerUpdater.compareAndSet(this, null, tracer),
        "Are you creating multiple streams per call? This class doesn't yet support this case");
  } else {
    checkState(
        streamTracer == null,
        "Are you creating multiple streams per call? This class doesn't yet support this case");
    streamTracer = tracer;
  }
  if (module.propagateTags) {
    headers.discardAll(module.statsHeader);
    if (!module.tagger.empty().equals(parentCtx)) {
      headers.put(module.statsHeader, parentCtx);
    }
  }
  return tracer;
}
 

@VisibleForTesting
static void prepareHeaders(
    Metadata headers,
    DecompressorRegistry decompressorRegistry,
    Compressor compressor,
    boolean fullStreamDecompression) {
  headers.discardAll(MESSAGE_ENCODING_KEY);
  if (compressor != Codec.Identity.NONE) {
    headers.put(MESSAGE_ENCODING_KEY, compressor.getMessageEncoding());
  }

  headers.discardAll(MESSAGE_ACCEPT_ENCODING_KEY);
  byte[] advertisedEncodings =
      InternalDecompressorRegistry.getRawAdvertisedMessageEncodings(decompressorRegistry);
  if (advertisedEncodings.length != 0) {
    headers.put(MESSAGE_ACCEPT_ENCODING_KEY, advertisedEncodings);
  }

  headers.discardAll(CONTENT_ENCODING_KEY);
  headers.discardAll(CONTENT_ACCEPT_ENCODING_KEY);
  if (fullStreamDecompression) {
    headers.put(CONTENT_ACCEPT_ENCODING_KEY, FULL_STREAM_DECOMPRESSION_ENCODINGS);
  }
}
 

@Override
public ClientStreamTracer newClientStreamTracer(
    ClientStreamTracer.StreamInfo info, Metadata headers) {
  Attributes transportAttrs = checkNotNull(info.getTransportAttrs(), "transportAttrs");
  Attributes eagAttrs =
      checkNotNull(transportAttrs.get(GrpcAttributes.ATTR_CLIENT_EAG_ATTRS), "eagAttrs");
  String token = eagAttrs.get(GrpclbConstants.TOKEN_ATTRIBUTE_KEY);
  headers.discardAll(GrpclbConstants.TOKEN_METADATA_KEY);
  if (token != null) {
    headers.put(GrpclbConstants.TOKEN_METADATA_KEY, token);
  }
  if (delegate != null) {
    return delegate.newClientStreamTracer(info, headers);
  } else {
    return NOOP_TRACER;
  }
}
 

@Override
public ClientStreamTracer newClientStreamTracer(
    ClientStreamTracer.StreamInfo info, Metadata headers) {
  ClientTracer tracer = new ClientTracer(module, startCtx);
  // TODO(zhangkun83): Once retry or hedging is implemented, a ClientCall may start more than
  // one streams.  We will need to update this file to support them.
  if (streamTracerUpdater != null) {
    checkState(
        streamTracerUpdater.compareAndSet(this, null, tracer),
        "Are you creating multiple streams per call? This class doesn't yet support this case");
  } else {
    checkState(
        streamTracer == null,
        "Are you creating multiple streams per call? This class doesn't yet support this case");
    streamTracer = tracer;
  }
  if (module.propagateTags) {
    headers.discardAll(module.statsHeader);
    if (!module.tagger.empty().equals(parentCtx)) {
      headers.put(module.statsHeader, parentCtx);
    }
  }
  return tracer;
}
 

@Override
public PickResult picked(Metadata headers) {
  headers.discardAll(GrpclbConstants.TOKEN_METADATA_KEY);
  if (token != null) {
    headers.put(GrpclbConstants.TOKEN_METADATA_KEY, token);
  }
  return result;
}
 

public static Http2Headers convertServerHeaders(Metadata headers) {
  // Discard any application supplied duplicates of the reserved headers
  headers.discardAll(CONTENT_TYPE_KEY);
  headers.discardAll(GrpcUtil.TE_HEADER);
  headers.discardAll(GrpcUtil.USER_AGENT_KEY);

  return GrpcHttp2OutboundHeaders.serverResponseHeaders(toHttp2Headers(headers));
}
 

@Override
public void sendHeaders(Metadata headers) {
  checkState(!sendHeadersCalled, "sendHeaders has already been called");
  checkState(!closeCalled, "call is closed");

  headers.discardAll(MESSAGE_ENCODING_KEY);
  if (compressor == null) {
    compressor = Codec.Identity.NONE;
  } else {
    if (messageAcceptEncoding != null) {
      // TODO(carl-mastrangelo): remove the string allocation.
      if (!GrpcUtil.iterableContains(
          ACCEPT_ENCODING_SPLITTER.split(new String(messageAcceptEncoding, GrpcUtil.US_ASCII)),
          compressor.getMessageEncoding())) {
        // resort to using no compression.
        compressor = Codec.Identity.NONE;
      }
    } else {
      compressor = Codec.Identity.NONE;
    }
  }

  // Always put compressor, even if it's identity.
  headers.put(MESSAGE_ENCODING_KEY, compressor.getMessageEncoding());

  stream.setCompressor(compressor);

  headers.discardAll(MESSAGE_ACCEPT_ENCODING_KEY);
  byte[] advertisedEncodings =
      InternalDecompressorRegistry.getRawAdvertisedMessageEncodings(decompressorRegistry);
  if (advertisedEncodings.length != 0) {
    headers.put(MESSAGE_ACCEPT_ENCODING_KEY, advertisedEncodings);
  }

  // Don't check if sendMessage has been called, since it requires that sendHeaders was already
  // called.
  sendHeadersCalled = true;
  stream.writeHeaders(headers);
}
 

private void addStatusToTrailers(Metadata trailers, Status status) {
  trailers.discardAll(InternalStatus.CODE_KEY);
  trailers.discardAll(InternalStatus.MESSAGE_KEY);
  trailers.put(InternalStatus.CODE_KEY, status);
  if (status.getDescription() != null) {
    trailers.put(InternalStatus.MESSAGE_KEY, status.getDescription());
  }
}
 

@Override
public ClientStreamTracer newClientStreamTracer(CallOptions callOptions, Metadata headers) {
  if (span != BlankSpan.INSTANCE) {
    headers.discardAll(tracingHeader);
    headers.put(tracingHeader, span.getContext());
  }
  return new ClientTracer(span);
}
 

@Override
public PickResult picked(Metadata headers) {
  headers.discardAll(GrpclbConstants.TOKEN_METADATA_KEY);
  if (token != null) {
    headers.put(GrpclbConstants.TOKEN_METADATA_KEY, token);
  }
  return result;
}
 

private void addStatusToTrailers(Metadata trailers, Status status) {
  trailers.discardAll(InternalStatus.CODE_KEY);
  trailers.discardAll(InternalStatus.MESSAGE_KEY);
  trailers.put(InternalStatus.CODE_KEY, status);
  if (status.getDescription() != null) {
    trailers.put(InternalStatus.MESSAGE_KEY, status.getDescription());
  }
}
 

@Override
public ClientStreamTracer newClientStreamTracer(
    ClientStreamTracer.StreamInfo info, Metadata headers) {
  if (span != BlankSpan.INSTANCE) {
    headers.discardAll(tracingHeader);
    headers.put(tracingHeader, span.getContext());
  }
  return new ClientTracer(span);
}
 

private void sendHeadersInternal(Metadata headers) {
  checkState(!sendHeadersCalled, "sendHeaders has already been called");
  checkState(!closeCalled, "call is closed");

  headers.discardAll(MESSAGE_ENCODING_KEY);
  if (compressor == null) {
    compressor = Codec.Identity.NONE;
  } else {
    if (messageAcceptEncoding != null) {
      // TODO(carl-mastrangelo): remove the string allocation.
      if (!GrpcUtil.iterableContains(
          ACCEPT_ENCODING_SPLITTER.split(new String(messageAcceptEncoding, GrpcUtil.US_ASCII)),
          compressor.getMessageEncoding())) {
        // resort to using no compression.
        compressor = Codec.Identity.NONE;
      }
    } else {
      compressor = Codec.Identity.NONE;
    }
  }

  // Always put compressor, even if it's identity.
  headers.put(MESSAGE_ENCODING_KEY, compressor.getMessageEncoding());

  stream.setCompressor(compressor);

  headers.discardAll(MESSAGE_ACCEPT_ENCODING_KEY);
  byte[] advertisedEncodings =
      InternalDecompressorRegistry.getRawAdvertisedMessageEncodings(decompressorRegistry);
  if (advertisedEncodings.length != 0) {
    headers.put(MESSAGE_ACCEPT_ENCODING_KEY, advertisedEncodings);
  }

  // Don't check if sendMessage has been called, since it requires that sendHeaders was already
  // called.
  sendHeadersCalled = true;
  stream.writeHeaders(headers);
}
 

private static Metadata toMetadata(com.google.rpc.Status statusProto, Metadata metadata) {
  checkNotNull(metadata, "metadata must not be null");
  metadata.discardAll(STATUS_DETAILS_KEY);
  metadata.put(STATUS_DETAILS_KEY, statusProto);
  return metadata;
}
 

/**
 * Serializes the given headers and creates a list of OkHttp {@link Header}s to be used when
 * creating a stream. Since this serializes the headers, this method should be called in the
 * application thread context.
 */
public static List<Header> createRequestHeaders(
    Metadata headers, String defaultPath, String authority, String userAgent, boolean useGet) {
  Preconditions.checkNotNull(headers, "headers");
  Preconditions.checkNotNull(defaultPath, "defaultPath");
  Preconditions.checkNotNull(authority, "authority");

  // Discard any application supplied duplicates of the reserved headers
  headers.discardAll(GrpcUtil.CONTENT_TYPE_KEY);
  headers.discardAll(GrpcUtil.TE_HEADER);
  headers.discardAll(GrpcUtil.USER_AGENT_KEY);

  // 7 is the number of explicit add calls below.
  List<Header> okhttpHeaders = new ArrayList<>(7 + InternalMetadata.headerCount(headers));

  // Set GRPC-specific headers.
  okhttpHeaders.add(SCHEME_HEADER);
  if (useGet) {
    okhttpHeaders.add(METHOD_GET_HEADER);
  } else {
    okhttpHeaders.add(METHOD_HEADER);
  }

  okhttpHeaders.add(new Header(Header.TARGET_AUTHORITY, authority));
  String path = defaultPath;
  okhttpHeaders.add(new Header(Header.TARGET_PATH, path));

  okhttpHeaders.add(new Header(GrpcUtil.USER_AGENT_KEY.name(), userAgent));

  // All non-pseudo headers must come after pseudo headers.
  okhttpHeaders.add(CONTENT_TYPE_HEADER);
  okhttpHeaders.add(TE_HEADER);

  // Now add any application-provided headers.
  byte[][] serializedHeaders = TransportFrameUtil.toHttp2Headers(headers);
  for (int i = 0; i < serializedHeaders.length; i += 2) {
    ByteString key = ByteString.of(serializedHeaders[i]);
    String keyString = key.utf8();
    if (isApplicationHeader(keyString)) {
      ByteString value = ByteString.of(serializedHeaders[i + 1]);
      okhttpHeaders.add(new Header(key, value));
    }
  }

  return okhttpHeaders;
}
 

/**
 * Strip HTTP transport implementation details so they don't leak via metadata into
 * the application layer.
 */
private static void stripTransportDetails(Metadata metadata) {
  metadata.discardAll(HTTP2_STATUS);
  metadata.discardAll(InternalStatus.CODE_KEY);
  metadata.discardAll(InternalStatus.MESSAGE_KEY);
}
 

private static Metadata toMetadata(com.google.rpc.Status statusProto, Metadata metadata) {
  checkNotNull(metadata, "metadata must not be null");
  metadata.discardAll(STATUS_DETAILS_KEY);
  metadata.put(STATUS_DETAILS_KEY, statusProto);
  return metadata;
}
 

/**
 * Serializes the given headers and creates a list of OkHttp {@link Header}s to be used when
 * creating a stream. Since this serializes the headers, this method should be called in the
 * application thread context.
 */
public static List<Header> createRequestHeaders(
    Metadata headers,
    String defaultPath,
    String authority,
    String userAgent,
    boolean useGet,
    boolean usePlaintext) {
  Preconditions.checkNotNull(headers, "headers");
  Preconditions.checkNotNull(defaultPath, "defaultPath");
  Preconditions.checkNotNull(authority, "authority");

  // Discard any application supplied duplicates of the reserved headers
  headers.discardAll(GrpcUtil.CONTENT_TYPE_KEY);
  headers.discardAll(GrpcUtil.TE_HEADER);
  headers.discardAll(GrpcUtil.USER_AGENT_KEY);

  // 7 is the number of explicit add calls below.
  List<Header> okhttpHeaders = new ArrayList<>(7 + InternalMetadata.headerCount(headers));

  // Set GRPC-specific headers.
  if (usePlaintext) {
    okhttpHeaders.add(HTTP_SCHEME_HEADER);
  } else {
    okhttpHeaders.add(HTTPS_SCHEME_HEADER);
  }
  if (useGet) {
    okhttpHeaders.add(METHOD_GET_HEADER);
  } else {
    okhttpHeaders.add(METHOD_HEADER);
  }

  okhttpHeaders.add(new Header(Header.TARGET_AUTHORITY, authority));
  String path = defaultPath;
  okhttpHeaders.add(new Header(Header.TARGET_PATH, path));

  okhttpHeaders.add(new Header(GrpcUtil.USER_AGENT_KEY.name(), userAgent));

  // All non-pseudo headers must come after pseudo headers.
  okhttpHeaders.add(CONTENT_TYPE_HEADER);
  okhttpHeaders.add(TE_HEADER);

  // Now add any application-provided headers.
  byte[][] serializedHeaders = TransportFrameUtil.toHttp2Headers(headers);
  for (int i = 0; i < serializedHeaders.length; i += 2) {
    ByteString key = ByteString.of(serializedHeaders[i]);
    String keyString = key.utf8();
    if (isApplicationHeader(keyString)) {
      ByteString value = ByteString.of(serializedHeaders[i + 1]);
      okhttpHeaders.add(new Header(key, value));
    }
  }

  return okhttpHeaders;
}
 

/**
 * Strip HTTP transport implementation details so they don't leak via metadata into
 * the application layer.
 */
private static void stripTransportDetails(Metadata metadata) {
  metadata.discardAll(HTTP2_STATUS);
  metadata.discardAll(InternalStatus.CODE_KEY);
  metadata.discardAll(InternalStatus.MESSAGE_KEY);
}