io.grpc.internal.GrpcUtil Maven / Gradle / Ivy
/*
* Copyright 2014 The gRPC Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package io.grpc.internal;
import static com.google.common.base.Preconditions.checkArgument;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Objects;
import com.google.common.base.Preconditions;
import com.google.common.base.Splitter;
import com.google.common.base.Stopwatch;
import com.google.common.base.Supplier;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.MoreExecutors;
import com.google.common.util.concurrent.ThreadFactoryBuilder;
import io.grpc.CallOptions;
import io.grpc.ClientStreamTracer;
import io.grpc.InternalChannelz.SocketStats;
import io.grpc.InternalLogId;
import io.grpc.InternalMetadata;
import io.grpc.InternalMetadata.TrustedAsciiMarshaller;
import io.grpc.LoadBalancer.PickResult;
import io.grpc.LoadBalancer.Subchannel;
import io.grpc.Metadata;
import io.grpc.MethodDescriptor;
import io.grpc.ProxiedSocketAddress;
import io.grpc.ProxyDetector;
import io.grpc.Status;
import io.grpc.internal.ClientStreamListener.RpcProgress;
import io.grpc.internal.SharedResourceHolder.Resource;
import io.grpc.internal.StreamListener.MessageProducer;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.net.HttpURLConnection;
import java.net.InetSocketAddress;
import java.net.SocketAddress;
import java.net.URI;
import java.net.URISyntaxException;
import java.nio.charset.Charset;
import java.util.Collection;
import java.util.concurrent.Executor;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.TimeUnit;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.annotation.Nullable;
/**
* Common utilities for GRPC.
*/
public final class GrpcUtil {
private static final Logger log = Logger.getLogger(GrpcUtil.class.getName());
public static final Charset US_ASCII = Charset.forName("US-ASCII");
// AppEngine runtimes have constraints on threading and socket handling
// that need to be accommodated.
public static final boolean IS_RESTRICTED_APPENGINE =
System.getProperty("com.google.appengine.runtime.environment") != null
&& "1.7".equals(System.getProperty("java.specification.version"));
/**
* {@link io.grpc.Metadata.Key} for the timeout header.
*/
public static final Metadata.Key TIMEOUT_KEY =
Metadata.Key.of(GrpcUtil.TIMEOUT, new TimeoutMarshaller());
/**
* {@link io.grpc.Metadata.Key} for the message encoding header.
*/
public static final Metadata.Key MESSAGE_ENCODING_KEY =
Metadata.Key.of(GrpcUtil.MESSAGE_ENCODING, Metadata.ASCII_STRING_MARSHALLER);
/**
* {@link io.grpc.Metadata.Key} for the accepted message encodings header.
*/
public static final Metadata.Key MESSAGE_ACCEPT_ENCODING_KEY =
InternalMetadata.keyOf(GrpcUtil.MESSAGE_ACCEPT_ENCODING, new AcceptEncodingMarshaller());
/**
* {@link io.grpc.Metadata.Key} for the stream's content encoding header.
*/
public static final Metadata.Key CONTENT_ENCODING_KEY =
Metadata.Key.of(GrpcUtil.CONTENT_ENCODING, Metadata.ASCII_STRING_MARSHALLER);
/**
* {@link io.grpc.Metadata.Key} for the stream's accepted content encoding header.
*/
public static final Metadata.Key CONTENT_ACCEPT_ENCODING_KEY =
InternalMetadata.keyOf(GrpcUtil.CONTENT_ACCEPT_ENCODING, new AcceptEncodingMarshaller());
private static final class AcceptEncodingMarshaller implements TrustedAsciiMarshaller {
@Override
public byte[] toAsciiString(byte[] value) {
return value;
}
@Override
public byte[] parseAsciiString(byte[] serialized) {
return serialized;
}
}
/**
* {@link io.grpc.Metadata.Key} for the Content-Type request/response header.
*/
public static final Metadata.Key CONTENT_TYPE_KEY =
Metadata.Key.of("content-type", Metadata.ASCII_STRING_MARSHALLER);
/**
* {@link io.grpc.Metadata.Key} for the Transfer encoding.
*/
public static final Metadata.Key TE_HEADER =
Metadata.Key.of("te", Metadata.ASCII_STRING_MARSHALLER);
/**
* {@link io.grpc.Metadata.Key} for the Content-Type request/response header.
*/
public static final Metadata.Key USER_AGENT_KEY =
Metadata.Key.of("user-agent", Metadata.ASCII_STRING_MARSHALLER);
/**
* The default port for plain-text connections.
*/
public static final int DEFAULT_PORT_PLAINTEXT = 80;
/**
* The default port for SSL connections.
*/
public static final int DEFAULT_PORT_SSL = 443;
/**
* Content-Type used for GRPC-over-HTTP/2.
*/
public static final String CONTENT_TYPE_GRPC = "application/grpc";
/**
* The HTTP method used for GRPC requests.
*/
public static final String HTTP_METHOD = "POST";
/**
* The TE (transport encoding) header for requests over HTTP/2.
*/
public static final String TE_TRAILERS = "trailers";
/**
* The Timeout header name.
*/
public static final String TIMEOUT = "grpc-timeout";
/**
* The message encoding (i.e. compression) that can be used in the stream.
*/
public static final String MESSAGE_ENCODING = "grpc-encoding";
/**
* The accepted message encodings (i.e. compression) that can be used in the stream.
*/
public static final String MESSAGE_ACCEPT_ENCODING = "grpc-accept-encoding";
/**
* The content-encoding used to compress the full gRPC stream.
*/
public static final String CONTENT_ENCODING = "content-encoding";
/**
* The accepted content-encodings that can be used to compress the full gRPC stream.
*/
public static final String CONTENT_ACCEPT_ENCODING = "accept-encoding";
/**
* The default maximum uncompressed size (in bytes) for inbound messages. Defaults to 4 MiB.
*/
public static final int DEFAULT_MAX_MESSAGE_SIZE = 4 * 1024 * 1024;
/**
* The default maximum size (in bytes) for inbound header/trailer.
*/
// Update documentation in public-facing Builders when changing this value.
public static final int DEFAULT_MAX_HEADER_LIST_SIZE = 8192;
public static final Splitter ACCEPT_ENCODING_SPLITTER = Splitter.on(',').trimResults();
private static final String IMPLEMENTATION_VERSION = "1.19.0"; // CURRENT_GRPC_VERSION
/**
* The default delay in nanos before we send a keepalive.
*/
public static final long DEFAULT_KEEPALIVE_TIME_NANOS = TimeUnit.MINUTES.toNanos(1);
/**
* The default timeout in nanos for a keepalive ping request.
*/
public static final long DEFAULT_KEEPALIVE_TIMEOUT_NANOS = TimeUnit.SECONDS.toNanos(20L);
/**
* The magic keepalive time value that disables client keepalive.
*/
public static final long KEEPALIVE_TIME_NANOS_DISABLED = Long.MAX_VALUE;
/**
* The default delay in nanos for server keepalive.
*/
public static final long DEFAULT_SERVER_KEEPALIVE_TIME_NANOS = TimeUnit.HOURS.toNanos(2L);
/**
* The default timeout in nanos for a server keepalive ping request.
*/
public static final long DEFAULT_SERVER_KEEPALIVE_TIMEOUT_NANOS = TimeUnit.SECONDS.toNanos(20L);
/**
* The magic keepalive time value that disables keepalive.
*/
public static final long SERVER_KEEPALIVE_TIME_NANOS_DISABLED = Long.MAX_VALUE;
/**
* The default proxy detector.
*/
public static final ProxyDetector DEFAULT_PROXY_DETECTOR = new ProxyDetectorImpl();
/**
* A proxy detector that always claims no proxy is needed.
*/
public static final ProxyDetector NOOP_PROXY_DETECTOR = new ProxyDetector() {
@Nullable
@Override
public ProxiedSocketAddress proxyFor(SocketAddress targetServerAddress) {
return null;
}
};
/**
* The very default load-balancing policy.
*/
public static final String DEFAULT_LB_POLICY = "pick_first";
/**
* RPCs created on the Channel returned by {@link io.grpc.LoadBalancer.Subchannel#asChannel}
* will have this option with value {@code true}. They will be treated differently from
* the ones created by application.
*/
public static final CallOptions.Key CALL_OPTIONS_RPC_OWNED_BY_BALANCER =
CallOptions.Key.create("io.grpc.internal.CALL_OPTIONS_RPC_OWNED_BY_BALANCER");
/**
* Returns true if an RPC with the given properties should be counted when calculating the
* in-use state of a transport.
*/
public static boolean shouldBeCountedForInUse(CallOptions callOptions) {
return !Boolean.TRUE.equals(callOptions.getOption(CALL_OPTIONS_RPC_OWNED_BY_BALANCER));
}
/**
* Returns a proxy detector appropriate for the current environment.
*/
public static ProxyDetector getDefaultProxyDetector() {
if (IS_RESTRICTED_APPENGINE) {
return NOOP_PROXY_DETECTOR;
} else {
return DEFAULT_PROXY_DETECTOR;
}
}
/**
* Maps HTTP error response status codes to transport codes, as defined in
* http-grpc-status-mapping.md. Never returns a status for which {@code status.isOk()} is
* {@code true}.
*/
public static Status httpStatusToGrpcStatus(int httpStatusCode) {
return httpStatusToGrpcCode(httpStatusCode).toStatus()
.withDescription("HTTP status code " + httpStatusCode);
}
private static Status.Code httpStatusToGrpcCode(int httpStatusCode) {
if (httpStatusCode >= 100 && httpStatusCode < 200) {
// 1xx. These headers should have been ignored.
return Status.Code.INTERNAL;
}
switch (httpStatusCode) {
case HttpURLConnection.HTTP_BAD_REQUEST: // 400
case 431: // Request Header Fields Too Large
// TODO(carl-mastrangelo): this should be added to the http-grpc-status-mapping.md doc.
return Status.Code.INTERNAL;
case HttpURLConnection.HTTP_UNAUTHORIZED: // 401
return Status.Code.UNAUTHENTICATED;
case HttpURLConnection.HTTP_FORBIDDEN: // 403
return Status.Code.PERMISSION_DENIED;
case HttpURLConnection.HTTP_NOT_FOUND: // 404
return Status.Code.UNIMPLEMENTED;
case 429: // Too Many Requests
case HttpURLConnection.HTTP_BAD_GATEWAY: // 502
case HttpURLConnection.HTTP_UNAVAILABLE: // 503
case HttpURLConnection.HTTP_GATEWAY_TIMEOUT: // 504
return Status.Code.UNAVAILABLE;
default:
return Status.Code.UNKNOWN;
}
}
/**
* All error codes identified by the HTTP/2 spec. Used in GOAWAY and RST_STREAM frames.
*/
public enum Http2Error {
/**
* Servers implementing a graceful shutdown of the connection will send {@code GOAWAY} with
* {@code NO_ERROR}. In this case it is important to indicate to the application that the
* request should be retried (i.e. {@link Status#UNAVAILABLE}).
*/
NO_ERROR(0x0, Status.UNAVAILABLE),
PROTOCOL_ERROR(0x1, Status.INTERNAL),
INTERNAL_ERROR(0x2, Status.INTERNAL),
FLOW_CONTROL_ERROR(0x3, Status.INTERNAL),
SETTINGS_TIMEOUT(0x4, Status.INTERNAL),
STREAM_CLOSED(0x5, Status.INTERNAL),
FRAME_SIZE_ERROR(0x6, Status.INTERNAL),
REFUSED_STREAM(0x7, Status.UNAVAILABLE),
CANCEL(0x8, Status.CANCELLED),
COMPRESSION_ERROR(0x9, Status.INTERNAL),
CONNECT_ERROR(0xA, Status.INTERNAL),
ENHANCE_YOUR_CALM(0xB, Status.RESOURCE_EXHAUSTED.withDescription("Bandwidth exhausted")),
INADEQUATE_SECURITY(0xC, Status.PERMISSION_DENIED.withDescription("Permission denied as "
+ "protocol is not secure enough to call")),
HTTP_1_1_REQUIRED(0xD, Status.UNKNOWN);
// Populate a mapping of code to enum value for quick look-up.
private static final Http2Error[] codeMap = buildHttp2CodeMap();
private static Http2Error[] buildHttp2CodeMap() {
Http2Error[] errors = Http2Error.values();
int size = (int) errors[errors.length - 1].code() + 1;
Http2Error[] http2CodeMap = new Http2Error[size];
for (Http2Error error : errors) {
int index = (int) error.code();
http2CodeMap[index] = error;
}
return http2CodeMap;
}
private final int code;
// Status is not guaranteed to be deeply immutable. Don't care though, since that's only true
// when there are exceptions in the Status, which is not true here.
@SuppressWarnings("ImmutableEnumChecker")
private final Status status;
Http2Error(int code, Status status) {
this.code = code;
this.status = status.augmentDescription("HTTP/2 error code: " + this.name());
}
/**
* Gets the code for this error used on the wire.
*/
public long code() {
return code;
}
/**
* Gets the {@link Status} associated with this HTTP/2 code.
*/
public Status status() {
return status;
}
/**
* Looks up the HTTP/2 error code enum value for the specified code.
*
* @param code an HTTP/2 error code value.
* @return the HTTP/2 error code enum or {@code null} if not found.
*/
public static Http2Error forCode(long code) {
if (code >= codeMap.length || code < 0) {
return null;
}
return codeMap[(int) code];
}
/**
* Looks up the {@link Status} from the given HTTP/2 error code. This is preferred over {@code
* forCode(code).status()}, to more easily conform to HTTP/2:
*
* Unknown or unsupported error codes MUST NOT trigger any special behavior.
* These MAY be treated by an implementation as being equivalent to INTERNAL_ERROR.
*
* @param code the HTTP/2 error code.
* @return a {@link Status} representing the given error.
*/
public static Status statusForCode(long code) {
Http2Error error = forCode(code);
if (error == null) {
// This "forgets" the message of INTERNAL_ERROR while keeping the same status code.
Status.Code statusCode = INTERNAL_ERROR.status().getCode();
return Status.fromCodeValue(statusCode.value())
.withDescription("Unrecognized HTTP/2 error code: " + code);
}
return error.status();
}
}
/**
* Indicates whether or not the given value is a valid gRPC content-type.
*/
public static boolean isGrpcContentType(String contentType) {
if (contentType == null) {
return false;
}
if (CONTENT_TYPE_GRPC.length() > contentType.length()) {
return false;
}
contentType = contentType.toLowerCase();
if (!contentType.startsWith(CONTENT_TYPE_GRPC)) {
// Not a gRPC content-type.
return false;
}
if (contentType.length() == CONTENT_TYPE_GRPC.length()) {
// The strings match exactly.
return true;
}
// The contentType matches, but is longer than the expected string.
// We need to support variations on the content-type (e.g. +proto, +json) as defined by the
// gRPC wire spec.
char nextChar = contentType.charAt(CONTENT_TYPE_GRPC.length());
return nextChar == '+' || nextChar == ';';
}
/**
* Gets the User-Agent string for the gRPC transport.
*/
public static String getGrpcUserAgent(
String transportName, @Nullable String applicationUserAgent) {
StringBuilder builder = new StringBuilder();
if (applicationUserAgent != null) {
builder.append(applicationUserAgent);
builder.append(' ');
}
builder.append("grpc-java-");
builder.append(transportName);
builder.append('/');
builder.append(IMPLEMENTATION_VERSION);
return builder.toString();
}
/**
* Parse an authority into a URI for retrieving the host and port.
*/
public static URI authorityToUri(String authority) {
Preconditions.checkNotNull(authority, "authority");
URI uri;
try {
uri = new URI(null, authority, null, null, null);
} catch (URISyntaxException ex) {
throw new IllegalArgumentException("Invalid authority: " + authority, ex);
}
return uri;
}
/**
* Verify {@code authority} is valid for use with gRPC. The syntax must be valid and it must not
* include userinfo.
*
* @return the {@code authority} provided
*/
public static String checkAuthority(String authority) {
URI uri = authorityToUri(authority);
checkArgument(uri.getHost() != null, "No host in authority '%s'", authority);
checkArgument(uri.getUserInfo() == null,
"Userinfo must not be present on authority: '%s'", authority);
return authority;
}
/**
* Combine a host and port into an authority string.
*/
public static String authorityFromHostAndPort(String host, int port) {
try {
return new URI(null, null, host, port, null, null, null).getAuthority();
} catch (URISyntaxException ex) {
throw new IllegalArgumentException("Invalid host or port: " + host + " " + port, ex);
}
}
/**
* Shared executor for channels.
*/
public static final Resource SHARED_CHANNEL_EXECUTOR =
new Resource() {
private static final String NAME = "grpc-default-executor";
@Override
public Executor create() {
return Executors.newCachedThreadPool(getThreadFactory(NAME + "-%d", true));
}
@Override
public void close(Executor instance) {
((ExecutorService) instance).shutdown();
}
@Override
public String toString() {
return NAME;
}
};
/**
* Shared single-threaded executor for managing channel timers.
*/
public static final Resource TIMER_SERVICE =
new Resource() {
@Override
public ScheduledExecutorService create() {
// We don't use newSingleThreadScheduledExecutor because it doesn't return a
// ScheduledThreadPoolExecutor.
ScheduledExecutorService service = Executors.newScheduledThreadPool(
1,
getThreadFactory("grpc-timer-%d", true));
// If there are long timeouts that are cancelled, they will not actually be removed from
// the executors queue. This forces immediate removal upon cancellation to avoid a
// memory leak. Reflection is used because we cannot use methods added in Java 1.7. If
// the method does not exist, we give up. Note that the method is not present in 1.6, but
// _is_ present in the android standard library.
try {
Method method = service.getClass().getMethod("setRemoveOnCancelPolicy", boolean.class);
method.invoke(service, true);
} catch (NoSuchMethodException e) {
// no op
} catch (RuntimeException e) {
throw e;
} catch (Exception e) {
throw new RuntimeException(e);
}
return Executors.unconfigurableScheduledExecutorService(service);
}
@Override
public void close(ScheduledExecutorService instance) {
instance.shutdown();
}
};
/**
* Get a {@link ThreadFactory} suitable for use in the current environment.
* @param nameFormat to apply to threads created by the factory.
* @param daemon {@code true} if the threads the factory creates are daemon threads, {@code false}
* otherwise.
* @return a {@link ThreadFactory}.
*/
public static ThreadFactory getThreadFactory(String nameFormat, boolean daemon) {
if (IS_RESTRICTED_APPENGINE) {
@SuppressWarnings("BetaApi")
ThreadFactory factory = MoreExecutors.platformThreadFactory();
return factory;
} else {
return new ThreadFactoryBuilder()
.setDaemon(daemon)
.setNameFormat(nameFormat)
.build();
}
}
/**
* The factory of default Stopwatches.
*/
public static final Supplier STOPWATCH_SUPPLIER = new Supplier() {
@Override
public Stopwatch get() {
return Stopwatch.createUnstarted();
}
};
/**
* Returns the host via {@link InetSocketAddress#getHostString} if it is possible,
* i.e. in jdk >= 7.
* Otherwise, return it via {@link InetSocketAddress#getHostName} which may incur a DNS lookup.
*/
public static String getHost(InetSocketAddress addr) {
try {
Method getHostStringMethod = InetSocketAddress.class.getMethod("getHostString");
return (String) getHostStringMethod.invoke(addr);
} catch (NoSuchMethodException e) {
// noop
} catch (IllegalAccessException e) {
// noop
} catch (InvocationTargetException e) {
// noop
}
return addr.getHostName();
}
/**
* Marshals a nanoseconds representation of the timeout to and from a string representation,
* consisting of an ASCII decimal representation of a number with at most 8 digits, followed by a
* unit:
* n = nanoseconds
* u = microseconds
* m = milliseconds
* S = seconds
* M = minutes
* H = hours
*
* The representation is greedy with respect to precision. That is, 2 seconds will be
* represented as `2000000u`.
*
* See the
* request header definition
*/
@VisibleForTesting
static class TimeoutMarshaller implements Metadata.AsciiMarshaller {
@Override
public String toAsciiString(Long timeoutNanos) {
long cutoff = 100000000;
TimeUnit unit = TimeUnit.NANOSECONDS;
if (timeoutNanos < 0) {
throw new IllegalArgumentException("Timeout too small");
} else if (timeoutNanos < cutoff) {
return timeoutNanos + "n";
} else if (timeoutNanos < cutoff * 1000L) {
return unit.toMicros(timeoutNanos) + "u";
} else if (timeoutNanos < cutoff * 1000L * 1000L) {
return unit.toMillis(timeoutNanos) + "m";
} else if (timeoutNanos < cutoff * 1000L * 1000L * 1000L) {
return unit.toSeconds(timeoutNanos) + "S";
} else if (timeoutNanos < cutoff * 1000L * 1000L * 1000L * 60L) {
return unit.toMinutes(timeoutNanos) + "M";
} else {
return unit.toHours(timeoutNanos) + "H";
}
}
@Override
public Long parseAsciiString(String serialized) {
checkArgument(serialized.length() > 0, "empty timeout");
checkArgument(serialized.length() <= 9, "bad timeout format");
long value = Long.parseLong(serialized.substring(0, serialized.length() - 1));
char unit = serialized.charAt(serialized.length() - 1);
switch (unit) {
case 'n':
return value;
case 'u':
return TimeUnit.MICROSECONDS.toNanos(value);
case 'm':
return TimeUnit.MILLISECONDS.toNanos(value);
case 'S':
return TimeUnit.SECONDS.toNanos(value);
case 'M':
return TimeUnit.MINUTES.toNanos(value);
case 'H':
return TimeUnit.HOURS.toNanos(value);
default:
throw new IllegalArgumentException(String.format("Invalid timeout unit: %s", unit));
}
}
}
/**
* Returns a transport out of a PickResult, or {@code null} if the result is "buffer".
*/
@Nullable
static ClientTransport getTransportFromPickResult(PickResult result, boolean isWaitForReady) {
final ClientTransport transport;
Subchannel subchannel = result.getSubchannel();
if (subchannel != null) {
transport = ((AbstractSubchannel) subchannel).obtainActiveTransport();
} else {
transport = null;
}
if (transport != null) {
final ClientStreamTracer.Factory streamTracerFactory = result.getStreamTracerFactory();
if (streamTracerFactory == null) {
return transport;
}
return new ClientTransport() {
@Override
public ClientStream newStream(
MethodDescriptor, ?> method, Metadata headers, CallOptions callOptions) {
return transport.newStream(
method, headers, callOptions.withStreamTracerFactory(streamTracerFactory));
}
@Override
public void ping(PingCallback callback, Executor executor) {
transport.ping(callback, executor);
}
@Override
public InternalLogId getLogId() {
return transport.getLogId();
}
@Override
public ListenableFuture getStats() {
return transport.getStats();
}
};
}
if (!result.getStatus().isOk()) {
if (result.isDrop()) {
return new FailingClientTransport(result.getStatus(), RpcProgress.DROPPED);
}
if (!isWaitForReady) {
return new FailingClientTransport(result.getStatus(), RpcProgress.PROCESSED);
}
}
return null;
}
/** Quietly closes all messages in MessageProducer. */
static void closeQuietly(MessageProducer producer) {
InputStream message;
while ((message = producer.next()) != null) {
closeQuietly(message);
}
}
/**
* Closes an InputStream, ignoring IOExceptions.
* This method exists because Guava's {@code Closeables.closeQuietly()} is beta.
*/
public static void closeQuietly(@Nullable InputStream message) {
if (message == null) {
return;
}
try {
message.close();
} catch (IOException ioException) {
// do nothing except log
log.log(Level.WARNING, "exception caught in closeQuietly", ioException);
}
}
/**
* Checks whether the given item exists in the iterable. This is copied from Guava Collect's
* {@code Iterables.contains()} because Guava Collect is not Android-friendly thus core can't
* depend on it.
*/
static boolean iterableContains(Iterable iterable, T item) {
if (iterable instanceof Collection) {
Collection> collection = (Collection>) iterable;
try {
return collection.contains(item);
} catch (NullPointerException e) {
return false;
} catch (ClassCastException e) {
return false;
}
}
for (T i : iterable) {
if (Objects.equal(i, item)) {
return true;
}
}
return false;
}
private GrpcUtil() {}
}