Poc/xds filter v2

core/src/main/java/com/linecorp/armeria/client/AbstractClientOptionsBuilder.java

@@ -57,6 +57,7 @@ public class AbstractClientOptionsBuilder {
 
     private final Map<ClientOption<?>, ClientOptionValue<?>> options = new LinkedHashMap<>();
     private final ClientDecorationBuilder decoration = ClientDecoration.builder();
+    private final ClientPreprocessorsBuilder clientPreprocessorsBuilder = new ClientPreprocessorsBuilder();
     private final HttpHeadersBuilder headers = HttpHeaders.builder();
 
     @Nullable
@@ -127,6 +128,8 @@ public <T> AbstractClientOptionsBuilder option(ClientOptionValue<T> optionValue)
         } else if (opt == ClientOptions.HEADERS) {
             final HttpHeaders h = (HttpHeaders) optionValue.value();
             setHeaders(h);
+        } else if (opt == ClientOptions.PREPROCESSORS) {
+            clientPreprocessorsBuilder.add((ClientPreprocessors) optionValue.value());
         } else {
             options.put(opt, optionValue);
         }
@@ -520,6 +523,26 @@ public AbstractClientOptionsBuilder responseTimeoutMode(ResponseTimeoutMode resp
                       requireNonNull(responseTimeoutMode, "responseTimeoutMode"));
     }
 
+    /**
+     * Adds the specified HTTP-level {@code preprocessor}.
+     *
+     * @param preprocessor the {@link HttpPreprocessor} that preprocesses an invocation
+     */
+    public AbstractClientOptionsBuilder preprocessor(HttpPreprocessor preprocessor) {
+        clientPreprocessorsBuilder.add(preprocessor);
+        return this;
+    }
+
+    /**
+     * Adds the specified RPC-level {@code rpcPreprocessor}.
+     *
+     * @param rpcPreprocessor the {@link RpcPreprocessor} that preprocesses an invocation
+     */
+    public AbstractClientOptionsBuilder rpcPreprocessor(RpcPreprocessor rpcPreprocessor) {
+        clientPreprocessorsBuilder.addRpc(rpcPreprocessor);
+        return this;
+    }
+
     /**
      * Builds {@link ClientOptions} with the given options and the
      * {@linkplain ClientOptions#of() default options}.
@@ -538,6 +561,7 @@ protected final ClientOptions buildOptions(@Nullable ClientOptions baseOptions)
                 ImmutableList.builder();
         additionalValues.addAll(optVals);
         additionalValues.add(ClientOptions.DECORATION.newValue(decoration.build()));
+        additionalValues.add(ClientOptions.PREPROCESSORS.newValue(clientPreprocessorsBuilder.build()));
         additionalValues.add(ClientOptions.HEADERS.newValue(headers.build()));
         additionalValues.add(ClientOptions.CONTEXT_HOOK.newValue(contextHook));
         if (contextCustomizer != null) {

core/src/main/java/com/linecorp/armeria/client/AbstractWebClientBuilder.java

@@ -17,6 +17,7 @@
 
 import static com.google.common.base.Preconditions.checkArgument;
 import static com.linecorp.armeria.common.SessionProtocol.httpAndHttpsValues;
+import static com.linecorp.armeria.internal.client.ClientBuilderParamsUtil.preprocessorToUri;
 import static com.linecorp.armeria.internal.client.ClientUtil.UNDEFINED_URI;
 import static java.util.Objects.requireNonNull;
 
@@ -28,6 +29,7 @@
 import com.linecorp.armeria.common.SerializationFormat;
 import com.linecorp.armeria.common.SessionProtocol;
 import com.linecorp.armeria.common.annotation.Nullable;
+import com.linecorp.armeria.internal.client.ClientBuilderParamsUtil;
 
 /**
  * A skeletal builder implementation for {@link WebClient}.
@@ -47,7 +49,7 @@ public abstract class AbstractWebClientBuilder extends AbstractClientOptionsBuil
      * Creates a new instance.
      */
     protected AbstractWebClientBuilder() {
-        this(UNDEFINED_URI, null, null, null);
+        this(UNDEFINED_URI, null, null, null, DefaultWebClientPreprocessor.INSTANCE);
     }
 
     /**
@@ -69,25 +71,42 @@ protected AbstractWebClientBuilder(URI uri) {
     protected AbstractWebClientBuilder(SessionProtocol sessionProtocol, EndpointGroup endpointGroup,
                                        @Nullable String path) {
         this(null, validateSessionProtocol(sessionProtocol),
-             requireNonNull(endpointGroup, "endpointGroup"), path);
+             requireNonNull(endpointGroup, "endpointGroup"), path, null);
+    }
+
+    /**
+     * TBU.
+     */
+    protected AbstractWebClientBuilder(HttpPreprocessor httpPreprocessor, @Nullable String path) {
+        this(preprocessorToUri(httpPreprocessor, path), null, null, null, httpPreprocessor);
     }
 
     /**
      * Creates a new instance.
      */
     protected AbstractWebClientBuilder(@Nullable URI uri, @Nullable Scheme scheme,
                                        @Nullable EndpointGroup endpointGroup, @Nullable String path) {
+        this(uri, scheme, endpointGroup, path, maybeDefaultPreprocessor(uri));
+    }
+
+    private AbstractWebClientBuilder(@Nullable URI uri, @Nullable Scheme scheme,
+                                     @Nullable EndpointGroup endpointGroup, @Nullable String path,
+                                     @Nullable HttpPreprocessor httpPreprocessor) {
         assert uri != null || (scheme != null && endpointGroup != null);
         assert path == null || uri == null;
         this.uri = uri;
         this.scheme = scheme;
         this.endpointGroup = endpointGroup;
         this.path = validatePath(path);
+
+        if (httpPreprocessor != null) {
+            preprocessor(httpPreprocessor);
+        }
     }
 
     private static URI validateUri(URI uri) {
         requireNonNull(uri, "uri");
-        if (Clients.isUndefinedUri(uri)) {
+        if (ClientBuilderParamsUtil.isInternalUri(uri)) {
             return uri;
         }
         final String givenScheme = requireNonNull(uri, "uri").getScheme();
@@ -129,6 +148,21 @@ private static String validatePath(@Nullable String path) {
         return path;
     }
 
+    @Nullable
+    private static HttpPreprocessor maybeDefaultPreprocessor(@Nullable URI uri) {
+        if (uri != null && Clients.isUndefinedUri(uri)) {
+            return DefaultWebClientPreprocessor.INSTANCE;
+        }
+        return null;
+    }
+
+    private static URI maybeResolvePath(@Nullable String path) {
+        if (path == null) {
+            return UNDEFINED_URI;
+        }
+        return UNDEFINED_URI.resolve(path);
+    }
+
     /**
      * Returns a newly-created web client based on the properties of this builder.
      *
@@ -184,4 +218,10 @@ public AbstractWebClientBuilder rpcDecorator(Function<? super RpcClient, ? exten
     public AbstractWebClientBuilder rpcDecorator(DecoratingRpcClientFunction decorator) {
         throw new UnsupportedOperationException("RPC decorator cannot be added to the web client builder.");
     }
+
+    @Deprecated
+    @Override
+    public AbstractClientOptionsBuilder rpcPreprocessor(RpcPreprocessor rpcPreprocessor) {
+        throw new UnsupportedOperationException("RPC preprocessor cannot be added to the web client builder.");
+    }
 }

core/src/main/java/com/linecorp/armeria/client/ClientBuilder.java

@@ -29,13 +29,16 @@
 import com.linecorp.armeria.client.redirect.RedirectConfig;
 import com.linecorp.armeria.common.RequestId;
 import com.linecorp.armeria.common.Scheme;
+import com.linecorp.armeria.common.SerializationFormat;
+import com.linecorp.armeria.common.SessionProtocol;
 import com.linecorp.armeria.common.SuccessFunction;
 import com.linecorp.armeria.common.annotation.Nullable;
 import com.linecorp.armeria.common.annotation.UnstableApi;
 import com.linecorp.armeria.common.auth.AuthToken;
 import com.linecorp.armeria.common.auth.BasicToken;
 import com.linecorp.armeria.common.auth.OAuth1aToken;
 import com.linecorp.armeria.common.auth.OAuth2Token;
+import com.linecorp.armeria.internal.client.ClientBuilderParamsUtil;
 
 /**
  * Creates a new client that connects to the specified {@link URI} using the builder pattern. Use the factory
@@ -95,6 +98,18 @@ public final class ClientBuilder extends AbstractClientOptionsBuilder {
         this.scheme = scheme;
     }
 
+    ClientBuilder(SerializationFormat serializationFormat,
+                  ClientPreprocessors preprocessors, @Nullable String path) {
+        checkArgument(!preprocessors.isEmpty(),
+                      "At least one preprocessor must be set in ClientPreprocessors.");
+        endpointGroup = null;
+        this.path = path;
+        scheme = Scheme.of(serializationFormat, SessionProtocol.UNDEFINED);
+        uri = ClientBuilderParamsUtil.preprocessorToUri(scheme, preprocessors, path);
+        preprocessors.preprocessors().forEach(this::preprocessor);
+        preprocessors.rpcPreprocessors().forEach(this::rpcPreprocessor);
+    }
+
     /**
      * Returns a newly-created client which implements the specified {@code clientType}, based on the
      * properties of this builder.
@@ -300,4 +315,14 @@ public ClientBuilder contextHook(Supplier<? extends AutoCloseable> contextHook)
     public ClientBuilder responseTimeoutMode(ResponseTimeoutMode responseTimeoutMode) {
         return (ClientBuilder) super.responseTimeoutMode(responseTimeoutMode);
     }
+
+    @Override
+    public ClientBuilder preprocessor(HttpPreprocessor decorator) {
+        return (ClientBuilder) super.preprocessor(decorator);
+    }
+
+    @Override
+    public ClientBuilder rpcPreprocessor(RpcPreprocessor decorator) {
+        return (ClientBuilder) super.rpcPreprocessor(decorator);
+    }
 }

core/src/main/java/com/linecorp/armeria/client/ClientBuilderParams.java

@@ -80,4 +80,11 @@ static ClientBuilderParams of(Scheme scheme, EndpointGroup endpointGroup,
      * Returns the options of the client.
      */
     ClientOptions options();
+
+    /**
+     * TBU.
+     */
+    default ClientBuilderParamsBuilder paramsBuilder() {
+        return new ClientBuilderParamsBuilder(this);
+    }
 }

core/src/main/java/com/linecorp/armeria/client/ClientBuilderParamsBuilder.java

@@ -0,0 +1,118 @@
+/*
+ * Copyright 2024 LINE Corporation
+ *
+ * LINE Corporation licenses this file to you 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:
+ *
+ *   https://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 com.linecorp.armeria.client;
+
+import static com.google.common.base.MoreObjects.firstNonNull;
+import static com.linecorp.armeria.internal.client.ClientBuilderParamsUtil.nullOrEmptyToSlash;
+
+import java.net.URI;
+import java.net.URISyntaxException;
+
+import com.linecorp.armeria.common.Scheme;
+import com.linecorp.armeria.common.SerializationFormat;
+import com.linecorp.armeria.common.annotation.Nullable;
+
+/**
+ * TBU.
+ */
+public final class ClientBuilderParamsBuilder {
+
+    private final ClientBuilderParams params;
+
+    @Nullable
+    private SerializationFormat serializationFormat;
+    @Nullable
+    private String absolutePathRef;
+    @Nullable
+    private Class<?> type;
+    @Nullable
+    private ClientOptions options;
+
+    ClientBuilderParamsBuilder(ClientBuilderParams params) {
+        this.params = params;
+    }
+
+    /**
+     * TBU.
+     */
+    public ClientBuilderParamsBuilder serializationFormat(SerializationFormat serializationFormat) {
+        this.serializationFormat = serializationFormat;
+        return this;
+    }
+
+    /**
+     * TBU.
+     */
+    public ClientBuilderParamsBuilder absolutePathRef(String absolutePathRef) {
+        this.absolutePathRef = absolutePathRef;
+        return this;
+    }
+
+    /**
+     * TBU.
+     */
+    public ClientBuilderParamsBuilder clientType(Class<?> type) {
+        this.type = type;
+        return this;
+    }
+
+    /**
+     * TBU.
+     */
+    public ClientBuilderParamsBuilder options(ClientOptions options) {
+        this.options = options;
+        return this;
+    }
+
+    /**
+     * TBU.
+     */
+    public ClientBuilderParams build() {
+        final Scheme scheme;
+        final String schemeStr;
+        if (serializationFormat != null) {
+            scheme = Scheme.of(serializationFormat, params.scheme().sessionProtocol());
+            if (scheme.serializationFormat() == SerializationFormat.NONE) {
+                schemeStr = scheme.sessionProtocol().uriText();
+            } else {
+                schemeStr = scheme.uriText();
+            }
+        } else {
+            scheme = params.scheme();
+            schemeStr = params.uri().getScheme();
+        }
+
+        final String path;
+        if (absolutePathRef != null) {
+            path = nullOrEmptyToSlash(absolutePathRef);
+        } else {
+            path = params.absolutePathRef();
+        }
+
+        final URI prevUri = params.uri();
+        final URI uri;
+        try {
+            uri = new URI(schemeStr, prevUri.getRawAuthority(), path,
+                          prevUri.getRawQuery(), prevUri.getRawFragment());
+        } catch (URISyntaxException e) {
+            throw new IllegalArgumentException(e);
+        }
+        return new DefaultClientBuilderParams(scheme, params.endpointGroup(), uri.getRawPath(),
+                                              uri, firstNonNull(type, params.clientType()),
+                                              firstNonNull(options, params.options()));
+    }
+}

core/src/main/java/com/linecorp/armeria/client/ClientExecution.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2024 LINE Corporation
+ *
+ * LINE Corporation licenses this file to you 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:
+ *
+ *   https://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 com.linecorp.armeria.client;
+
+import com.linecorp.armeria.common.Request;
+import com.linecorp.armeria.common.Response;
+
+/**
+ * TBU.
+ */
+@FunctionalInterface
+public interface ClientExecution<I extends Request, O extends Response> {
+
+    /**
+     * TBU.
+     */
+    O execute(PartialClientRequestContext ctx, I req) throws Exception;
+}

core/src/main/java/com/linecorp/armeria/client/ClientFactory.java

@@ -45,6 +45,7 @@
 import com.linecorp.armeria.common.util.ReleasableHolder;
 import com.linecorp.armeria.common.util.ShutdownHooks;
 import com.linecorp.armeria.common.util.Unwrappable;
+import com.linecorp.armeria.internal.client.ClientBuilderParamsUtil;
 
 import io.micrometer.core.instrument.MeterRegistry;
 import io.netty.channel.EventLoop;
@@ -291,7 +292,7 @@ default ClientFactory unwrap() {
     default URI validateUri(URI uri) {
         requireNonNull(uri, "uri");
 
-        if (Clients.isUndefinedUri(uri)) {
+        if (ClientBuilderParamsUtil.isInternalUri(uri)) {
             // We use a special singleton marker URI for clients that do not explicitly define a
             // host or scheme at construction time.
             // As this isn't created by users, we don't need to normalize it.