HTTP/2 set initial settings

servicetalk-http-api/src/main/java/io/servicetalk/http/api/Http2Settings.java

@@ -0,0 +1,84 @@
+/*
+ * Copyright © 2022 Apple Inc. and the ServiceTalk project 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.servicetalk.http.api;
+
+import java.util.function.BiConsumer;
+import javax.annotation.Nullable;
+
+/**
+ * Object representing a <a href="https://datatracker.ietf.org/doc/html/rfc7540#section-6.5.1">HTTP/2 Setting</a> frame.
+ */
+public interface Http2Settings {
+    /**
+     * Get the value for
+     * <a href="https://datatracker.ietf.org/doc/html/rfc7540#section-6.5.2">SETTINGS_HEADER_TABLE_SIZE</a>.
+     * @return the value for
+     * <a href="https://datatracker.ietf.org/doc/html/rfc7540#section-6.5.2">SETTINGS_HEADER_TABLE_SIZE</a>.
+     */
+    @Nullable
+    Long headerTableSize();
+
+    /**
+     * Get the value for
+     * <a href="https://datatracker.ietf.org/doc/html/rfc7540#section-6.5.2">SETTINGS_MAX_CONCURRENT_STREAMS</a>.
+     * @return the value for
+     * <a href="https://datatracker.ietf.org/doc/html/rfc7540#section-6.5.2">SETTINGS_MAX_CONCURRENT_STREAMS</a>.
+     */
+    @Nullable
+    Long maxConcurrentStreams();
+
+    /**
+     * Get the value for
+     * <a href="https://datatracker.ietf.org/doc/html/rfc7540#section-6.5.2">SETTINGS_INITIAL_WINDOW_SIZE</a>.
+     * @return the value for
+     * <a href="https://datatracker.ietf.org/doc/html/rfc7540#section-6.5.2">SETTINGS_INITIAL_WINDOW_SIZE</a>.
+     */
+    @Nullable
+    Integer initialWindowSize();
+
+    /**
+     * Get the value for
+     * <a href="https://datatracker.ietf.org/doc/html/rfc7540#section-6.5.2">SETTINGS_MAX_FRAME_SIZE</a>.
+     * @return the value for
+     * <a href="https://datatracker.ietf.org/doc/html/rfc7540#section-6.5.2">SETTINGS_MAX_FRAME_SIZE</a>.
+     */
+    @Nullable
+    Integer maxFrameSize();
+
+    /**
+     * Get the value for
+     * <a href="https://datatracker.ietf.org/doc/html/rfc7540#section-6.5.2">SETTINGS_MAX_HEADER_LIST_SIZE</a>.
+     * @return the value for
+     * <a href="https://datatracker.ietf.org/doc/html/rfc7540#section-6.5.2">SETTINGS_MAX_HEADER_LIST_SIZE</a>.
+     */
+    @Nullable
+    Long maxHeaderListSize();
+
+    /**
+     * Get the setting value associated with an
+     * <a href="https://datatracker.ietf.org/doc/html/rfc7540#section-6.5.1">identifier</a>.
+     * @param identifier the <a href="https://datatracker.ietf.org/doc/html/rfc7540#section-6.5.1">identifier</a>.
+     * @return {@code null} if no setting value corresponding {@code identifier} exists, otherwise the value.
+     */
+    @Nullable
+    Long settingValue(char identifier);
+
+    /**
+     * Iterate over all the &lt;identifier, value&gt; tuple in this settings object.
+     * @param action Invoked on each &lt;identifier, value&gt; tuple.
+     */
+    void forEach(BiConsumer<? super Character, ? super Long> action);
+}

servicetalk-http-api/src/main/java/io/servicetalk/http/api/Http2SettingsBuilder.java

@@ -0,0 +1,252 @@
+/*
+ * Copyright © 2022 Apple Inc. and the ServiceTalk project 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.servicetalk.http.api;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.function.BiConsumer;
+import javax.annotation.Nullable;
+
+/**
+ * Builder to help create a {@link Map} for
+ * <a href="https://datatracker.ietf.org/doc/html/rfc7540#section-6.5.1">HTTP/2 Setting</a>.
+ */
+public final class Http2SettingsBuilder {
+    private static final long MAX_UNSIGNED_INT = 0xffffffffL;
+    private static final int MAX_FRAME_SIZE_LOWER_BOUND = 0x4000;
+    private static final int MAX_FRAME_SIZE_UPPER_BOUND = 0xffffff;
+    /**
+     * Identifier <a href="https://datatracker.ietf.org/doc/html/rfc7540#section-6.5.2">SETTINGS_HEADER_TABLE_SIZE</a>.
+     */
+    private static final char HEADER_TABLE_SIZE = 0x1;
+    /**
+     * Identifier <a href="https://datatracker.ietf.org/doc/html/rfc7540#section-6.5.2">SETTINGS_ENABLE_PUSH</a>.
+     */
+    private static final char ENABLE_PUSH = 0x2;
+    /**
+     * Identifier <a href="https://datatracker.ietf.org/doc/html/rfc7540#section-6.5.2">
+     *     SETTINGS_MAX_CONCURRENT_STREAMS</a>.
+     */
+    private static final char MAX_CONCURRENT_STREAMS = 0x3;
+    /**
+     * Identifier <a href="https://datatracker.ietf.org/doc/html/rfc7540#section-6.5.2">
+     *     SETTINGS_INITIAL_WINDOW_SIZE</a>.
+     */
+    private static final char INITIAL_WINDOW_SIZE = 0x4;
+    /**
+     * Identifier <a href="https://datatracker.ietf.org/doc/html/rfc7540#section-6.5.2">SETTINGS_MAX_FRAME_SIZE</a>.
+     */
+    private static final char MAX_FRAME_SIZE = 0x5;
+    /**
+     * Identifier <a href="https://datatracker.ietf.org/doc/html/rfc7540#section-6.5.2">
+     *     SETTINGS_MAX_HEADER_LIST_SIZE</a>.
+     */
+    private static final char MAX_HEADER_LIST_SIZE = 0x6;
+    private final Map<Character, Long> settings;
+
+    /**
+     * Create a new instance.
+     */
+    public Http2SettingsBuilder() {
+        settings = new HashMap<>(6);
+    }
+
+    /**
+     * Set the value for
+     * <a href="https://datatracker.ietf.org/doc/html/rfc7540#section-6.5.2">SETTINGS_HEADER_TABLE_SIZE</a>.
+     *
+     * @param value The value.
+     * @return {@code this}.
+     */
+    public Http2SettingsBuilder headerTableSize(long value) {
+        validate32Unsigned(value);
+        settings.put(HEADER_TABLE_SIZE, value);
+        return this;
+    }
+
+    /**
+     * Set the value for
+     * <a href="https://datatracker.ietf.org/doc/html/rfc7540#section-6.5.2">SETTINGS_MAX_CONCURRENT_STREAMS</a>.
+     *
+     * @param value The value.
+     * @return {@code this}.
+     */
+    public Http2SettingsBuilder maxConcurrentStreams(long value) {
+        validate32Unsigned(value);
+        settings.put(MAX_CONCURRENT_STREAMS, value);
+        return this;
+    }
+
+    /**
+     * Set the value for
+     * <a href="https://datatracker.ietf.org/doc/html/rfc7540#section-6.5.2">SETTINGS_INITIAL_WINDOW_SIZE</a>.
+     *
+     * @param value The value.
+     * @return {@code this}.
+     */
+    public Http2SettingsBuilder initialWindowSize(long value) {
+        validate31Unsigned(value);
+        settings.put(INITIAL_WINDOW_SIZE, value);
+        return this;
+    }
+
+    /**
+     * Set the value for
+     * <a href="https://datatracker.ietf.org/doc/html/rfc7540#section-6.5.2">SETTINGS_MAX_FRAME_SIZE</a>.
+     *
+     * @param value The value.
+     * @return {@code this}.
+     */
+    public Http2SettingsBuilder maxFrameSize(int value) {
+        if (value < MAX_FRAME_SIZE_LOWER_BOUND || value > MAX_FRAME_SIZE_UPPER_BOUND) {
+            throw new IllegalArgumentException("value: " + value + "(expected [" + MAX_FRAME_SIZE_LOWER_BOUND + ", " +
+                    MAX_FRAME_SIZE_UPPER_BOUND + "]");
+        }
+        settings.put(MAX_FRAME_SIZE, (long) value);
+        return this;
+    }
+
+    /**
+     * Set the value for
+     * <a href="https://datatracker.ietf.org/doc/html/rfc7540#section-6.5.2">SETTINGS_MAX_HEADER_LIST_SIZE</a>.
+     *
+     * @param value The value.
+     * @return {@code this}.
+     */
+    public Http2SettingsBuilder maxHeaderListSize(long value) {
+        validate32Unsigned(value);
+        settings.put(MAX_HEADER_LIST_SIZE, value);
+        return this;
+    }
+
+    /**
+     * Build the {@link Map} that represents
+     * <a href="https://datatracker.ietf.org/doc/html/rfc7540#section-6.5.1">HTTP/2 Setting</a>.
+     * @return the {@link Map} that represents
+     * <a href="https://datatracker.ietf.org/doc/html/rfc7540#section-6.5.1">HTTP/2 Setting</a>.
+     */
+    public Http2Settings build() {
+        return new DefaultHttp2Settings(new HashMap<>(settings));
+    }
+
+    private static void validate32Unsigned(long value) {
+        if (value < 0 || value >= MAX_UNSIGNED_INT) {
+            throw new IllegalArgumentException("value: " + value + "(expected [0, " + MAX_UNSIGNED_INT + "]");
+        }
+    }
+
+    private static void validate31Unsigned(long value) {
+        if (value < 0 || value >= Integer.MAX_VALUE) {
+            throw new IllegalArgumentException("value: " + value + "(expected [0, " + Integer.MAX_VALUE + "]");
+        }
+    }
+
+    private static final class DefaultHttp2Settings implements Http2Settings {
+        private final Map<Character, Long> settings;
+
+        private DefaultHttp2Settings(final Map<Character, Long> settings) {
+            this.settings = settings;
+        }
+
+        @Nullable
+        @Override
+        public Long headerTableSize() {
+            return settings.get(HEADER_TABLE_SIZE);
+        }
+
+        @Nullable
+        @Override
+        public Long maxConcurrentStreams() {
+            return settings.get(MAX_CONCURRENT_STREAMS);
+        }
+
+        @Nullable
+        @Override
+        public Integer initialWindowSize() {
+            return toInteger(settings.get(INITIAL_WINDOW_SIZE));
+        }
+
+        @Nullable
+        @Override
+        public Integer maxFrameSize() {
+            return toInteger(settings.get(MAX_FRAME_SIZE));
+        }
+
+        @Nullable
+        @Override
+        public Long maxHeaderListSize() {
+            return settings.get(MAX_HEADER_LIST_SIZE);
+        }
+
+        @Nullable
+        @Override
+        public Long settingValue(final char identifier) {
+            return settings.get(identifier);
+        }
+
+        @Override
+        public void forEach(final BiConsumer<? super Character, ? super Long> action) {
+            settings.forEach(action);
+        }
+
+        @Override
+        public String toString() {
+            final StringBuilder sb = new StringBuilder(settings.size() * 10);
+            final String separator = ", ";
+            sb.append('{');
+            settings.forEach((identity, value) ->
+                    sb.append(identityToString(identity)).append('=').append(value).append(separator));
+            if (sb.length() > separator.length()) {
+                sb.setLength(sb.length() - separator.length());
+            }
+            return sb.append('}').toString();
+        }
+
+        @Override
+        public int hashCode() {
+            return settings.hashCode();
+        }
+
+        @Override
+        public boolean equals(Object o) {
+            return o instanceof DefaultHttp2Settings && settings.equals(((DefaultHttp2Settings) o).settings);
+        }
+
+        private static String identityToString(Character identity) {
+            switch (identity) {
+                case HEADER_TABLE_SIZE:
+                    return "HEADER_TABLE_SIZE";
+                case ENABLE_PUSH:
+                    return "ENABLE_PUSH";
+                case MAX_CONCURRENT_STREAMS:
+                    return "MAX_CONCURRENT_STREAMS";
+                case INITIAL_WINDOW_SIZE:
+                    return "INITIAL_WINDOW_SIZE";
+                case MAX_FRAME_SIZE:
+                    return "MAX_FRAME_SIZE";
+                case MAX_HEADER_LIST_SIZE:
+                    return "MAX_HEADER_LIST_SIZE";
+                default:
+                    return identity.toString();
+            }
+        }
+
+        @Nullable
+        private static Integer toInteger(@Nullable Long value) {
+            return value == null ? null : value.intValue();
+        }
+    }
+}

servicetalk-http-netty/gradle/spotbugs/main-exclusions.xml

@@ -131,4 +131,9 @@
     <Method name="handlerAdded"/>
     <Bug pattern="THROWS_METHOD_THROWS_CLAUSE_BASIC_EXCEPTION"/>
   </Match>
+  <Match>
+    <Class name="io.servicetalk.http.netty.H2ProtocolConfigBuilder"/>
+    <Field name="h2Settings"/>
+    <Bug pattern="EI_EXPOSE_REP2"/>
+  </Match>
 </FindBugsFilter>