Introduce Helidon Pico

.gitignore

@@ -82,4 +82,4 @@ docs/se/config/images
 jmh-baseline.json
 
 # benchmark results
-nima/tests/benchmark/techempower/results
+nima/tests/benchmark/techempower/results

bom/pom.xml

@@ -1345,6 +1345,19 @@
                 <artifactId>helidon-nima-fault-tolerance</artifactId>
                 <version>${helidon.version}</version>
             </dependency>
+
+            <!-- Pico -->
+            <dependency>
+                <groupId>io.helidon.pico</groupId>
+                <artifactId>helidon-pico-api</artifactId>
+                <version>${helidon.version}</version>
+            </dependency>
+            <dependency>
+                <groupId>io.helidon.pico</groupId>
+                <artifactId>helidon-pico-types</artifactId>
+                <version>${helidon.version}</version>
+            </dependency>
+
         </dependencies>
     </dependencyManagement>
 </project>

pico/api/pom.xml

@@ -0,0 +1,33 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+
+    Copyright (c) 2022 Oracle and/or its affiliates.
+
+    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.
+
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <groupId>io.helidon.pico</groupId>
+        <artifactId>helidon-pico-project</artifactId>
+        <version>4.0.0-SNAPSHOT</version>
+        <relativePath>../pom.xml</relativePath>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>helidon-pico-api</artifactId>
+    <name>Helidon Pico API</name>
+
+</project>

pico/api/src/main/java/io/helidon/pico/api/Contract.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2022 Oracle and/or its affiliates.
+ *
+ * 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.helidon.pico.api;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * The Contract annotation is used to relay significance to the type. While remaining optional in its use, it is typically placed
+ * on an interface definition to signify that the given type can be used for lookup in the service registry, or otherwise be
+ * eligible for injection via standard @Inject. It could also be used on other types (e.g., abstract class) as well.
+ * <p>
+ *
+ * If the developer does not have access to the source to place this annotation on the interface definition then consider using
+ * {@link ExternalContracts} instead - this annotation can be placed on the implementation class implementing the given interface.
+ * See io.helidon.pico.spi.ServiceInfo#getContractsImplemented()
+ */
+@Documented
+@Retention(RetentionPolicy.RUNTIME)
+@Target(java.lang.annotation.ElementType.TYPE)
+public @interface Contract {
+
+}

pico/api/src/main/java/io/helidon/pico/api/ExternalContracts.java

@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2022 Oracle and/or its affiliates.
+ *
+ * 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.helidon.pico.api;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Placed on the implementation of a service as an alternative to using a {@link Contract}.
+ * <p>
+ * Use this annotation when it is impossible to place an annotation on the interface itself - for instance of the interface comes
+ * from a 3rd party library/provider.
+ */
+@Documented
+@Retention(RetentionPolicy.RUNTIME)
+@Target(java.lang.annotation.ElementType.TYPE)
+public @interface ExternalContracts {
+
+    /**
+     * The advertised contract type(s) for the service class implementation.
+     *
+     * @return the external contract(s)
+     */
+    Class<?>[] value();
+
+    /**
+     * The optional set of module names where this contract is expected to reside.
+     *
+     * @return the optional module names
+     */
+    String[] moduleNames() default {};
+
+}

pico/api/src/main/java/io/helidon/pico/api/RunLevel.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2022 Oracle and/or its affiliates.
+ *
+ * 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.helidon.pico.api;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.Inherited;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+import static java.lang.annotation.ElementType.TYPE;
+
+/**
+ * Indicates the desired startup sequence for a service class.
+ */
+@Documented
+@Retention(RetentionPolicy.RUNTIME)
+@Target(TYPE)
+@Inherited
+public @interface RunLevel {
+
+    /**
+     * Represents an eager singleton.
+     */
+    int STARTUP = 0;
+
+    /**
+     * Anything > 0 is left to the underlying provider implementation's discretion for meaning; this is just a default for something
+     * that is deemed "other than startup".
+     */
+    int NORMAL = 100;
+
+    /**
+     * The service ranking applied when not declared explicitly.
+     *
+     * @return the startup int value, defaulting to {@link #NORMAL}
+     */
+    int value() default NORMAL;
+
+}

pico/api/src/main/java/io/helidon/pico/api/package-info.java

@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2022 Oracle and/or its affiliates.
+ *
+ * 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.
+ */
+
+/**
+ * Types that are Pico API/consumer facing. The Pico API provide types that are generally useful at compile time
+ * to assign special meaning to the type. In this way it also helps with readability and intentions of the code itself.
+ * <p>
+ * <li> {@link io.helidon.pico.api.Contract} - signifies that the type can be used for lookup in the service registry.
+ * <li> {@link io.helidon.pico.api.ExternalContracts} - same as Contract, but applied to the implementation class instead.
+ * <li> {@link io.helidon.pico.api.RunLevel} - ascribes meaning for when the service should start.
+ */
+package io.helidon.pico.api;

pico/api/src/main/java/module-info.java

@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2022 Oracle and/or its affiliates.
+ *
+ * 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.
+ */
+
+/**
+ * Pico API module.
+ */
+module io.helidon.pico.api {
+    exports io.helidon.pico.api;
+}

pico/pom.xml

@@ -0,0 +1,82 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+
+    Copyright (c) 2022 Oracle and/or its affiliates.
+
+    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.
+
+-->
+
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>io.helidon</groupId>
+        <artifactId>helidon-project</artifactId>
+        <version>4.0.0-SNAPSHOT</version>
+        <relativePath>../pom.xml</relativePath>
+    </parent>
+
+    <groupId>io.helidon.pico</groupId>
+    <artifactId>helidon-pico-project</artifactId>
+    <name>Helidon Pico Project</name>
+
+    <packaging>pom</packaging>
+
+    <properties>
+        <!-- all pico modules should be backward compatible with 11 -->
+        <version.java>11</version.java>
+
+        <!-- pico supports legacy javax.inject and javax.annotations in tooling -->
+        <javax.injection.version>1</javax.injection.version>
+    </properties>
+
+    <!-- this will show the progression of what has come over, and what is left to come over -->
+    <modules>
+        <module>api</module>
+<!--        <module>spi</module>-->
+        <module>types</module>
+<!--        <module>builder</module>-->
+<!--        <module>config</module>-->
+<!--        <module>pico</module>-->
+<!--        <module>tck</module>-->
+<!--        <module>tools</module>-->
+<!--        <module>processor</module>-->
+<!--        <module>maven-plugin</module>-->
+<!--        <module>test-support</module>-->
+<!--        <module>test-utils</module>-->
+<!--        <module>test-resources</module>-->
+<!--        <module>test-extended-resources</module>-->
+<!--        <module>test-pico</module>-->
+<!--        <module>test-tck-jsr330</module>-->
+<!--        <module>examples</module>-->
+    </modules>
+
+    <build>
+        <pluginManagement>
+            <plugins>
+                <plugin>
+                    <groupId>org.apache.maven.plugins</groupId>
+                    <artifactId>maven-javadoc-plugin</artifactId>
+                    <configuration>
+                        <!-- This module is Java 11, we must remove enable-preview from parent project -->
+                        <additionalOptions combine.self="override"/>
+                    </configuration>
+                </plugin>
+            </plugins>
+        </pluginManagement>
+    </build>
+
+</project>

pico/types/pom.xml

@@ -0,0 +1,34 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+
+    Copyright (c) 2022 Oracle and/or its affiliates.
+
+    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.
+
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <groupId>io.helidon.pico</groupId>
+        <artifactId>helidon-pico-project</artifactId>
+        <version>4.0.0-SNAPSHOT</version>
+        <relativePath>../pom.xml</relativePath>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>helidon-pico-types</artifactId>
+    <name>Helidon Pico Types</name>
+    <description>Provides the runtime types (a subset of SPI) useful for Pico</description>
+
+</project>