RFC: adds proto-kotlin and protoc-plugin-kotlin

kotlin/core/.gitignore

@@ -0,0 +1,3 @@
+# Gradle
+build
+.gradle

kotlin/core/README.md

@@ -0,0 +1 @@
+# proto-kotlin: Google's Kotlin bindings for protobuf

kotlin/core/build.gradle

@@ -0,0 +1,118 @@
+plugins {
+    id 'org.jetbrains.kotlin.jvm' version'1.3.61'
+    id 'com.google.protobuf' version '0.8.8'
+
+    // Generate IntelliJ IDEA's .idea & .iml project files
+    // Starting with 0.8.4 of protobuf-gradle-plugin, *.proto and the gen output files are added
+    // to IntelliJ as sources. It is no longer necessary to add them manually to the idea {} block
+    // to jump to definitions from Java and Kotlin files.
+    // For best results, install the Protobuf and Kotlin plugins for IntelliJ.
+    id 'idea'
+
+    // Provide convenience executables for trying out the examples.
+    id 'application'
+    id 'maven-publish'
+}
+
+apply plugin : "java"
+
+mainClassName = 'com.google.protobuf.kotlin.generator.GeneratorRunner'
+applicationName = 'proto-kotlin'
+
+// Generate the jar file to be used by our custom plugin
+jar {
+    manifest {
+        attributes 'Main-Class': mainClassName
+    }
+    from { configurations.compile.collect { it.isDirectory() ? it : zipTree(it) } }
+}
+
+repositories {
+    google()
+    jcenter()
+    mavenCentral()
+    mavenLocal()
+}
+
+// Feel free to delete the comment at the next line. It is just for safely
+// updating the version in our release process.
+def coroutinesVersion = '1.3.3'
+def kotlinVersion = '1.3.61'
+
+dependencies {
+    // Kotlin
+    compile "org.jetbrains.kotlin:kotlin-stdlib-jdk8:${kotlinVersion}"
+
+    // Protobuf
+    compile "com.google.protobuf:protobuf-kotlin-util:0.1"
+    compile 'com.google.protobuf:protobuf-gradle-plugin:0.8.11'
+    compile 'com.google.protobuf:protobuf-java:3.11.0'
+
+    compile 'com.squareup:kotlinpoet:1.5.0'
+    compile "org.jetbrains.kotlin:kotlin-reflect:1.3.61"
+
+    // Testing
+    testImplementation "com.google.truth:truth:1.0.1"
+    testImplementation "com.google.truth.extensions:truth-proto-extension:1.0"
+    testImplementation 'org.jetbrains.kotlinx:kotlinx-coroutines-debug:1.3.2'
+    testImplementation "org.jetbrains.kotlin:kotlin-android-extensions:$kotlinVersion"
+    testImplementation "junit:junit:4.12"
+    testImplementation "com.google.jimfs:jimfs:1.1"
+}
+
+protobuf {
+    protoc { artifact = 'com.google.protobuf:protoc:3.11.0' }
+    plugins {
+        // Specify protoc to generate using our kotlin plugin
+        kotlin {
+            path = 'build/install/proto-kotlin/bin/proto-kotlin'
+        }
+    }
+    generateProtoTasks {
+        all().each { task ->
+            // Generate the protoc binary first so we can generate the files for
+            // our tests
+            if (task.name.startsWith('generateTestProto')) {
+                task.dependsOn { installDist }
+            }
+            task.plugins {
+                // Add kotlin output without any option. This yields
+                // "--custom_out=/path/to/output" on the protoc commandline.
+                kotlin {}
+            }
+        }
+    }
+}
+
+def artifactForGradlePlugin(MavenPublication pub, String os, String arch) {
+    if (os == "windows") {
+        pub.artifact("src/main/dist/protoc-gen-kotlin.bat" as File) {
+            classifier os + "-" + arch
+            extension "exe"
+        }
+    } else {
+        pub.artifact("src/main/dist/protoc-gen-kotlin" as File) {
+            classifier os + "-" + arch
+            extension "exe"
+        }
+    }
+}
+
+publishing {
+    publications {
+        maven(MavenPublication) {
+            groupId = 'com.google.protobuf'
+            artifactId = 'protobuf-kotlin'
+            version = '0.1'
+            from components.java
+
+            // Generate the artifacts expected by protobuf-gradle-plugin
+            artifactForGradlePlugin(it, 'linux', 'aarch_64')
+            artifactForGradlePlugin(it, 'linux', 'x86_32')
+            artifactForGradlePlugin(it, 'linux', 'x86_64')
+            artifactForGradlePlugin(it, 'osx', 'x86_64')
+            artifactForGradlePlugin(it, 'windows', 'x86_32')
+            artifactForGradlePlugin(it, 'windows', 'x86_64')
+        }
+    }
+}

kotlin/core/example/src/main/kotlin/com/example/tutorial/AddPerson.kt

@@ -0,0 +1,92 @@
+/*
+ * Copyright 2020 Google LLC
+ *
+ * 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 com.example.tutorial
+
+import com.example.tutorial.AddressBookProtos.AddressBook
+import com.example.tutorial.AddressBookProtos.Person
+import com.example.tutorial.AddressBookProtosKt.PersonKt.phoneNumber
+import com.example.tutorial.AddressBookProtosKt.person
+import java.io.BufferedReader
+import java.io.FileInputStream
+import java.io.FileNotFoundException
+import java.io.FileOutputStream
+import java.io.InputStreamReader
+import java.io.PrintStream
+import kotlin.system.exitProcess
+
+object AddPerson {
+  fun promptForAddress(input: BufferedReader, output: PrintStream): Person {
+    return person {
+      output.print("Enter person ID: ")
+      id = input.readLine().toInt()
+
+      output.print("Enter name: ")
+      name = input.readLine()
+
+      output.print("Enter email address (blank for none): ")
+      val email = input.readLine()
+      if (email.isNotEmpty()) {
+        this.email = email
+      }
+
+      while (true) {
+        output.print("Enter a phone number (or leave blank to finish): ")
+        val number = input.readLine()
+        if (number.isEmpty()) {
+          break
+        }
+
+        phone += phoneNumber {
+          this.number = number
+          output.print("Is this a mobile, home, or work phone? ")
+          when (input.readLine()) {
+            "mobile" -> type = Person.PhoneType.MOBILE
+            "home" -> type = Person.PhoneType.HOME
+            "work" -> type = Person.PhoneType.WORK
+            else -> output.println("Unknown phone type.  Using default.")
+          }
+        }
+      }
+    }
+  }
+
+  @JvmStatic
+  fun main(args: Array<String>) {
+    if (args.size != 1) {
+      System.err.println("Usage: AddPerson ADDRESS_BOOK_FILE")
+      exitProcess(-1)
+    }
+
+    val addressBook = try {
+      FileInputStream(args.single()).use {
+        AddressBook.parseFrom(it)
+      }
+    } catch (e: FileNotFoundException) {
+      AddressBook.getDefaultInstance()
+    }
+
+    val newAddressBook = addressBook.copy {
+      BufferedReader(InputStreamReader(System.`in`, Charsets.UTF_8)).use {
+        person += promptForAddress(it, System.out)
+      }
+    }
+
+    FileOutputStream(args.single()).use {
+      newAddressBook.writeTo(it)
+    }
+  }
+}

kotlin/core/example/src/main/kotlin/com/example/tutorial/ListPeople.kt

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2020 Google LLC
+ *
+ * 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 com.example.tutorial
+
+import com.example.tutorial.AddressBookProtos.AddressBook
+import java.io.FileInputStream
+import kotlin.system.exitProcess
+
+object ListPeople {
+  fun print(addressBook: AddressBook) {
+    for (person in addressBook.personList) {
+      println("Person ID: ${person.id}")
+      println("  Name: ${person.name}")
+      if (person.hasEmail()) {
+        println("  E-mail address: ${person.email}")
+      }
+      for (phoneNumber in person.phoneList) {
+        when (phoneNumber.type) {
+          AddressBookProtos.Person.PhoneType.MOBILE -> print("  Mobile phone #: ")
+          AddressBookProtos.Person.PhoneType.HOME -> print("  Home phone #: ")
+          AddressBookProtos.Person.PhoneType.WORK -> print("  Work phone #: ")
+        }
+        println(phoneNumber.number)
+      }
+    }
+  }
+
+  @JvmStatic
+  fun main(args: Array<String>) {
+    if (args.size != 1) {
+      System.err.println("Usage:  ListPeople ADDRESS_BOOK_FILE")
+      exitProcess(-1)
+    }
+    print(FileInputStream(args.single()).use {
+      AddressBook.parseFrom(it)
+    })
+  }
+}

kotlin/core/example/src/main/proto/addressbook.proto

@@ -0,0 +1,29 @@
+syntax = "proto2";
+
+package tutorial;
+
+option java_package = "com.example.tutorial";
+option java_outer_classname = "AddressBookProtos";
+
+message Person {
+  required string name = 1;
+  required int32 id = 2;
+  optional string email = 3;
+
+  enum PhoneType {
+    MOBILE = 0;
+    HOME = 1;
+    WORK = 2;
+  }
+
+  message PhoneNumber {
+    required string number = 1;
+    optional PhoneType type = 2 [default = HOME];
+  }
+
+  repeated PhoneNumber phone = 4;
+}
+
+message AddressBook {
+  repeated Person person = 1;
+}

kotlin/core/src/main/dist/protoc-gen-kotlin

@@ -0,0 +1,26 @@
+#!/bin/bash
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`" >/dev/null
+APP_HOME="`pwd -P`"
+APP_BASE_NAME=`basename "$0"`
+
+# Get jar file name from current filename by stripping os and arch
+JAR_FILENAME=${APP_BASE_NAME%.*}
+JAR_FILENAME=${JAR_FILENAME/-linux-aarch_64/}
+JAR_FILENAME=${JAR_FILENAME/-linux-x86_32/}
+JAR_FILENAME=${JAR_FILENAME/-linux-x86_64/}
+JAR_FILENAME=${JAR_FILENAME/-osx-x86_64/}
+
+# Call the jar and pass our args
+java -jar $JAR_FILENAME.jar $1 $2