[DAT-641] Add measurement proto file (#1)

* [DAT-641] Add measurement proto file

* Follow Style Guide

* Update readme

* Add gradle files

* Add byte size test

* Remove fixme from proto

* Explicitly set elevation.isNull to true if single elevations are unset

* Fix CI build

.github/workflows/build.yml

@@ -0,0 +1,38 @@
+name: Standard CI
+
+on:
+  push:
+    branches:
+      - main
+      - release
+  pull_request:
+    branches:
+      - main
+      - release
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-java@v1
+        with:
+          java-version: 11
+
+      - name: Download & unzip protoc
+        run: |
+          wget https://github.com/protocolbuffers/protobuf/releases/download/v3.17.0/protoc-3.17.0-linux-x86_64.zip \
+            -O protoc-3.zip
+          unzip protoc-3.zip -d protoc-3
+          mv protoc-3/bin/protoc protoc
+
+      - name: Compile java files from `proto` file
+        run: |
+          mkdir -p src/main/java
+          ./protoc --java_out=./src/main/java/ src/main/protos/de/cyface/protos/model/measurement.proto
+
+      - name: Build with Gradle
+        run: ./gradlew build
+        env:
+          USERNAME: ${{ github.actor }}
+          PASSWORD: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/publish-jar.yml

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+name: Publish to GitHub Packages
+
+on: 
+  push:
+    tags:
+      - '*'
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-java@v1
+        with:
+          java-version: 11
+
+      - name: Download & unzip protoc
+        run: |
+          wget https://github.com/protocolbuffers/protobuf/releases/download/v3.17.0/protoc-3.17.0-linux-x86_64.zip \
+            -O protoc-3.zip
+          unzip protoc-3.zip -d protoc-3
+          mv protoc-3/bin/protoc protoc
+
+      - name: Compile java files from `proto` file
+        run: |
+          ./protoc --java_out=./src/main/java/ src/main/protos/de/cyface/protos/model/measurement.proto
+
+      # Publish slim JARS to Github Package Registry
+      - name: Publish package
+        run: ./gradlew publish
+        env:
+          USERNAME: ${{ github.actor }}
+          PASSWORD: ${{ secrets.GITHUB_TOKEN }}
+
+      # Automatically mark this tag as release on Github
+      - uses: actions/create-release@v1
+        id: create_release
+        with:
+          tag_name: ${{ github.ref }}
+          release_name: ${{ github.ref }}
+          draft: false
+          # Release tags of format `1.2.3-beta1 / -alpha1 / -test1` are considered a pre-release
+          prerelease: ${{ contains(github.ref, 'test') || contains(github.ref, 'alpha') || contains(github.ref, 'beta') }}
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.gitignore

@@ -0,0 +1,61 @@
+#
+# Copyright 2018 Cyface GmbH
+#
+# This file is part of the Cyface Data Collector.
+#
+# The Cyface Data Collector is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# The Cyface Data Collector is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with the Cyface Data Collector.  If not, see <http://www.gnu.org/licenses/>.
+#
+# Eclipse Files
+.classpath
+.settings
+bin
+.project
+
+# Intellij Idea Files
+.idea
+.editorconfig
+out
+*.iml
+
+# Gradle Temporary Files
+.gradle
+build
+local.properties
+gradle.properties
+
+# Ignore local test maven repositories
+**/repo
+
+# Vim Temporary Files
+**/*.swp
+
+# Cyface Temporary Files
+**/file-uploads
+**/.vertx
+**/conf.json
+**/*.log
+**/secrets
+*.json
+
+# Generated java classes from proto files
+src/main/java/
+
+# Temporary Git Files
+**/*.orig
+
+# Ignore logging configurations
+**/logback.xml
+
+# Vertx Config files
+**/config.json

README.adoc

@@ -0,0 +1,75 @@
+= Cyface Protocol Buffer Messages
+
+This repository defines the Cyface Models as schemas such as Protocol Buffer Schemas.
+This allows to de-/serialize the Cyface Binary Data from in different programming languages.
+
+For more details on Protocol Buffers (short: Protobuf) check out it's link:https://developers.google.com/protocol-buffers[documentation].
+
+
+== Message Format Definitions
+
+This is a collection of `.proto` files describe the data structure of the Cyface Models.
+
+- This allows Protobuf to automatically de-/encode the the data from/to binary files.
+- Supports later extensions of the format with backward-compatibility
+- Following the link:https://developers.google.com/protocol-buffers/docs/style[Style Guide]
+
+At the time of writing the latest release is link:https://developers.google.com/protocol-buffers/docs/proto3[Protocol Buffer Version 3].
+
+
+=== Notes
+Reminders from the documentation which need to be considered for future updates:
+
+ - optional fields are default in proto3, `required` fields have been removed.
+
+ - link:https://developers.google.com/protocol-buffers/docs/proto3#updating[Updating A Message Type]
+
+ - link:https://developers.google.com/protocol-buffers/docs/javatutorial#extending-a-protocol-buffer[Extending a Protocol Buffer]
+
+ - Deprecated field link:https://developers.google.com/protocol-buffers/docs/proto3#options[annotations]
+
+ - link:https://developers.google.com/protocol-buffers/docs/proto3#default[Default values]
+
+ - Scalar message fields, once parsed, cannot tell if a field was not set or set the the default value afterwards.
+ - Default values are not serialized on the wire.
+ - Keep this in mind when defining e.g. booleans, make sure you want that "default" `false` behavior on.
+
+Other message types:
+
+ - link:https://developers.google.com/protocol-buffers/docs/proto3#using_oneof[One-of] if only one of many fields can be set / should be interpreted. link:https://developers.google.com/protocol-buffers/docs/proto3#backwards-compatibility_issues[Be careful] with these fields.
+ - link:https://developers.google.com/protocol-buffers/docs/proto3#maps[Maps]
+ - link:https://developers.google.com/protocol-buffers/docs/proto3#json[JSON Mapping]
+ - There are also "well known" message types from Google, e.g. for `JSON`
+ - link:https://developers.google.com/protocol-buffers/docs/javatutorial#advanced-usage[Reflections]
+
+
+== Compiling the Message Definitions
+
+Generates serializer, deserializer, etc. in a chosen language, e.g. `.java` files for Java.
+
+Java classes can be compiled with link:https://developers.google.com/protocol-buffers/docs/javatutorial#compiling-your-protocol-buffers[protoc] (Protocol Buffers `v3.17.0`):
+
+  protoc --java_out=./src/main/java/ src/main/protos/de/cyface/protos/model/measurement.proto
+
+However, the pre-compiled `JARs` are also published to the link:https://github.com/orgs/cyface-de/packages?repo_name=protos[Github Package Registry].
+
+- how to use with link:https://github.com/protocolbuffers/protobuf/tree/master/java#gradle[Gradle]
+- how to use with link:https://github.com/protocolbuffers/protobuf/tree/master/java#use-java-protocol-buffers-on-android[Android]
+
+The serializers encode the data in an efficient way, the decision process is documented link:https://cyface.atlassian.net/wiki/spaces/IM/pages/1535148033/Datenformat+bertragungsprotokoll+2021[internally].
+
+
+== Using the generated Code
+
+____
+Protocol Buffers and Object Oriented Design Protocol buffer classes are basically dumb data holders (like structs in C); they don't make good first class citizens in an object model. If you want to add richer behavior to a generated class, the best way to do this is to wrap the generated protocol buffer class in an application-specific class.
+____
+link:https://developers.google.com/protocol-buffers/docs/javatutorial#builders[Source]
+
+
+[#_licensing]
+== Licensing
+
+Copyright (C) 2021 Cyface GmbH - All Rights Reserved
+Unauthorized copying of this file, via any medium is strictly prohibited
+Proprietary and confidential

build.gradle

@@ -0,0 +1,112 @@
+/*
+ * Copyright 2021 Cyface GmbH
+ *
+ * This file is part of the Cyface Protocol Buffer Messages.
+ *
+ *  The Cyface Protocol Buffer Messages is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The Cyface Protocol Buffer Messages is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with the Cyface Protocol Buffer Messages.  If not, see <http://www.gnu.org/licenses/>.
+ */
+/**
+ * The root build gradle file.
+ *
+ * @author Armin Schnabel
+ */
+buildscript {
+  repositories {
+    mavenCentral()
+  }
+}
+
+plugins {
+  id 'java'
+  id 'application'
+  id 'eclipse'
+  id 'idea'
+  id 'maven-publish'
+  //noinspection SpellCheckingInspection
+  id 'com.github.johnrengelman.shadow' version '6.1.0' apply false
+}
+
+group = 'de.cyface'
+version = '0.0.0'
+
+tasks.withType(JavaCompile) {
+  options.encoding = 'UTF-8'
+
+  sourceCompatibility = JavaVersion.VERSION_11
+  targetCompatibility = JavaVersion.VERSION_11
+}
+
+ext {
+  commonsLangVersion = '3.8.1'
+  gradleWrapperVersion = '6.8.3'
+  protobufVersion = '3.17.0'
+
+  // Versions of testing dependencies
+  junitVersion = '5.7.0'
+  mockitoVersion = '3.3.3'
+  hamcrestVersion = '2.2'
+  flapdoodleVersion = '3.0.0'
+}
+
+wrapper {
+  gradleVersion = "$gradleWrapperVersion"
+}
+
+repositories {
+  mavenCentral()
+}
+
+// Code Quality Checker
+dependencies {
+  // Protobuf generated java files
+  implementation "com.google.protobuf:protobuf-java:$protobufVersion"
+
+  // Utility
+  implementation "org.apache.commons:commons-lang3:$commonsLangVersion" // Using Validate
+
+  // Testing Dependencies
+  testImplementation(platform("org.junit:junit-bom:$junitVersion"))
+  testImplementation "org.junit.jupiter:junit-jupiter-api"
+  //testImplementation "org.junit.jupiter:junit-jupiter-params"  // Required for parameterized tests
+  testImplementation "org.hamcrest:hamcrest:$hamcrestVersion"
+  testImplementation "org.mockito:mockito-core:$mockitoVersion"
+  testImplementation "org.mockito:mockito-junit-jupiter:$mockitoVersion"
+  testRuntimeOnly "org.junit.jupiter:junit-jupiter-engine"
+}
+
+test {
+  useJUnitPlatform()
+  testLogging {
+    events "passed", "skipped", "failed"
+  }
+}
+
+// Definitions for the maven-publish Plugin
+publishing {
+  // The following repositories are used to publish artifacts to.
+  repositories {
+    maven {
+      name = 'github'
+      url = uri("https://maven.pkg.github.com/cyface-de/protos")
+      credentials {
+        username = project.findProperty("gpr.user") ?: System.getenv("USERNAME")
+        password = project.findProperty("gpr.key") ?: System.getenv("PASSWORD")
+      }
+    }
+    maven {
+      name = 'local'
+      url = "file://${rootProject.buildDir}/repo"
+    }
+  }
+}

gradle.properties.template

@@ -0,0 +1,2 @@
+gpr.user=<GITHUB_USERNAME>
+gpr.key=<GITHUB_ACCESS_TOKEN>

gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.8.3-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists