refactor(common, news): unified data models, entity events and auto JSON serialization

build.gradle

@@ -1,21 +1,27 @@
 buildscript {
+    ext.kotlin_version = '1.3.61'
+
     repositories {
         mavenCentral()
         google()
     }
+    dependencies {
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
+        classpath "org.jetbrains.kotlin:kotlin-serialization:$kotlin_version"
+    }
 }
 
-plugins {
-    id 'org.jetbrains.kotlin.jvm' version'1.3.50'
-}
+apply plugin: 'kotlin'
 
 subprojects {
     buildscript {
         repositories {
+            jcenter()
             mavenCentral()
         }
         dependencies {
-            classpath("org.jetbrains.kotlin:kotlin-gradle-plugin:1.3.50")
+            classpath("org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version")
+            classpath("org.jetbrains.kotlin:kotlin-serialization:$kotlin_version")
             classpath("com.github.jengelman.gradle.plugins:shadow:5.1.0")
         }
     }

common/build.gradle

@@ -1,16 +1,26 @@
 plugins {
+    id "idea"
     id "kotlin"
     id "application"
 }
+apply plugin: 'kotlinx-serialization'
 
 dependencies {
-    api("org.jetbrains.kotlin:kotlin-stdlib:1.3.50")
+    api("org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version")
+    api("org.jetbrains.kotlin:kotlin-reflect:$kotlin_version")
+    api("org.jetbrains.kotlinx:kotlinx-serialization-runtime:0.14.0")
 
     // API
     api("com.google.protobuf:protobuf-java:3.6.1")
     api("io.grpc:grpc-stub:1.18.0")
-    api("de.hpi.cloud:hpi-cloud:0.0.11")
+    api("de.hpi.cloud:hpi-cloud:0.0.12")
 
     // Storage
     api("com.couchbase.client:java-client:2.7.9")
 }
+
+compileKotlin {
+    kotlinOptions {
+        freeCompilerArgs += "-Xuse-experimental=kotlin.Experimental"
+    }
+}

common/src/main/kotlin/de/hpi/cloud/common/Context.kt

@@ -0,0 +1,9 @@
+package de.hpi.cloud.common
+
+import de.hpi.cloud.common.entity.Id
+import java.util.*
+
+data class Context(
+    val author: Id<Party>,
+    val languageRanges: List<Locale.LanguageRange>
+)

common/src/main/kotlin/de/hpi/cloud/common/Party.kt

@@ -0,0 +1,11 @@
+package de.hpi.cloud.common
+
+import de.hpi.cloud.common.entity.Entity
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class Party(
+    val name: String
+) : Entity<Party>() {
+    companion object : Entity.Companion<Party>("party")
+}

common/src/main/kotlin/de/hpi/cloud/common/Persistable.kt

@@ -0,0 +1,10 @@
+package de.hpi.cloud.common
+
+import com.google.protobuf.GeneratedMessageV3
+
+abstract class Persistable<P : Persistable<P>> {
+    interface ProtoSerializer<P : Persistable<P>, Proto : GeneratedMessageV3> {
+        fun fromProto(proto: Proto, context: Context): P
+        fun toProto(persistable: P, context: Context): Proto
+    }
+}

service-common/src/main/kotlin/de/hpi/cloud/common/Service.kt → common/src/main/kotlin/de/hpi/cloud/common/Service.kt

@@ -3,7 +3,9 @@ package de.hpi.cloud.common
 import com.couchbase.client.java.Bucket
 import com.couchbase.client.java.CouchbaseCluster
 import com.google.protobuf.GeneratedMessageV3
-import de.hpi.cloud.common.utils.couchbase.openCouchbase
+import de.hpi.cloud.common.couchbase.openCouchbase
+import de.hpi.cloud.common.entity.Id
+import de.hpi.cloud.common.grpc.preferredLocales
 import de.hpi.cloud.common.utils.removeFirst
 import io.grpc.*
 
@@ -17,9 +19,17 @@ class Service<S : BindableService>(
         const val PORT_DEFAULT = 50051
         const val PORT_VARIABLE = "HPI_CLOUD_PORT"
 
-        private val requestMetadata = mutableListOf<RequestWithMetadata<GeneratedMessageV3>>()
-        fun metadataForRequest(request: GeneratedMessageV3): Metadata? =
-            requestMetadata.firstOrNull { it.request === request }?.metadata
+        private val requestMetadata = mutableListOf<RequestWithMetadata>()
+        fun contextForRequest(request: Any): Context? {
+            return requestMetadata.firstOrNull { it.request === request }
+                ?.metadata
+                ?.let {
+                    Context(
+                        author = Id("0"),
+                        languageRanges = it.preferredLocales
+                    )
+                }
+        }
     }
 
     private val server: Server
@@ -55,7 +65,12 @@ class Service<S : BindableService>(
                             require(message is GeneratedMessageV3)
 
                             request = message
-                            requestMetadata.add(RequestWithMetadata(message, headers))
+                            requestMetadata.add(
+                                RequestWithMetadata(
+                                    message,
+                                    headers
+                                )
+                            )
                             super.onMessage(message)
                         }
 
@@ -86,7 +101,7 @@ class Service<S : BindableService>(
     }
 
     fun stop() {
-        if (isStopped) throw IllegalStateException("$name is already stopped")
+        check(!isStopped) { "$name is already stopped" }
         isStopped = true
 
         println("Stopping $name")
@@ -105,8 +120,8 @@ class Service<S : BindableService>(
         server.awaitTermination()
     }
 
-    data class RequestWithMetadata<ReqT : GeneratedMessageV3>(
-        val request: ReqT,
+    data class RequestWithMetadata(
+        val request: Any,
         val metadata: Metadata?
     )
 }

common/src/main/kotlin/de/hpi/cloud/common/utils/couchbase/Constants.kt → common/src/main/kotlin/de/hpi/cloud/common/couchbase/Constants.kt

@@ -1,11 +1,12 @@
-package de.hpi.cloud.common.utils.couchbase
+package de.hpi.cloud.common.couchbase
 
 const val KEY_TYPE = "type"
 const val KEY_VERSION = "version"
 const val KEY_ID = "id"
 const val KEY_METADATA = "meta"
-const val KEY_METADATA_CREATED_AT = "createdAt"
 const val KEY_VALUE = "value"
 
+const val NESTED_SEPARATOR = "."
+
 fun devDesignDoc(designDoc: String) = "dev_$designDoc"
 const val VIEW_BY_ID = "byId"

common/src/main/kotlin/de/hpi/cloud/common/utils/couchbase/CouchbaseCluster.kt → common/src/main/kotlin/de/hpi/cloud/common/couchbase/CouchbaseCluster.kt

@@ -1,11 +1,9 @@
-package de.hpi.cloud.common.utils.couchbase
+package de.hpi.cloud.common.couchbase
 
 import com.couchbase.client.java.Bucket
 import com.couchbase.client.java.CouchbaseAsyncCluster
 import com.couchbase.client.java.CouchbaseCluster
 import com.couchbase.client.java.env.DefaultCouchbaseEnvironment
-import com.couchbase.client.java.view.ViewQuery
-import com.couchbase.client.java.view.ViewResult
 
 const val COUCHBASE_CONNECT_TIMEOUT = 15000L
 const val COUCHBASE_NODES_VARIABLE = "HPI_CLOUD_COUCHBASE_NODES"
@@ -36,5 +34,3 @@ fun withBucket(bucket: String, nodesOverride: List<String> = emptyList(), runnab
             .close()
     }.disconnect()
 }
-
-fun ViewQuery.execute(bucket: Bucket): ViewResult = bucket.query(this)

common/src/main/kotlin/de/hpi/cloud/common/couchbase/Document.kt

@@ -0,0 +1,31 @@
+package de.hpi.cloud.common.couchbase
+
+import com.couchbase.client.java.AsyncBucket
+import com.couchbase.client.java.Bucket
+import com.couchbase.client.java.document.RawJsonDocument
+import de.hpi.cloud.common.entity.Entity
+import de.hpi.cloud.common.entity.Id
+import de.hpi.cloud.common.entity.Wrapper
+import kotlinx.serialization.json.Json
+import kotlinx.serialization.json.JsonConfiguration
+import rx.Observable
+
+val jsonConfiguration = JsonConfiguration.Stable.copy(
+    strictMode = true,
+    allowStructuredMapKeys = false
+)
+val json = Json(jsonConfiguration)
+
+inline fun <reified E : Entity<E>> RawJsonDocument.parseWrapper(): Wrapper<E> {
+    return json.parse(Wrapper.jsonSerializerFor<E>(), content())
+}
+
+inline fun <reified E : Entity<E>> Bucket.get(id: Id<E>): Wrapper<E>? {
+    return get(id.documentId<E>(), RawJsonDocument::class.java)?.parseWrapper()
+        ?: return null
+}
+
+inline fun <reified E : Entity<E>> AsyncBucket.get(id: Id<E>): Observable<Wrapper<E>> {
+    return get(id.documentId<E>(), RawJsonDocument::class.java)
+        .map { it.parseWrapper<E>() }
+}

common/src/main/kotlin/de/hpi/cloud/common/utils/couchbase/N1ql.kt → common/src/main/kotlin/de/hpi/cloud/common/couchbase/N1ql.kt

@@ -1,12 +1,11 @@
-package de.hpi.cloud.common.utils.couchbase
+package de.hpi.cloud.common.couchbase
 
 import com.couchbase.client.java.query.dsl.Expression
 import com.couchbase.client.java.query.dsl.Expression.*
 import com.couchbase.client.java.query.dsl.Sort
 import com.couchbase.client.java.query.dsl.Sort.asc
 import com.couchbase.client.java.query.dsl.Sort.desc
-import de.hpi.cloud.common.utils.protobuf.TIMESTAMP_MILLIS
-import de.hpi.cloud.common.utils.protobuf.TIMESTAMP_NANOS
+import de.hpi.cloud.common.types.LocalDateTime
 
 fun and(vararg expressions: Expression?): Expression {
     return expressions.filterNotNull().run {
@@ -16,18 +15,24 @@ fun and(vararg expressions: Expression?): Expression {
 }
 
 fun ascTimestamp(field: Expression): Array<Sort> {
-    return arrayOf(asc("$field.$TIMESTAMP_MILLIS"), asc("$field.$TIMESTAMP_NANOS"))
+    return arrayOf(
+        asc("$field.${LocalDateTime.JsonSerializer.KEY_MILLIS}"),
+        asc("$field.${LocalDateTime.JsonSerializer.KEY_NANOS}")
+    )
 }
 
 fun descTimestamp(field: Expression): Array<Sort> {
-    return arrayOf(desc("$field.$TIMESTAMP_MILLIS"), desc("$field.$TIMESTAMP_NANOS"))
+    return arrayOf(
+        desc("$field.${LocalDateTime.JsonSerializer.KEY_MILLIS}"),
+        desc("$field.${LocalDateTime.JsonSerializer.KEY_NANOS}")
+    )
 }
 
 /**
  * Builds an expression for a *nested* field with proper escaping.
  */
 fun n(vararg part: String): Expression {
-    return x(part.joinToString(NESTED_SEPARATOR.toString()) { i(it).toString() })
+    return x(part.joinToString(NESTED_SEPARATOR) { i(it).toString() })
 }
 
 /**