[WAYANG-32] Base structure for Wayang Experiments Storage functionali…

…ties

wayang-commons/wayang-utils/pom.xml

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<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>
+        <artifactId>wayang-commons</artifactId>
+        <groupId>org.apache.wayang</groupId>
+        <version>0.6.0-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>wayang-utils</artifactId>
+    <packaging>pom</packaging>
+
+    <modules>
+        <module>wayang-profile-db</module>
+    </modules>
+
+
+</project>

wayang-commons/wayang-utils/wayang-profile-db/pom.xml

@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<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>
+        <artifactId>wayang-utils</artifactId>
+        <groupId>org.apache.wayang</groupId>
+        <version>0.6.0-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>wayang-profile-db</artifactId>
+
+    <dependencies>
+        <!-- https://mvnrepository.com/artifact/com.google.code.gson/gson -->
+        <dependency>
+            <groupId>com.google.code.gson</groupId>
+            <artifactId>gson</artifactId>
+        </dependency>
+
+    </dependencies>
+
+
+</project>

wayang-commons/wayang-utils/wayang-profile-db/readme.md

@@ -0,0 +1,3 @@
+Base on
+
+https://github.com/sekruse/profiledb-java.git

wayang-commons/wayang-utils/wayang-profile-db/src/main/java/profiledb/ProfileDB.java

@@ -0,0 +1,105 @@
+package profiledb;
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import profiledb.json.MeasurementDeserializer;
+import profiledb.json.MeasurementSerializer;
+import profiledb.model.Experiment;
+import profiledb.model.Measurement;
+import profiledb.storage.Storage;
+
+import java.io.*;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.function.Consumer;
+
+/**
+ * This class provides facilities to save and load {@link Experiment}s.
+ */
+public class ProfileDB {
+
+    /**
+     * Maintains the full list of {@link Class}es for {@link Measurement}s. Which are required for deserialization.
+     */
+    private List<Class<? extends Measurement>> measurementClasses = new LinkedList<>();
+
+    /**
+     * Controls how conducted experiments will be persisted and loaded
+     */
+    private Storage storage;
+
+    /**
+     * Maintains actions to preparate {@link Gson}.
+     */
+    private List<Consumer<GsonBuilder>> gsonPreparationSteps = new LinkedList<>();
+
+    /**
+     * Maintains a {@link Gson} object for efficiency. It will be dropped on changes, though.
+     */
+    private Gson gson;
+
+    /**
+     * Creates a new instance.
+     */
+    public ProfileDB(Storage storage) {
+
+        this.storage = storage;
+        this.storage.setContext(this);
+        //this.measurementClasses.add(TimeMeasurement.class);
+    }
+
+    /**
+     * To work with storage object provided to persist or load experiments
+     *
+     * @return Storage object proportioned for this instance
+     */
+    public Storage getStorage() {
+        return storage;
+    }
+
+    /**
+     * Register a {@link Measurement} type. This is required before being able to load that type.
+     *
+     * @param measurementClass the {@link Measurement} {@link Class}
+     * @return this instance
+     */
+    public ProfileDB registerMeasurementClass(Class<? extends Measurement> measurementClass) {
+        this.measurementClasses.add(measurementClass);
+        this.gson = null;
+        return this;
+    }
+
+    /**
+     * Apply any changes necessary to {@link Gson} so that it can be used for de/serialization of custom objects.
+     *
+     * @param preparation a preparatory step performed on a {@link GsonBuilder}
+     * @return this instance
+     */
+    public ProfileDB withGsonPreparation(Consumer<GsonBuilder> preparation) {
+        this.gsonPreparationSteps.add(preparation);
+        this.gson = null;
+        return this;
+    }
+
+    /**
+     * Provide a {@link Gson} object.
+     *
+     * @return the {@link Gson} object
+     */
+    public Gson getGson() {
+        if (this.gson == null) {
+            MeasurementSerializer measurementSerializer = new MeasurementSerializer();
+            MeasurementDeserializer measurementDeserializer = new MeasurementDeserializer();
+            this.measurementClasses.forEach(measurementDeserializer::register);
+            final GsonBuilder gsonBuilder = new GsonBuilder()
+                    .registerTypeAdapter(Measurement.class, measurementDeserializer)
+                    .registerTypeAdapter(Measurement.class, measurementSerializer);
+            this.gsonPreparationSteps.forEach(step -> step.accept(gsonBuilder));
+            this.gson = gsonBuilder.create();
+        }
+        return this.gson;
+    }
+
+}

wayang-commons/wayang-utils/wayang-profile-db/src/main/java/profiledb/json/MeasurementDeserializer.java

@@ -0,0 +1,40 @@
+package profiledb.json;
+
+import com.google.gson.JsonDeserializationContext;
+import com.google.gson.JsonDeserializer;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonParseException;
+import profiledb.model.Measurement;
+
+import java.lang.reflect.Type;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Custom deserializer for {@link Measurement}s
+ * Detects actual subclass of serialized instances and then delegates the deserialization to that subtype.
+ */
+public class MeasurementDeserializer implements JsonDeserializer<Measurement> {
+
+    private final Map<String, Class<? extends Measurement>> measurementTypes = new HashMap<>();
+
+    public void register(Class<? extends Measurement> measurementClass) {
+        String typeName = Measurement.getTypeName(measurementClass);
+        this.measurementTypes.put(typeName, measurementClass);
+    }
+
+    @Override
+    public Measurement deserialize(JsonElement jsonElement, Type type, JsonDeserializationContext jsonDeserializationContext) throws JsonParseException {
+        final JsonElement typeElement = jsonElement.getAsJsonObject().get("type");
+        if (typeElement == null) {
+            throw new IllegalArgumentException("Missing type in " + jsonElement);
+        }
+        final String typeName = typeElement.getAsString();
+        final Class<? extends Measurement> measurementClass = this.measurementTypes.get(typeName);
+        if (measurementClass == null) {
+            throw new JsonParseException("Unknown measurement type: " + typeName);
+        }
+        return jsonDeserializationContext.deserialize(jsonElement, measurementClass);
+    }
+
+}

wayang-commons/wayang-utils/wayang-profile-db/src/main/java/profiledb/json/MeasurementSerializer.java

@@ -0,0 +1,23 @@
+package profiledb.json;
+
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonSerializationContext;
+import com.google.gson.JsonSerializer;
+import profiledb.model.Measurement;
+
+import java.lang.reflect.Type;
+
+/**
+ * Custom serializer for {@link Measurement}s
+ * Detects actual subclass of given instances, encodes this class membership, and then delegates serialization to that subtype.
+ */
+public class MeasurementSerializer implements JsonSerializer<Measurement> {
+
+    @Override
+    public JsonElement serialize(Measurement measurement, Type type, JsonSerializationContext jsonSerializationContext) {
+        final JsonObject jsonObject = (JsonObject) jsonSerializationContext.serialize(measurement);
+        jsonObject.addProperty("type", measurement.getType());
+        return jsonObject;
+    }
+}

wayang-commons/wayang-utils/wayang-profile-db/src/main/java/profiledb/model/Experiment.java

@@ -0,0 +1,163 @@
+package profiledb.model;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.LinkedList;
+import java.util.Objects;
+
+/**
+ * An experiment comprises {@link Measurement}s from one specific {@link Subject} execution.
+ */
+public class Experiment {
+
+    /**
+     * Identifier for this instance.
+     */
+    private String id;
+
+    /**
+     * Description for this instance. (Optional)
+     */
+    private String description;
+
+    /**
+     * When this experiment has been started.
+     */
+    private long startTime;
+
+    /**
+     * Tags to group multiple Experiment instances. (Optional)
+     */
+    private Collection<String> tags;
+
+    /**
+     * {@link Measurement}s captured for this instance.
+     */
+    private Collection<Measurement> measurements;
+
+    /**
+     * The {@link Subject} being experimented with.
+     */
+    private Subject subject;
+
+    /**
+     * For deserialization.
+     */
+    private Experiment() {
+    }
+
+    /**
+     * Create a new instance that is starting right now.
+     *
+     * @param id      Identifier for the new instance
+     * @param subject the {@link Subject}
+     * @param tags    tags to group several experiments
+     */
+    public Experiment(String id, Subject subject, String... tags) {
+        this(id, subject, System.currentTimeMillis(), tags);
+    }
+
+    /**
+     * Create a new instance.
+     *
+     * @param id        Identifier for the new instance
+     * @param subject   the {@link Subject} of this experiment
+     * @param startTime start timestamp of this experiment
+     * @param tags      tags to group several experiments
+     */
+    public Experiment(String id, Subject subject, long startTime, String... tags) {
+        this.id = id;
+        this.subject = subject;
+        this.startTime = startTime;
+        this.tags = Arrays.asList(tags);
+        this.measurements = new LinkedList<>();
+    }
+
+    /**
+     * Adds a description for this instance.
+     *
+     * @param description the description
+     * @return this instance
+     */
+    public Experiment withDescription(String description) {
+        this.description = description;
+        return this;
+    }
+
+
+    public String getId() {
+        return id;
+    }
+
+    public void setId(String id) {
+        this.id = id;
+    }
+
+    public String getDescription() {
+        return description;
+    }
+
+    public void setDescription(String description) {
+        this.description = description;
+    }
+
+    public long getStartTime() {
+        return startTime;
+    }
+
+    public void setStartTime(long startTime) {
+        this.startTime = startTime;
+    }
+
+    public Collection<String> getTags() {
+        return tags;
+    }
+
+    public void setTags(Collection<String> tags) {
+        this.tags = tags;
+    }
+
+    public void addMeasurement(Measurement measurement) {
+        this.measurements.add(measurement);
+    }
+
+    public Collection<Measurement> getMeasurements() {
+        return measurements;
+    }
+
+    public Subject getSubject() {
+        return this.subject;
+    }
+
+    public void setSubject(Subject subject) {
+        this.subject = subject;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Experiment that = (Experiment) o;
+        return startTime == that.startTime &&
+                Objects.equals(id, that.id) &&
+                Objects.equals(description, that.description) &&
+                Objects.equals(tags, that.tags) &&
+                Objects.equals(subject, that.subject);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(id, startTime);
+    }
+
+    @Override
+    public String toString() {
+        return String.format(
+                "%s[%s, %d tags, %d measurements]",
+                this.getClass().getSimpleName(),
+                this.id,
+                this.tags.size(),
+                this.measurements.size()
+        );
+    }
+}