feat: added a working connection to Redis, and a scaffolding for the RESTful APIHEADmaster

7 files changed, 133 insertions, 27 deletions

diff --git a/opendc-common/build.gradle.kts b/opendc-common/build.gradle.kts
index 9fe4710c..dc323140 100644
--- a/opendc-common/build.gradle.kts
+++ b/opendc-common/build.gradle.kts
@@ -68,6 +68,9 @@ dependencies {
 
     implementation("io.javalin:javalin:6.7.0")
 
+    // Source: https://mvnrepository.com/artifact/redis.clients/jedis
+    implementation("redis.clients:jedis:7.3.0")
+
 }
 
 
diff --git a/opendc-common/src/main/kotlin/org/opendc/common/utils/HTTPClient.kt b/opendc-common/src/main/kotlin/org/opendc/common/utils/HTTPClient.kt
new file mode 100644
index 00000000..cc89d48f
--- /dev/null
+++ b/opendc-common/src/main/kotlin/org/opendc/common/utils/HTTPClient.kt
@@ -0,0 +1,50 @@
+package org.opendc.common.utils
+
+import java.io.File
+import java.net.URI
+import java.net.http.*
+import java.net.http.HttpResponse.BodyHandlers.ofString
+/**
+ * Singleton class representing the real datacenter client.
+ * The client is asynchronous and initiates the connection first.
+ *
+ * @constructor Initiates the connection.
+ *
+ * @author Mateusz Kwiatkowski
+ */
+
+public class HTTPClient private constructor() {
+    public companion object {
+        private var instance: HTTPClient? = null
+        private var client: HttpClient? = null
+        private var handshake = HttpRequest.newBuilder()
+            .uri(URI.create("http://localhost:8080/"))
+            .build()
+
+        public fun getInstance(): HTTPClient? {
+            if (instance == null) {
+                try {
+                    client = HttpClient.newBuilder().build()
+                    val response = client?.send(handshake, ofString())
+                    check(response?.statusCode() == 200)
+                } catch (e: IllegalStateException) {
+                    println("${e.message}")
+                }
+                instance = HTTPClient()
+            }
+            return instance
+        }
+    }
+
+    // TODO: this class must send the experiment JSON file to the digital twin
+    public fun sendExperiment(experiment: File) {
+        val body : HttpRequest.BodyPublisher
+        val request = HttpRequest.newBuilder()
+            .uri(URI.create("http://localhost:8080/"))
+            .header("Content-type", "application/json")
+            // TODO: this is obviously wrong, find an efficient way to send JSON over network
+            .POST(HttpRequest.BodyPublishers.ofString(experiment))
+            .build()
+        println("Haha")
+    }
+}
\ No newline at end of file
diff --git a/opendc-common/src/main/kotlin/org/opendc/common/utils/JavalinRunner.kt b/opendc-common/src/main/kotlin/org/opendc/common/utils/JavalinRunner.kt
index 9db7bfaf..a43e23a8 100644
--- a/opendc-common/src/main/kotlin/org/opendc/common/utils/JavalinRunner.kt
+++ b/opendc-common/src/main/kotlin/org/opendc/common/utils/JavalinRunner.kt
@@ -1,25 +1,50 @@
 package org.opendc.common.utils
 
 import io.javalin.Javalin
-import io.javalin.http.Context
 import io.javalin.http.Handler
 
+/**
+ * Represents the digital twin monitoring server.
+ * @author Mateusz Kwiatkowski
+ * @see <a href=https://javalin.io/documentation>https://javalin.io/documentation</a>
+ */
+
 public class JavalinRunner {
+    private val handshake: Handler = Handler { ctx -> ctx.status(200) }
 
-    private val handleHello: Handler = Handler { ctx ->
-        ctx.status(200)
-        ctx.contentType("application/x-protobuf")
-        ctx.result("Hello world")
+    private val scenario: Handler = Handler { ctx ->
     }
 
     init {
+        // Make a CRUD RESTful API
+        // Specify server config
         val app = Javalin.create().start()
 
-        app.get("/hello", handleHello)
+        // returns a list of all experiments
+        app.get("/experiment", handshake)
+
+        // returns a specific experiment
+        app.get("/experiment/:id", handshake)
+
+        // you need another endpoint for the metrics
+
+        // get the results for the metrics evaluation
+        app.get("/results/:id", handshake)
+
+        // returns all results
+        app.get("/results", handshake)
+
+        // sends a specific experiment
+        app.post("/experiment", scenario)
+
+        // changes a specific experiment
+        app.put("/experiment/:id", scenario)
+        // this should delete metrics associated with the experiment
+
+        // deletes an experiment with id
+        app.delete("/experiment/:id", scenario)
 
-        app.exception<Exception?>(Exception::class.java, { e: Exception?, ctx: Context? ->
-            e!!.printStackTrace()
-            ctx!!.status(500)
-        })
+        // deletes all experiments
+        app.delete("/experiment", scenario)
     }
 }
\ No newline at end of file
diff --git a/opendc-common/src/main/kotlin/org/opendc/common/utils/Kafka.kt b/opendc-common/src/main/kotlin/org/opendc/common/utils/Kafka.kt
index d7ccd385..1430898e 100644
--- a/opendc-common/src/main/kotlin/org/opendc/common/utils/Kafka.kt
+++ b/opendc-common/src/main/kotlin/org/opendc/common/utils/Kafka.kt
@@ -38,19 +38,4 @@ public class Kafka(private val topic: String) {
             }
         }
     }
-
-    // TODO: fix
-    public fun getReceive() : () -> Unit {
-        val consumer = KafkaConsumer<String, ProtobufMetrics.ProtoExport>(properties)
-        return fun() : Unit {
-            try {
-                consumer.subscribe(listOf(topic))
-                while (true) {
-                    consumer.poll(1.microseconds.toJavaDuration())
-                }
-            } catch (e: Exception) {
-                println("${e.message}")
-            }
-        }
-    }
 }
\ No newline at end of file
diff --git a/opendc-common/src/main/kotlin/org/opendc/common/utils/PostgresqlDB.kt b/opendc-common/src/main/kotlin/org/opendc/common/utils/PostgresqlDB.kt
index 03fd902c..35d03feb 100644
--- a/opendc-common/src/main/kotlin/org/opendc/common/utils/PostgresqlDB.kt
+++ b/opendc-common/src/main/kotlin/org/opendc/common/utils/PostgresqlDB.kt
@@ -47,7 +47,6 @@ public class PostgresqlDB {
 
     private fun String.asJdbc(database : String) : String {
         return "jdbc:postgresql://$this/$database"
-
     }
 
 }
\ No newline at end of file
diff --git a/opendc-common/src/main/kotlin/org/opendc/common/utils/Redis.kt b/opendc-common/src/main/kotlin/org/opendc/common/utils/Redis.kt
new file mode 100644
index 00000000..67547778
--- /dev/null
+++ b/opendc-common/src/main/kotlin/org/opendc/common/utils/Redis.kt
@@ -0,0 +1,44 @@
+package org.opendc.common.utils
+
+import com.fasterxml.jackson.dataformat.toml.TomlMapper
+import redis.clients.jedis.RedisClient
+import redis.clients.jedis.StreamEntryID
+import redis.clients.jedis.params.XReadParams
+import java.util.Properties
+
+/**
+ * This class represents the Redis server instance.
+ * @author Mateusz Kwiatkowski
+ * @see <a href=https://redis.io/docs/latest/>https://redis.io/docs/latest/</a>
+ *
+ * @see <a href=https://redis.io/docs/latest/develop/data-types/streams/>https://redis.io/docs/latest/develop/data-types/streams/</a>
+ */
+
+@Suppress("DEPRECATION")
+public class Redis {
+    private var properties : Properties
+
+    init {
+        properties  = TomlMapper().readerFor(Properties().javaClass)
+            .readValue(Kafka::class.java.getResource("/producer.toml"))
+    }
+
+        public fun run() {
+            val jedis : RedisClient = RedisClient.create("redis://localhost:6379")
+
+            val res5 = jedis.xread(
+                XReadParams.xReadParams().block(300).count(100),
+                object : HashMap<String?, StreamEntryID?>() {
+                    init {
+                        put("${properties.getProperty("table")}", StreamEntryID())
+                    }
+                })
+
+            // in Redis you can subscribe to updates to a stream.
+            // you should base your application off this.
+            // you can listen for new items with XREAD
+            println(res5)
+            jedis.close()
+        }
+
+}
\ No newline at end of file
diff --git a/opendc-common/src/main/resources/database.toml b/opendc-common/src/main/resources/database.toml
index 35e1d159..c9aaa253 100644
--- a/opendc-common/src/main/resources/database.toml
+++ b/opendc-common/src/main/resources/database.toml
@@ -2,4 +2,4 @@
 "username" = "matt"
 "password" = "admin"
 "database" = "opendc"
-"table" = "postgres_topic"
\ No newline at end of file
+"stream" = "postgres_topic"
\ No newline at end of file