feat(exp/base): Add service registry for cloud services

This change adds a new module called opendc-experiments-base which will
provide a base for doing experiments with OpenDC. The initial feature we
introduce is the service registry which acts as DNS for services to
register during experimentation.

1 files changed, 111 insertions, 0 deletions

diff --git a/opendc-experiments/opendc-experiments-base/src/test/kotlin/org/opendc/experiments/ServiceRegistryTest.kt b/opendc-experiments/opendc-experiments-base/src/test/kotlin/org/opendc/experiments/ServiceRegistryTest.kt
new file mode 100644
index 00000000..f69c07c1
--- /dev/null
+++ b/opendc-experiments/opendc-experiments-base/src/test/kotlin/org/opendc/experiments/ServiceRegistryTest.kt
@@ -0,0 +1,111 @@
+/*
+ * Copyright (c) 2022 AtLarge Research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package org.opendc.experiments
+
+import org.junit.jupiter.api.Assertions.*
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.assertThrows
+import org.opendc.experiments.internal.ServiceRegistryImpl
+
+/**
+ * Test suite for the [ServiceRegistry] implementation.
+ */
+class ServiceRegistryTest {
+    @Test
+    fun testRetrievalSuccess() {
+        val registry = ServiceRegistryImpl()
+
+        registry.register("opendc.org", String::class.java, "Comment")
+
+        assertEquals("Comment", registry.resolve("opendc.org", String::class.java))
+    }
+
+    @Test
+    fun testRetrievalFailure() {
+        val registry = ServiceRegistryImpl()
+        assertNull(registry.resolve("opendc.org", String::class.java))
+    }
+
+    @Test
+    fun testDuplicate() {
+        val registry = ServiceRegistryImpl()
+
+        registry.register("opendc.org", String::class.java, "Comment")
+
+        assertThrows<IllegalStateException> { registry.register("opendc.org", String::class.java, "Comment2") }
+    }
+
+    @Test
+    fun testRemove() {
+        val registry = ServiceRegistryImpl()
+
+        registry.register("opendc.org", String::class.java, "Comment")
+        registry.remove("opendc.org", String::class.java)
+
+        assertAll(
+            { assertDoesNotThrow { registry.remove("opendc.org", String::class.java) } },
+            { assertNull(registry.resolve("opendc.org", String::class.java)) }
+        )
+    }
+
+    @Test
+    fun testRemoveNonExistent() {
+        val registry = ServiceRegistryImpl()
+
+        assertAll(
+            { assertNull(registry.resolve("opendc.org", String::class.java)) },
+            { assertDoesNotThrow { registry.remove("opendc.org", String::class.java) } }
+        )
+    }
+
+    @Test
+    fun testRemoveAll() {
+        val registry = ServiceRegistryImpl()
+
+        registry.register("opendc.org", String::class.java, "Comment")
+        registry.register("opendc.org", Int::class.java, 1)
+
+        println(registry)
+
+        registry.remove("opendc.org")
+
+        assertAll(
+            { assertNull(registry.resolve("opendc.org", String::class.java)) },
+            { assertNull(registry.resolve("opendc.org", Int::class.java)) },
+        )
+    }
+
+    @Test
+    fun testClone() {
+        val registry = ServiceRegistryImpl()
+        registry.register("opendc.org", String::class.java, "Comment")
+
+        val clone = registry.clone()
+        clone.remove("opendc.org")
+
+        assertAll(
+            { assertEquals("Comment", registry.resolve("opendc.org", String::class.java)) },
+            { assertNull(clone.resolve("opendc.org", String::class.java)) }
+        )
+    }
+}