merge: Expose metrics directly to user (#80)

This pull request adds the ability to access the metrics of resources modeled
by the OpenDC Compute, Workflow, FaaS, and TensorFlow services directly from
their corresponding interfaces. Previously, users would have to interact with
OpenTelemetry to obtain these values, which is complex and provides
significant overhead.

With this pull request, users can access the metrics of all cloud resources
modeled by OpenDC via methods such as `getSchedulerStats()`, etc.

** Breaking Changes **

- `ComputeService.hostCount` removed in favour of `ComputeService.hosts.size`

2 files changed, 2 insertions, 9 deletions

diff --git a/opendc-compute/opendc-compute-service/src/test/kotlin/org/opendc/compute/service/ComputeServiceTest.kt b/opendc-compute/opendc-compute-service/src/test/kotlin/org/opendc/compute/service/ComputeServiceTest.kt
index 7b8d0fe2..eb106817 100644
--- a/opendc-compute/opendc-compute-service/src/test/kotlin/org/opendc/compute/service/ComputeServiceTest.kt
+++ b/opendc-compute/opendc-compute-service/src/test/kotlin/org/opendc/compute/service/ComputeServiceTest.kt
@@ -24,7 +24,6 @@ package org.opendc.compute.service
 
 import io.mockk.*
 import io.opentelemetry.api.metrics.MeterProvider
-import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.delay
 import org.junit.jupiter.api.Assertions.assertEquals
 import org.junit.jupiter.api.Assertions.assertNull
@@ -48,10 +47,9 @@ import java.util.*
 /**
  * Test suite for the [ComputeService] interface.
  */
-@OptIn(ExperimentalCoroutinesApi::class)
 internal class ComputeServiceTest {
-    lateinit var scope: SimulationCoroutineScope
-    lateinit var service: ComputeService
+    private lateinit var scope: SimulationCoroutineScope
+    private lateinit var service: ComputeService
 
     @BeforeEach
     fun setUp() {
@@ -128,14 +126,12 @@ internal class ComputeServiceTest {
         every { host.model } returns HostModel(4 * 2600.0, 4, 2048)
         every { host.state } returns HostState.UP
 
-        assertEquals(0, service.hostCount)
         assertEquals(emptySet<Host>(), service.hosts)
 
         service.addHost(host)
 
         verify(exactly = 1) { host.addListener(any()) }
 
-        assertEquals(1, service.hostCount)
         assertEquals(1, service.hosts.size)
 
         service.removeHost(host)
@@ -150,7 +146,6 @@ internal class ComputeServiceTest {
         every { host.model } returns HostModel(4 * 2600.0, 4, 2048)
         every { host.state } returns HostState.DOWN
 
-        assertEquals(0, service.hostCount)
         assertEquals(emptySet<Host>(), service.hosts)
 
         service.addHost(host)
diff --git a/opendc-compute/opendc-compute-service/src/test/kotlin/org/opendc/compute/service/InternalServerTest.kt b/opendc-compute/opendc-compute-service/src/test/kotlin/org/opendc/compute/service/InternalServerTest.kt
index dfd3bc67..4e5a37ae 100644
--- a/opendc-compute/opendc-compute-service/src/test/kotlin/org/opendc/compute/service/InternalServerTest.kt
+++ b/opendc-compute/opendc-compute-service/src/test/kotlin/org/opendc/compute/service/InternalServerTest.kt
@@ -23,7 +23,6 @@
 package org.opendc.compute.service
 
 import io.mockk.*
-import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.yield
 import org.junit.jupiter.api.Assertions.*
 import org.junit.jupiter.api.Test
@@ -41,7 +40,6 @@ import java.util.*
 /**
  * Test suite for the [InternalServer] implementation.
  */
-@OptIn(ExperimentalCoroutinesApi::class)
 class InternalServerTest {
     @Test
     fun testEquality() {