feat(#12): Implement Instrumentation API

These changes contain the specification of the new Instrumentation API for the simulator, in addition to the implementation for the Omega kernel. As an example, the API allows users to measure data from processes in simulation and interpolate data points between the measurements.

Closes #11, #12

1 files changed, 124 insertions, 0 deletions

diff --git a/opendc-stdlib/src/main/kotlin/com/atlarge/opendc/simulator/instrumentation/Interpolation.kt b/opendc-stdlib/src/main/kotlin/com/atlarge/opendc/simulator/instrumentation/Interpolation.kt
new file mode 100644
index 00000000..439813e8
--- /dev/null
+++ b/opendc-stdlib/src/main/kotlin/com/atlarge/opendc/simulator/instrumentation/Interpolation.kt
@@ -0,0 +1,124 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 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 com.atlarge.opendc.simulator.instrumentation
+
+import kotlinx.coroutines.experimental.Unconfined
+import kotlinx.coroutines.experimental.channels.ReceiveChannel
+import kotlinx.coroutines.experimental.channels.consume
+import kotlinx.coroutines.experimental.channels.produce
+import kotlin.coroutines.experimental.CoroutineContext
+
+/**
+ * Interpolate [n] amount of elements between every two occurrences of elements passing through the channel.
+ *
+ * The operation is _intermediate_ and _stateless_.
+ * This function [consumes][consume] all elements of the original [ReceiveChannel].
+ *
+ * @param context The context of the coroutine.
+ * @param n The amount of elements to interpolate between the actual elements in the channel.
+ * @param interpolator A function to interpolate between the two element occurrences.
+ */
+fun <E> ReceiveChannel<E>.interpolate(n: Int, context: CoroutineContext = Unconfined,
+                                      interpolator: (Double, E, E) -> E): ReceiveChannel<E> =
+    produce(context) {
+        consume {
+            val iterator = iterator()
+
+            if (!iterator.hasNext())
+                return@produce
+
+            var a = iterator.next()
+            send(a)
+
+            while (iterator.hasNext()) {
+                val b = iterator.next()
+                for (i in 1..n) {
+                    send(interpolator(i.toDouble() / (n + 1), a, b))
+                }
+                send(b)
+                a = b
+            }
+        }
+    }
+
+/**
+ * Perform a linear interpolation on the given double values.
+ *
+ * @param a The start value
+ * @param b The end value
+ * @param f The amount to interpolate which represents the position between the two values as a percentage in [0, 1].
+ * @return The interpolated double result between the double values.
+ */
+fun lerp(a: Double, b: Double, f: Double): Double = a + f * (b - a)
+
+/**
+ * Perform a linear interpolation on the given float values.
+ *
+ * @param a The start value
+ * @param b The end value
+ * @param f The amount to interpolate which represents the position between the two values as a percentage in [0, 1].
+ * @return The interpolated float result between the float values.
+ */
+fun lerp(a: Float, b: Float, f: Float): Float = a + f * (b - a)
+
+/**
+ * Perform a linear interpolation on the given integer values.
+ *
+ * @param a The start value
+ * @param b The end value
+ * @param f The amount to interpolate which represents the position between the two values as a percentage in [0, 1].
+ * @return The interpolated integer result between the integer values.
+ */
+fun lerp(a: Int, b: Int, f: Float): Int = lerp(a.toFloat(), b.toFloat(), f).toInt()
+
+/**
+ * Perform a linear interpolation on the given integer values.
+ *
+ * @param a The start value
+ * @param b The end value
+ * @param f The amount to interpolate which represents the position between the two values as a percentage in [0, 1].
+ * @return The interpolated integer result between the integer values.
+ */
+fun lerp(a: Int, b: Int, f: Double): Int = lerp(a.toDouble(), b.toDouble(), f).toInt()
+
+/**
+ * Perform a linear interpolation on the given long values.
+ *
+ * @param a The start value
+ * @param b The end value
+ * @param f The amount to interpolate which represents the position between the two values as a percentage in [0, 1].
+ * @return The interpolated long result between the long values.
+ */
+fun lerp(a: Long, b: Long, f: Double): Long = lerp(a.toDouble(), b.toDouble(), f).toLong()
+
+/**
+ * Perform a linear interpolation on the given long values.
+ *
+ * @param a The start value
+ * @param b The end value
+ * @param f The amount to interpolate which represents the position between the two values as a percentage in [0, 1].
+ * @return The interpolated long result between the long values.
+ */
+fun lerp(a: Long, b: Long, f: Float): Long = lerp(a.toFloat(), b.toFloat(), f).toLong()