1 files changed, 42 insertions, 0 deletions
diff --git a/srv/src/http/static/trading-in-the-rain/Distributor.js b/srv/src/http/static/trading-in-the-rain/Distributor.js
new file mode 100644
index 0000000..fa6e9f2
--- /dev/null
+++ b/srv/src/http/static/trading-in-the-rain/Distributor.js
@@ -0,0 +1,42 @@
+function distribute(val, minOld, maxOld, minNew, maxNew) {
+  let scalar = (val - minOld) / (maxOld - minOld);
+  return minNew + ((maxNew - minNew) * scalar);
+}
+
+function Distributor(capacity) {
+  this.cap = capacity;
+
+  this.reset = () => {
+    this.arr = [];
+    this.arrSorted = [];
+    this.length = 0;
+  };
+  this.reset();
+
+  // add adds the given value into the series, shifting off the oldest value if
+  // the series is at capacity.
+  this.add = (val) => {
+    this.arr.push(val);
+    if (this.arr.length >= this.cap) this.arr.shift();
+    this.arrSorted = this.arr.slice(); // copy array
+    this.arrSorted.sort();
+    this.length = this.arr.length;
+  };
+
+  // distribute finds where the given value falls within the series, and then
+  // scales that into the given range (inclusive).
+  this.distribute = (val, min, max) => {
+    if (this.length == 0) throw "cannot locate within empty Distributor";
+
+    let idx = this.length;
+    for (i in this.arrSorted) {
+      if (val < this.arrSorted[i]) {
+        idx = i;
+        break;
+      }
+    }
+
+    return distribute(idx, 0, this.length, min, max);
+  };
+}
+