Better Sparklines (#72)

* Cleaner renders
* Add timestamps to Sparklines
* Keep track of chart history up to 1h in the past

packages/backend/src/Node.ts

@@ -5,6 +5,7 @@ import { noop, timestamp, Maybe, Types, NumStats } from '@dotstats/common';
 import { parseMessage, getBestBlock, Message, BestBlock, SystemInterval } from './message';
 import { locate, Location } from './location';
 import { getId, refreshId } from './nodeId';
+import { MeanList } from './MeanList';
 
 const BLOCK_TIME_HISTORY = 10;
 const MEMORY_RECORDS = 20;
@@ -39,8 +40,9 @@ export default class Node {
 
   private peers = 0 as Types.PeerCount;
   private txcount = 0 as Types.TransactionCount;
-  private memory = Array<Types.MemoryUse>();
-  private cpu = Array<Types.CPUUse>();
+  private memory = new MeanList<Types.MemoryUse>();
+  private cpu = new MeanList<Types.CPUUse>();
+  private chartstamps = new MeanList<Types.Timestamp>();
 
   private readonly ip: string;
   private readonly socket: WebSocket;
@@ -177,7 +179,7 @@ export default class Node {
   }
 
   public nodeStats(): Types.NodeStats {
-    return [this.peers, this.txcount, this.memory, this.cpu];
+    return [this.peers, this.txcount, this.memory.get(), this.cpu.get(), this.chartstamps.get()];
   }
 
   public blockDetails(): Types.BlockDetails {
@@ -232,22 +234,10 @@ export default class Node {
     this.peers = peers;
     this.txcount = txcount;
 
-    if (cpu) {
-      if (this.cpu.length === CPU_RECORDS) {
-        this.cpu.copyWithin(0, 1);
-        this.cpu[CPU_RECORDS-1] = cpu;
-      } else {
-        this.cpu.push(cpu);
-      }
-    }
-
-    if (memory) {
-      if (this.memory.length === MEMORY_RECORDS) {
-        this.memory.copyWithin(0, 1);
-        this.memory[MEMORY_RECORDS-1] = memory;
-      } else {
-        this.memory.push(memory);
-      }
+    if (cpu != null && memory != null) {
+      this.cpu.push(cpu);
+      this.memory.push(memory);
+      this.chartstamps.push(timestamp());
     }
 
     this.events.emit('stats');