Deploy script (#52)

* No-downtime deploy script
* Easier to use helper for average numbers

.gitignore

@@ -1,4 +1,5 @@
 # See https://help.github.com/ignore-files/ for more about ignoring files.
+htdocs
 
 # dependencies
 node_modules

package.json

@@ -9,7 +9,9 @@
     "packages/*"
   ],
   "scripts": {
+    "deploy": "scripts/deploy.sh",
     "start:frontend": "scripts/start-frontend.sh",
+    "build:frontend": "scripts/build-frontend.sh",
     "start:backend": "scripts/start-backend.sh",
     "build:backend": "scripts/build-backend.sh",
     "check:backend": "tsc -p packages/backend --noEmit",

packages/backend/src/Chain.ts

@@ -2,7 +2,7 @@ import * as EventEmitter from 'events';
 import Node from './Node';
 import Feed from './Feed';
 import FeedSet from './FeedSet';
-import { Maybe, Types, FeedMessage, blockAverage } from '@dotstats/common';
+import { Maybe, Types, FeedMessage, NumStats } from '@dotstats/common';
 
 const BLOCK_TIME_HISTORY = 10;
 
@@ -16,7 +16,7 @@ export default class Chain {
   public height = 0 as Types.BlockNumber;
   public blockTimestamp = 0 as Types.Timestamp;
 
-  private blockTimes: Array<number> = new Array(BLOCK_TIME_HISTORY).fill(0);
+  private blockTimes = new NumStats<Types.Milliseconds>(BLOCK_TIME_HISTORY);
   private averageBlockTime: Maybe<Types.Milliseconds> = null;
 
   constructor(label: Types.ChainLabel) {
@@ -110,9 +110,9 @@ export default class Chain {
   }
 
   private updateAverageBlockTime(height: Types.BlockNumber, now: Types.Timestamp) {
-    this.blockTimes[height % BLOCK_TIME_HISTORY] = now - this.blockTimestamp;
+    this.blockTimes.push((now - this.blockTimestamp) as Types.Milliseconds);
 
     // We are guaranteed that count > 0
-    this.averageBlockTime = blockAverage(this.blockTimes);
+    this.averageBlockTime = this.blockTimes.average();
   }
 }

packages/backend/src/Node.ts

@@ -1,7 +1,7 @@
 import * as WebSocket from 'ws';
 import * as EventEmitter from 'events';
 
-import { noop, timestamp, Maybe, Types, blockAverage } from '@dotstats/common';
+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';
@@ -42,7 +42,7 @@ export default class Node {
 
   private readonly ip: string;
   private readonly socket: WebSocket;
-  private blockTimes: Array<number> = new Array(BLOCK_TIME_HISTORY);
+  private blockTimes = new NumStats<Types.Milliseconds>(BLOCK_TIME_HISTORY);
   private lastBlockAt: Maybe<Date> = null;
   private pingStart = 0 as Types.Timestamp;
   private throttle = false;
@@ -189,7 +189,7 @@ export default class Node {
   }
 
   public get average(): Types.Milliseconds {
-    return blockAverage(this.blockTimes);
+    return this.blockTimes.average();
   }
 
   public get localBlockAt(): Types.Milliseconds {
@@ -265,7 +265,7 @@ export default class Node {
       this.height = height;
       this.blockTimestamp = timestamp();
       this.lastBlockAt = time;
-      this.blockTimes[height % BLOCK_TIME_HISTORY] = blockTime;
+      this.blockTimes.push(blockTime);
       this.blockTime = blockTime;
 
       if (blockTime > 100) {

packages/common/src/block.ts

@@ -1,19 +0,0 @@
-import { Milliseconds } from './types';
-
-export function blockAverage(blockTimes: Array<number>): Milliseconds {
-  let count = 0;
-  let sum = 0;
-
-  for (const time of blockTimes) {
-    if (time) {
-      count += 1;
-      sum += time;
-    }
-  }
-
-  if (count === 0) {
-    return 0 as Milliseconds;
-  }
-
-  return (sum / count) as Milliseconds;
-}

packages/common/src/helpers.ts

@@ -35,3 +35,80 @@ export function sleep(time: Milliseconds): Promise<void> {
 export const timestamp = Date.now as () => Timestamp;
 
 export function noop() {}
+
+/**
+ * Keep track of last N numbers pushed onto internal stack.
+ * Provides means to get an average of said numbers.
+ */
+export class NumStats<T extends number> {
+  private readonly stack: Array<T>;
+  private readonly history: number;
+  private index: 0;
+
+  constructor(history: number) {
+    if (history < 1) {
+      throw new Error('Must track at least one number');
+    }
+
+    this.history = history;
+    this.stack = new Array(history);
+  }
+
+  public push(val: T) {
+    this.stack[this.index++ % this.history] = val;
+  }
+
+  /**
+   * Get average value of all values on the stack.
+   *
+   * @return {T} average value
+   */
+  public average(): T {
+    if (this.index === 0) {
+      return 0 as T;
+    }
+
+    const list = this.nonEmpty();
+    let sum = 0;
+
+    for (const n of list as Array<number>) {
+      sum += n;
+    }
+
+    return (sum / list.length) as T;
+  }
+
+  /**
+   * Get average value of all values of the stack after filtering
+   * out a number of highest and lowest values
+   *
+   * @param  {number} extremes number of high/low values to ignore
+   * @return {T}               average value
+   */
+  public averageWithoutExtremes(extremes: number): T {
+    if (this.index === 0) {
+      return 0 as T;
+    }
+
+    const list = this.nonEmpty();
+    const count = list.length - extremes * 2;
+
+    if (count < 1) {
+      // Not enough entries to remove desired number of extremes,
+      // fall back to regular average
+      return this.average();
+    }
+
+    let sum = 0;
+
+    for (const n of list.sort((a, b) => a - b).slice(extremes, -extremes)) {
+      sum += n;
+    }
+
+    return (sum / count) as T;
+  }
+
+  private nonEmpty(): Readonly<Array<number>> {
+    return this.index < this.history ? this.stack.slice(0, this.index) : this.stack;
+  }
+}

packages/common/src/index.ts

@@ -1,6 +1,5 @@
 export * from './helpers';
 export * from './id';
-export * from './block';
 export * from './stringify';
 
 import * as Types from './types';
@@ -9,4 +8,4 @@ import * as FeedMessage from './feed';
 export { Types, FeedMessage };
 
 // Increment this if breaking changes were made to types in `feed.ts`
-export const VERSION: Types.FeedVersion = 13 as Types.FeedVersion;
+export const VERSION: Types.FeedVersion = 14 as Types.FeedVersion;

scripts/build-frontend.sh

@@ -0,0 +1 @@
+cd ./packages/frontend && yarn run build && cp -r ./build ../../htdocs && cd ../../

scripts/deploy.sh

@@ -0,0 +1 @@
+yarn run build:common && yarn run build:backend && yarn run build:frontend && pm2 restart all