From 727ad2ff501bd1b0460bd477e982de809fbb02d3 Mon Sep 17 00:00:00 2001
From: Cofresi <cofresi@dash.org>
Date: Fri, 31 May 2019 11:53:21 -0400
Subject: [PATCH] Fix and speed up addHeaders() (#21)

* add test section for adding testnet headers

* add testnet tests

* update dark gravity wave

* reactivate mainnet headers

* reactivate mainnet headers

* update dark-gravity-wave

* bump version

* update package lock

* remove bn.js from deps

* bump patch version

* update eslint-plugin-import dep

* update package lock

* revert superfluous bump

* update package lock

* simplify validation for header chunks

* disable some tests for quicker testing

* disable blockstore tests

* add fn getTipHeader()

* add fn appendHeaderToLongestChain()

* reactivate blockstore tests

* disable eslint no-param-reassign

* break reduce function on bad header

* bump version

* update package lock

* refactor to prepare for orphan chunks

* refactor & fix
---
 lib/spvchain.js   | 64 ++++++++++++++++++++++++++++++++++++++++++-----
 package-lock.json |  8 +++---
 package.json      |  2 +-
 3 files changed, 63 insertions(+), 11 deletions(-)

diff --git a/lib/spvchain.js b/lib/spvchain.js
index 6172eb9..9cf1d40 100644
--- a/lib/spvchain.js
+++ b/lib/spvchain.js
@@ -8,6 +8,7 @@ const SpvChain = class {
     this.root = null;
     this.allBranches = [];
     this.orphanBlocks = [];
+    this.orphanChunks = [];
     this.confirmsBeforeFinal = confirms;
     this.init(chainType, startBlock);
     this.store = new BlockStore();
@@ -87,6 +88,10 @@ const SpvChain = class {
     return this.getLongestChain().slice(-1)[0].hash;
   }
 
+  getTipHeader() {
+    return this.getLongestChain().slice(-1)[0];
+  }
+
   getHeader(hash) {
     return this.store.get(hash)
       .then((blockInDB) => {
@@ -123,6 +128,12 @@ const SpvChain = class {
     }
   }
 
+  appendHeadersToLongestChain(headers) {
+    const newLongestChain = this.getLongestChain().concat(headers);
+    this.allBranches = [];
+    this.allBranches.push(newLongestChain);
+  }
+
   getAllBranches() {
     return this.allBranches;
   }
@@ -160,8 +171,7 @@ const SpvChain = class {
   addHeader(header) {
     const headerNormalised = utils.normalizeHeader(header);
 
-    if (Consensus.isValidBlockHeader(headerNormalised, this.getLongestChain(), this.network)
-      && !this.isDuplicate(headerNormalised.hash)) {
+    if (this.isValid(headerNormalised, this.getLongestChain())) {
       headerNormalised.children = [];
       this.processValidHeader(headerNormalised);
       this.setAllBranches();
@@ -171,15 +181,57 @@ const SpvChain = class {
     return false;
   }
 
+  /* eslint-disable no-param-reassign */
+  static isParentChild(header, previousHeader) {
+    if (utils.getCorrectedHash(header.prevHash) !== previousHeader.hash) {
+      return false;
+    }
+    if (!header.children) {
+      header.children = [];
+    }
+    if (!previousHeader.children) {
+      previousHeader.children = [];
+    }
+    previousHeader.children.push(header);
+    return true;
+  }
+  /* eslint-enable no-param-reassign */
+
+  isValid(header, previousHeaders) {
+    return !!(Consensus.isValidBlockHeader(header, previousHeaders, this.network)
+      && !this.isDuplicate(header.hash));
+  }
+
   addHeaders(headers) {
     const self = this;
-    const allAdded = headers.reduce(
-      (acc, header) => acc && self.addHeader(header, this.network), true,
+    const normalizedHeaders = headers.map(h => utils.normalizeHeader(h));
+    const isOrphan = !SpvChain.isParentChild(normalizedHeaders[0], this.getTipHeader());
+
+    const allValid = normalizedHeaders.reduce(
+      (acc, header, index, array) => {
+        const previousHeaders = normalizedHeaders.slice(0, index);
+        if (index !== 0) {
+          if (!SpvChain.isParentChild(header, array[index - 1])
+            || !self.isValid(header, previousHeaders)) {
+            throw new Error('Some headers are invalid');
+          }
+          return acc && true;
+        }
+        if (!self.isValid(header, self.getLongestChain())) {
+          throw new Error('Some headers are invalid');
+        }
+        return acc && true;
+      }, true,
     );
-
-    if (!allAdded) {
+    if (!allValid) {
       throw new Error('Some headers are invalid');
     }
+    if (isOrphan) {
+      this.orphanChunks.push(headers);
+    } else {
+      self.appendHeadersToLongestChain(normalizedHeaders);
+    }
+    this.checkPruneBlocks();
   }
 };
 
diff --git a/package-lock.json b/package-lock.json
index bb54f2e..d14c59f 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "@dashevo/dash-spv",
-  "version": "1.1.3",
+  "version": "1.1.4",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
@@ -1427,9 +1427,9 @@
       }
     },
     "readable-stream": {
-      "version": "3.3.0",
-      "resolved": "https://registry.npmjs.org/readable-stream/-/readable-stream-3.3.0.tgz",
-      "integrity": "sha512-EsI+s3k3XsW+fU8fQACLN59ky34AZ14LoeVZpYwmZvldCFo0r0gnelwF2TcMjLor/BTL5aDJVBMkss0dthToPw==",
+      "version": "3.4.0",
+      "resolved": "https://registry.npmjs.org/readable-stream/-/readable-stream-3.4.0.tgz",
+      "integrity": "sha512-jItXPLmrSR8jmTRmRWJXCnGJsfy85mB3Wd/uINMXA65yrnFo0cPClFIUWzo2najVNSl+mx7/4W8ttlLWJe99pQ==",
       "requires": {
         "inherits": "^2.0.3",
         "string_decoder": "^1.1.1",
diff --git a/package.json b/package.json
index a193f40..271f787 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@dashevo/dash-spv",
-  "version": "1.1.3",
+  "version": "1.1.4",
   "description": "Temporary repo until spv functions moved into dashcore-lib",
   "main": "index.js",
   "scripts": {