From ade93e55580ddf3a5757ff4882ad32fce6db9b8e Mon Sep 17 00:00:00 2001
From: Primoz Z <pzagor2@gmail.com>
Date: Fri, 2 Nov 2018 22:16:03 +0100
Subject: [PATCH] Update levelup dependency

---
 README.md     | 7 +++----
 index.js      | 9 ++++-----
 package.json  | 3 +--
 test/index.js | 9 ++++-----
 4 files changed, 12 insertions(+), 16 deletions(-)

diff --git a/README.md b/README.md
index 7e63ce3..cba6944 100644
--- a/README.md
+++ b/README.md
@@ -11,17 +11,16 @@ A module to store and interact with blocks.
 
 # EXAMPLE
 
-The following is an example to iterate through an existing Geth DB (needs ``leveldown`` to be
+The following is an example to iterate through an existing Geth DB (needs ``level`` to be
 installed separately):
 
 ```javascript
-const levelup = require('levelup')
-const leveldown = require('leveldown')
+const level = require('level')
 const Blockchain = require('ethereumjs-blockchain')
 const utils = require('ethereumjs-util')
 
 const gethDbPath = './chaindata' // Add your own path here
-const db = levelup(gethDbPath, { db: leveldown })
+const db = level(gethDbPath)
 
 new Blockchain({db: db}).iterator('i', (block, reorg, cb) => {
   const blockNumber = utils.bufferToInt(block.header.number)
diff --git a/index.js b/index.js
index 6fa9f90..2d5ba7c 100644
--- a/index.js
+++ b/index.js
@@ -3,8 +3,7 @@
 const async = require('async')
 const Stoplight = require('flow-stoplight')
 const semaphore = require('semaphore')
-const levelup = require('levelup')
-const memdown = require('memdown')
+const level = require('level-mem')
 const Block = require('ethereumjs-block')
 const Common = require('ethereumjs-common')
 const ethUtil = require('ethereumjs-util')
@@ -55,7 +54,7 @@ function Blockchain (opts) {
   self.db = opts.db || opts.blockDb
 
   // defaults
-  self.db = self.db ? self.db : levelup('', { db: memdown })
+  self.db = self.db ? self.db : level()
   self.validate = (opts.validate === undefined ? true : opts.validate)
   self.ethash = self.validate ? new Ethash(self.db) : null
   self._heads = {}
@@ -938,7 +937,7 @@ Blockchain.prototype._iterator = function (name, func, cb) {
       } else {
         blockNumber = false
         // No more blocks, return
-        if (err instanceof levelup.errors.NotFoundError) {
+        if (err instanceof level.errors.NotFoundError) {
           return cb2()
         }
       }
@@ -1001,7 +1000,7 @@ Blockchain.prototype._numberToHash = function (number, cb) {
   const self = this
 
   if (number.ltn(0)) {
-    return cb(new levelup.errors.NotFoundError())
+    return cb(new level.errors.NotFoundError())
   }
   var key = numberToHashKey(number)
   var hash = self._cache.numberToHash.get(key)
diff --git a/package.json b/package.json
index 0313809..4d0dc35 100644
--- a/package.json
+++ b/package.json
@@ -30,9 +30,8 @@
     "ethereumjs-common": "~0.6.0",
     "ethereumjs-util": "~6.0.0",
     "flow-stoplight": "^1.0.0",
-    "levelup": "^1.3.2",
+    "level-mem": "^3.0.1",
     "lru-cache": "^4.1.3",
-    "memdown": "^1.1.0",
     "safe-buffer": "^5.1.2",
     "semaphore": "^1.1.0"
   },
diff --git a/test/index.js b/test/index.js
index a87d930..ebba9d2 100644
--- a/test/index.js
+++ b/test/index.js
@@ -6,8 +6,7 @@ const Block = require('ethereumjs-block')
 const Common = require('ethereumjs-common')
 const async = require('async')
 const ethUtil = require('ethereumjs-util')
-const levelup = require('levelup')
-const memdown = require('memdown')
+const level = require('level-mem')
 const testData = require('./testdata.json')
 const BN = require('bn.js')
 const rlp = ethUtil.rlp
@@ -45,7 +44,7 @@ test('blockchain test', function (t) {
       })
     },
     function alternateConstructors (done) {
-      var db = levelup('', { db: memdown })
+      var db = level()
       var blockchain = new Blockchain(db)
       t.equals(db, blockchain.db, 'support constructor with db parameter')
       blockchain = new Blockchain({detailsDb: db, blockDb: db})
@@ -375,7 +374,7 @@ test('blockchain test', function (t) {
       })
     },
     function saveHeads (done) {
-      var db = levelup('', { db: memdown })
+      var db = level()
       var blockchain = new Blockchain({db: db, validate: false})
       var header = new Block.Header()
       header.number = ethUtil.toBuffer(1)
@@ -523,7 +522,7 @@ function isConsecutive (blocks) {
 function createTestDB (cb) {
   var genesis = new Block()
   genesis.setGenesisParams()
-  var db = levelup('', { db: memdown })
+  var db = level()
   db.batch([{
     type: 'put',
     key: Buffer.from('6800000000000000006e', 'hex'),