From cdca51a8445e3a5c582fd58afc88aefb5637fff1 Mon Sep 17 00:00:00 2001
From: Nodar Chkuaselidze <nodar.chkuaselidze@gmail.com>
Date: Fri, 17 May 2019 20:35:21 +0400
Subject: [PATCH] addrindexer: minor. * allocate one buffer istead of concat. *
 return results instead of mutating array.

---
 lib/indexer/addrindexer.js |  7 ++-----
 lib/mempool/addrindexer.js | 11 ++++++++---
 2 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/lib/indexer/addrindexer.js b/lib/indexer/addrindexer.js
index d864be6b9..925315915 100644
--- a/lib/indexer/addrindexer.js
+++ b/lib/indexer/addrindexer.js
@@ -211,8 +211,6 @@ class AddrIndexer extends Indexer {
    */
 
   async getHashesByAddress(addr, options = {}) {
-    const txs = [];
-
     const {after, reverse} = options;
     let {limit} = options;
 
@@ -230,7 +228,7 @@ class AddrIndexer extends Indexer {
       reverse,
       parse: (key) => {
         const [,, height, index] = layout.A.decode(key);
-        txs.push([height, index]);
+        return [height, index];
       }
     };
 
@@ -265,8 +263,7 @@ class AddrIndexer extends Indexer {
       opts.lte = layout.A.max(prefix, hash);
     }
 
-    await this.db.keys(opts);
-
+    const txs = await this.db.keys(opts);
     const hashes = [];
 
     for (const [height, index] of txs)
diff --git a/lib/mempool/addrindexer.js b/lib/mempool/addrindexer.js
index f2d4b34f3..311dbd3e9 100644
--- a/lib/mempool/addrindexer.js
+++ b/lib/mempool/addrindexer.js
@@ -44,10 +44,15 @@ class AddrIndexer {
     if (prefix < 0)
       return null;
 
-    const raw = Buffer.allocUnsafe(1);
-    raw.writeUInt8(prefix);
+    const hash = addr.getHash();
+    const size = hash.length + 1;
+    const raw = Buffer.allocUnsafe(size);
 
-    return Buffer.concat([raw, addr.getHash()]);
+    let written = raw.writeUInt8(prefix);
+    written += hash.copy(raw, 1);
+    assert(written === size);
+
+    return raw;
   }
 
   /**