From 970deec2a4e3ccff8c00d3caedb96b9044c1ef69 Mon Sep 17 00:00:00 2001
From: Vasco Santos <vasco.santos@ua.pt>
Date: Tue, 13 Nov 2018 10:46:51 +0000
Subject: [PATCH] feat: add maxNumProviders to findprovs (#283)

* feat: add maxNumProviders to findprovs

* chore: upgrade libp2p-kad-dht
---
 README.md                    |  2 +-
 package.json                 |  2 +-
 src/content-routing.js       |  1 +
 test/content-routing.node.js | 16 ++++++++++++++++
 4 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/README.md b/README.md
index 5c642d5c17..30b5f8192b 100644
--- a/README.md
+++ b/README.md
@@ -261,12 +261,12 @@ Required keys in the `options` object:
 - `key`: Buffer
 - `options`: object of options
 - `options.maxTimeout`: Number milliseconds
+- `options.maxNumProviders` maximum number of providers to find
 
 #### `libp2p.contentRouting.provide(key, callback)`
 
 - `key`: Buffer
 
-
 #### `libp2p.handle(protocol, handlerFunc [, matchFunc])`
 
 > Handle new protocol
diff --git a/package.json b/package.json
index b9cbd7ce8f..28c340d251 100644
--- a/package.json
+++ b/package.json
@@ -67,7 +67,7 @@
     "libp2p-circuit": "~0.3.0",
     "libp2p-delegated-content-routing": "~0.2.2",
     "libp2p-delegated-peer-routing": "~0.2.2",
-    "libp2p-kad-dht": "~0.10.6",
+    "libp2p-kad-dht": "~0.11.1",
     "libp2p-mdns": "~0.12.0",
     "libp2p-mplex": "~0.8.2",
     "libp2p-secio": "~0.10.1",
diff --git a/src/content-routing.js b/src/content-routing.js
index 6c94bd7327..3ebacb59fa 100644
--- a/src/content-routing.js
+++ b/src/content-routing.js
@@ -20,6 +20,7 @@ module.exports = (node) => {
      * @param {CID} key The CID key of the content to find
      * @param {object} options
      * @param {number} options.maxTimeout How long the query should run
+     * @param {number} options.maxNumProviders - maximum number of providers to find
      * @param {function(Error, Result<Array>)} callback
      * @returns {void}
      */
diff --git a/test/content-routing.node.js b/test/content-routing.node.js
index 7f8adb07fb..4bfa58e19f 100644
--- a/test/content-routing.node.js
+++ b/test/content-routing.node.js
@@ -107,6 +107,22 @@ describe('.contentRouting', () => {
         })
       })
 
+      it('nodeE.contentRouting.findProviders with limited number of providers', (done) => {
+        parallel([
+          (cb) => nodeA.contentRouting.provide(cid, cb),
+          (cb) => nodeB.contentRouting.provide(cid, cb),
+          (cb) => nodeC.contentRouting.provide(cid, cb)
+        ], (err) => {
+          expect(err).to.not.exist()
+
+          nodeE.contentRouting.findProviders(cid, { maxNumProviders: 2 }, (err, providers) => {
+            expect(err).to.not.exist()
+            expect(providers).to.have.length(2)
+            done()
+          })
+        })
+      })
+
       it('nodeC.contentRouting.findProviders for non existing record (timeout)', (done) => {
         const cid = new CID('QmTp9VkYvnHyrqKQuFPiuZkiX9gPcqj6x5LJ1rmWuSnnnn')