Calculate follows using ssb-contact

Avoid use of `live: true` which triggers a bug in the query engine.
Use a single live stream to keep called-back objects up-to-date

2 files changed, 47 insertions, 32 deletions

diff --git a/lib/app.js b/lib/app.js
index 643b317..fc395a2 100644
--- a/lib/app.js
+++ b/lib/app.js
@@ -8,6 +8,7 @@ var multicb = require('multicb')
 var paramap = require('pull-paramap')
 var Contacts = require('ssb-contact')
 var About = require('./about')
+var Follows = require('./follows')
 var Serve = require('./serve')
 var Render = require('./render')
 var Git = require('./git')
@@ -49,7 +50,6 @@ function App(sbot, config) {
   this.reverseEmojiNameCache = lru(500)
   this.getBlobSize = memo({cache: this.blobSizeCache = lru(100)},
     sbot.blobs.size.bind(sbot.blobs))
-  this.getFollows = memo(this._getFollows.bind(this))
   this.getVotes = memo({cache: lru(100)}, this._getVotes.bind(this))
 
   this.unboxMsg = this.unboxMsg.bind(this)
@@ -57,6 +57,7 @@ function App(sbot, config) {
   this.render = new Render(this, this.opts)
   this.git = new Git(this)
   this.contacts = new Contacts(this.sbot)
+  this.follows = new Follows(this.sbot, this.contacts)
 
   this.monitorBlobWants()
 }
@@ -690,7 +691,7 @@ App.prototype.filterMsg = function (msg, opts, cb) {
    || author === myId
    || author === opts.feed
    || msg.key === opts.msgId) return cb(null, show)
-  self.getFollows(myId, function (err, follows) {
+  self.follows.getFollows(myId, function (err, follows) {
     if (err) return cb(err)
     if (follows[author]) return cb(null, show)
     self.getVotes(msg.key, function (err, votes) {
@@ -707,41 +708,12 @@ App.prototype.filterMsg = function (msg, opts, cb) {
 
 App.prototype.isFollowing = function (src, dest, cb) {
   var self = this
-  self.getFollows(src, function (err, follows) {
+  self.follows.getFollows(src, function (err, follows) {
     if (err) return cb(err)
     return cb(null, follows[dest])
   })
 }
 
-App.prototype._getFollows = function (id, cb) {
-  var follows = {}
-  function ready(err) {
-    if (!cb) return
-    var _cb = cb
-    cb = null
-    _cb(err, follows)
-  }
-  pull(
-    this.sbot.links2.read({
-      live: true,
-      query: [
-        {$filter: {
-          source: id,
-          rel: [{$prefix: 'contact'}]
-        }},
-        {$map: {
-          following: ['rel', 1],
-          feed: 'dest'
-        }}
-      ]
-    }),
-    pull.drain(function (link) {
-      if (link.sync) return ready()
-      follows[link.feed] = link.following
-    }, ready)
-  )
-}
-
 App.prototype._getVotes = function (id, cb) {
   var votes = {}
   pull(
diff --git a/lib/follows.js b/lib/follows.js
new file mode 100644
index 0000000..b262520
--- /dev/null
+++ b/lib/follows.js
@@ -0,0 +1,43 @@
+var pull = require('pull-stream')
+var memo = require('asyncmemo')
+var lru = require('hashlru')
+
+module.exports = Follows
+
+function Follows(sbot, contacts) {
+  if (!(this instanceof Follows)) return new Follows(sbot)
+
+  this.sbot = sbot
+  this.contacts = contacts
+  var followsCache = lru(100)
+  this.getFollows = memo({cache: followsCache}, this.getFollows)
+
+  pull(
+    sbot.messagesByType({type: 'contact', old: false}),
+    pull.drain(function (msg) {
+      var author = msg && msg.value && msg.value.author
+      var c = msg && msg.value && msg.value.content
+      var follows = author && followsCache.get(author)
+      if (follows && c && c.contact) follows[c.contact] = c.following
+    }, function (err) {
+      if (err) console.trace(err)
+    })
+  )
+}
+
+Follows.prototype.getFollows = function (id, cb) {
+  var follows = {}
+  pull(
+    this.contacts.createFollowsStream(id),
+    pull.drain(function (feed) {
+      follows[feed] = true
+    }, function (err) {
+      if (err) return cb(err)
+      cb(null, follows)
+    })
+  )
+}
+
+Follows.prototype.close = function (cb) {
+  this.sbot.close(cb)
+}