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

1 files changed, 43 insertions, 0 deletions

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)
+}