var Graphmitter = require('graphmitter') var pull = require('pull-stream') var mlib = require('ssb-msgs') var memview = require('level-memview') var pushable = require('pull-pushable') var mdm = require('mdmanifest') var valid = require('scuttlebot/lib/validators') var apidoc = require('scuttlebot/lib/apidocs').friends // friends plugin // methods to analyze the social graph // maintains a 'follow' and 'flag' graph function isFunction (f) { return 'function' === typeof f } function isString (s) { return 'string' === typeof s } function isFriend (friends, a, b) { return friends[a] && friends[b] && friends[a][b] && friends[b][a] } exports.name = 'friends' exports.version = '1.0.0' exports.manifest = mdm.manifest(apidoc) exports.init = function (sbot, config) { var graphs = { follow: new Graphmitter(), flag: new Graphmitter() } // view processor var syncCbs = [] function awaitSync (cb) { if (syncCbs) syncCbs.push(cb) else cb() } // read/watch the log for changes to the social graph pull(sbot.createLogStream({ live: true }), pull.drain(function (msg) { if (msg.sync) { syncCbs.forEach(function (cb) { cb() }) syncCbs = null if (sbot.gossip) { // prioritize friends var friends = graphs['follow'].toJSON() sbot.gossip.peers().forEach(function(peer) { if (isFriend(friends, sbot.id, peer.key)) { sbot.gossip.add(peer, 'friends') } }) } return } var c = msg.value.content if (c.type == 'contact') { mlib.asLinks(c.contact, 'feed').forEach(function (link) { if ('following' in c) { if (c.following) graphs.follow.edge(msg.value.author, link.link, true) else graphs.follow.del(msg.value.author, link.link) } if ('flagged' in c) { if (c.flagged) graphs.flag.edge(msg.value.author, link.link, c.flagged) else graphs.flag.del(msg.value.author, link.link) } }) } })) return { get: valid.sync(function (opts) { var g = graphs[opts.graph || 'follow'] if(!g) throw new Error('opts.graph must be provided') return g.get(opts.source, opts.dest) }, 'object?'), all: valid.async(function (graph, cb) { if (typeof graph == 'function') { cb = graph graph = null } if (!graph) graph = 'follow' awaitSync(function () { cb(null, graphs[graph] ? graphs[graph].toJSON() : null) }) }, 'string?'), path: valid.sync(function (opts) { if(isString(opts)) opts = {source: sbot.id, dest: opts} return graphs.follow.path(opts) }, 'string|object'), createFriendStream: valid.source(function (opts) { opts = opts || {} var live = opts.live === true var meta = opts.meta === true var start = opts.start || sbot.id var graph = graphs[opts.graph || 'follow'] if(!graph) return pull.error(new Error('unknown graph:' + opts.graph)) var cancel, ps = pushable(function () { cancel && cancel() }) function push (to, hops) { return ps.push(meta ? {id: to, hops: hops} : to) } //by default, also emit your own key. if(opts.self !== false) push(start, 0) var conf = config.friends || {} cancel = graph.traverse({ start: start, hops: opts.hops || conf.hops || 3, max: opts.dunbar || conf.dunbar || 150, each: function (_, to, hops) { if(to !== start) push(to, hops) } }) if(!live) { cancel(); ps.end() } return ps }, 'createFriendStreamOpts?'), hops: valid.async(function (start, graph, opts, cb) { if (typeof opts == 'function') { // (start|opts, graph, cb) cb = opts opts = null } else if (typeof graph == 'function') { // (start|opts, cb) cb = graph opts = graph = null } opts = opts || {} if(isString(start)) { // (start, ...) // first arg is id string opts.start = start } else if (start && typeof start == 'object') { // (opts, ...) // first arg is opts for (var k in start) opts[k] = start[k] } var conf = config.friends || {} opts.start = opts.start || sbot.id opts.dunbar = opts.dunbar || conf.dunbar || 150 opts.hops = opts.hops || conf.hops || 3 var g = graphs[graph || 'follow'] if (!g) return cb(new Error('Invalid graph type: '+graph)) awaitSync(function () { cb(null, g.traverse(opts)) }) }, ['feedId', 'string?', 'object?'], ['createFriendStreamOpts']) } }