rethinkql -- basic change feed support working in the browser :-)

salvus/client.coffee

@@ -471,7 +471,8 @@ class exports.Connection extends EventEmitter
                 cb(mesg.error)
             else
                 cb(undefined, mesg)
-            delete @call_callbacks[id]
+            if not mesg.multi_response
+                delete @call_callbacks[id]
 
         # Finally, give other listeners a chance to do something with this message.
         @emit('message', mesg)
@@ -2417,14 +2418,20 @@ class exports.Connection extends EventEmitter
     # Queries directly to the database (sort of like Facebook's GraphQL)
     query: (opts) =>
         opts = defaults opts,
-            query : required
+            query   : required
+            changes : undefined
             options : undefined
-            cb    : required
-        @call
-            message     : message.query(query:opts.query, options:opts.options)
-            error_event : true
+            cb      : required
+        mesg = message.query
+            query          : opts.query
+            options        : opts.options
+            changes        : opts.changes
+            multi_response : opts.changes
+        @call
+            message        : mesg
+            error_event    : true
             cb          : (err, resp) =>
-                opts.cb(err, if not err then resp.query)
+                opts.cb(err, if not err then resp)
 
 
 #################################################

salvus/hub.coffee

@@ -3426,18 +3426,23 @@ class Client extends EventEmitter
             return
         dbg = @dbg("user_query")
         dbg("account_id=#{@account_id} makes query='#{misc.to_json(query)}'")
-        options = mesg.options
-        if not options? or options.length == 0
-            options = [{limit: 100}]
+        first = true
         database.user_query
             account_id : @account_id
             query      : query
-            options    : options
+            options    : mesg.options
+            changes    : if mesg.changes then mesg.id
             cb         : (err, result) =>
                 if err
                     @error_to_client(id:mesg.id, error:err)
                 else
-                    mesg.query = result
+                    if mesg.changes and not first
+                        delete mesg.query
+                        for k, v of result
+                            mesg[k] = v
+                    else
+                        first = false
+                        mesg.query = result
                     @push_to_client(mesg)
 
 

salvus/message.coffee

@@ -1779,9 +1779,11 @@ message
 #############
 
 message
-    event : 'query'
-    id    : undefined
-    query : required
+    event   : 'query'
+    id      : undefined
+    query   : required
+    changes : undefined
+    multi_response : false
     options : undefined
 
 

salvus/rethink.coffee

@@ -1724,7 +1724,8 @@ class RethinkDB
         opts = defaults opts,
             account_id : required
             query      : required
-            options    : {}
+            options    : []
+            changes    : undefined
             cb         : required   # cb(err, result)
         if misc.is_array(opts.query)
             # array of queries
@@ -1742,6 +1743,9 @@ class RethinkDB
         subs =
             '{account_id}' : opts.account_id
 
+        if opts.changes
+            changes = opts.cb
+
         # individual query
         result = {}
         f = (table, cb) =>
@@ -1764,6 +1768,7 @@ class RethinkDB
                         query      : query
                         options    : opts.options
                         multi      : multi
+                        changes    : changes
                         cb         : (err, x) =>
                             result[table] = x; cb(err)
                 else
@@ -2096,6 +2101,7 @@ class RethinkDB
             query      : required
             multi      : required
             options    : required
+            changes    : undefined  # if given, should be a function to call with additional changes
             cb         : required   # cb(err, result)
         ###
         # User queries are of the form
@@ -2105,6 +2111,9 @@ class RethinkDB
         Using the whitelist rules specified in SCHEMA, we
         determine each of get_all, filter, pluck, and options,
         then run the query.
+
+        If no error in query, and changes is a given uuid, then sets up a change
+        feed that calls opts.cb on changes as well.
         ###
 
         # get data about user queries on this table
@@ -2162,7 +2171,17 @@ class RethinkDB
                 else if limit and x.length == limit
                     x.push('...')
                 opts.cb(undefined, x)
-
+                if opts.changes?
+                    # no errors -- setup changefeed now
+                    winston.debug("FEED -- setting up a feed")
+                    db_query.changes().run (err, feed) =>
+                        if err
+                            winston.debug("FEED -- error setting up #{misc.to_json(err)}")
+                            opts.cb(err)
+                        else
+                            feed.each (err, x) =>
+                                winston.debug("FEED -- saw a change! #{misc.to_json([err,x])}")
+                                opts.changes(err, x)
 
 
 has_null_leaf = (obj) ->