Search completion; make completion lookup asynchronous.

5 files changed, 77 insertions, 46 deletions

diff --git a/background_scripts/completion.coffee b/background_scripts/completion.coffee
index c8650f45..fee4778a 100644
--- a/background_scripts/completion.coffee
+++ b/background_scripts/completion.coffee
@@ -346,29 +346,31 @@ class SearchEngineCompleter
       suggestions[0].autoSelect = true
       queryTerms = queryTerms[1..]
 
-    # For custom search-engine queries, this adds suggestions only if we have a completer.  For other queries,
-    # this adds suggestions for the default search engine (if we have a completer for that).
-    SearchEngines.complete searchUrl, queryTerms, (searchSuggestions = []) =>
-
-      # Scoring:
-      #   - The score does not depend upon the actual suggestion (so, it does not depend upon word relevancy).
-      #     We assume that the completion engine has already factored that in.
-      #   - The score is higher if the query is longer.  The idea is that search suggestions are more likely
-      #     to be relevant if, after typing quite some number of characters, the user hasn't yet found a
-      #     useful suggestion from another completer.
-      #   - Scores are weighted such that they retain the ordering provided by the completion engine.
-      characterCount = query.length - queryTerms.length + 1
-      score = 0.8 * (Math.min(characterCount, 12.0)/12.0)
-
-      for suggestion in searchSuggestions
-        suggestions.push @mkSuggestion true, queryTerms, type, mkUrl(suggestion), suggestion, @computeRelevancy, score
-        score *= 0.9
-
-      if custom
-        for suggestion in suggestions
-          suggestion.reinsertPrefix = "#{keyword} " if suggestion.insertText
-
-      onComplete suggestions
+    onComplete suggestions, (onComplete) =>
+      suggestions = []
+      # For custom search-engine queries, this adds suggestions only if we have a completer.  For other queries,
+      # this adds suggestions for the default search engine (if we have a completer for that).
+      SearchEngines.complete searchUrl, queryTerms, (searchSuggestions = []) =>
+
+        # Scoring:
+        #   - The score does not depend upon the actual suggestion (so, it does not depend upon word relevancy).
+        #     We assume that the completion engine has already factored that in.
+        #   - The score is higher if the query is longer.  The idea is that search suggestions are more likely
+        #     to be relevant if, after typing quite some number of characters, the user hasn't yet found a
+        #     useful suggestion from another completer.
+        #   - Scores are weighted such that they retain the ordering provided by the completion engine.
+        characterCount = query.length - queryTerms.length + 1
+        score = 0.8 * (Math.min(characterCount, 12.0)/12.0)
+
+        for suggestion in searchSuggestions
+          suggestions.push @mkSuggestion true, queryTerms, type, mkUrl(suggestion), suggestion, @computeRelevancy, score
+          score *= 0.9
+
+        if custom
+          for suggestion in suggestions
+            suggestion.reinsertPrefix = "#{keyword} " if suggestion.insertText
+
+        onComplete suggestions
 
   mkSuggestion: (insertText, args...) ->
     suggestion = new Suggestion args...
@@ -410,9 +412,11 @@ class SearchEngineCompleter
 # A completer which calls filter() on many completers, aggregates the results, ranks them, and returns the top
 # 10. Queries from the vomnibar frontend script come through a multi completer.
 class MultiCompleter
-  constructor: (@completers) -> @maxResults = 10
+  constructor: (@completers) ->
+    @maxResults = 10
 
-  refresh: -> completer.refresh() for completer in @completers when completer.refresh
+  refresh: ->
+    completer.refresh?() for completer in @completers
 
   filter: (queryTerms, onComplete) ->
     # Allow only one query to run at a time.
@@ -424,21 +428,40 @@ class MultiCompleter
     @filterInProgress = true
     suggestions = []
     completersFinished = 0
+    continuation = null
     for completer in @completers
       # Call filter() on every source completer and wait for them all to finish before returning results.
-      completer.filter queryTerms, (newSuggestions) =>
-        suggestions = suggestions.concat(newSuggestions)
-        completersFinished += 1
-        if completersFinished >= @completers.length
-          results = @sortSuggestions(suggestions)[0...@maxResults]
-          result.generateHtml() for result in results
-          onComplete(results)
-          @filterInProgress = false
-          @filter(@mostRecentQuery.queryTerms, @mostRecentQuery.onComplete) if @mostRecentQuery
-
-  sortSuggestions: (suggestions) ->
-    suggestion.computeRelevancy(@queryTerms) for suggestion in suggestions
+      # At most one of the completers (SearchEngineCompleter) may pass a continuation function, which will be
+      # called asynchronously after the results of all of the other completers have been posted.  Any
+      # additional results from this continuation will be added to the existing results and posted.  We don't
+      # call the continuation if another query is already waiting.
+      completer.filter queryTerms, (newSuggestions, cont = null) =>
+        # Allow completers to execute concurrently.
+        Utils.nextTick =>
+          suggestions = suggestions.concat newSuggestions
+          continuation = cont if cont?
+          completersFinished += 1
+          if completersFinished >= @completers.length
+            onComplete @prepareSuggestions(suggestions), keepAlive: continuation?
+            onDone = =>
+              @filterInProgress = false
+              @filter @mostRecentQuery.queryTerms, @mostRecentQuery.onComplete if @mostRecentQuery
+            # We add a very short delay.  It is possible for all of this processing to have been handled
+            # pretty-much synchronously, which would have prevented any newly-arriving queries from
+            # registering.
+            Utils.setTimeout 10, =>
+              if continuation? and not @mostRecentQuery
+                continuation (newSuggestions) =>
+                  onComplete @prepareSuggestions suggestions.concat(newSuggestions)
+                  onDone()
+              else
+                onDone()
+
+  prepareSuggestions: (suggestions) ->
+    suggestion.computeRelevancy @queryTerms for suggestion in suggestions
     suggestions.sort (a, b) -> b.relevancy - a.relevancy
+    suggestions = suggestions[0...@maxResults]
+    suggestion.generateHtml() for suggestion in suggestions
     suggestions
 
 # Utilities which help us compute a relevancy score for a given item.
diff --git a/background_scripts/main.coffee b/background_scripts/main.coffee
index 4d2546fc..45619023 100644
--- a/background_scripts/main.coffee
+++ b/background_scripts/main.coffee
@@ -50,11 +50,13 @@ completionSources =
   searchEngines: new SearchEngineCompleter()
 
 completers =
-  omni: new MultiCompleter([
-    completionSources.searchEngines,
-    completionSources.bookmarks,
-    completionSources.history,
-    completionSources.domains])
+  omni: new MultiCompleter [
+    completionSources.bookmarks
+    completionSources.history
+    completionSources.domains
+    # This comes last, because it delivers additional, asynchronous results.
+    completionSources.searchEngines
+    ]
   bookmarks: new MultiCompleter([completionSources.bookmarks])
   tabs: new MultiCompleter([completionSources.tabs])
 
@@ -220,7 +222,8 @@ refreshCompleter = (request) -> completers[request.name].refresh()
 whitespaceRegexp = /\s+/
 filterCompleter = (args, port) ->
   queryTerms = if (args.query == "") then [] else args.query.split(whitespaceRegexp)
-  completers[args.name].filter(queryTerms, (results) -> port.postMessage({ id: args.id, results: results }))
+  completers[args.name].filter queryTerms, (results, extra = {}) ->
+    port.postMessage extend extra, id: args.id, results: results
 
 chrome.tabs.onSelectionChanged.addListener (tabId, selectionInfo) ->
   if (selectionChangedHandlers.length > 0)
diff --git a/background_scripts/search_engines.coffee b/background_scripts/search_engines.coffee
index a80c218c..abf8c86e 100644
--- a/background_scripts/search_engines.coffee
+++ b/background_scripts/search_engines.coffee
@@ -134,8 +134,7 @@ SearchEngines =
 
     @requests[searchUrl] = xhr = new XMLHttpRequest()
     xhr.open "GET", url, true
-    # We set a fairly short timeout.  If we block for too long, then we block *all* completers.
-    xhr.timeout = 500
+    xhr.timeout = 750
     xhr.ontimeout = => @cancel searchUrl, callback
     xhr.onerror = => @cancel searchUrl, callback
     xhr.send()
diff --git a/lib/utils.coffee b/lib/utils.coffee
index 5d9696e1..07528714 100644
--- a/lib/utils.coffee
+++ b/lib/utils.coffee
@@ -183,6 +183,12 @@ Utils =
       return true if re.test string
     false
 
+  # Convenience wrapper for setTimeout (with the arguments around the other way).
+  setTimeout: (ms, func) -> setTimeout func, ms
+
+  # Like Nodejs's nextTick.
+  nextTick: (func) -> @setTimeout 0, func
+
 
 # This creates a new function out of an existing function, where the new function takes fewer arguments. This
 # allows us to pass around functions instead of functions + a partial list of arguments.
diff --git a/pages/vomnibar.coffee b/pages/vomnibar.coffee
index 2076fea6..3fb63177 100644
--- a/pages/vomnibar.coffee
+++ b/pages/vomnibar.coffee
@@ -239,7 +239,7 @@ class BackgroundCompleter
     id = BackgroundCompleter.messageId += 1
     @filterPort.onMessage.addListener handler = (msg) =>
       if msg.id == id
-        @filterPort.onMessage.removeListener handler
+        @filterPort.onMessage.removeListener handler unless msg.keepAlive and id == BackgroundCompleter.messageId
         if id == BackgroundCompleter.messageId
           # The result objects coming from the background page will be of the form:
           #   { html: "", type: "", url: "" }