Really optimise activation speed

index.js

@@ -107,6 +107,13 @@ module.exports = {
       },
 
       fetchRevisions: function(context) {
+        if (this.readConfig('disableFetchRevisions')) {
+          this.log('fetchRevisions - not fetching any revisions', { verbose: true });
+          return {
+            activations: []
+          };
+        }
+
         return this._list(context)
           .then(function(revisions) {
             return {
@@ -116,6 +123,12 @@ module.exports = {
       },
 
       fetchInitialRevisions: function(context) {
+
+        if (this.readConfig('fetchOnlyRelevantRevisions')) {
+          this.log('fetchInitialRevisions - fetching only enough revisions to find the active revision', { verbose: true });
+          return this._fetchActiveRevision();
+        }
+
         return this._list(context)
           .then(function(revisions) {
             return {
@@ -124,6 +137,24 @@ module.exports = {
           });
       },
 
+      _fetchActiveRevision: function() {
+        var bucket      = this.readConfig('bucket');
+        var prefix      = this.readConfig('prefix');
+        var filePattern = this.readConfig('filePattern');
+
+        var options = {
+          bucket: bucket,
+          prefix: prefix,
+          filePattern: filePattern,
+        };
+
+        var s3 = new this.S3({ plugin: this });
+        return s3.getActiveRevision(options)
+          .then((activeRevision) => {
+            return { initialRevisions: [activeRevision] };
+          });
+      },
+
       _list: function(/* context */) {
         var bucket      = this.readConfig('bucket');
         var prefix      = this.readConfig('prefix');

lib/s3.js

@@ -152,6 +152,36 @@ module.exports = CoreObject.extend({
       .then((response) => response.Contents.find((element) => element.Key === revisionPrefix));
   },
 
+  getActiveRevision(options) {
+    var client         = this._client;
+    var bucket         = options.bucket;
+    var prefix         = options.prefix;
+    var revisionPrefix = joinUriSegments(prefix, options.filePattern + ":");
+    var indexKey       = joinUriSegments(prefix, options.filePattern);
+
+    return headObject(client, { Bucket: bucket, Key: indexKey })
+      .then((current) => {
+        if (current === undefined) {
+          return;
+        }
+
+        return this.listAllObjects(
+          { Bucket: bucket, Prefix: revisionPrefix }, 
+          (element) => element.ETag === current.ETag
+        )
+        .then((elements) => {
+          let activeRevision = elements.find((element) => element.ETag === current.ETag);
+          if (!activeRevision) {
+            return;
+          }
+
+          var revision = activeRevision.Key.substr(revisionPrefix.length);
+          return { active: true, revision, timestamp: activeRevision.LastModified };
+        })
+      });
+
+  },
+
   fetchRevisions: function(options) {
     var client         = this._client;
     var bucket         = options.bucket;
@@ -174,7 +204,7 @@ module.exports = CoreObject.extend({
     });
   },
 
-  listAllObjects: function(options) {
+  listAllObjects: function(options, until) {
     var client         = this._client;
     var listObjects    = RSVP.denodeify(client.listObjects.bind(client));
     var allRevisions   = [];
@@ -183,13 +213,14 @@ module.exports = CoreObject.extend({
       return listObjects(options).then(function(response) {
         [].push.apply(allRevisions, response.Contents);
 
-        if (response.IsTruncated) {
-          var nextMarker = response.Contents[response.Contents.length - 1].Key;
-          options.Marker = nextMarker;
-          return listObjectRecursively(options);
-        } else {
+        var isComplete = !response.IsTruncated || (until && response.Contents.some(until));
+
+        if (isComplete) {
           return allRevisions;
         }
+        var nextMarker = response.Contents[response.Contents.length - 1].Key;
+        options.Marker = nextMarker;
+        return listObjectRecursively(options);
       });
     }