Merge branch 'sh_develop' into bump_finagle_save_txns

.travis.yml

@@ -1,7 +1,6 @@
 language: scala
 scala:
   - 2.10.4
-  - 2.9.3
 before_script:
   - mysql -u root -e "create database storehaus_test;"
   - mysql -u root -e "create user 'storehaususer'@'localhost' identified by 'test1234';"

project/Build.scala

@@ -57,9 +57,9 @@ object StorehausBuild extends Build {
 
   val sharedSettings = extraSettings ++ ciSettings ++ Seq(
     organization := "com.twitter",
-    scalaVersion := "2.9.3",
+    scalaVersion := "2.10.4",
     version := "0.9.1",
-    crossScalaVersions := Seq("2.9.3", "2.10.4"),
+    crossScalaVersions := Seq("2.10.4"),
     javacOptions ++= Seq("-source", "1.6", "-target", "1.6"),
     javacOptions in doc := Seq("-source", "1.6"),
     libraryDependencies <+= scalaVersion(specs2Import(_)),
@@ -117,14 +117,14 @@ object StorehausBuild extends Build {
   def youngestForwardCompatible(subProj: String) =
     Some(subProj)
       .filterNot(unreleasedModules.contains(_))
-      .map { s => "com.twitter" % ("storehaus-" + s + "_2.9.3") % "0.9.0" }
+      .map { s => "com.twitter" % ("storehaus-" + s + "_2.10") % "0.10.0" }
 
   val algebirdVersion = "0.7.0"
   val bijectionVersion = "0.6.3"
   val utilVersion = "6.22.0"
   val scaldingVersion = "0.11.1"
-
   lazy val storehaus = Project(
+
     id = "storehaus",
     base = file("."),
     settings = sharedSettings ++ DocGen.publishSettings

storehaus-core/src/main/scala/com/twitter/storehaus/ReadThroughStore.scala

@@ -72,12 +72,17 @@ class ReadThroughStore[K, V](backingStore: ReadableStore[K, V], cache: Store[K,
         val hits = responses.filter { !_._2.isEmpty }
         val missedKeys = responses.filter { _._2.isEmpty }.keySet
 
-        FutureOps.mapCollect(backingStore.multiGet(missedKeys ++ failedKeys)).flatMap { storeResult =>
-          // write fetched keys to cache, best effort
-          mutex.acquire.flatMap { p =>
-            FutureOps.mapCollect(cache.multiPut(storeResult))(FutureCollector.bestEffort[(K1, Unit)])
-              .map { u => hits ++ storeResult }
-              .ensure { p.release }
+        val remaining = missedKeys ++ failedKeys
+        if (remaining.isEmpty) {
+          Future.value(hits) // no cache misses
+        } else {
+          FutureOps.mapCollect(backingStore.multiGet(remaining)).flatMap { storeResult =>
+            // write fetched keys to cache, best effort
+            mutex.acquire.flatMap { p =>
+              FutureOps.mapCollect(cache.multiPut(storeResult))(FutureCollector.bestEffort[(K1, Unit)])
+                .map { u => hits ++ storeResult }
+                .ensure { p.release }
+            }
           }
         }
       }