Merge pull request #11 from nubank/snapshot-streams2

Snapshot streams2

Author: NodariAtNubank

src/prevayler_clj_aws/core.clj

@@ -46,24 +46,12 @@
       unmarshal-fn))
 
 (defn- read-snapshot [s3-cli s3-sdk-cli bucket snapshot-path]
-  (if (snapshot-exists? s3-cli bucket snapshot-path)
-    (let [v2-path (snapshot-v2-path snapshot-path)
-          snap1 (read-object s3-sdk-cli bucket snapshot-path unmarshal)]
-      (try
-        (if (snapshot-exists? s3-cli bucket v2-path)
-          (let [snap2 (read-object s3-sdk-cli bucket v2-path unmarshal-from-in)]
-            (println "Snapshot v1" (if (= snap1 snap2) "IS" "IS NOT") "equal to v2"))
-          (println v2-path "object not found in bucket."))
-        (catch Exception e
-          (.printStackTrace e)))
-      snap1)
-    {:partkey 0}))
-
-(defn- save-snapshot! [s3-cli s3-sdk-cli bucket snapshot-path snapshot]
-  (util/aws-invoke s3-cli {:op      :PutObject
-                           :request {:Bucket bucket
-                                     :Key    snapshot-path
-                                     :Body   (marshal snapshot)}})
+  (let [v2-path (snapshot-v2-path snapshot-path)]
+    (if (snapshot-exists? s3-cli bucket v2-path)
+      (read-object s3-sdk-cli bucket v2-path unmarshal-from-in)
+      {:partkey 0})))
+
+(defn- save-snapshot! [s3-sdk-cli bucket snapshot-path snapshot]
   (try
     (let [v2-path (snapshot-v2-path snapshot-path)
           temp-file (java.io.File/createTempFile "snapshot" "")] ; We use an intermediary file to easily determine the length of the stream. Otherwise, to determine its length, Amazon's SDK would buffer the entire stream in RAM, defeating our purpose.
@@ -160,7 +148,7 @@
                          (println "Saving snapshot to bucket...")
                          ; Since s3 update is atomic, if saving snapshot fails next prevayler will pick the previous state
                          ; and restore events from the previous partkey
-                         (save-snapshot! s3-client s3-sdk-cli s3-bucket snapshot-path {:state @state-atom
+                         (save-snapshot! s3-sdk-cli s3-bucket snapshot-path {:state @state-atom
                                                                             :partkey (inc @snapshot-index-atom)})
                          (println "Snapshot done.")
                          (swap! snapshot-index-atom inc)

test/prevayler_clj_aws/core_test.clj

@@ -80,12 +80,12 @@
   (testing "snapshot-v2 is the default snapshot file name"
     (let [{{:keys [s3-client s3-bucket]} :aws-opts :as opts} (gen-opts)
           _ (prev! opts)]
-      (is (match? [{:Key "snapshot"} {:Key "snapshot-v2"}] (list-objects s3-client s3-bucket)))))
+      (is (match? [{:Key "snapshot-v2"}] (list-objects s3-client s3-bucket)))))
 
   (testing "can override snapshot file name"
     (let [{{:keys [s3-client s3-bucket]} :aws-opts :as opts} (gen-opts :aws-opts {:snapshot-path "my-path"})
           _ (prev! opts)]
-      (is (match? [{:Key "my-path"} {:Key "my-path-v2"}] (list-objects s3-client s3-bucket)))))
+      (is (match? [{:Key "my-path-v2"}] (list-objects s3-client s3-bucket)))))
 
   (testing "default initial state is empty map"
     (let [prevayler (prev! (gen-opts))]
@@ -154,15 +154,4 @@
       (prevayler/snapshot! prev1)
       (prevayler/snapshot! prev1)
       (let [prev2 (prev! (assoc opts :business-fn (constantly "rubbish")))]
-        (is (= ["A" "B" "C" "D"] @prev2)))))
-
-  (testing "it generates snapshot v2"
-    (let [{{:keys [s3-client s3-sdk-cli s3-bucket]} :aws-opts :as opts} (gen-opts)
-          _ (util/aws-invoke s3-client {:op :PutObject
-                                        :request {:Bucket s3-bucket
-                                                  :Key "snapshot"
-                                                  :Body (#'core/marshal {:partkey 0
-                                                                         :state :state})}})
-          prev (prev! opts)] ;; saves snapshot-v2
-      (is (= :state @prev))
-      (is (= {:state :state :partkey 1} (#'core/read-object s3-sdk-cli s3-bucket "snapshot-v2" #'core/unmarshal-from-in))))))
+        (is (= ["A" "B" "C" "D"] @prev2))))))