From d1005aa61ade346309d916283539a05b9ace2b90 Mon Sep 17 00:00:00 2001
From: Klaus Wuestefeld <klauswuestefeld@gmail.com>
Date: Tue, 21 May 2024 16:03:49 -0300
Subject: [PATCH] WIP

---
 src/prevayler_clj_aws/core.clj       | 73 +++++++++++++++-------------
 test/prevayler_clj_aws/core_test.clj |  4 +-
 2 files changed, 42 insertions(+), 35 deletions(-)

diff --git a/src/prevayler_clj_aws/core.clj b/src/prevayler_clj_aws/core.clj
index 256ae95..cf2dc34 100644
--- a/src/prevayler_clj_aws/core.clj
+++ b/src/prevayler_clj_aws/core.clj
@@ -110,41 +110,48 @@
                 snapshot-path   "snapshot"
                 page-size       1000}} aws-opts
         _ (println "Reading snapshot bucket...")
-        {state :state previous-snapshot-index :partkey} (read-snapshot s3-client s3-bucket snapshot-path)
+        {state :state snapshot-index :partkey} (read-snapshot s3-client s3-bucket snapshot-path)
         _ (println "Reading snapshot bucket done.")
         state-atom (atom (or state initial-state))
-        snapshot-index-atom (atom (inc previous-snapshot-index))
-        order-atom (atom 0)]
-
+        snapshot-index-atom (atom snapshot-index)]
+    
     (println "Restoring events...")
-    (restore-events! dynamodb-client business-fn state-atom dynamodb-table previous-snapshot-index page-size)
+    (restore-events! dynamodb-client business-fn state-atom dynamodb-table @snapshot-index-atom page-size)
     (println "Restoring events done.")
 
-    ; 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-bucket snapshot-path {:state @state-atom :partkey @snapshot-index-atom})
-    (println "Saving snapshot done.")
-
-    (reify
-      Prevayler
-      (handle! [this event]
-        (locking this ; (I)solation: strict serializability.
-          (let [current-state @state-atom
-                timestamp (timestamp-fn)
-                new-state (business-fn current-state event timestamp)] ; (C)onsistency: must be guaranteed by the handler. The event won't be journalled when the handler throws an exception.)
-            (when-not (identical? new-state current-state)
-              (write-event! dynamodb-client dynamodb-table @snapshot-index-atom
-                            (swap! order-atom inc) ; Skips an order number if there is an exception, but that's OK.
-                            [timestamp event (hash new-state)]) ; (D)urability
-              (reset! state-atom new-state)) ; (A)tomicity
-            new-state)))
-
-      #_(snapshot! [this]
-        (locking this
-          (start-new-journal! journal-file data-out-atom @state-atom backup)))
-
-      (timestamp [_] (timestamp-fn))
-
-      IDeref (deref [_] @state-atom)
-
-      Closeable (close [_] (aws/stop dynamodb-client)))))
+    (let [order-atom (atom 0)
+          snapshot-fn! (fn []
+                         (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-bucket snapshot-path {:state @state-atom
+                                                                            :partkey (inc @snapshot-index-atom)})
+                         (println "Snapshot done.")
+                         (swap! snapshot-index-atom inc)
+                         (reset! order-atom 0))]
+      
+      (snapshot-fn!)
+
+      (reify
+        Prevayler
+        (handle! [this event]
+          (locking this ; (I)solation: strict serializability.
+            (let [current-state @state-atom
+                  timestamp (timestamp-fn)
+                  new-state (business-fn current-state event timestamp)] ; (C)onsistency: must be guaranteed by the handler. The event won't be journalled when the handler throws an exception.)
+              (when-not (identical? new-state current-state)
+                (write-event! dynamodb-client dynamodb-table @snapshot-index-atom
+                              (swap! order-atom inc) ; Skips an order number if there is an exception, but that's OK.
+                              [timestamp event (hash new-state)]) ; (D)urability
+                (reset! state-atom new-state)) ; (A)tomicity
+              new-state)))
+
+        (snapshot! [this]
+          (locking this
+            (snapshot-fn!)))
+
+        (timestamp [_] (timestamp-fn))
+
+        IDeref (deref [_] @state-atom)
+
+        Closeable (close [_] (aws/stop dynamodb-client))))))
diff --git a/test/prevayler_clj_aws/core_test.clj b/test/prevayler_clj_aws/core_test.clj
index cf8346d..20ed38d 100644
--- a/test/prevayler_clj_aws/core_test.clj
+++ b/test/prevayler_clj_aws/core_test.clj
@@ -27,8 +27,8 @@
         dynamodb-table (gen-name)
         hostname (or (System/getenv "LOCALSTACK_HOST") "localhost")
         endpoint-override {:protocol "http" :hostname hostname :port (localstack-port)}
-        s3-cli       (aws/client {:api :s3       :endpoint-override endpoint-override #_#_:region "us-east-1"})
-        dynamodb-cli (aws/client {:api :dynamodb :endpoint-override endpoint-override #_#_:region "us-east-1"})]
+        s3-cli       (aws/client {:api :s3       :endpoint-override endpoint-override})
+        dynamodb-cli (aws/client {:api :dynamodb :endpoint-override endpoint-override})]
     (util/aws-invoke s3-cli {:op :CreateBucket :request {:Bucket s3-bucket}})
     (util/aws-invoke dynamodb-cli {:op :CreateTable :request {:TableName dynamodb-table
                                                               :AttributeDefinitions [{:AttributeName "partkey"