Store previous snapshots in encrypted

Author: abuabraham-ttd

src/main/java/com/uid2/admin/store/writer/EncryptedSaltStoreWriter.java

@@ -18,14 +18,18 @@
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.ArrayList;
 import java.util.Base64;
 import java.util.Collection;
+import java.util.List;
 
 public class EncryptedSaltStoreWriter extends SaltStoreWriter implements StoreWriter {
     private StoreScope scope;
     private RotatingCloudEncryptionKeyProvider cloudEncryptionKeyProvider;
     private Integer siteId;
 
+    private final List<RotatingSaltProvider.SaltSnapshot> previousSeenSnapshots = new ArrayList<>();
+
     private static final Logger LOGGER = LoggerFactory.getLogger(EncryptedSaltStoreWriter.class);
     public EncryptedSaltStoreWriter(JsonObject config, RotatingSaltProvider provider, FileManager fileManager,
                                     TaggableCloudStorage cloudStorage, VersionGenerator versionGenerator, StoreScope scope,
@@ -91,6 +95,16 @@ protected void refreshProvider() {
        // we do not need to refresh the provider on encrypted writers
     }
 
+    @Override
+    protected List<RotatingSaltProvider.SaltSnapshot> getSnapshots(RotatingSaltProvider.SaltSnapshot data){
+    /*
+    Since metadata.json is overwritten during the process, we maintain a history of all snapshots seen so far.
+    On the final write, we append this history to metadata.json to ensure no snapshots are lost.
+    */
+        this.previousSeenSnapshots.add(data);
+        return this.previousSeenSnapshots;
+    }
+
     @Override
     public void upload(Object data, JsonObject extraMeta) throws Exception {
         for(RotatingSaltProvider.SaltSnapshot saltSnapshot: (Collection<RotatingSaltProvider.SaltSnapshot>) data) {

src/main/java/com/uid2/admin/store/writer/SaltStoreWriter.java

@@ -43,6 +43,12 @@ public SaltStoreWriter(JsonObject config, RotatingSaltProvider provider, FileMan
         this.versionGenerator = versionGenerator;
     }
 
+    protected List<RotatingSaltProvider.SaltSnapshot> getSnapshots(RotatingSaltProvider.SaltSnapshot data){
+        return Stream.concat(provider.getSnapshots().stream(), Stream.of(data))
+                .sorted(Comparator.comparing(RotatingSaltProvider.SaltSnapshot::getEffective))
+                .collect(Collectors.toList());
+     }
+
     public void upload(RotatingSaltProvider.SaltSnapshot data) throws Exception {
         final Instant now = Instant.now();
         final long generated = now.getEpochSecond();
@@ -65,15 +71,8 @@ public void upload(RotatingSaltProvider.SaltSnapshot data) throws Exception {
         metadata.put("salts", snapshotsMetadata);
 
         List<RotatingSaltProvider.SaltSnapshot> currentSnapshots = provider.getSnapshots();
-        List<RotatingSaltProvider.SaltSnapshot> snapshots = null;
-
-        if (currentSnapshots != null) {
-            snapshots = Stream.concat(currentSnapshots.stream(), Stream.of(data))
-                    .sorted(Comparator.comparing(RotatingSaltProvider.SaltSnapshot::getEffective))
-                    .collect(Collectors.toList());
-        } else {
-            snapshots = List.of(data);
-        }
+        List<RotatingSaltProvider.SaltSnapshot> snapshots = this.getSnapshots(data);
+
         // of the currently effective snapshots keep only the most recent one
         RotatingSaltProvider.SaltSnapshot newestEffectiveSnapshot = snapshots.stream()
                 .filter(snapshot -> snapshot.isEffective(now))