Add LegacyReadonlyPhysicalStore as default to handle indy legacy storage

.gitignore

@@ -14,6 +14,7 @@ log/
 # idea
 .idea
 *.iml
+.vscode
 
 # Mobile Tools for Java (J2ME)
 .mtj.tmp/

src/main/java/org/commonjava/service/storage/core/FileManagerProducer.java

@@ -72,7 +72,7 @@ public PathMappedFileManager getFileManager()
         }
         else
         {
-            physicalStore = new FileBasedPhysicalStore( storageConfig.baseDir() );
+            physicalStore = new LegacyReadonlyPhysicalStore( storageConfig.baseDir() );
         }
 
         return new PathMappedFileManager( config, pathDB, physicalStore );

src/main/java/org/commonjava/service/storage/core/LegacyReadonlyPhysicalStore.java

@@ -0,0 +1,63 @@
+/**
+ * Copyright (C) 2021 Red Hat, Inc. (https://github.com/Commonjava/service-parent)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *         http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.commonjava.service.storage.core;
+
+import org.commonjava.storage.pathmapped.core.FileBasedPhysicalStore;
+import org.commonjava.storage.pathmapped.spi.FileInfo;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.File;
+
+/**
+ * Treat legacy package folders (generic-http, maven, npm) as read-only.
+ * Reads are allowed, while writes target the newer hashed layout.
+ * Operations that would delete legacy paths are skipped.
+ */
+public class LegacyReadonlyPhysicalStore extends FileBasedPhysicalStore
+{
+    public static final String PKG_TYPE_MAVEN = "maven";
+
+    public static final String PKG_TYPE_NPM = "npm";
+
+    public static final String PKG_TYPE_GENERIC_HTTP = "generic-http";
+
+    private final Logger logger = LoggerFactory.getLogger( getClass() );
+
+    public LegacyReadonlyPhysicalStore( File baseDir )
+    {
+        super( baseDir );
+    }
+
+    @Override
+    public boolean delete( FileInfo fileInfo )
+    {
+        String fileStorage = fileInfo.getFileStorage();
+        if ( isLegacyFile( fileStorage ) )
+        {
+            logger.debug( "Skip read-only legacy file: {}", fileStorage );
+            return true;
+        }
+        return super.delete( fileInfo );
+    }
+
+    //Legacy folders: generic-http, maven, npm
+    private boolean isLegacyFile( String fileStorage )
+    {
+        return fileStorage != null && ( fileStorage.startsWith( PKG_TYPE_MAVEN ) || fileStorage.startsWith(
+                        PKG_TYPE_GENERIC_HTTP ) || fileStorage.startsWith( PKG_TYPE_NPM ) );
+    }
+}