ACS-1582 : Storage classes - java api (#467)

* ACS-1582 : Storage classes - java api
   - added ContentContext updates
   - added StorageClasses related exception

data-model/src/main/java/org/alfresco/repo/content/ContentContext.java

@@ -26,6 +26,7 @@
 package org.alfresco.repo.content;
 
 import java.io.Serializable;
+import java.util.Set;
 
 import org.alfresco.service.cmr.repository.ContentReader;
 
@@ -49,6 +50,7 @@ public class ContentContext implements Serializable
 
     private ContentReader existingContentReader;
     private String contentUrl;
+    private Set<String> storageClasses;
     
     /**
      * Construct the instance with the content URL.
@@ -88,5 +90,22 @@ public class ContentContext implements Serializable
     {
         return contentUrl;
     }
-    
+
+    /**
+     * @return Returns the storage classes for the content- may be <tt>null</tt>
+     */
+    public Set<String> getStorageClasses()
+    {
+        return storageClasses;
+    }
+
+    /**
+     * Sets the storage classes for the content- may be <tt>null</tt>
+     *
+     * @param storageClasses
+     */
+    public void setStorageClasses(Set<String> storageClasses)
+    {
+        this.storageClasses = storageClasses;
+    }
 }

data-model/src/main/java/org/alfresco/repo/content/ContentStore.java

@@ -25,6 +25,11 @@
  */
 package org.alfresco.repo.content;
 
+import java.util.Collections;
+import java.util.Date;
+import java.util.Map;
+import java.util.Set;
+
 import org.alfresco.api.AlfrescoPublicApi;
 import org.alfresco.service.cmr.repository.ContentAccessor;
 import org.alfresco.service.cmr.repository.ContentIOException;
@@ -33,8 +38,6 @@ import org.alfresco.service.cmr.repository.ContentStreamListener;
 import org.alfresco.service.cmr.repository.ContentWriter;
 import org.alfresco.service.cmr.repository.DirectAccessUrl;
 
-import java.util.Date;
-
 /**
  * Provides low-level retrieval of content
  * {@link org.alfresco.service.cmr.repository.ContentReader readers} and
@@ -88,6 +91,16 @@ public interface ContentStore
      * The delimiter that must be found in all URLS, i.e <b>://</b>
      */
     public static final String PROTOCOL_DELIMITER = "://";
+
+    /**
+     * The 'default' storage class
+     *
+     * A content is considered to have a default storage class if:
+     * the value is a Set.of("default")
+     * the value is an empty set
+     * the value is null
+     */
+    public static final String DEFAULT_SC = "default";
     
     /**
      * Check if the content URL format is supported by the store.
@@ -263,4 +276,64 @@ public interface ContentStore
     {
         return false;
     }
+
+    /**
+     * Checks whether or not the current {@link ContentStore} supports the provided {@link Set} storage classes
+     *
+     * @param storageClasses The storage classes that will be checked whether or not are supported
+     * @return true if the storage classes are supported, false otherwise.
+     */
+    default boolean isStorageClassesSupported(Set<String> storageClasses)
+    {
+        return storageClasses == null ||
+            storageClasses.isEmpty() ||
+            (1 == storageClasses.size() && storageClasses.contains(DEFAULT_SC));
+    }
+
+    /**
+     * @return Returns the complete {@link Set} of supported storage classes by this {@link ContentStore}
+     */
+    default Set<String> getSupportedStorageClasses()
+    {
+        return Set.of(DEFAULT_SC);
+    }
+
+    /**
+     * Updates the storage class for content
+     *
+     * @param contentUrl The URL of the content that will have its storage classes updated
+     * @param storageClasses The new storage classes
+     * @param parameters extra parameters
+     */
+    default void updateStorageClasses(String contentUrl, Set<String> storageClasses, Map<String, Object> parameters)
+    {
+
+    }
+
+    /**
+     * @param contentUrl the URL of the content for which the storage classes are to be requested
+     * @return Returns the current storage classes for the content found at the contentUrl
+     */
+    default Set<String> findStorageClasses(String contentUrl)
+    {
+        return Collections.emptySet();
+    }
+
+    /**
+     * @return Returns the complete collection of allowed storage classes transitions.
+     * The key represents the source storage classes while the value (as a {@link Set}) represents all the possible target storage classes.
+     */
+    default Map<Set<String>, Set<Set<String>>> getStorageClassesTransitions()
+    {
+        return Collections.emptyMap();
+    }
+
+    /**
+     * @param contentUrl the URL of the content for which the storage classes transitions are to be requested
+     * @return Returns the complete collection of allowed storage classes transitions for the content found at content URL
+     */
+    default Map<Set<String>, Set<Set<String>>> findStorageClassesTransitions(String contentUrl)
+    {
+        return Collections.emptyMap();
+    }
 }

data-model/src/main/java/org/alfresco/repo/content/UnsupportedStorageClassException.java

@@ -0,0 +1,58 @@
+/*
+ * #%L
+ * Alfresco Data model classes
+ * %%
+ * Copyright (C) 2005 - 2021 Alfresco Software Limited
+ * %%
+ * This file is part of the Alfresco software.
+ * If the software was purchased under a paid Alfresco license, the terms of
+ * the paid license agreement will prevail.  Otherwise, the software is
+ * provided under the following open source license terms:
+ *
+ * Alfresco is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Alfresco is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
+ * #L%
+ */
+package org.alfresco.repo.content;
+
+import java.util.Set;
+
+import org.alfresco.error.AlfrescoRuntimeException;
+
+/**
+ * Thrown when an operation regarding the storage classes of the content failed to execute.
+ *
+ * @author Lucian Tuca
+ */
+public class UnsupportedStorageClassException extends AlfrescoRuntimeException
+{
+    private final ContentStore contentStore;
+    private final Set<String> storageClasses;
+
+    public UnsupportedStorageClassException(ContentStore contentStore, Set<String> storageClasses, String msg)
+    {
+        super(msg);
+        this.contentStore = contentStore;
+        this.storageClasses = storageClasses;
+    }
+
+    public ContentStore getContentStore()
+    {
+        return contentStore;
+    }
+
+    public Set<String> getStorageClasses()
+    {
+        return storageClasses;
+    }
+}