Partially implement rename operations on SAF files

* java/org/gnu/emacs/EmacsSafThread.java
(postInvalidateCacheDir):
* java/org/gnu/emacs/EmacsService.java (renameDocument): New
functions.
* src/android.c (android_init_emacs_service):
* src/android.h (struct android_emacs_service): Link to new JNI
function.
* src/androidvfs.c (android_saf_rename_document): New function.
(android_saf_tree_rename): Implement in terms of that function
if possible.

2 files changed, 113 insertions, 2 deletions

diff --git a/java/org/gnu/emacs/EmacsSafThread.java b/java/org/gnu/emacs/EmacsSafThread.java
index b0d014ffe94..007ea9acfbd 100644
--- a/java/org/gnu/emacs/EmacsSafThread.java
+++ b/java/org/gnu/emacs/EmacsSafThread.java
@@ -134,7 +134,7 @@ public final class EmacsSafThread extends HandlerThread
   }
 
 
-  private final class CacheToplevel
+  private static final class CacheToplevel
   {
     /* Map between document names and children.  */
     HashMap<String, DocIdEntry> children;
@@ -232,7 +232,7 @@ public final class EmacsSafThread extends HandlerThread
     }
   };
 
-  private final class CacheEntry
+  private static final class CacheEntry
   {
     /* The type of this document.  */
     String type;
@@ -545,6 +545,80 @@ public final class EmacsSafThread extends HandlerThread
       });
   }
 
+  /* Invalidate the cache entry denoted by DOCUMENT_ID, within the
+     document tree URI.
+     Call this after deleting a document or directory.
+
+     At the same time, remove the child referring to DOCUMENTID from
+     within CACHENAME's cache entry if it exists.  */
+
+  public void
+  postInvalidateCacheDir (final Uri uri, final String documentId,
+                          final String cacheName)
+  {
+    handler.post (new Runnable () {
+        @Override
+        public void
+        run ()
+        {
+          CacheToplevel toplevel;
+          HashMap<String, DocIdEntry> children;
+          String[] components;
+          CacheEntry entry;
+          DocIdEntry idEntry;
+          Iterator<DocIdEntry> iter;
+
+          toplevel = getCache (uri);
+          toplevel.idCache.remove (documentId);
+
+          /* Now remove DOCUMENTID from CACHENAME's cache entry, if
+             any.  */
+
+          children = toplevel.children;
+          components = cacheName.split ("/");
+
+          for (String component : components)
+            {
+              /* Java `split' removes trailing empty matches but not
+                 leading or intermediary ones.  */
+              if (component.isEmpty ())
+                continue;
+
+              /* Search for this component within the last level
+                 of the cache.  */
+
+              idEntry = children.get (component);
+
+              if (idEntry == null)
+                /* Not cached, so return.  */
+                return;
+
+              entry = toplevel.idCache.get (idEntry.documentId);
+
+              if (entry == null)
+                /* Not cached, so return.  */
+                return;
+
+              /* Locate the next component within this
+                 directory.  */
+              children = entry.children;
+            }
+
+          iter = children.values ().iterator ();
+          while (iter.hasNext ())
+            {
+              idEntry = iter.next ();
+
+              if (idEntry.documentId.equals (documentId))
+                {
+                  iter.remove ();
+                  break;
+                }
+            }
+        }
+      });
+  }
+
 
 
   /* ``Prototypes'' for nested functions that are run within the SAF
diff --git a/java/org/gnu/emacs/EmacsService.java b/java/org/gnu/emacs/EmacsService.java
index 5186dec974a..07e585ad37c 100644
--- a/java/org/gnu/emacs/EmacsService.java
+++ b/java/org/gnu/emacs/EmacsService.java
@@ -1698,4 +1698,41 @@ public final class EmacsService extends Service
 
     return -1;
   }
+
+  /* Rename the document designated by DOCID inside the directory tree
+     identified by URI, which should be within the directory
+     designated by DIR, to NAME.  If the file can't be renamed because
+     it doesn't support renaming, return -1, 0 otherwise.  */
+
+  public int
+  renameDocument (String uri, String docId, String dir, String name)
+    throws FileNotFoundException
+  {
+    Uri tree, uriObject;
+
+    tree = Uri.parse (uri);
+    uriObject = DocumentsContract.buildDocumentUriUsingTree (tree, docId);
+
+    try
+      {
+        if (DocumentsContract.renameDocument (resolver, uriObject,
+                                              name)
+            != null)
+          {
+            /* Invalidate the cache.  */
+            if (storageThread != null)
+              storageThread.postInvalidateCacheDir (tree, docId,
+                                                    name);
+            return 0;
+          }
+      }
+    catch (UnsupportedOperationException e)
+      {
+        ;;
+      }
+
+    /* Handle unsupported operation exceptions specially, so
+       `android_rename' can return ENXDEV.  */
+    return -1;
+  }
 };