Implemented new Directory::IsEmpty() method.

Amiga-FFS Directory::Lookup() now only creates a HashIterator if needed.


git-svn-id: file:///srv/svn/repos/haiku/trunk/current@4887 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/kernel/boot/loader/file_systems/amiga_ffs/Directory.cpp

@@ -80,15 +80,15 @@ Directory::Close(void *cookie)
 Node *
 Directory::Lookup(const char *name, bool traverseLinks)
 {
-	HashIterator iterator(fVolume.Device(), fNode);
-	if (iterator.InitCheck() != B_OK)
-		return NULL;
-
 	if (!strcmp(name, ".")) {
 		Acquire();
 		return this;
 	}
 
+	HashIterator iterator(fVolume.Device(), fNode);
+	if (iterator.InitCheck() != B_OK)
+		return NULL;
+
 	iterator.Goto(fNode.HashIndexFor(fVolume.Type(), name));
 
 	NodeBlock *node;
@@ -140,6 +140,14 @@ Directory::Rewind(void *cookie)
 }
 
 
+bool 
+Directory::IsEmpty()
+{
+	int32 index;
+	return fNode.FirstHashValue(index) == -1;
+}
+
+
 status_t 
 Directory::GetName(char *name, size_t size) const
 {

src/kernel/boot/loader/file_systems/amiga_ffs/Directory.h

@@ -32,6 +32,7 @@ class Directory : public ::Directory {
 		virtual status_t GetNextEntry(void *cookie, char *nameBuffer, size_t bufferSize);
 		virtual status_t GetNextNode(void *cookie, Node **_node);
 		virtual status_t Rewind(void *cookie);
+		virtual bool IsEmpty();
 
 		virtual status_t GetName(char *name, size_t size) const;
 

src/kernel/boot/loader/file_systems/bfs/Directory.cpp

@@ -128,6 +128,30 @@ Directory::Rewind(void *cookie)
 }
 
 
+bool 
+Directory::IsEmpty()
+{
+	TreeIterator iterator(&fTree);
+
+	// index and attribute directories are really empty when they are
+	// empty - directories for standard files always contain ".", and
+	// "..", so we need to ignore those two
+
+	uint32 count = 0;
+	char name[BPLUSTREE_MAX_KEY_LENGTH];
+	uint16 length;
+	off_t id;
+	while (iterator.GetNextEntry(name, &length, B_FILE_NAME_LENGTH, &id) == B_OK) {
+		if (fStream.Mode() & (S_ATTR_DIR | S_INDEX_DIR))
+			return false;
+
+		if (++count > 2 || strcmp(".", name) && strcmp("..", name))
+			return false;
+	}
+	return true;
+}
+
+
 status_t 
 Directory::GetName(char *name, size_t size) const
 {

src/kernel/boot/loader/file_systems/bfs/Directory.h

@@ -32,6 +32,7 @@ class Directory : public ::Directory {
 		virtual status_t GetNextEntry(void *cookie, char *nameBuffer, size_t bufferSize);
 		virtual status_t GetNextNode(void *cookie, Node **_node);
 		virtual status_t Rewind(void *cookie);
+		virtual bool IsEmpty();
 
 		virtual status_t GetName(char *name, size_t size) const;