From 2986d46fd3950f59ed42551ca9507b447b67ec3e Mon Sep 17 00:00:00 2001
From: Norman Feske <norman.feske@genode-labs.com>
Date: Fri, 27 Jan 2023 17:33:41 +0100
Subject: [PATCH] fs_tool: add <copy-all-files> operation

Related to issue #4744
---
 repos/gems/src/app/fs_tool/main.cc | 75 ++++++++++++++++++++++++++++--
 1 file changed, 71 insertions(+), 4 deletions(-)

diff --git a/repos/gems/src/app/fs_tool/main.cc b/repos/gems/src/app/fs_tool/main.cc
index 83e566a620..4e82304651 100644
--- a/repos/gems/src/app/fs_tool/main.cc
+++ b/repos/gems/src/app/fs_tool/main.cc
@@ -21,10 +21,22 @@
 
 namespace Fs_tool {
 	using namespace Genode;
+	struct Byte_buffer;
 	struct Main;
 }
 
 
+struct Fs_tool::Byte_buffer : Byte_range_ptr
+{
+	Allocator &_alloc;
+
+	Byte_buffer(Allocator &alloc, size_t size)
+	: Byte_range_ptr((char *)alloc.alloc(size), size), _alloc(alloc) { }
+
+	~Byte_buffer() { _alloc.free(start, num_bytes); }
+};
+
+
 struct Fs_tool::Main
 {
 	Env &_env;
@@ -46,9 +58,11 @@ struct Fs_tool::Main
 
 	typedef Directory::Path Path;
 
-	void _remove_file(Xml_node);
+	void _copy_file(Path const &from, Path const &to, Byte_range_ptr const &);
 
-	void _new_file(Xml_node);
+	void _remove_file    (Xml_node const &);
+	void _new_file       (Xml_node const &);
+	void _copy_all_files (Xml_node const &);
 
 	void _handle_config()
 	{
@@ -67,6 +81,9 @@ struct Fs_tool::Main
 
 			if (operation.has_type("new-file"))
 				_new_file(operation);
+
+			if (operation.has_type("copy-all-files"))
+				_copy_all_files(operation);
 		});
 
 		if (config.attribute_value("exit", false)) {
@@ -83,7 +100,7 @@ struct Fs_tool::Main
 };
 
 
-void Fs_tool::Main::_remove_file(Xml_node operation)
+void Fs_tool::Main::_remove_file(Xml_node const &operation)
 {
 	Path const path = operation.attribute_value("path", Path());
 
@@ -108,7 +125,7 @@ void Fs_tool::Main::_remove_file(Xml_node operation)
 }
 
 
-void Fs_tool::Main::_new_file(Xml_node operation)
+void Fs_tool::Main::_new_file(Xml_node const &operation)
 {
 	Path const path { operation.attribute_value("path", Path()) };
 
@@ -140,5 +157,55 @@ void Fs_tool::Main::_new_file(Xml_node operation)
 }
 
 
+void Fs_tool::Main::_copy_file(Path const &from, Path const &to,
+                               Byte_range_ptr const &buffer)
+{
+	try {
+		Readonly_file const src { _root_dir, from };
+		New_file            dst { _root_dir, to };
+
+		Readonly_file::At at { 0 };
+
+		for (;;) {
+
+			size_t const read_bytes = src.read(at, buffer);
+
+			dst.append(buffer.start, read_bytes);
+
+			at.value += read_bytes;
+
+			if (read_bytes < buffer.num_bytes)
+				break;
+		}
+	}
+	catch (...) {
+		error("failed to copy ", from, " to ", to); }
+}
+
+
+void Fs_tool::Main::_copy_all_files(Xml_node const &operation)
+{
+	Number_of_bytes const default_buffer { 1024*1024 };
+	Byte_buffer buffer(_heap, operation.attribute_value("buffer", default_buffer));
+
+	Path const from = operation.attribute_value("from", Path());
+	Path const to   = operation.attribute_value("to",   Path());
+
+	if (!_root_dir.directory_exists(from))
+		return;
+
+	Directory(_root_dir, from).for_each_entry([&] (Directory::Entry const &entry) {
+
+		bool const continous_file =
+			(entry.type() == Vfs::Directory_service::Dirent_type::CONTINUOUS_FILE);
+
+		if (continous_file)
+			_copy_file(Path(from, "/", entry.name()),
+			           Path(to,   "/", entry.name()),
+			           buffer);
+	});
+}
+
+
 void Component::construct(Genode::Env &env) { static Fs_tool::Main main(env); }