From 70797fe87914be7f3e928a73275f176f5c9f436a Mon Sep 17 00:00:00 2001
From: Martin Stein <martin.stein@genode-labs.com>
Date: Sat, 13 Mar 2021 22:07:01 +0100
Subject: [PATCH] fs_tool: add <new-file> operation

Adds the <new-file> operation to the fs_tool. When configured, the
<new-file path="...">...</new-file> tag will cause creation or overwriting of
the file given through the 'path' attribute. The file will contain the text
content of the tag.

Ref #4032
---
 repos/gems/recipes/pkg/test-fs_tool/runtime | 25 ++++++++++++
 repos/gems/src/app/fs_tool/README           |  8 ++++
 repos/gems/src/app/fs_tool/main.cc          | 42 ++++++++++++++++++++-
 3 files changed, 73 insertions(+), 2 deletions(-)

diff --git a/repos/gems/recipes/pkg/test-fs_tool/runtime b/repos/gems/recipes/pkg/test-fs_tool/runtime
index 34278e5b03..c2616b0c89 100644
--- a/repos/gems/recipes/pkg/test-fs_tool/runtime
+++ b/repos/gems/recipes/pkg/test-fs_tool/runtime
@@ -11,6 +11,10 @@
 			[init -> report_rom]   &lt;listing>
 			[init -> report_rom]   	&lt;dir path="/fs/items">
 			[init -> report_rom]   		&lt;file name="1" writeable="yes">first&lt;/file>
+			[init -> report_rom]   		&lt;file name="5" writeable="yes">fifth&lt;/file>
+			[init -> report_rom]   	&lt;/dir>
+			[init -> report_rom]   	&lt;dir path="/fs/new/file/at/subdir">
+			[init -> report_rom]   		&lt;file name="content" writeable="yes">new file&lt;/file>
 			[init -> report_rom]   	&lt;/dir>
 			[init -> report_rom]   &lt;/listing>
 		</log>
@@ -81,6 +85,26 @@
 					</config>
 				</start>
 
+				<start name="new-file" caps="500">
+					<binary name="fs_tool"/>
+					<config verbose="yes" exit="yes">
+						<vfs>
+							<fs writeable="yes"/>
+						</vfs>
+						<new-file path="/items/5">fifth</new-file>
+						<new-file path="/new/file/at/subdir/content">new file</new-file>
+					</config>
+				</start>
+
+				<start name="sleep" caps="100">
+					<resource name="RAM" quantum="4M"/>
+					<binary name="dummy"/>
+					<config>
+						<sleep ms="500"/>
+						<exit/>
+					</config>
+				</start>
+
 				<start name="remove" caps="500">
 					<binary name="fs_tool"/>
 					<config verbose="yes" exit="yes">
@@ -99,6 +123,7 @@
 					<config>
 						<vfs> <dir name="fs"> <fs/> </dir> </vfs>
 						<query path="/fs/items" content="yes"/>
+						<query path="/fs/new/file/at/subdir" content="yes"/>
 					</config>
 				</start>
 
diff --git a/repos/gems/src/app/fs_tool/README b/repos/gems/src/app/fs_tool/README
index 5949470b8e..a421194a08 100644
--- a/repos/gems/src/app/fs_tool/README
+++ b/repos/gems/src/app/fs_tool/README
@@ -5,9 +5,17 @@ configured VFS. The file operations are given the configuration as follows:
 !   <vfs>
 !     ...
 !   </vfs>
+!   <new-file path="/path/to/file">Content to write to the file</new-file>
 !   <remove-file path="/path/to/file" />
 ! </config>
 
 The 'exit="yes"' attribute instructs the component to exit after completing
 the sequence. Otherwise, the component keeps responding to configuration
 changes by executing the operations found in the updated configurations.
+
+The <new-file> operation creates the new file or overwrites the existing file
+given through the 'path' attribute with the content that is given inside the
+tag.
+
+The <remove-file> tag removes the existing file given through the 'path'
+attribute.
diff --git a/repos/gems/src/app/fs_tool/main.cc b/repos/gems/src/app/fs_tool/main.cc
index 3b5e07b903..7d952538d9 100644
--- a/repos/gems/src/app/fs_tool/main.cc
+++ b/repos/gems/src/app/fs_tool/main.cc
@@ -17,6 +17,7 @@
 #include <base/attached_rom_dataspace.h>
 #include <base/heap.h>
 #include <os/vfs.h>
+#include <base/buffered_output.h>
 
 namespace Fs_tool {
 	using namespace Genode;
@@ -60,6 +61,8 @@ struct Fs_tool::Main
 
 	void _remove_file(Xml_node);
 
+	void _new_file(Xml_node);
+
 	void _handle_config()
 	{
 		_config.update();
@@ -71,9 +74,12 @@ struct Fs_tool::Main
 		_root_dir_fs.apply_config(config.sub_node("vfs"));
 
 		config.for_each_sub_node([&] (Xml_node operation) {
-			if (operation.has_type("remove-file")) {
+
+			if (operation.has_type("remove-file"))
 				_remove_file(operation);
-			}
+
+			if (operation.has_type("new-file"))
+				_new_file(operation);
 		});
 
 		if (config.attribute_value("exit", false)) {
@@ -115,5 +121,37 @@ void Fs_tool::Main::_remove_file(Xml_node operation)
 }
 
 
+void Fs_tool::Main::_new_file(Xml_node operation)
+{
+	Path const path { operation.attribute_value("path", Path()) };
+
+	bool write_error  = false;
+	bool create_error = false;
+
+	try {
+		New_file new_file(_root_dir, path);
+		auto write = [&] (char const *str)
+		{
+			if (new_file.append(str, strlen(str)) != New_file::Append_result::OK)
+				write_error = true;
+		};
+		Buffered_output<128, decltype(write)> output(write);
+
+		operation.with_raw_content([&] (char const *start, size_t size) {
+			print(output, Cstring(start, size)); });
+	}
+	catch (New_file::Create_failed) {
+		create_error = true; }
+
+	if (create_error && _verbose)
+		warning("operation <new-file path=\"", path, "\"> "
+		        "failed because creating the file failed");
+
+	if (write_error && _verbose)
+		warning("operation <new-file path=\"", path, "\"> "
+		        "failed because writing to the file failed");
+}
+
+
 void Component::construct(Genode::Env &env) { static Fs_tool::Main main(env); }