Feature #20497
closedTempfile.create_io
Description
I propose Tempfile.create_io.
It is similar to Tempfile.create but the actual file is unlinked before returning the method.
https://github.com/ruby/ruby/pull/10803
Purpose:
Sometimes, applications need a temporary file but it is not required to access via a pathname.
In this case, the created file can be unlinked just after temporary file creation.
This removes the obligation of removing the file from applications.
So, Tempfile.create_io is easier to use than Tempfile.create.
Example:
tmpio = Tempfile.create_io # => #<IO:fd 5> tmpio.class # => IO tmpio.path # => nil tmpio.stat.mode.to_s(8) # => "100600" tmpio.puts "foo" tmpio.rewind tmpio.read # => "foo\n" tmpio.close
Portability:
This feature (unlink just after file creation) is supported on Unix for a long time.
Linux 3.11 has O_TMPFILE to create an unnamed file.
The current implementation uses it.
I heard that it is possible on Windows. (O_SHARE_DELETE?)
I'm not sure how to use it.
Updated by matz (Yukihiro Matsumoto)11 months ago
From what I understand, the real intent of this proposal is to "let the OS clean up after the generated tempfile". If so, I don't think the name create_io
represents the intent.
I vote for adding a keyword argument to Tempfile.create
.
Matz.
Updated by shyouhei (Shyouhei Urabe)11 months ago
Previous discussions:
- https://bugs.ruby-lang.org/issues/11715@akr (Akira Tanaka) thinks it's a good idea to have an anonymous file, then name it afterwards.
- https://bugs.ruby-lang.org/issues/13743@akr (Akira Tanaka) is against the pull request which actually adds such feature (maybe it was the implementation and the idea was OK though).
Because the proposed Tempfile.create_io returns a non-File IO instance, there is no way to assign a path in this ticket.
Updated by akr (Akira Tanaka)11 months ago
matz (Yukihiro Matsumoto) wrote in #note-1:
From what I understand, the real intent of this proposal is to "let the OS clean up after the generated tempfile". If so, I don't think the name
create_io
represents the intent.
I vote for adding a keyword argument toTempfile.create
.
I updated the PR to change the interface:
I added unlink_first
keyword argument for Tempfile.create
.
f = Tempfile.create(unlink_first: true) # The file is already removed because unlink_first f.path # => "/tmp/" (no filename since no file) f.puts "foo" f.rewind f.read # => "foo\n" f.close Tempfile.create(unlink_first: true) {|f| # The file is already removed because unlink_first f.path # => "/tmp/" (no filename since no file) f.puts "foo" f.rewind f.read # => "foo\n" }
Updated by akr (Akira Tanaka)11 months ago
Several candidates for the keyword argument:
unlink_first: true
remove_immediately: true
delete_on_creation: true
unnamed: true
nameless: true
anonymous: true
named: false
Updated by byroot (Jean Boussier)11 months ago
My personal preference would go to anonymous: true
, probably followed by linked: false
.
Updated by austin (Austin Ziegler)11 months ago
I have a minor preference for unnamed: true
, but anonymous: true
is probably more approachable overall.
Updated by akr (Akira Tanaka)11 months ago
I talked with Matz today.
He said anonymous: true
is acceptable.
Updated by akr (Akira Tanaka)11 months ago
- Status changed from Open to Closed
Applied in changeset git|3ee83c73c38070d695537d4322ce4decb970a54a.
Tempfile.create(anonymous: true) implemented. (#10803)
The keyword argument anonymous
is implemented for Tempfile.create
The default is anonymous: false
.
The behavior is not changed as before.
The created temporary file is immediately removed if anonymous: true
is specified.
So applications don't need to remove the file.
The actual storage of the file is reclaimed by the OS when the file is closed.
It uses O_TMPFILE
for Linux 3.11 or later.
It creates an anonymous file from the beginning.
It uses FILE_SHARE_DELETE for Windows.
It makes it possible to remove the opened file.
[Feature #20497]