Module: Canon::Rebaseliner::AtomicWriter

Defined in:
lib/canon/rebaseliner/atomic_writer.rb

Overview

Write a file atomically by writing to a same-directory tempfile and renaming over the target. Preserves the original file's mode. Avoids half-written files on Ctrl-C.

Class Method Summary collapse

Class Method Details

.write(path, contents) ⇒ void

This method returns an undefined value.

Parameters:

  • path (String) —

    absolute path to write

  • contents (String) —

    new file contents



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# File 'lib/canon/rebaseliner/atomic_writer.rb', line 17

def write(path, contents)
  original_mode = File.stat(path).mode
  dir = File.dirname(path)
  Tempfile.create(["canon-rebaseline", ".tmp"], dir) do |tmp|
    tmp.binmode
    tmp.write(contents)
    tmp.flush
    tmp.fsync
    tmp.close
    File.chmod(original_mode, tmp.path)
    File.rename(tmp.path, path)
  end
end