Sha256: 5c99f58802acd6ed953db05983f9ccc81270b471f8e487aed4bd0fd2f7c688f6
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Size: 1.86 KB
Versions: 25
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Stored size: 1.86 KB
Contents
# encoding: utf-8
# code downloaded from Ruby on Rails 4.2.1
# https://raw.githubusercontent.com/rails/rails/v4.2.1/activesupport/lib/active_support/core_ext/file/atomic.rb
# change method name to avoid borking active_support and vice versa
require 'fileutils'
module FileHelper
extend self
# Write to a file atomically. Useful for situations where you don't
# want other processes or threads to see half-written files.
#
# File.write_atomically('important.file') do |file|
# file.write('hello')
# end
def write_atomically(file_name)
if File.exist?(file_name)
# Get original file permissions
old_stat = File.stat(file_name)
else
# If not possible, probe which are the default permissions in the
# destination directory.
old_stat = probe_stat_in(File.dirname(file_name))
end
mode = old_stat ? old_stat.mode : nil
# Create temporary file with identical permissions
temp_file = File.new(rand_filename(file_name), "w", mode)
temp_file.binmode
return_val = yield temp_file
temp_file.close
# Overwrite original file with temp file
File.rename(temp_file.path, file_name)
# Unable to get permissions of the original file => return
return return_val if old_stat.nil?
# Set correct uid/gid on new file
File.chown(old_stat.uid, old_stat.gid, file_name) if old_stat
return_val
end
def device?(file_name)
File.chardev?(file_name) || File.blockdev?(file_name)
end
# Private utility method.
def probe_stat_in(dir) #:nodoc:
basename = rand_filename(".permissions_check")
file_name = File.join(dir, basename)
FileUtils.touch(file_name)
File.stat(file_name)
rescue
# ...
ensure
FileUtils.rm_f(file_name) if File.exist?(file_name)
end
def rand_filename(prefix)
[ prefix, Thread.current.object_id, Process.pid, rand(1000000) ].join('.')
end
end
Version data entries
25 entries across 25 versions & 1 rubygems