Module: RailsAiContext::SafeFile

Defined in:
lib/rails_ai_context/safe_file.rb

Overview

Safe file reading with size limits and error handling. Returns String on success, nil on any failure (missing, too large, unreadable). Designed as a drop-in replacement for unguarded File.read calls across introspectors and tools where nil is already handled.

Class Method Summary collapse

Class Method Details

.atomic_write(path, content) ⇒ Object

Write through a temp file in the same directory, then rename. A reader racing the write sees either the old file or the new one, never a half-written one.



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# File 'lib/rails_ai_context/safe_file.rb', line 15

def self.atomic_write(path, content)
  dir = File.dirname(path)
  FileUtils.mkdir_p(dir)
  tmp = File.join(dir, ".#{File.basename(path)}.#{SecureRandom.hex(4)}.tmp")
  File.write(tmp, content)
  File.rename(tmp, path)
end

.read(path, max_size: nil) ⇒ Object 



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# File 'lib/rails_ai_context/safe_file.rb', line 23

def self.read(path, max_size: nil)
  return nil unless path && File.file?(path)

  limit = max_size || RailsAiContext.configuration.max_file_size
  return nil if File.size(path) > limit

  # The encoding options only apply while TRANSCODING; a file read as
  # UTF-8 that contains invalid bytes comes back tagged UTF-8 but
  # invalid, and the first regex over it raises ArgumentError. scrub
  # guarantees every consumer gets valid UTF-8.
  File.read(path, encoding: "UTF-8", invalid: :replace, undef: :replace).scrub("?")
rescue Errno::ENOENT, Errno::EACCES, Errno::EISDIR, Errno::ENAMETOOLONG, SystemCallError
  nil
end