formula: add make_deduplication_links_in

Library/Homebrew/formula.rb

@@ -1939,6 +1939,48 @@
  end
  end
 
+ # Replace duplicate files with links to reduce disk space.
+ #
+ # FIXME: Hardlinks are not fully supported so using `hardlink: true` will only
+ # reduce the bottle size or source build but will be duplicated on bottle pour.
+ #
+ # ### Example
+ #
+ # ```ruby
+ # make_deduplication_links_in libexec, extension: "jar"
+ # ```
+ sig { params(dir: Pathname, extension: T.nilable(String), allow_noop: T::Boolean, hardlink: T::Boolean).void }
+ def make_deduplication_links_in(dir, extension: nil, allow_noop: false, hardlink: false)
+ raise ArgumentError, "#{dir} is not a valid directory!" if !dir.directory? || dir.symlink?
+ raise ArgumentError, "#{dir} must be within #{prefix}!" unless dir.realpath.to_s.start_with?(prefix.realpath)
+
+ # Use Pathname.new to avoid caching information during build
+ odebug "Pre-deduplication disk usage of #{dir}: #{disk_usage_readable(Pathname.new(dir).disk_usage)}"
+
+ pattern = "**/*"
+ pattern += ".#{extension}" if extension
+ base_files = {}
+
+ nlinks = dir.realpath.glob(pattern).count do |path|
+ next false if !path.file? || path.symlink?
+
+ base_file = base_files[path.basename.to_s] ||= path
+ next false if base_file == path || !compare_file(base_file, path)
+
+ rm(path)
+ if hardlink
+ path.make_link base_file
+ else
+ path.parent.install_symlink base_file
+ end
+ true
+ end
+
+ odebug "Post-deduplication disk usage of #{dir}: #{disk_usage_readable(Pathname.new(dir).disk_usage)}"
+ odebug "#{nlinks} #{Utils.pluralize("#{hardlink ? "hard" : "sym"}link", nlinks)} created"
+ raise "No links were created!" if !allow_noop && nlinks.zero?
+ end
+
  # Replaces a universal binary with its native slice.
  #
  # If called with no parameters, does this with all compatible