1 files changed, 38 insertions, 0 deletions
diff --git a/activesupport/lib/active_support/gzip.rb b/activesupport/lib/active_support/gzip.rb
new file mode 100644
index 0000000000..7ffa6d90a2
--- /dev/null
+++ b/activesupport/lib/active_support/gzip.rb
@@ -0,0 +1,38 @@
+# frozen_string_literal: true
+
+require "zlib"
+require "stringio"
+
+module ActiveSupport
+  # A convenient wrapper for the zlib standard library that allows
+  # compression/decompression of strings with gzip.
+  #
+  #   gzip = ActiveSupport::Gzip.compress('compress me!')
+  #   # => "\x1F\x8B\b\x00o\x8D\xCDO\x00\x03K\xCE\xCF-(J-.V\xC8MU\x04\x00R>n\x83\f\x00\x00\x00"
+  #
+  #   ActiveSupport::Gzip.decompress(gzip)
+  #   # => "compress me!"
+  module Gzip
+    class Stream < StringIO
+      def initialize(*)
+        super
+        set_encoding "BINARY"
+      end
+      def close; rewind; end
+    end
+
+    # Decompresses a gzipped string.
+    def self.decompress(source)
+      Zlib::GzipReader.wrap(StringIO.new(source), &:read)
+    end
+
+    # Compresses a string using gzip.
+    def self.compress(source, level = Zlib::DEFAULT_COMPRESSION, strategy = Zlib::DEFAULT_STRATEGY)
+      output = Stream.new
+      gz = Zlib::GzipWriter.new(output, level, strategy)
+      gz.write(source)
+      gz.close
+      output.string
+    end
+  end
+end