Merge bundler to standard libraries.

  rubygems 2.7.x depends bundler-1.15.x. This is preparation for
  rubygems and bundler migration.

  * lib/bundler.rb, lib/bundler/*: files of bundler-1.15.4
  * spec/bundler/*: rspec examples of bundler-1.15.4. I applied patches.
    * https://github.com/bundler/bundler/pull/6007
    * Exclude not working examples on ruby repository.
    * Fake ruby interpriter instead of installed ruby.
  * Makefile.in: Added test task named `test-bundler`. This task is only
    working macOS/linux yet. I'm going to support Windows environment later.
  * tool/sync_default_gems.rb: Added sync task for bundler.

  [Feature #12733][ruby-core:77172]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59779 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 106 insertions, 0 deletions

diff --git a/lib/bundler/compact_index_client/updater.rb b/lib/bundler/compact_index_client/updater.rb
new file mode 100644
index 0000000000..dc26095040
--- /dev/null
+++ b/lib/bundler/compact_index_client/updater.rb
@@ -0,0 +1,106 @@
+# frozen_string_literal: true
+require "fileutils"
+require "stringio"
+require "tmpdir"
+require "zlib"
+
+module Bundler
+  class CompactIndexClient
+    class Updater
+      class MisMatchedChecksumError < Error
+        def initialize(path, server_checksum, local_checksum)
+          @path = path
+          @server_checksum = server_checksum
+          @local_checksum = local_checksum
+        end
+
+        def message
+          "The checksum of /#{@path} does not match the checksum provided by the server! Something is wrong " \
+            "(local checksum is #{@local_checksum.inspect}, was expecting #{@server_checksum.inspect})."
+        end
+      end
+
+      def initialize(fetcher)
+        @fetcher = fetcher
+      end
+
+      def update(local_path, remote_path, retrying = nil)
+        headers = {}
+
+        Dir.mktmpdir("bundler-compact-index-") do |local_temp_dir|
+          local_temp_path = Pathname.new(local_temp_dir).join(local_path.basename)
+
+          # first try to fetch any new bytes on the existing file
+          if retrying.nil? && local_path.file?
+            FileUtils.cp local_path, local_temp_path
+            headers["If-None-Match"] = etag_for(local_temp_path)
+            headers["Range"] =
+              if local_temp_path.size.nonzero?
+                # Subtract a byte to ensure the range won't be empty.
+                # Avoids 416 (Range Not Satisfiable) responses.
+                "bytes=#{local_temp_path.size - 1}-"
+              else
+                "bytes=#{local_temp_path.size}-"
+              end
+          else
+            # Fastly ignores Range when Accept-Encoding: gzip is set
+            headers["Accept-Encoding"] = "gzip"
+          end
+
+          response = @fetcher.call(remote_path, headers)
+          return nil if response.is_a?(Net::HTTPNotModified)
+
+          content = response.body
+          if response["Content-Encoding"] == "gzip"
+            content = Zlib::GzipReader.new(StringIO.new(content)).read
+          end
+
+          SharedHelpers.filesystem_access(local_temp_path) do
+            if response.is_a?(Net::HTTPPartialContent) && local_temp_path.size.nonzero?
+              local_temp_path.open("a") {|f| f << slice_body(content, 1..-1) }
+            else
+              local_temp_path.open("w") {|f| f << content }
+            end
+          end
+
+          response_etag = (response["ETag"] || "").gsub(%r{\AW/}, "")
+          if etag_for(local_temp_path) == response_etag
+            SharedHelpers.filesystem_access(local_path) do
+              FileUtils.mv(local_temp_path, local_path)
+            end
+            return nil
+          end
+
+          if retrying
+            raise MisMatchedChecksumError.new(remote_path, response_etag, etag_for(local_temp_path))
+          end
+
+          update(local_path, remote_path, :retrying)
+        end
+      end
+
+      def etag_for(path)
+        sum = checksum_for_file(path)
+        sum ? %("#{sum}") : nil
+      end
+
+      def slice_body(body, range)
+        if body.respond_to?(:byteslice)
+          body.byteslice(range)
+        else # pre-1.9.3
+          body.unpack("@#{range.first}a#{range.end + 1}").first
+        end
+      end
+
+      def checksum_for_file(path)
+        return nil unless path.file?
+        # This must use IO.read instead of Digest.file().hexdigest
+        # because we need to preserve \n line endings on windows when calculating
+        # the checksum
+        SharedHelpers.filesystem_access(path, :read) do
+          Digest::MD5.hexdigest(IO.read(path))
+        end
+      end
+    end
+  end
+end