3 files changed, 160 insertions, 0 deletions
diff --git a/lib/rubygems/request/connection_pools.rb b/lib/rubygems/request/connection_pools.rb
new file mode 100644
index 0000000000..01e7e0629a
--- /dev/null
+++ b/lib/rubygems/request/connection_pools.rb
@@ -0,0 +1,96 @@
+# frozen_string_literal: true
+
+class Gem::Request::ConnectionPools # :nodoc:
+  @client = Gem::Net::HTTP
+
+  class << self
+    attr_accessor :client
+  end
+
+  def initialize(proxy_uri, cert_files, pool_size = 1)
+    @proxy_uri  = proxy_uri
+    @cert_files = cert_files
+    @pools      = {}
+    @pool_mutex = Thread::Mutex.new
+    @pool_size  = pool_size
+  end
+
+  def pool_for(uri)
+    http_args = net_http_args(uri, @proxy_uri)
+    key       = http_args + [https?(uri)]
+    @pool_mutex.synchronize do
+      @pools[key] ||=
+        if https? uri
+          Gem::Request::HTTPSPool.new(http_args, @cert_files, @proxy_uri, @pool_size)
+        else
+          Gem::Request::HTTPPool.new(http_args, @cert_files, @proxy_uri, @pool_size)
+        end
+    end
+  end
+
+  def close_all
+    @pools.each_value(&:close_all)
+  end
+
+  private
+
+  ##
+  # Returns list of no_proxy entries (if any) from the environment
+
+  def get_no_proxy_from_env
+    env_no_proxy = ENV["no_proxy"] || ENV["NO_PROXY"]
+
+    return [] if env_no_proxy.nil? || env_no_proxy.empty?
+
+    env_no_proxy.split(/\s*,\s*/)
+  end
+
+  def https?(uri)
+    uri.scheme.casecmp("https").zero?
+  end
+
+  def no_proxy?(host, env_no_proxy)
+    host = host.downcase
+
+    env_no_proxy.any? do |pattern|
+      env_no_proxy_pattern = pattern.downcase.dup
+
+      # Remove dot in front of pattern for wildcard matching
+      env_no_proxy_pattern[0] = "" if env_no_proxy_pattern[0] == "."
+
+      host_tokens = host.split(".")
+      pattern_tokens = env_no_proxy_pattern.split(".")
+
+      intersection = (host_tokens - pattern_tokens) | (pattern_tokens - host_tokens)
+
+      # When we do the split into tokens we miss a dot character, so add it back if we need it
+      missing_dot = intersection.length > 0 ? 1 : 0
+      start = intersection.join(".").size + missing_dot
+
+      no_proxy_host = host[start..-1]
+
+      env_no_proxy_pattern == no_proxy_host
+    end
+  end
+
+  def net_http_args(uri, proxy_uri)
+    hostname = uri.hostname
+    net_http_args = [hostname, uri.port]
+
+    no_proxy = get_no_proxy_from_env
+
+    if proxy_uri && !no_proxy?(hostname, no_proxy)
+      proxy_hostname = proxy_uri.respond_to?(:hostname) ? proxy_uri.hostname : proxy_uri.host
+      net_http_args + [
+        proxy_hostname,
+        proxy_uri.port,
+        Gem::UriFormatter.new(proxy_uri.user).unescape,
+        Gem::UriFormatter.new(proxy_uri.password).unescape,
+      ]
+    elsif no_proxy? hostname, no_proxy
+      net_http_args + [nil, nil]
+    else
+      net_http_args
+    end
+  end
+end
diff --git a/lib/rubygems/request/http_pool.rb b/lib/rubygems/request/http_pool.rb
new file mode 100644
index 0000000000..468502ca6b
--- /dev/null
+++ b/lib/rubygems/request/http_pool.rb
@@ -0,0 +1,54 @@
+# frozen_string_literal: true
+
+##
+# A connection "pool" that only manages one connection for now.  Provides
+# thread safe `checkout` and `checkin` methods.  The pool consists of one
+# connection that corresponds to `http_args`.  This class is private, do not
+# use it.
+
+class Gem::Request::HTTPPool # :nodoc:
+  attr_reader :cert_files, :proxy_uri
+
+  def initialize(http_args, cert_files, proxy_uri, pool_size)
+    @http_args  = http_args
+    @cert_files = cert_files
+    @proxy_uri  = proxy_uri
+    @pool_size  = pool_size
+
+    @queue      = Thread::SizedQueue.new @pool_size
+    setup_queue
+  end
+
+  def checkout
+    @queue.pop || make_connection
+  end
+
+  def checkin(connection)
+    @queue.push connection
+  end
+
+  def close_all
+    until @queue.empty?
+      if (connection = @queue.pop(true)) && connection.started?
+        connection.finish
+      end
+    end
+
+    setup_queue
+  end
+
+  private
+
+  def make_connection
+    setup_connection Gem::Request::ConnectionPools.client.new(*@http_args)
+  end
+
+  def setup_connection(connection)
+    connection.start
+    connection
+  end
+
+  def setup_queue
+    @pool_size.times { @queue.push(nil) }
+  end
+end
diff --git a/lib/rubygems/request/https_pool.rb b/lib/rubygems/request/https_pool.rb
new file mode 100644
index 0000000000..cb1d4b59b6
--- /dev/null
+++ b/lib/rubygems/request/https_pool.rb
@@ -0,0 +1,10 @@
+# frozen_string_literal: true
+
+class Gem::Request::HTTPSPool < Gem::Request::HTTPPool # :nodoc:
+  private
+
+  def setup_connection(connection)
+    Gem::Request.configure_connection_for_https(connection, @cert_files)
+    super
+  end
+end