[PATCH 2/1] make kgio entirely optional

[Eric Wong <e@80x24.org>]

We may emulate Kgio.poll inefficiently using IO.select; and
perhaps IO.select in Ruby can be modified to transparently use
ppoll() on Linux...
---
 http_spew.gemspec              |  1 -
 lib/http_spew/class_methods.rb | 30 +++++++++++++++++++++++++++++-
 2 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/http_spew.gemspec b/http_spew.gemspec
index d4d38da..a5e4908 100644
--- a/http_spew.gemspec
+++ b/http_spew.gemspec
@@ -16,7 +16,6 @@ Gem::Specification.new do |s|
   s.summary = summary
   s.test_files = Dir["test/test_*.rb"]
   s.add_dependency(%q<kcar>, [ "~> 0.3", ">= 0.3.1"])
-  s.add_dependency(%q<kgio>, "~> 2.6")
   s.add_development_dependency(%q<olddoc>, "~> 1.0")
   s.required_ruby_version = '>= 2.3'
   s.licenses = %w(GPL-2.0+)
diff --git a/lib/http_spew/class_methods.rb b/lib/http_spew/class_methods.rb
index 79b3e47..dda0e19 100644
--- a/lib/http_spew/class_methods.rb
+++ b/lib/http_spew/class_methods.rb
@@ -110,7 +110,7 @@ module HTTP_Spew::ClassMethods
       break if pollset.empty?
 
       busy = pollset.keys
-      rv = with_timeout(t) { Kgio.poll(pollset, (t[0] * 1000).to_i) } or break
+      rv = with_timeout(t) { do_poll(pollset, t[0]) } or break
     end while t[0] > 0.0 && requests = rv.keys.concat(busy).uniq!
 
     ready.concat(failed)
@@ -121,4 +121,32 @@ module HTTP_Spew::ClassMethods
     end
     ready
   end
+
+  begin
+    require 'kgio'
+    def do_poll(pollset, sec) # :nodoc:
+      Kgio.poll(pollset, (sec * 1000).to_i)
+    end
+  rescue LoadError
+    # emulate Kgio.poll with IO.select
+    def do_poll(pollset, sec) # :nodoc:
+      rd = []
+      wr = []
+      pollset.each do |io, events|
+        case events
+        when :wait_readable
+          rd << io
+        when :wait_writable
+          wr << io
+        else
+          raise "BUG: unsupported event #{event.inspect} for #{io.inspect}"
+        end
+      end
+      ready = IO.select(rd, wr, nil, sec) or return
+      pollset.clear
+      ready[0].each { |io| pollset[io] = 1 } # POLLIN
+      ready[1].each { |io| pollset[io] = 4 } # POLLOUT
+      pollset
+    end
+  end
 end
-- 
EW