allow configuration curl multi MAX_HOST_CONNECTIONS

https://curl.se/libcurl/c/CURLMOPT_MAX_HOST_CONNECTIONS.html

Author: HoneyryderChuck

ext/curb_multi.c

@@ -187,6 +187,25 @@ static VALUE ruby_curl_multi_max_connects(VALUE self, VALUE count) {
   return count;
 }
 
+/*
+ * call-seq:
+ * multi = Curl::Multi.new
+ * multi.max_host_connections = 1
+ *
+ * Set the max number of connections per host
+ */
+static VALUE ruby_curl_multi_max_host_connections(VALUE self, VALUE count) {
+#ifdef HAVE_CURLMOPT_MAX_HOST_CONNECTIONS
+  ruby_curl_multi *rbcm;
+
+  Data_Get_Struct(self, ruby_curl_multi, rbcm);
+
+  curl_multi_setopt(rbcm->handle, CURLMOPT_MAX_HOST_CONNECTIONS, NUM2LONG(count));
+#endif
+
+  return count;
+}
+
 /*
  * call-seq:
  * multi = Curl::Multi.new
@@ -704,6 +723,7 @@ void init_curb_multi() {
   rb_define_singleton_method(cCurlMulti, "autoclose", ruby_curl_multi_get_autoclose, 0);
   /* Instance methods */
   rb_define_method(cCurlMulti, "max_connects=", ruby_curl_multi_max_connects, 1);
+  rb_define_method(cCurlMulti, "max_host_connections=", ruby_curl_multi_max_host_connections, 1);
   rb_define_method(cCurlMulti, "pipeline=", ruby_curl_multi_pipeline, 1);
   rb_define_method(cCurlMulti, "_add", ruby_curl_multi_add, 1);
   rb_define_method(cCurlMulti, "_remove", ruby_curl_multi_remove, 1);

ext/extconf.rb

@@ -338,6 +338,9 @@ def have_constant(name)
 have_constant :CURL_SSLVERSION_SSLv2
 have_constant :CURL_SSLVERSION_SSLv3
 
+# Added in 7.30.0
+have_constant "curlmopt_max_host_connections"
+
 # Added in 7.34.0
 have_constant :CURL_SSLVERSION_TLSv1_0
 have_constant :CURL_SSLVERSION_TLSv1_1

tests/tc_curl_multi.rb

@@ -552,6 +552,25 @@ def test_multi_easy_http_with_max_connects
     end
   end
 
+  def test_multi_easy_http_with_max_host_connections
+    urls = [
+      { :url => TestServlet.url + '?q=1', :method => :get },
+      { :url => TestServlet.url + '?q=2', :method => :get },
+      { :url => TestServlet.url + '?q=3', :method => :get }
+    ]
+    Curl::Multi.http(urls, {:pipeline => true, :max_host_connections => 1}) do|easy, code, method|
+      assert_equal 200, code
+      case method
+      when :post
+        assert_match(/POST/, easy.body)
+      when :get
+        assert_match(/GET/, easy.body)
+      when :put
+        assert_match(/PUT/, easy.body)
+      end
+    end
+  end
+
   def test_multi_recieves_500
     m = Curl::Multi.new
     e = Curl::Easy.new("http://127.0.0.1:9129/methods")