Add a subchannel factory decorator library

1 files changed, 82 insertions, 0 deletions

diff --git a/src/core/client_config/subchannel_factory_decorators/merge_channel_args.c b/src/core/client_config/subchannel_factory_decorators/merge_channel_args.c
new file mode 100644
index 0000000000..17e89d6d4d
--- /dev/null
+++ b/src/core/client_config/subchannel_factory_decorators/merge_channel_args.c
@@ -0,0 +1,82 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/client_config/subchannel_factory_decorators/merge_channel_args.h"
+#include <grpc/support/alloc.h>
+#include "src/core/channel/channel_args.h"
+
+typedef struct {
+  grpc_subchannel_factory base;
+  gpr_refcount refs;
+  grpc_subchannel_factory *wrapped;
+  grpc_channel_args *merge_args;
+} merge_args_factory;
+
+static void merge_args_factory_ref(grpc_subchannel_factory *scf) {
+  merge_args_factory *f = (merge_args_factory *)scf;
+  gpr_ref(&f->refs);
+}
+
+static void merge_args_factory_unref(grpc_subchannel_factory *scf) {
+  merge_args_factory *f = (merge_args_factory *)scf;
+  if (gpr_unref(&f->refs)) {
+  	grpc_subchannel_factory_unref(f->wrapped);
+    grpc_channel_args_destroy(f->merge_args);
+    gpr_free(f);
+  }
+}
+
+static grpc_subchannel *merge_args_factory_create_subchannel(
+    grpc_subchannel_factory *scf, grpc_subchannel_args *args) {
+  merge_args_factory *f = (merge_args_factory *)scf;
+  grpc_channel_args *final_args =
+      grpc_channel_args_merge(args->args, f->merge_args);
+  grpc_subchannel *s;
+  s = grpc_subchannel_factory_create_subchannel(f->wrapped, args);
+  grpc_channel_args_destroy(final_args);
+  return s;
+}
+
+static const grpc_subchannel_factory_vtable merge_args_factory_vtable = {
+    merge_args_factory_ref, merge_args_factory_unref,
+    merge_args_factory_create_subchannel};
+
+grpc_subchannel_factory *grpc_subchannel_factory_merge_channel_args(
+		grpc_subchannel_factory *input, const grpc_channel_args *args) {
+  merge_args_factory *f = gpr_malloc(sizeof(*f));
+  f->base.vtable = &merge_args_factory_vtable;
+  gpr_ref_init(&f->refs, 1);
+  f->wrapped = input;
+  f->merge_args = grpc_channel_args_copy(args);
+  return &f->base;
+}