1 files changed, 94 insertions, 0 deletions
diff --git a/src/objective-c/GRPCClient/private/ChannelArgsUtil.m b/src/objective-c/GRPCClient/private/ChannelArgsUtil.m
new file mode 100644
index 0000000000..c1c65c3384
--- /dev/null
+++ b/src/objective-c/GRPCClient/private/ChannelArgsUtil.m
@@ -0,0 +1,94 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#import "ChannelArgsUtil.h"
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/string_util.h>
+
+#include <limits.h>
+
+static void *copy_pointer_arg(void *p) {
+  // Add ref count to the object when making copy
+  id obj = (__bridge id)p;
+  return (__bridge_retained void *)obj;
+}
+
+static void destroy_pointer_arg(void *p) {
+  // Decrease ref count to the object when destroying
+  CFRelease((CFTypeRef)p);
+}
+
+static int cmp_pointer_arg(void *p, void *q) { return p == q; }
+
+static const grpc_arg_pointer_vtable objc_arg_vtable = {copy_pointer_arg, destroy_pointer_arg,
+                                                        cmp_pointer_arg};
+
+void GRPCFreeChannelArgs(grpc_channel_args *channel_args) {
+  for (size_t i = 0; i < channel_args->num_args; ++i) {
+    grpc_arg *arg = &channel_args->args[i];
+    gpr_free(arg->key);
+    if (arg->type == GRPC_ARG_STRING) {
+      gpr_free(arg->value.string);
+    }
+  }
+  gpr_free(channel_args->args);
+  gpr_free(channel_args);
+}
+
+grpc_channel_args *GRPCBuildChannelArgs(NSDictionary *dictionary) {
+  if (dictionary.count == 0) {
+    return NULL;
+  }
+
+  NSArray *keys = [dictionary allKeys];
+  NSUInteger argCount = [keys count];
+
+  grpc_channel_args *channelArgs = gpr_malloc(sizeof(grpc_channel_args));
+  channelArgs->args = gpr_malloc(argCount * sizeof(grpc_arg));
+
+  // TODO(kriswuollett) Check that keys adhere to GRPC core library requirements
+
+  NSUInteger j = 0;
+  for (NSUInteger i = 0; i < argCount; ++i) {
+    grpc_arg *arg = &channelArgs->args[j];
+    arg->key = gpr_strdup([keys[i] UTF8String]);
+
+    id value = dictionary[keys[i]];
+    if ([value respondsToSelector:@selector(UTF8String)]) {
+      arg->type = GRPC_ARG_STRING;
+      arg->value.string = gpr_strdup([value UTF8String]);
+      j++;
+    } else if ([value respondsToSelector:@selector(intValue)]) {
+      int64_t value64 = [value longLongValue];
+      if (value64 <= INT_MAX || value64 >= INT_MIN) {
+        arg->type = GRPC_ARG_INTEGER;
+        arg->value.integer = (int)value64;
+        j++;
+      }
+    } else if (value != nil) {
+      arg->type = GRPC_ARG_POINTER;
+      arg->value.pointer.p = (__bridge_retained void *)value;
+      arg->value.pointer.vtable = &objc_arg_vtable;
+      j++;
+    }
+  }
+  channelArgs->num_args = j;
+
+  return channelArgs;
+}