C++ bindings

mojo/public/bindings/sample_test.cc

+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <assert.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <new>
+#include <vector>
+
+#include "mojo/public/bindings/generated/sample_service.h"
+#include "mojo/public/bindings/generated/sample_service_proxy.h"
+#include "mojo/public/bindings/generated/sample_service_stub.h"
+
+static void PrintSpacer(int depth) {
+  for (int i = 0; i < depth; ++i)
+    printf("   ");
+}
+
+static void Print(int depth, const char* name, bool value) {
+  PrintSpacer(depth);
+  printf("%s: %s\n", name, value ? "true" : "false");
+}
+
+static void Print(int depth, const char* name, int32_t value) {
+  PrintSpacer(depth);
+  printf("%s: %d\n", name, value);
+}
+
+static void Print(int depth, const char* name, uint8_t value) {
+  PrintSpacer(depth);
+  printf("%s: %u\n", name, value);
+}
+
+static void Print(int depth, const char* name, const sample::Bar* bar) {
+  PrintSpacer(depth);
+  printf("%s: %p\n", name, bar);
+  if (bar) {
+    ++depth;
+    Print(depth, "alpha", bar->alpha());
+    Print(depth, "beta", bar->beta());
+    Print(depth, "gamma", bar->gamma());
+    --depth;
+  }
+}
+
+template <typename T>
+static void Print(int depth, const char* name, const mojo::Array<T>* array) {
+  PrintSpacer(depth);
+  printf("%s: %p\n", name, array);
+  if (array) {
+    ++depth;
+    for (size_t i = 0; i < array->size(); ++i) {
+      char buf[32];
+      sprintf(buf, "%lu", i);
+      Print(depth, buf, array->at(i));
+    }
+    --depth;
+  }
+}
+
+static void Print(int depth, const char* name, const sample::Foo* foo) {
+  PrintSpacer(depth);
+  printf("%s: %p\n", name, foo);
+  if (foo) {
+    ++depth;
+    Print(depth, "x", foo->x());
+    Print(depth, "y", foo->y());
+    Print(depth, "a", foo->a());
+    Print(depth, "b", foo->b());
+    Print(depth, "c", foo->c());
+    Print(depth, "bar", foo->bar());
+    Print(depth, "data", foo->data());
+    Print(depth, "extra_bars", foo->extra_bars());
+    --depth;
+  }
+}
+
+class ServiceImpl : public sample::ServiceStub {
+ public:
+  virtual void Frobinate(const sample::Foo* foo, bool baz) {
+    // Users code goes here to handle the incoming Frobinate message.
+    // We'll just dump the Foo structure and all of its members.
+
+    printf("Frobinate:\n");
+
+    int depth = 1;
+    Print(depth, "foo", foo);
+    Print(depth, "baz", baz);
+  }
+};
+
+//----
+
+class SimpleMessageSender : public mojo::MessageSender {
+ public:
+  virtual void Send(const mojo::Message& message) {
+    // Imagine some IPC happened here.
+
+    // In the receiving process, an implementation of ServiceStub is known to
+    // the system. It receives the incoming message.
+    ServiceImpl impl;
+
+    sample::ServiceStub* stub = &impl;
+    stub->OnMessageReceived(message);
+  }
+};
+
+int main() {
+  SimpleMessageSender sender;
+
+  // User has a proxy to a Service somehow.
+  sample::Service* service = new sample::ServiceProxy(&sender);
+
+  // User constructs a message to send.
+
+  // Notice that it doesn't matter in what order the structs / arrays are
+  // allocated. Here, the various members of Foo are allocated before Foo is
+  // allocated.
+
+  mojo::MessageBuffer buf;
+
+  sample::Bar* bar = buf.Alloc<sample::Bar>();
+  bar->set_alpha(20);
+  bar->set_beta(40);
+  bar->set_gamma(60);
+
+  const size_t kNumDataElements = 10;
+  mojo::Array<uint8_t>* data = buf.AllocArray<uint8_t>(kNumDataElements);
+  for (size_t i = 0; i < kNumDataElements; ++i)
+    (*data)[i] = static_cast<uint8_t>(kNumDataElements - i);
+
+  const size_t kNumExtraBarsElements = 3;
+  mojo::Array<sample::Bar*>* extra_bars =
+      buf.AllocArray<sample::Bar*>(kNumExtraBarsElements);
+  for (size_t i = 0; i < kNumExtraBarsElements; ++i) {
+    sample::Bar* bar = buf.Alloc<sample::Bar>();
+    bar->set_alpha(i * 100);
+    bar->set_beta(i * 100 + 20);
+    bar->set_gamma(i * 100 + 40);
+    (*extra_bars)[i] = bar;
+  }
+
+  sample::Foo* foo = buf.Alloc<sample::Foo>();
+  foo->set_x(1);
+  foo->set_y(2);
+  foo->set_a(false);
+  foo->set_b(true);
+  foo->set_c(false);
+  foo->set_bar(bar);

[viettrungluu, 2013/10/01 00:51:04]

I'm a little concerned that this and (even more so) set_extra_bars() may be too
inconvenient and error-prone to use. (Though I guess you did say we'll probably
end up with more sugar.)

+  foo->set_data(data);
+  foo->set_extra_bars(extra_bars);
+
+  service->Frobinate(foo, true);
+
+  return 0;
+}