Support Serializing and Deserializing RepeatedField / RepeatedPtrField in IPC::Message

ipc/ipc_message_protobuf_utils.h

+// Copyright 2017 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.
+
+#ifndef IPC_IPC_MESSAGE_PROTOBUF_UTILS_H_
+#define IPC_IPC_MESSAGE_PROTOBUF_UTILS_H_
+
+#include "build/build_config.h"
+
+#if defined(OS_NACL_NONSFI)
+static_assert(false,
+              "ipc_message_protobuf_utils is not able to work with "
+              "nacl_nonsfi configuration.");
+#endif
+
+#include "base/pickle.h"
+#include "ipc/ipc_param_traits.h"
+#include "ipc/ipc_message_utils.h"
+#include "third_party/protobuf/src/google/protobuf/repeated_field.h"
+
+namespace IPC {
+
+template <class RepeatedFieldLike, class StorageType>
+struct RepeatedFieldParamTraits {
+  typedef RepeatedFieldLike param_type;

[xyzzyz, 2017/07/18 20:34:55]

Type names start with a capital letter and have a capital letter for each new
word, with no underscores: MyExcitingClass, MyExcitingEnum.
The names of all types — classes, structs, type aliases, enums, and type
template parameters — have the same naming convention. 

https://google.github.io/styleguide/cppguide.html#Type_Names

[Hzj_jie, 2017/07/18 20:46:11]

This is a requirement in IPC AFAICT.

+  static void GetSize(base::PickleSizer* sizer, const param_type& p) {
+    GetParamSize(sizer, p.size());
+    for (int i = 0; i < p.size(); i++)
+      GetParamSize(sizer, p.Get(i));
+  }
+  static void Write(base::Pickle* m, const param_type& p) {
+    WriteParam(m, p.size());
+    for (int i = 0; i < p.size(); i++)
+      WriteParam(m, p.Get(i));
+  }
+  static bool Read(const base::Pickle* m,
+                   base::PickleIterator* iter,
+                   param_type* r) {
+    int size;
+    // ReadLength() checks for < 0 itself.
+    if (!iter->ReadLength(&size))
+      return false;
+    // Avoid integer overflow / assertion failure in Reserve() function.
+    if (INT_MAX / sizeof(StorageType) <= static_cast<size_t>(size))
+      return false;
+    r->Reserve(size);
+    for (int i = 0; i < size; i++) {
+      if (!ReadParam(m, iter, r->Add()))
+        return false;
+    }
+    return true;
+  }
+  static void Log(const param_type& p, std::string* l) {
+    for (int i = 0; i < p.size(); ++i) {
+      if (i != 0)
+        l->append(" ");
+      LogParam(p.Get(i), l);
+    }
+  }
+};
+
+template <class P>
+struct ParamTraits<google::protobuf::RepeatedField<P>> :
+    RepeatedFieldParamTraits<google::protobuf::RepeatedField<P>, P> {};
+
+template <class P>
+struct ParamTraits<google::protobuf::RepeatedPtrField<P>> :
+    RepeatedFieldParamTraits<google::protobuf::RepeatedPtrField<P>, void*> {};
+
+}  // namespace IPC
+
+#endif  // IPC_IPC_MESSAGE_PROTOBUF_UTILS_H_