Var serialization-related proxy stuff. This allows vars to be sent over IPC...

ppapi/proxy/host_var_serialization_rules.cc

+// Copyright (c) 2010 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 "ppapi/proxy/host_var_serialization_rules.h"
+
+#include "base/logging.h"
+#include "ppapi/c/dev/ppb_var_deprecated.h"
+
+namespace pp {
+namespace proxy {
+
+HostVarSerializationRules::HostVarSerializationRules(
+    const PPB_Var_Deprecated* var_interface,
+    PP_Module pp_module)
+    : var_interface_(var_interface),
+      pp_module_(pp_module) {
+}
+
+HostVarSerializationRules::~HostVarSerializationRules() {
+}
+
+void HostVarSerializationRules::SendCallerOwned(const PP_Var& var,
+                                                std::string* str_val) {
+  if (var.type == PP_VARTYPE_STRING)
+    VarToString(var, str_val);
+}
+
+PP_Var HostVarSerializationRules::BeginReceiveCallerOwned(
+    const PP_Var& var,
+    const std::string* str_val) {
+  if (var.type == PP_VARTYPE_STRING) {
+    // Convert the string to the context of the current process.
+    return var_interface_->VarFromUtf8(pp_module_, str_val->c_str(),
+                                       static_cast<uint32_t>(str_val->size()));
+  }
+  return var;
+}
+
+void HostVarSerializationRules::EndReceiveCallerOwned(const PP_Var& var) {
+  if (var.type == PP_VARTYPE_STRING) {
+    // Destroy the string BeginReceiveCallerOwned created above.
+    var_interface_->Release(var);
+  }
+}
+
+PP_Var HostVarSerializationRules::ReceivePassRef(const PP_Var& var,
+                                                 const std::string& str_val) {
+  if (var.type == PP_VARTYPE_STRING) {
+    // Convert the string to the context of the current process.
+    return var_interface_->VarFromUtf8(pp_module_, str_val.c_str(),
+                                       static_cast<uint32_t>(str_val.size()));
+  }
+
+  // See PluginVarSerialization::BeginSendPassRef for an example.
+  if (var.type == PP_VARTYPE_OBJECT)
+    var_interface_->AddRef(var);
+  return var;
+}
+
+void HostVarSerializationRules::BeginSendPassRef(const PP_Var& var,
+                                                 std::string* str_val) {
+  // See PluginVarSerialization::ReceivePassRef for an example. We don't need
+  // to do anything here other than convert the string.
+  if (var.type == PP_VARTYPE_STRING)
+    VarToString(var, str_val);
+}
+
+void HostVarSerializationRules::EndSendPassRef(const PP_Var& var) {
+  // See PluginVarSerialization::ReceivePassRef for an example. We don't need
+  // to do anything here.
+}
+
+void HostVarSerializationRules::VarToString(const PP_Var& var,
+                                            std::string* str) {
+  DCHECK(var.type == PP_VARTYPE_STRING);
+
+  // This could be optimized to avoid an extra string copy by going to a lower
+  // level of the browser's implementation of strings where we already have
+  // a std::string.
+  uint32_t len = 0;
+  const char* data = var_interface_->VarToUtf8(var, &len);
+  str->assign(data, len);
+}
+
+void HostVarSerializationRules::ReleaseObjectRef(const PP_Var& var) {
+  var_interface_->Release(var);
+}
+
+}  // namespace proxy
+}  // namespace pp