Linux pairing registry delegate implementation

remoting/host/pairing_registry_delegate_linux.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 "remoting/host/pairing_registry_delegate_linux.h"
+
+#include "base/bind.h"
+#include "base/environment.h"
+#include "base/file_util.h"
+#include "base/files/important_file_writer.h"
+#include "base/json/json_file_value_serializer.h"
+#include "base/json/json_string_value_serializer.h"
+#include "base/location.h"
+#include "base/single_thread_task_runner.h"
+#include "base/string_number_conversions.h"
+#include "base/thread_task_runner_handle.h"
+#include "base/values.h"
+#include "remoting/host/branding.h"
+
+namespace {
+const char kRegistryFilename[] = "paired-clients.json";
+const char kCreatedTimeKey[] = "created-time";
+const char kClientIdKey[] = "client-id";
+const char kClientNameKey[] = "client-name";
+const char kSharedSecretKey[] = "shared-secret";
+}  // namespace
+
+namespace remoting {
+namespace protocol {
+
+PairingRegistryDelegateLinux::PairingRegistryDelegateLinux(
+    scoped_refptr<base::TaskRunner> task_runner)
+    : task_runner_(task_runner),
+      weak_factory_(this) {
+}
+
+PairingRegistryDelegateLinux::~PairingRegistryDelegateLinux() {
+}
+
+void PairingRegistryDelegateLinux::AddPairing(
+    const PairingRegistry::Pairing& new_paired_client,
+      const PairingRegistry::AddPairingCallback& callback) {

[Lambros, 2013/06/20 17:59:20]

nit: indentation

[Jamie, 2013/06/20 20:17:09]

Done.

+  // If a callback was supplied, wrap it in a helper function that will
+  // run it on this thread.
+  PairingRegistry::AddPairingCallback run_callback_on_this_thread;
+  if (!callback.is_null()) {
+    run_callback_on_this_thread =
+        base::Bind(&PairingRegistryDelegateLinux::RunAddPairingCallbackOnThread,

[Lambros, 2013/06/20 17:59:20]

RunAddPairingCallbackOnThread doesn't access any members. Might as well make it
static, and then you don't need to bind it to a WeakPtr. I wonder if this could
be further simplified, since that method is just a one-liner, maybe can combine
the two Binds into one? Or look at TaskRunner::PostTaskAndReply().

[Jamie, 2013/06/20 20:17:09]

I'm made the methods static, but I don't see how to simplify further, since
PostTaskAndReply (and similarly any attempt to combine the Binds) requires a
closure, and we only have a partially-bound function.

+                   weak_factory_.GetWeakPtr(),
+                   base::ThreadTaskRunnerHandle::Get(),
+                   callback);
+  }
+  task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&PairingRegistryDelegateLinux::DoAddPairing,
+                 weak_factory_.GetWeakPtr(),
+                 new_paired_client,
+                 run_callback_on_this_thread));
+}
+
+void PairingRegistryDelegateLinux::GetPairing(
+    const std::string& client_id,
+    const  PairingRegistry::GetPairingCallback& callback) {

[Lambros, 2013/06/20 17:59:20]

nit: remove extra space

[Jamie, 2013/06/20 20:17:09]

Done.

+  // Wrap the callback in a helper function that will run it on this thread.
+  // Note that, unlike AddPairing, the GetPairing callback is mandatory.
+  PairingRegistry::GetPairingCallback run_callback_on_this_thread =
+      base::Bind(&PairingRegistryDelegateLinux::RunGetPairingCallbackOnThread,
+                 weak_factory_.GetWeakPtr(),
+                 base::ThreadTaskRunnerHandle::Get(),
+                 callback);
+  task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&PairingRegistryDelegateLinux::DoGetPairing,
+                 weak_factory_.GetWeakPtr(),
+                 client_id,
+                 run_callback_on_this_thread));
+}
+
+void PairingRegistryDelegateLinux::RunAddPairingCallbackOnThread(
+    scoped_refptr<base::TaskRunner> task_runner,
+    const PairingRegistry::AddPairingCallback& callback,
+    bool success) {
+  task_runner->PostTask(FROM_HERE, base::Bind(callback, success));
+}
+
+void PairingRegistryDelegateLinux::RunGetPairingCallbackOnThread(
+      scoped_refptr<base::TaskRunner> task_runner,
+      const PairingRegistry::GetPairingCallback& callback,
+      PairingRegistry::Pairing pairing) {
+  task_runner->PostTask(FROM_HERE, base::Bind(callback, pairing));
+}
+
+void PairingRegistryDelegateLinux::DoAddPairing(
+    const PairingRegistry::Pairing& new_paired_client,
+    const PairingRegistry::AddPairingCallback& callback) {
+  PairingRegistry::PairedClients paired_clients = LoadPairings();
+  paired_clients[new_paired_client.client_id()] = new_paired_client;
+  SavePairings(paired_clients);
+  if (!callback.is_null()) {
+    callback.Run(true);
+  }
+}
+
+void PairingRegistryDelegateLinux::DoGetPairing(
+    const std::string& client_id,
+    const  PairingRegistry::GetPairingCallback& callback) {
+  PairingRegistry::PairedClients paired_clients = LoadPairings();
+  PairingRegistry::PairedClients::const_iterator i =
+      paired_clients.find(client_id);
+  PairingRegistry::Pairing result;
+  if (i != paired_clients.end()) {
+    result = i->second;
+  }
+  callback.Run(result);
+}
+
+PairingRegistry::PairedClients PairingRegistryDelegateLinux::LoadPairings() {
+  PairingRegistry::PairedClients result;
+
+  base::FilePath registry_path = GetRegistryFilePath();
+  JSONFileValueSerializer registry(registry_path);
+  int error_code;
+  std::string error_message;
+  scoped_ptr<base::Value> root(
+      registry.Deserialize(&error_code, &error_message));
+  if (!root) {
+    LOG(ERROR) << "Failed to load paired clients: " << error_message
+               << " (" << error_code << ").";
+    return result;
+  }
+
+  base::ListValue* root_list = NULL;
+  if (!root->GetAsList(&root_list)) {
+    LOG(ERROR) << "Failed to load paired clients: root node is not a list.";
+    return result;
+  }
+
+  for (size_t i = 0; i < root_list->GetSize(); ++i) {
+    base::DictionaryValue* pairing = NULL;
+    std::string created_time, client_name, client_id, shared_secret;
+    if (root_list->GetDictionary(i, &pairing) &&
+        pairing->GetString(kCreatedTimeKey, &created_time) &&
+        pairing->GetString(kClientNameKey, &client_name) &&
+        pairing->GetString(kClientIdKey, &client_id) &&
+        pairing->GetString(kSharedSecretKey, &shared_secret)) {
+      int64 created_time_value;
+      if (!base::StringToInt64(created_time, &created_time_value)) {
+        LOG(ERROR) << "Paired client " << i << " has invalid creation time.";
+        continue;
+      }
+      result[client_id] = PairingRegistry::Pairing(
+          base::Time::FromInternalValue(created_time_value),
+          client_name, client_id, shared_secret);
+    } else {
+      LOG(ERROR) << "Paired client " << i << " has unexpected format.";
+    }
+  }
+
+  return result;
+}
+
+void PairingRegistryDelegateLinux::SavePairings(
+    const PairingRegistry::PairedClients& paired_clients) {
+  base::ListValue root;
+  for (PairingRegistry::PairedClients::const_iterator i =
+           paired_clients.begin(); i != paired_clients.end(); ++i) {
+    base::DictionaryValue* pairing = new base::DictionaryValue();
+    std::string created_time =
+        base::Int64ToString(i->second.created_time().ToInternalValue());
+    pairing->SetString(kCreatedTimeKey, created_time);
+    pairing->SetString(kClientNameKey, i->second.client_name());
+    pairing->SetString(kClientIdKey, i->second.client_id());
+    pairing->SetString(kSharedSecretKey, i->second.shared_secret());
+    root.Append(pairing);
+  }
+
+  std::string pairings_json;
+  JSONStringValueSerializer serializer(&pairings_json);
+  serializer.Serialize(root);
+
+  base::FilePath registry_path = GetRegistryFilePath();
+  base::FilePath parent_directory = registry_path.DirName();
+  base::PlatformFileError error;
+  if (!file_util::CreateDirectoryAndGetError(parent_directory, &error)) {
+    LOG(ERROR) << "Could not create pairing registry directory: " << error;
+    return;
+  }
+  if (!base::ImportantFileWriter::WriteFileAtomically(registry_path,
+                                                      pairings_json)) {
+    LOG(ERROR) << "Could not save pairing registry.";
+  }
+}
+
+base::FilePath PairingRegistryDelegateLinux::GetRegistryFilePath() {
+  if (!filename_for_testing_.empty()) {
+    return filename_for_testing_;
+  }
+
+  base::FilePath config_dir = remoting::GetConfigDir();
+  return config_dir.Append(kRegistryFilename);
+}
+
+void PairingRegistryDelegateLinux::SetFilenameForTesting(
+    const base::FilePath &filename) {
+  filename_for_testing_ = filename;
+}
+
+
+scoped_ptr<PairingRegistry::Delegate> PairingRegistry::CreateDelegate(
+    scoped_refptr<base::TaskRunner> task_runner) {
+  return scoped_ptr<PairingRegistry::Delegate>(
+      new PairingRegistryDelegateLinux(task_runner));
+}
+
+}  // namespace protocol
+}  // namespace remoting