[GCM] Add RMQ storage and MCS message passing support

google_apis/gcm/engine/rmq_store.cc

+// Copyright (c) 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 "google_apis/gcm/engine/rmq_store.h"
+
+#include "base/basictypes.h"
+#include "base/bind.h"
+#include "base/callback.h"
+#include "base/files/file_path.h"
+#include "base/logging.h"
+#include "base/message_loop/message_loop_proxy.h"
+#include "base/sequenced_task_runner.h"
+#include "base/stl_util.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/string_piece.h"
+#include "base/tracked_objects.h"
+#include "components/webdata/encryptor/encryptor.h"
+#include "google_apis/gcm/base/mcs_message.h"
+#include "google_apis/gcm/base/mcs_util.h"
+#include "google_apis/gcm/protocol/gcm.pb.h"
+#include "third_party/leveldatabase/src/include/leveldb/db.h"
+
+namespace gcm {
+
+namespace {
+
+// ---- LevelDB keys. ----
+// Key for this device's android id.
+const char kDeviceAIDKey[] = "device_aid_key";
+// Key for this device's android security token.
+const char kDeviceTokenKey[] = "device_token_key";
+// Lowest lexicographically ordered incoming message key.
+// Used for prefixing messages.
+const char kIncomingMsgKeyStart[] = "incoming1-";
+// Key guaranteed to be higher than all incoming message keys.
+// Used for limiting iteration.
+const char kIncomingMsgKeyEnd[] = "incoming2-";
+// Lowest lexicographically ordered outgoing message key.
+// Used for prefixing outgoing messages.
+const char kOutgoingMsgKeyStart[] = "outgoing1-";
+// Key guaranteed to be higher than all outgoing message keys.
+// Used for limiting iteration.
+const char kOutgoingMsgKeyEnd[] = "outgoing2-";
+
+std::string MakeIncomingKey(const std::string& persistent_id) {
+  return kIncomingMsgKeyStart + persistent_id;
+}
+
+std::string MakeOutgoingKey(const std::string& persistent_id) {
+  return kOutgoingMsgKeyStart + persistent_id;
+}
+
+std::string ParseOutgoingKey(const std::string& key) {
+  return key.substr(arraysize(kOutgoingMsgKeyStart) - 1);
+}
+
+leveldb::Slice MakeSlice(const base::StringPiece& s) {
+  return leveldb::Slice(s.begin(), s.size());
+}
+
+}  // namespace
+
+class RMQStore::Backend : public base::RefCountedThreadSafe<RMQStore::Backend> {
+ public:
+  Backend(const base::FilePath& path,
+          scoped_refptr<base::SequencedTaskRunner> foreground_runner);
+
+  // Blocking implementations of RMQStore methods.
+  void Load(const LoadCallback& callback);
+  void Destroy(const UpdateCallback& callback);
+  void SetDeviceCredentials(uint64 device_android_id,
+                            uint64 device_security_token,
+                            const UpdateCallback& callback);
+  void AddIncomingMessage(const std::string& persistent_id,
+                          const UpdateCallback& callback);
+  void RemoveIncomingMessages(const PersistentIdList& persistent_ids,
+                              const UpdateCallback& callback);
+  void AddOutgoingMessage(const std::string& persistent_id,
+                          const MCSMessage& message,
+                          const UpdateCallback& callback);
+  void RemoveOutgoingMessages(const PersistentIdList& persistent_ids,
+                              const UpdateCallback& callback);
+
+ private:
+  friend class base::RefCountedThreadSafe<Backend>;
+  ~Backend();
+
+  bool LoadDeviceCredentials(uint64* android_id, uint64* security_token);
+  bool LoadIncomingMessages(std::vector<std::string>* incoming_messages);
+  bool LoadOutgoingMessages(
+      std::map<std::string, google::protobuf::MessageLite*>* outgoing_messages);
+
+  const base::FilePath path_;
+  scoped_refptr<base::SequencedTaskRunner> foreground_task_runner_;
+
+  scoped_ptr<leveldb::DB> db_;
+};
+
+RMQStore::Backend::Backend(
+    const base::FilePath& path,
+    scoped_refptr<base::SequencedTaskRunner> foreground_task_runner)
+    : path_(path),
+      foreground_task_runner_(foreground_task_runner) {
+}
+
+RMQStore::Backend::~Backend() {
+}
+
+void RMQStore::Backend::Load(const LoadCallback& callback) {
+  LoadResult result;
+  std::vector<std::string> incoming_messages;
+  // Callee takes ownership of protobufs.
+  std::map<std::string, google::protobuf::MessageLite*> outgoing_messages;
+
+  leveldb::Options options;
+  options.create_if_missing = true;
+  leveldb::DB* db;
+  leveldb::Status status = leveldb::DB::Open(options, path_.value(), &db);
+  if (!status.ok()) {
+    LOG(ERROR) << "Failed to open database " << path_.value()
+               << ": " << status.ToString();
+    foreground_task_runner_->PostTask(FROM_HERE,
+                                      base::Bind(callback, result));
+    return;
+  }
+  db_.reset(db);
+
+  if (!LoadDeviceCredentials(&result.device_android_id,
+                             &result.device_security_token) ||
+      !LoadIncomingMessages(&result.incoming_messages) ||
+      !LoadOutgoingMessages(&result.outgoing_messages)) {
+    incoming_messages.clear();
+    STLDeleteContainerPairSecondPointers(outgoing_messages.begin(),
+                                         outgoing_messages.end());
+    outgoing_messages.clear();
+    foreground_task_runner_->PostTask(FROM_HERE,
+                                      base::Bind(callback, result));

[fgorski, 2013/11/01 20:26:10]

does it make sense to also clear android_id and security token of the device
before posting a callback?

[Nicolas Zea, 2013/11/01 21:18:49]

Done. (also fixed bug w.r.t. deleting/clearing wrong data)

+    return;
+  }
+
+  DVLOG(1) << "Succeeded in loading " << incoming_messages.size()
+          << " unacknowledged incoming messages and "
+          << outgoing_messages.size() << " unacknowledged outgoing messages.";
+  result.success = true;
+  foreground_task_runner_->PostTask(FROM_HERE,
+                                    base::Bind(callback, result));
+  return;
+}
+
+void RMQStore::Backend::Destroy(const UpdateCallback& callback) {
+  DVLOG(1) << "Destroying RMQ store.";
+  const leveldb::Status s =
+      leveldb::DestroyDB(path_.value(), leveldb::Options());
+  if (s.ok()) {
+    foreground_task_runner_->PostTask(FROM_HERE,
+                                      base::Bind(callback, true));
+    return;
+  }
+  LOG(ERROR) << "Destroy failed.";
+  foreground_task_runner_->PostTask(FROM_HERE,
+                                    base::Bind(callback, false));
+}
+
+void RMQStore::Backend::SetDeviceCredentials(uint64 device_android_id,
+                                             uint64 device_security_token,
+                                             const UpdateCallback& callback) {
+  DVLOG(1) << "Saving device credentials with AID " << device_android_id;
+  leveldb::WriteOptions write_options;
+  write_options.sync = true;
+
+  std::string encrypted_token;
+  Encryptor::EncryptString(base::Uint64ToString(device_security_token),
+                           &encrypted_token);
+  leveldb::Status s =
+      db_->Put(write_options,
+               MakeSlice(kDeviceAIDKey),
+               MakeSlice(base::Uint64ToString(device_android_id)));
+  if (s.ok()) {
+    s = db_->Put(write_options,
+                 MakeSlice(kDeviceTokenKey),
+                 MakeSlice(encrypted_token));
+  }
+  if (s.ok()) {
+    foreground_task_runner_->PostTask(FROM_HERE,
+                                      base::Bind(callback, true));
+    return;
+  }
+  LOG(ERROR) << "LevelDB put failed: " << s.ToString();
+  foreground_task_runner_->PostTask(FROM_HERE,
+                                    base::Bind(callback, false));
+}
+
+void RMQStore::Backend::AddIncomingMessage(const std::string& persistent_id,
+                                           const UpdateCallback& callback) {
+  DVLOG(1) << "Saving incoming message with id " << persistent_id;
+  leveldb::WriteOptions write_options;
+  write_options.sync = true;
+
+  const leveldb::Status s =
+      db_->Put(write_options,
+               MakeSlice(MakeIncomingKey(persistent_id)),
+               MakeSlice(persistent_id));
+  if (s.ok()) {
+    foreground_task_runner_->PostTask(FROM_HERE,
+                                      base::Bind(callback, true));
+    return;
+  }
+  LOG(ERROR) << "LevelDB put failed: " << s.ToString();
+  foreground_task_runner_->PostTask(FROM_HERE,
+                                    base::Bind(callback, false));
+}
+
+void RMQStore::Backend::RemoveIncomingMessages(
+    const PersistentIdList& persistent_ids,
+    const UpdateCallback& callback) {
+  leveldb::WriteOptions write_options;
+  write_options.sync = true;
+
+  leveldb::Status s;
+  for (PersistentIdList::const_iterator iter = persistent_ids.begin();
+       iter != persistent_ids.end(); ++iter){
+    DVLOG(1) << "Removing incoming message with id " << *iter;
+    s = db_->Delete(write_options,
+                    MakeSlice(MakeIncomingKey(*iter)));
+    if (!s.ok())
+      break;
+  }
+  if (s.ok()) {

[fgorski, 2013/11/01 20:26:10]

What is the default value of s.ok()?

[Nicolas Zea, 2013/11/01 21:18:49]

default is true.

+    foreground_task_runner_->PostTask(FROM_HERE,
+                                      base::Bind(callback, true));
+    return;
+  }
+  LOG(ERROR) << "LevelDB remove failed: " << s.ToString();
+  foreground_task_runner_->PostTask(FROM_HERE,
+                                    base::Bind(callback, false));
+}
+
+void RMQStore::Backend::AddOutgoingMessage(
+   const std::string& persistent_id,
+   const MCSMessage& message,
+   const UpdateCallback& callback) {
+  DVLOG(1) << "Saving outgoing message with id " << persistent_id;
+  leveldb::WriteOptions write_options;
+  write_options.sync = true;
+
+  std::string data = static_cast<char>(message.tag()) +
+      message.SerializeAsString();
+  const leveldb::Status s =
+      db_->Put(write_options,
+               MakeSlice(MakeOutgoingKey(persistent_id)),
+               MakeSlice(data));
+  if (s.ok()) {
+    foreground_task_runner_->PostTask(FROM_HERE,
+                                      base::Bind(callback, true));
+    return;
+  }
+  LOG(ERROR) << "LevelDB put failed: " << s.ToString();
+  foreground_task_runner_->PostTask(FROM_HERE,
+                                    base::Bind(callback, false));
+
+}
+
+void RMQStore::Backend::RemoveOutgoingMessages(
+    const PersistentIdList& persistent_ids,
+    const UpdateCallback& callback) {
+  leveldb::WriteOptions write_options;
+  write_options.sync = true;
+
+  leveldb::Status s;
+  for (PersistentIdList::const_iterator iter = persistent_ids.begin();
+       iter != persistent_ids.end(); ++iter){
+    DVLOG(1) << "Removing outgoing message with id " << *iter;
+    s = db_->Delete(write_options,
+                    MakeSlice(MakeOutgoingKey(*iter)));
+    if (!s.ok())
+      break;
+  }
+  if (s.ok()) {
+    foreground_task_runner_->PostTask(FROM_HERE,
+                                      base::Bind(callback, true));
+    return;
+  }
+  LOG(ERROR) << "LevelDB remove failed: " << s.ToString();
+  foreground_task_runner_->PostTask(FROM_HERE,
+                                    base::Bind(callback, false));
+}
+
+bool RMQStore::Backend::LoadDeviceCredentials(uint64* android_id,
+                                              uint64* security_token) {
+  leveldb::ReadOptions read_options;
+  read_options.verify_checksums = true;
+
+  std::string result;
+  leveldb::Status s = db_->Get(read_options,
+                               MakeSlice(kDeviceAIDKey),
+                               &result);
+  if (s.ok()) {
+    if (!base::StringToUint64(result, android_id)) {
+      LOG(ERROR) << "Failed to restore device id.";
+      return false;
+    }
+    result.clear();
+    s = db_->Get(read_options,
+                 MakeSlice(kDeviceTokenKey),
+                 &result);
+  }
+  if (s.ok()) {
+    std::string decrypted_token;
+    Encryptor::DecryptString(result, &decrypted_token);
+    if (!base::StringToUint64(decrypted_token, security_token)) {
+      LOG(ERROR) << "Failed to restore security token.";
+      return false;
+    }
+    return true;
+  }
+
+  if (s.IsNotFound()) {
+    DVLOG(1) << "No credentials found.";
+    return true;
+  }
+
+  LOG(ERROR) << "Error reading credentials from store.";
+  return false;
+}
+
+bool RMQStore::Backend::LoadIncomingMessages(
+    std::vector<std::string>* incoming_messages) {
+  leveldb::ReadOptions read_options;
+  read_options.verify_checksums = true;
+
+  scoped_ptr<leveldb::Iterator> iter(db_->NewIterator(read_options));
+  for (iter->Seek(MakeSlice(kIncomingMsgKeyStart));
+       iter->Valid() && iter->key().ToString() < kIncomingMsgKeyEnd;
+       iter->Next()) {
+    leveldb::Slice s = iter->value();
+    if (s.empty()) {
+      LOG(ERROR) << "Error reading incoming message with key "
+                 << iter->key().ToString();
+      return false;
+    }
+    DVLOG(1) << "Found incoming message with id " << s.ToString();
+    incoming_messages->push_back(s.ToString());
+  }
+
+  return true;
+}
+
+bool RMQStore::Backend::LoadOutgoingMessages(
+    std::map<std::string, google::protobuf::MessageLite*>*
+        outgoing_messages) {
+  leveldb::ReadOptions read_options;
+  read_options.verify_checksums = true;
+
+  scoped_ptr<leveldb::Iterator> iter(db_->NewIterator(read_options));
+  for (iter->Seek(MakeSlice(kOutgoingMsgKeyStart));
+       iter->Valid() && iter->key().ToString() < kOutgoingMsgKeyEnd;
+       iter->Next()) {
+    leveldb::Slice s = iter->value();
+    if (s.empty() || iter->value().size() <= 1) {

[fgorski, 2013/11/01 20:26:10]

replace iter->value() with s
check if it is possible to get rid of s.empty since you have <=1 

[Nicolas Zea, 2013/11/01 21:18:49]

Done.

+      LOG(ERROR) << "Error reading incoming message with key " << s.ToString();
+      return false;
+    }
+    uint8 tag = iter->value().data()[0];
+    std::string id = ParseOutgoingKey(iter->key().ToString());
+    scoped_ptr<google::protobuf::MessageLite> message(
+        BuildProtobufFromTag(tag));
+    if (!message.get() ||
+        !message->ParseFromString(iter->value().ToString().substr(1))) {
+      LOG(ERROR) << "Failed to parse outgoing message with id "
+                 << id << " and tag " << tag;
+      return false;
+    }
+    DVLOG(1) << "Found outgoing message with id " << id << " of type "
+             << base::IntToString(tag);
+    (*outgoing_messages)[id] = message.release();
+  }
+
+  return true;
+}
+
+RMQStore::LoadResult::LoadResult()
+    : success(false),
+      device_android_id(0),
+      device_security_token(0) {
+}
+RMQStore::LoadResult::~LoadResult() {}
+
+RMQStore::RMQStore(
+    const base::FilePath& path,
+    scoped_refptr<base::SequencedTaskRunner> blocking_task_runner)
+  : backend_(new Backend(path, base::MessageLoopProxy::current())),
+    blocking_task_runner_(blocking_task_runner) {
+}
+
+RMQStore::~RMQStore() {
+}
+
+void RMQStore::Load(const LoadCallback& callback) {
+  blocking_task_runner_->PostTask(FROM_HERE,
+                                  base::Bind(&RMQStore::Backend::Load,
+                                             backend_,
+                                             callback));
+}
+
+void RMQStore::Destroy(const UpdateCallback& callback) {
+  blocking_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&RMQStore::Backend::Destroy,
+                 backend_,
+                 callback));
+}
+
+void RMQStore::SetDeviceCredentials(uint64 device_android_id,
+                                    uint64 device_security_token,
+                                    const UpdateCallback& callback) {
+  blocking_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&RMQStore::Backend::SetDeviceCredentials,
+                 backend_,
+                 device_android_id,
+                 device_security_token,
+                 callback));
+}
+
+void RMQStore::AddIncomingMessage(const std::string& persistent_id,
+                                  const UpdateCallback& callback) {
+  blocking_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&RMQStore::Backend::AddIncomingMessage,
+                 backend_,
+                 persistent_id,
+                 callback));
+}
+
+void RMQStore::RemoveIncomingMessage(const std::string& persistent_id,
+                                     const UpdateCallback& callback) {
+  blocking_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&RMQStore::Backend::RemoveIncomingMessages,
+                 backend_,
+                 PersistentIdList(1, persistent_id),
+                 callback));
+}
+
+void RMQStore::RemoveIncomingMessages(const PersistentIdList& persistent_ids,
+                                      const UpdateCallback& callback) {
+  blocking_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&RMQStore::Backend::RemoveIncomingMessages,
+                 backend_,
+                 persistent_ids,
+                 callback));
+}
+
+void RMQStore::AddOutgoingMessage(const std::string& persistent_id,
+                                  const MCSMessage& message,
+                                  const UpdateCallback& callback) {
+  blocking_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&RMQStore::Backend::AddOutgoingMessage,
+                 backend_,
+                 persistent_id,
+                 message,
+                 callback));
+}
+
+void RMQStore::RemoveOutgoingMessage(const std::string& persistent_id,
+                                     const UpdateCallback& callback) {
+  blocking_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&RMQStore::Backend::RemoveOutgoingMessages,
+                 backend_,
+                 PersistentIdList(1, persistent_id),
+                 callback));
+}
+
+void RMQStore::RemoveOutgoingMessages(const PersistentIdList& persistent_ids,
+                                      const UpdateCallback& callback) {
+  blocking_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&RMQStore::Backend::RemoveOutgoingMessages,
+                 backend_,
+                 persistent_ids,
+                 callback));
+}
+
+}  // namespace gcm