| // Copyright 2014 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 "components/metrics/unsent_log_store.h" |
| |
| #include <cmath> |
| #include <memory> |
| #include <string> |
| #include <utility> |
| |
| #include "base/base64.h" |
| #include "base/hash/sha1.h" |
| #include "base/metrics/histogram_macros.h" |
| #include "base/strings/string_number_conversions.h" |
| #include "base/strings/string_util.h" |
| #include "base/timer/elapsed_timer.h" |
| #include "components/metrics/unsent_log_store_metrics.h" |
| #include "components/prefs/pref_service.h" |
| #include "components/prefs/scoped_user_pref_update.h" |
| #include "crypto/hmac.h" |
| #include "third_party/zlib/google/compression_utils.h" |
| |
| namespace metrics { |
| |
| namespace { |
| |
| const char kLogHashKey[] = "hash"; |
| const char kLogSignatureKey[] = "signature"; |
| const char kLogTimestampKey[] = "timestamp"; |
| const char kLogDataKey[] = "data"; |
| const char kLogUnsentCountKey[] = "unsent_samples_count"; |
| const char kLogSentCountKey[] = "sent_samples_count"; |
| const char kLogPersistedSizeInKbKey[] = "unsent_persisted_size_in_kb"; |
| const char kLogUserIdKey[] = "user_id"; |
| |
| std::string EncodeToBase64(const std::string& to_convert) { |
| DCHECK(to_convert.data()); |
| std::string base64_result; |
| base::Base64Encode(to_convert, &base64_result); |
| return base64_result; |
| } |
| |
| std::string DecodeFromBase64(const std::string& to_convert) { |
| std::string result; |
| base::Base64Decode(to_convert, &result); |
| return result; |
| } |
| |
| } // namespace |
| |
| UnsentLogStore::LogInfo::LogInfo() = default; |
| UnsentLogStore::LogInfo::LogInfo(const UnsentLogStore::LogInfo& other) = |
| default; |
| UnsentLogStore::LogInfo::~LogInfo() = default; |
| |
| void UnsentLogStore::LogInfo::Init(UnsentLogStoreMetrics* metrics, |
| const std::string& log_data, |
| const std::string& log_timestamp, |
| const std::string& signing_key, |
| const LogMetadata& optional_log_metadata) { |
| DCHECK(!log_data.empty()); |
| |
| if (!compression::GzipCompress(log_data, &compressed_log_data)) { |
| NOTREACHED(); |
| return; |
| } |
| |
| metrics->RecordCompressionRatio(compressed_log_data.size(), log_data.size()); |
| |
| hash = base::SHA1HashString(log_data); |
| |
| if (!ComputeHMACForLog(log_data, signing_key, &signature)) { |
| NOTREACHED() << "HMAC signing failed"; |
| } |
| |
| timestamp = log_timestamp; |
| this->log_metadata = optional_log_metadata; |
| } |
| |
| UnsentLogStore::UnsentLogStore(std::unique_ptr<UnsentLogStoreMetrics> metrics, |
| PrefService* local_state, |
| const char* log_data_pref_name, |
| const char* metadata_pref_name, |
| size_t min_log_count, |
| size_t min_log_bytes, |
| size_t max_log_size, |
| const std::string& signing_key) |
| : metrics_(std::move(metrics)), |
| local_state_(local_state), |
| log_data_pref_name_(log_data_pref_name), |
| metadata_pref_name_(metadata_pref_name), |
| min_log_count_(min_log_count), |
| min_log_bytes_(min_log_bytes), |
| max_log_size_(max_log_size != 0 ? max_log_size : static_cast<size_t>(-1)), |
| signing_key_(signing_key), |
| staged_log_index_(-1) { |
| DCHECK(local_state_); |
| // One of the limit arguments must be non-zero. |
| DCHECK(min_log_count_ > 0 || min_log_bytes_ > 0); |
| } |
| |
| UnsentLogStore::~UnsentLogStore() {} |
| |
| bool UnsentLogStore::has_unsent_logs() const { |
| return !!size(); |
| } |
| |
| // True if a log has been staged. |
| bool UnsentLogStore::has_staged_log() const { |
| return staged_log_index_ != -1; |
| } |
| |
| // Returns the compressed data of the element in the front of the list. |
| const std::string& UnsentLogStore::staged_log() const { |
| DCHECK(has_staged_log()); |
| return list_[staged_log_index_]->compressed_log_data; |
| } |
| |
| // Returns the hash of element in the front of the list. |
| const std::string& UnsentLogStore::staged_log_hash() const { |
| DCHECK(has_staged_log()); |
| return list_[staged_log_index_]->hash; |
| } |
| |
| // Returns the signature of element in the front of the list. |
| const std::string& UnsentLogStore::staged_log_signature() const { |
| DCHECK(has_staged_log()); |
| return list_[staged_log_index_]->signature; |
| } |
| |
| // Returns the timestamp of the element in the front of the list. |
| const std::string& UnsentLogStore::staged_log_timestamp() const { |
| DCHECK(has_staged_log()); |
| return list_[staged_log_index_]->timestamp; |
| } |
| |
| // Returns the user id of the current staged log. |
| absl::optional<uint64_t> UnsentLogStore::staged_log_user_id() const { |
| DCHECK(has_staged_log()); |
| return list_[staged_log_index_]->log_metadata.user_id; |
| } |
| |
| // static |
| bool UnsentLogStore::ComputeHMACForLog(const std::string& log_data, |
| const std::string& signing_key, |
| std::string* signature) { |
| crypto::HMAC hmac(crypto::HMAC::SHA256); |
| const size_t digest_length = hmac.DigestLength(); |
| unsigned char* hmac_data = reinterpret_cast<unsigned char*>( |
| base::WriteInto(signature, digest_length + 1)); |
| return hmac.Init(signing_key) && |
| hmac.Sign(log_data, hmac_data, digest_length); |
| } |
| |
| void UnsentLogStore::StageNextLog() { |
| // CHECK, rather than DCHECK, because swap()ing with an empty list causes |
| // hard-to-identify crashes much later. |
| CHECK(!list_.empty()); |
| DCHECK(!has_staged_log()); |
| staged_log_index_ = list_.size() - 1; |
| DCHECK(has_staged_log()); |
| } |
| |
| void UnsentLogStore::DiscardStagedLog() { |
| DCHECK(has_staged_log()); |
| DCHECK_LT(static_cast<size_t>(staged_log_index_), list_.size()); |
| list_.erase(list_.begin() + staged_log_index_); |
| staged_log_index_ = -1; |
| } |
| |
| void UnsentLogStore::MarkStagedLogAsSent() { |
| DCHECK(has_staged_log()); |
| DCHECK_LT(static_cast<size_t>(staged_log_index_), list_.size()); |
| auto samples_count = list_[staged_log_index_]->log_metadata.samples_count; |
| if (samples_count.has_value()) |
| total_samples_sent_ += samples_count.value(); |
| } |
| |
| void UnsentLogStore::TrimAndPersistUnsentLogs() { |
| ListPrefUpdate update(local_state_, log_data_pref_name_); |
| TrimLogs(); |
| WriteLogsToPrefList(update.Get()); |
| } |
| |
| void UnsentLogStore::LoadPersistedUnsentLogs() { |
| ReadLogsFromPrefList(*local_state_->GetList(log_data_pref_name_)); |
| RecordMetaDataMetrics(); |
| } |
| |
| void UnsentLogStore::StoreLog(const std::string& log_data, |
| const LogMetadata& log_metadata) { |
| LogInfo info; |
| info.Init(metrics_.get(), log_data, |
| base::NumberToString(base::Time::Now().ToTimeT()), signing_key_, |
| log_metadata); |
| list_.emplace_back(std::make_unique<LogInfo>(info)); |
| } |
| |
| const std::string& UnsentLogStore::GetLogAtIndex(size_t index) { |
| DCHECK_GE(index, 0U); |
| DCHECK_LT(index, list_.size()); |
| return list_[index]->compressed_log_data; |
| } |
| |
| std::string UnsentLogStore::ReplaceLogAtIndex(size_t index, |
| const std::string& new_log_data, |
| const LogMetadata& log_metadata) { |
| DCHECK_GE(index, 0U); |
| DCHECK_LT(index, list_.size()); |
| |
| // Avoid copying of long strings. |
| std::string old_log_data; |
| old_log_data.swap(list_[index]->compressed_log_data); |
| std::string old_timestamp; |
| old_timestamp.swap(list_[index]->timestamp); |
| |
| // TODO(rkaplow): Would be a bit simpler if we had a method that would |
| // just return a pointer to the logInfo so we could combine the next 3 lines. |
| LogInfo info; |
| info.Init(metrics_.get(), new_log_data, old_timestamp, signing_key_, |
| log_metadata); |
| |
| list_[index] = std::make_unique<LogInfo>(info); |
| return old_log_data; |
| } |
| |
| void UnsentLogStore::Purge() { |
| if (has_staged_log()) { |
| DiscardStagedLog(); |
| } |
| list_.clear(); |
| local_state_->ClearPref(log_data_pref_name_); |
| // The |total_samples_sent_| isn't cleared intentionally because it is still |
| // meaningful. |
| if (metadata_pref_name_) |
| local_state_->ClearPref(metadata_pref_name_); |
| } |
| |
| void UnsentLogStore::ReadLogsFromPrefList(const base::Value& list_value) { |
| if (list_value.GetListDeprecated().empty()) { |
| metrics_->RecordLogReadStatus(UnsentLogStoreMetrics::LIST_EMPTY); |
| return; |
| } |
| |
| const size_t log_count = list_value.GetListDeprecated().size(); |
| |
| DCHECK(list_.empty()); |
| list_.resize(log_count); |
| |
| for (size_t i = 0; i < log_count; ++i) { |
| const base::Value& value = list_value.GetListDeprecated()[i]; |
| const base::DictionaryValue* dict = nullptr; |
| if (value.is_dict()) |
| dict = &base::Value::AsDictionaryValue(value); |
| LogInfo info; |
| if (!dict || !dict->GetString(kLogDataKey, &info.compressed_log_data) || |
| !dict->GetString(kLogHashKey, &info.hash) || |
| !dict->GetString(kLogTimestampKey, &info.timestamp) || |
| !dict->GetString(kLogSignatureKey, &info.signature)) { |
| // Something is wrong, so we don't try to get any persisted logs. |
| list_.clear(); |
| metrics_->RecordLogReadStatus( |
| UnsentLogStoreMetrics::LOG_STRING_CORRUPTION); |
| return; |
| } |
| |
| info.compressed_log_data = DecodeFromBase64(info.compressed_log_data); |
| info.hash = DecodeFromBase64(info.hash); |
| info.signature = DecodeFromBase64(info.signature); |
| // timestamp doesn't need to be decoded. |
| |
| // Extract user id of the log if it exists. |
| std::string user_id_str; |
| if (dict->GetString(kLogUserIdKey, &user_id_str)) { |
| uint64_t user_id; |
| |
| // Only initialize the metadata if conversion was successful. |
| if (base::StringToUint64(DecodeFromBase64(user_id_str), &user_id)) |
| info.log_metadata.user_id = user_id; |
| } |
| |
| list_[i] = std::make_unique<LogInfo>(info); |
| } |
| |
| metrics_->RecordLogReadStatus(UnsentLogStoreMetrics::RECALL_SUCCESS); |
| } |
| |
| void UnsentLogStore::TrimLogs() { |
| std::vector<std::unique_ptr<LogInfo>> trimmed_list; |
| size_t bytes_used = 0; |
| |
| // The distance of the staged log from the end of the list of logs, which is |
| // usually 0 (end of list). This is used in case there is currently a staged |
| // log, which may or may not get trimmed. We want to keep track of the new |
| // position of the staged log after trimming so that we can update |
| // |staged_log_index_|. |
| absl::optional<size_t> staged_index_distance; |
| |
| // Reverse order, so newest ones are prioritized. |
| for (int i = list_.size() - 1; i >= 0; --i) { |
| size_t log_size = list_[i]->compressed_log_data.length(); |
| // Hit the caps, we can stop moving the logs. |
| if (bytes_used >= min_log_bytes_ && trimmed_list.size() >= min_log_count_) { |
| break; |
| } |
| // Omit overly large individual logs. |
| if (log_size > max_log_size_) { |
| metrics_->RecordDroppedLogSize(log_size); |
| continue; |
| } |
| |
| bytes_used += log_size; |
| |
| if (staged_log_index_ == i) { |
| staged_index_distance = trimmed_list.size(); |
| } |
| |
| trimmed_list.emplace_back(std::move(list_[i])); |
| } |
| |
| // We went in reverse order, but appended entries. So reverse list to correct. |
| std::reverse(trimmed_list.begin(), trimmed_list.end()); |
| |
| size_t dropped_logs_count = list_.size() - trimmed_list.size(); |
| if (dropped_logs_count > 0) |
| metrics_->RecordDroppedLogsNum(dropped_logs_count); |
| |
| // Put the trimmed list in the correct place. |
| list_.swap(trimmed_list); |
| |
| // We may need to adjust the staged index since the number of logs may be |
| // reduced. However, we want to make sure not to change the index if there is |
| // no log staged. |
| if (staged_index_distance.has_value()) { |
| staged_log_index_ = list_.size() - 1 - staged_index_distance.value(); |
| } else { |
| // Set |staged_log_index_| to -1. It might already be -1. E.g., at the time |
| // we are trimming logs, there was no staged log. However, it is also |
| // possible that we trimmed away the staged log, so we need to update the |
| // index to -1. |
| staged_log_index_ = -1; |
| } |
| } |
| |
| void UnsentLogStore::WriteLogsToPrefList(base::Value* list_value) const { |
| list_value->ClearList(); |
| |
| base::HistogramBase::Count unsent_samples_count = 0; |
| size_t unsent_persisted_size = 0; |
| |
| for (auto& log : list_) { |
| base::Value dict_value{base::Value::Type::DICTIONARY}; |
| dict_value.SetStringKey(kLogHashKey, EncodeToBase64(log->hash)); |
| dict_value.SetStringKey(kLogSignatureKey, EncodeToBase64(log->signature)); |
| dict_value.SetStringKey(kLogDataKey, |
| EncodeToBase64(log->compressed_log_data)); |
| dict_value.SetStringKey(kLogTimestampKey, log->timestamp); |
| |
| auto user_id = log->log_metadata.user_id; |
| if (user_id.has_value()) { |
| dict_value.SetStringKey( |
| kLogUserIdKey, EncodeToBase64(base::NumberToString(user_id.value()))); |
| } |
| list_value->Append(std::move(dict_value)); |
| |
| auto samples_count = log->log_metadata.samples_count; |
| if (samples_count.has_value()) { |
| unsent_samples_count += samples_count.value(); |
| } |
| unsent_persisted_size += log->compressed_log_data.length(); |
| } |
| WriteToMetricsPref(unsent_samples_count, total_samples_sent_, |
| unsent_persisted_size); |
| } |
| |
| void UnsentLogStore::WriteToMetricsPref( |
| base::HistogramBase::Count unsent_samples_count, |
| base::HistogramBase::Count sent_samples_count, |
| size_t unsent_persisted_size) const { |
| if (metadata_pref_name_ == nullptr) |
| return; |
| |
| DictionaryPrefUpdate update(local_state_, metadata_pref_name_); |
| base::Value* pref_data = update.Get(); |
| pref_data->SetKey(kLogUnsentCountKey, base::Value(unsent_samples_count)); |
| pref_data->SetKey(kLogSentCountKey, base::Value(sent_samples_count)); |
| // Round up to kb. |
| pref_data->SetKey( |
| kLogPersistedSizeInKbKey, |
| base::Value(static_cast<int>(std::ceil(unsent_persisted_size / 1024.0)))); |
| } |
| |
| void UnsentLogStore::RecordMetaDataMetrics() { |
| if (metadata_pref_name_ == nullptr) |
| return; |
| |
| const base::Value* value = local_state_->GetDictionary(metadata_pref_name_); |
| if (!value) |
| return; |
| |
| auto unsent_samples_count = value->FindIntKey(kLogUnsentCountKey); |
| auto sent_samples_count = value->FindIntKey(kLogSentCountKey); |
| auto unsent_persisted_size_in_kb = |
| value->FindIntKey(kLogPersistedSizeInKbKey); |
| |
| if (unsent_samples_count && sent_samples_count && |
| unsent_persisted_size_in_kb) { |
| metrics_->RecordLastUnsentLogMetadataMetrics( |
| unsent_samples_count.value(), sent_samples_count.value(), |
| unsent_persisted_size_in_kb.value()); |
| } |
| } |
| |
| } // namespace metrics |