| // 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. |
| |
| #ifndef COMPONENTS_METRICS_UNSENT_LOG_STORE_H_ |
| #define COMPONENTS_METRICS_UNSENT_LOG_STORE_H_ |
| |
| #include <stddef.h> |
| |
| #include <memory> |
| #include <string> |
| #include <vector> |
| |
| #include "base/logging.h" |
| #include "base/macros.h" |
| #include "base/values.h" |
| #include "components/metrics/log_store.h" |
| |
| class PrefService; |
| |
| namespace metrics { |
| |
| class UnsentLogStoreMetrics; |
| |
| // Maintains a list of unsent logs that are written and restored from disk. |
| class UnsentLogStore : public LogStore { |
| public: |
| // Constructs an UnsentLogStore that stores data in |local_state| under the |
| // preference |pref_name|. |
| // Calling code is responsible for ensuring that the lifetime of |local_state| |
| // is longer than the lifetime of UnsentLogStore. |
| // |
| // When saving logs to disk, stores either the first |min_log_count| logs, or |
| // at least |min_log_bytes| bytes of logs, whichever is greater. |
| // |
| // If the optional |max_log_size| parameter is non-zero, all logs larger than |
| // that limit will be skipped when writing to disk. |
| // |
| // |signing_key| is used to produce an HMAC-SHA256 signature of the logged |
| // data, which will be uploaded with the log and used to validate data |
| // integrity. |
| UnsentLogStore(std::unique_ptr<UnsentLogStoreMetrics> metrics, |
| PrefService* local_state, |
| const char* pref_name, |
| size_t min_log_count, |
| size_t min_log_bytes, |
| size_t max_log_size, |
| const std::string& signing_key); |
| ~UnsentLogStore(); |
| |
| // LogStore: |
| bool has_unsent_logs() const override; |
| bool has_staged_log() const override; |
| const std::string& staged_log() const override; |
| const std::string& staged_log_hash() const override; |
| const std::string& staged_log_signature() const override; |
| void StageNextLog() override; |
| void DiscardStagedLog() override; |
| void PersistUnsentLogs() const override; |
| void LoadPersistedUnsentLogs() override; |
| |
| // Adds a log to the list. |
| void StoreLog(const std::string& log_data); |
| |
| // Delete all logs, in memory and on disk. |
| void Purge(); |
| |
| // Returns the timestamp of the element in the front of the list. |
| const std::string& staged_log_timestamp() const; |
| |
| // The number of elements currently stored. |
| size_t size() const { return list_.size(); } |
| |
| private: |
| // Writes the list to the ListValue. |
| void WriteLogsToPrefList(base::ListValue* list) const; |
| |
| // Reads the list from the ListValue. |
| void ReadLogsFromPrefList(const base::ListValue& list); |
| |
| // An object for recording UMA metrics. |
| std::unique_ptr<UnsentLogStoreMetrics> metrics_; |
| |
| // A weak pointer to the PrefService object to read and write the preference |
| // from. Calling code should ensure this object continues to exist for the |
| // lifetime of the UnsentLogStore object. |
| PrefService* local_state_; |
| |
| // The name of the preference to serialize logs to/from. |
| const char* pref_name_; |
| |
| // We will keep at least this |min_log_count_| logs or |min_log_bytes_| bytes |
| // of logs, whichever is greater, when writing to disk. These apply after |
| // skipping logs greater than |max_log_size_|. |
| const size_t min_log_count_; |
| const size_t min_log_bytes_; |
| |
| // Logs greater than this size will not be written to disk. |
| const size_t max_log_size_; |
| |
| // Used to create a signature of log data, in order to verify reported data is |
| // authentic. |
| const std::string signing_key_; |
| |
| struct LogInfo { |
| LogInfo(); |
| LogInfo(const LogInfo& other); |
| ~LogInfo(); |
| |
| // Initializes the members based on uncompressed |log_data|, |
| // |log_timestamp|, and |signing_key|. |log_data| is the uncompressed |
| // serialized log protobuf. A hash and a signature are computed from |
| // |log_data|. The signature is produced using |signing_key|. |log_data| |
| // will be compressed and stored in |compressed_log_data|. |log_timestamp| |
| // is stored as is. |
| // |metrics| is the parent's metrics_ object, and should not be held. |
| void Init(UnsentLogStoreMetrics* metrics, |
| const std::string& log_data, |
| const std::string& log_timestamp, |
| const std::string& signing_key); |
| |
| // Compressed log data - a serialized protobuf that's been gzipped. |
| std::string compressed_log_data; |
| |
| // The SHA1 hash of the log. Computed in Init and stored to catch errors |
| // from memory corruption. |
| std::string hash; |
| |
| // The HMAC-SHA256 signature of the log, used to validate the log came from |
| // Chrome. It's computed in Init and stored, instead of computed on demand, |
| // to catch errors from memory corruption. |
| std::string signature; |
| |
| // The timestamp of when the log was created as a time_t value. |
| std::string timestamp; |
| }; |
| // A list of all of the stored logs, stored with SHA1 hashes to check for |
| // corruption while they are stored in memory. |
| std::vector<LogInfo> list_; |
| |
| // The index and type of the log staged for upload. If nothing has been |
| // staged, the index will be -1. |
| int staged_log_index_; |
| |
| DISALLOW_COPY_AND_ASSIGN(UnsentLogStore); |
| }; |
| |
| } // namespace metrics |
| |
| #endif // COMPONENTS_METRICS_UNSENT_LOG_STORE_H_ |