blob: b4f11a656959a8d8f94f1fd828e4f7d334db5bc9 [file] [log] [blame]
// 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 <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 {
// 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);
// 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);
// Gets log data at the given index in the list.
const std::string& GetLogAtIndex(size_t index);
// Replaces the compressed log at |index| in the store with given log data
// reusing the same timestamp from the original log, and returns old log data.
std::string ReplaceLogAtIndex(size_t index, const std::string& new_log_data);
// Deletes 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(); }
// 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(const LogInfo& other);
// 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_;
} // namespace metrics