1 // Copyright 2017 The Chromium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #ifndef COMPONENTS_METRICS_LOG_STORE_H_
6 #define COMPONENTS_METRICS_LOG_STORE_H_
10 #include "base/strings/string_piece.h"
11 #include "third_party/abseil-cpp/absl/types/optional.h"
15 // Interface for local storage of serialized logs to be reported.
16 // It allows consumers to check if there are logs to consume, consume them one
17 // at a time by staging and discarding logs, and persist/load the whole set.
20 virtual ~LogStore() = default;
22 // Returns true if there are any logs waiting to be uploaded.
23 virtual bool has_unsent_logs() const = 0;
25 // Returns true if there is a log that needs to be, or is being, uploaded.
26 virtual bool has_staged_log() const = 0;
28 // The text of the staged log, as a serialized protobuf.
29 // Will trigger a DCHECK if there is no staged log.
30 virtual const std::string& staged_log() const = 0;
32 // The SHA1 hash of the staged log. This is used to detect log corruption.
33 // Will trigger a DCHECK if there is no staged log.
34 virtual const std::string& staged_log_hash() const = 0;
36 // The HMAC-SHA256 signature of the staged log. This is used to validate that
37 // a log originated from Chrome, and to detect corruption.
38 // Will trigger a DCHECK if there is no staged log.
39 virtual const std::string& staged_log_signature() const = 0;
41 // User id associated with the staged log. Empty if the log was
42 // recorded during no particular user session or during guest session.
44 // Will trigger a DCHECK if there is no staged log.
45 virtual absl::optional<uint64_t> staged_log_user_id() const = 0;
47 // Populates staged_log() with the next stored log to send.
48 // The order in which logs are staged is up to the implementor.
49 // The staged_log must remain the same even if additional logs are added.
50 // Should only be called if has_unsent_logs() is true.
51 virtual void StageNextLog() = 0;
53 // Discards the staged log. |reason| is the reason why the log was discarded
54 // (used for debugging through chrome://metrics-internals).
55 virtual void DiscardStagedLog(base::StringPiece reason = "") = 0;
57 // Marks the staged log as sent, DiscardStagedLog() shall still be called if
58 // the staged log needs discarded.
59 virtual void MarkStagedLogAsSent() = 0;
61 // Trims saved logs and writes them to persistent storage. When
62 // |overwrite_in_memory_store| is false, we will still not persist logs that
63 // should be trimmed away, but they will still be available in memory
64 // (allowing them to still be eligible for upload this session).
65 // TODO(crbug/1171830): Revisit call sites and determine what value of
66 // |overwrite_in_memory_store| they should use.
67 virtual void TrimAndPersistUnsentLogs(bool overwrite_in_memory_store) = 0;
69 // Loads unsent logs from persistent storage.
70 virtual void LoadPersistedUnsentLogs() = 0;
73 } // namespace metrics
75 #endif // COMPONENTS_METRICS_LOG_STORE_H_