1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
|
// Copyright 2021 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CHROMEOS_ASH_COMPONENTS_FILE_MANAGER_SPEEDOMETER_H_
#define CHROMEOS_ASH_COMPONENTS_FILE_MANAGER_SPEEDOMETER_H_
#include "base/component_export.h"
#include "base/containers/ring_buffer.h"
#include "base/time/time.h"
namespace file_manager {
// Calculates the remaining time for an operation based on the initial total
// bytes and the amount of bytes transferred on each `sample`.
//
// It estimates when the total bytes will be reached and exposes the "remaining
// time" from now until the projected end time.
class COMPONENT_EXPORT(FILE_MANAGER) Speedometer {
public:
// Sets the expected total number of bytes for the operation.
void SetTotalBytes(int64_t total_bytes);
// Gets the number of samples currently maintained.
size_t GetSampleCount() const;
// Gets the projected remaining time. It can be negative, or TimeDelta::Max()
// if there aren't enough samples yet.
base::TimeDelta GetRemainingTime() const;
// Adds a sample with the current timestamp and the given number of bytes.
// Does nothing if the previous sample was received less than 3 seconds ago.
// Returns true if the sample was taken in account.
// `total_processed_bytes`: Total bytes processed by the task so far.
bool Update(int64_t bytes);
private:
struct Sample {
// Time when the sample was created.
base::TimeTicks time;
// Total bytes processed up to this point in time.
int64_t bytes;
};
// The expected total number of bytes, which will be reached when the task
// finishes.
int64_t total_bytes_ = 0;
// Maintains the 20 most recent samples.
base::RingBuffer<Sample, 20> samples_;
};
} // namespace file_manager
#endif // CHROMEOS_ASH_COMPONENTS_FILE_MANAGER_SPEEDOMETER_H_
|
