1 // Copyright 2013 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "chrome/browser/sync/test/integration/retry_verifier.h"
6
7 #include <algorithm>
8
9 #include "base/logging.h"
10 #include "sync/internal_api/public/engine/polling_constants.h"
11 #include "sync/internal_api/public/sessions/sync_session_snapshot.h"
12
13 namespace {
14 // Given the current delay calculate the minimum and maximum wait times for
15 // the next retry.
CalculateDelay(int64 current_delay)16 DelayInfo CalculateDelay(int64 current_delay) {
17 int64 backoff_s = std::max(static_cast<int64>(1), current_delay *
18 syncer::kBackoffRandomizationFactor);
19
20 DelayInfo delay_info;
21 delay_info.min_delay = backoff_s + (-1 * current_delay/
22 syncer::kBackoffRandomizationFactor);
23 delay_info.max_delay = backoff_s + current_delay/2;
24
25 delay_info.min_delay = std::max(static_cast<int64>(1),
26 std::min(delay_info.min_delay, syncer::kMaxBackoffSeconds));
27
28 delay_info.max_delay = std::max(static_cast<int64>(1),
29 std::min(delay_info.max_delay, syncer::kMaxBackoffSeconds));
30
31 return delay_info;
32 }
33
34 // Fills the table with the maximum and minimum values for each retry, upto
35 // |count| number of retries.
FillDelayTable(DelayInfo * delay_table,int count)36 void FillDelayTable(DelayInfo* delay_table, int count) {
37 DCHECK(count > 1);
38
39 // We start off with the minimum value of 2 seconds.
40 delay_table[0].min_delay = static_cast<int64>(2);
41 delay_table[0].max_delay = static_cast<int64>(2);
42
43 for (int i = 1 ; i < count ; ++i) {
44 delay_table[i].min_delay = CalculateDelay(delay_table[i-1].min_delay).
45 min_delay;
46 delay_table[i].max_delay = CalculateDelay(delay_table[i-1].max_delay).
47 max_delay;
48 }
49 }
50 } // namespace
51
52 // Verifies if the current retry is on time. Note that we dont use the
53 // maximum value of the retry range in verifying, only the minimum. Reason
54 // being there is no guarantee that the retry will be on the dot. However in
55 // practice it is on the dot. But making that assumption for all the platforms
56 // would make the test flaky. However we have the global timeout for the
57 // verification which would make sure all retries take place in a reasonable
58 // amount of time. The global timeout is defined in profile sync service
59 // harness as |kExponentialBackoffVerificationTimeoutMs|.
IsRetryOnTime(DelayInfo * delay_table,int retry_count,const base::TimeDelta & time_elapsed)60 bool IsRetryOnTime(DelayInfo* delay_table, int retry_count,
61 const base::TimeDelta& time_elapsed) {
62 DVLOG(1) << "Retry Count : " << retry_count
63 << " Time elapsed : " << time_elapsed.InSeconds()
64 << " Retry table min: " << delay_table[retry_count].min_delay
65 << " Retry table max: " << delay_table[retry_count].max_delay;
66 return ((time_elapsed.InSeconds() >= delay_table[retry_count].min_delay));
67 }
68
RetryVerifier()69 RetryVerifier::RetryVerifier() : retry_count_(0),
70 success_(false),
71 done_(false) {
72 memset(&delay_table_, 0, sizeof(delay_table_));
73 }
74
~RetryVerifier()75 RetryVerifier::~RetryVerifier() {
76 }
77
78 // Initializes the state for verification.
Initialize(const syncer::sessions::SyncSessionSnapshot & snap)79 void RetryVerifier::Initialize(
80 const syncer::sessions::SyncSessionSnapshot& snap) {
81 retry_count_ = 0;
82 last_sync_time_ = snap.sync_start_time();
83 FillDelayTable(delay_table_, kMaxRetry);
84 done_ = false;
85 success_ = false;
86 }
87
VerifyRetryInterval(const syncer::sessions::SyncSessionSnapshot & snap)88 void RetryVerifier::VerifyRetryInterval(
89 const syncer::sessions::SyncSessionSnapshot& snap) {
90 DCHECK(retry_count_ < kMaxRetry);
91 if (retry_count_ == 0) {
92 if (snap.sync_start_time() != last_sync_time_) {
93 retry_count_++;
94 last_sync_time_ = snap.sync_start_time();
95 }
96 success_ = true;
97 return;
98 }
99
100 // Check if the sync start time has changed. If so indicates a new sync
101 // has taken place.
102 if (snap.sync_start_time() != last_sync_time_) {
103 base::TimeDelta delta = snap.sync_start_time() - last_sync_time_;
104 success_ = IsRetryOnTime(delay_table_,retry_count_ -1, delta);
105 last_sync_time_ = snap.sync_start_time();
106 ++retry_count_;
107 done_ = (retry_count_ >= kMaxRetry);
108 return;
109 }
110 }
111
112