1 /*
2 * Copyright (C) 2024 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "chre/util/duplicate_message_detector.h"
18
19 #include "chre/platform/system_time.h"
20
21 #include <cstdint>
22
23 namespace chre {
24
findOrAdd(uint32_t messageSequenceNumber,uint16_t hostEndpoint,bool * outIsDuplicate)25 Optional<chreError> DuplicateMessageDetector::findOrAdd(
26 uint32_t messageSequenceNumber, uint16_t hostEndpoint,
27 bool *outIsDuplicate) {
28 DuplicateMessageDetector::ReliableMessageRecord *record =
29 findLocked(messageSequenceNumber, hostEndpoint);
30 if (outIsDuplicate != nullptr) {
31 *outIsDuplicate = record != nullptr;
32 }
33
34 if (record == nullptr) {
35 record = addLocked(messageSequenceNumber, hostEndpoint);
36 if (record == nullptr) {
37 LOG_OOM();
38 if (outIsDuplicate != nullptr) {
39 *outIsDuplicate = true;
40 }
41 return CHRE_ERROR_NO_MEMORY;
42 }
43 }
44 return record->error;
45 }
46
findAndSetError(uint32_t messageSequenceNumber,uint16_t hostEndpoint,chreError error)47 bool DuplicateMessageDetector::findAndSetError(uint32_t messageSequenceNumber,
48 uint16_t hostEndpoint,
49 chreError error) {
50 DuplicateMessageDetector::ReliableMessageRecord *record =
51 findLocked(messageSequenceNumber, hostEndpoint);
52 if (record == nullptr) {
53 return false;
54 }
55
56 record->error = error;
57 return true;
58 }
59
removeOldEntries()60 void DuplicateMessageDetector::removeOldEntries() {
61 Nanoseconds now = SystemTime::getMonotonicTime();
62 while (!mReliableMessageRecordQueue.empty()) {
63 ReliableMessageRecord &record = mReliableMessageRecordQueue.top();
64 if (record.timestamp + kTimeout <= now) {
65 mReliableMessageRecordQueue.pop();
66 } else {
67 break;
68 }
69 }
70 }
71
72 DuplicateMessageDetector::ReliableMessageRecord*
addLocked(uint32_t messageSequenceNumber,uint16_t hostEndpoint)73 DuplicateMessageDetector::addLocked(
74 uint32_t messageSequenceNumber,
75 uint16_t hostEndpoint) {
76 bool success = mReliableMessageRecordQueue.push(
77 ReliableMessageRecord{
78 .timestamp = SystemTime::getMonotonicTime(),
79 .messageSequenceNumber = messageSequenceNumber,
80 .hostEndpoint = hostEndpoint,
81 .error = Optional<chreError>()});
82 return success
83 ? findLocked(messageSequenceNumber, hostEndpoint, /* reverse= */ true)
84 : nullptr;
85 }
86
87 DuplicateMessageDetector::ReliableMessageRecord*
findLocked(uint32_t messageSequenceNumber,uint16_t hostEndpoint,bool reverse)88 DuplicateMessageDetector::findLocked(uint32_t messageSequenceNumber,
89 uint16_t hostEndpoint,
90 bool reverse) {
91 for (size_t i = 0; i < mReliableMessageRecordQueue.size(); ++i) {
92 size_t index = reverse ? mReliableMessageRecordQueue.size() - i - 1 : i;
93 ReliableMessageRecord &record = mReliableMessageRecordQueue[index];
94 if (record.messageSequenceNumber == messageSequenceNumber &&
95 record.hostEndpoint == hostEndpoint) {
96 return &record;
97 }
98 }
99 return nullptr;
100 }
101
102 } // namespace chre
103