1 // Copyright 2020 The Pigweed Authors
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not
4 // use this file except in compliance with the License. You may obtain a copy of
5 // the License at
6 //
7 // https://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
12 // License for the specific language governing permissions and limitations under
13 // the License.
14
15 #include "pw_kvs/checksum.h"
16
17 #include "gtest/gtest.h"
18 #include "pw_kvs/crc16_checksum.h"
19
20 namespace pw::kvs {
21 namespace {
22
23 using std::byte;
24
25 constexpr std::string_view kString =
26 "In the beginning the Universe was created. This has made a lot of "
27 "people very angry and been widely regarded as a bad move.";
28 constexpr uint16_t kStringCrc = 0xC184;
29
TEST(Checksum,UpdateAndVerify)30 TEST(Checksum, UpdateAndVerify) {
31 ChecksumCrc16 crc16_algo;
32 ChecksumAlgorithm& algo = crc16_algo;
33
34 algo.Update(kString.data(), kString.size());
35 EXPECT_EQ(OkStatus(), algo.Verify(std::as_bytes(std::span(&kStringCrc, 1))));
36 }
37
TEST(Checksum,Verify_Failure)38 TEST(Checksum, Verify_Failure) {
39 ChecksumCrc16 algo;
40 EXPECT_EQ(Status::DataLoss(),
41 algo.Verify(std::as_bytes(std::span(kString.data(), 2))));
42 }
43
TEST(Checksum,Verify_InvalidSize)44 TEST(Checksum, Verify_InvalidSize) {
45 ChecksumCrc16 algo;
46 EXPECT_EQ(Status::InvalidArgument(), algo.Verify({}));
47 EXPECT_EQ(Status::InvalidArgument(),
48 algo.Verify(std::as_bytes(std::span(kString.substr(0, 1)))));
49 }
50
TEST(Checksum,Verify_LargerState_ComparesToTruncatedData)51 TEST(Checksum, Verify_LargerState_ComparesToTruncatedData) {
52 byte crc[3] = {byte{0x84}, byte{0xC1}, byte{0x33}};
53 ChecksumCrc16 algo;
54 ASSERT_GT(sizeof(crc), algo.size_bytes());
55
56 algo.Update(std::as_bytes(std::span(kString)));
57
58 EXPECT_EQ(OkStatus(), algo.Verify(crc));
59 }
60
TEST(Checksum,Reset)61 TEST(Checksum, Reset) {
62 ChecksumCrc16 crc_algo;
63 crc_algo.Update(std::as_bytes(std::span(kString)));
64 crc_algo.Reset();
65
66 std::span state = crc_algo.Finish();
67 EXPECT_EQ(state[0], byte{0xFF});
68 EXPECT_EQ(state[1], byte{0xFF});
69 }
70
TEST(IgnoreChecksum,NeverUpdate_VerifyWithoutData)71 TEST(IgnoreChecksum, NeverUpdate_VerifyWithoutData) {
72 IgnoreChecksum checksum;
73
74 EXPECT_EQ(OkStatus(), checksum.Verify({}));
75 }
76
TEST(IgnoreChecksum,NeverUpdate_VerifyWithData)77 TEST(IgnoreChecksum, NeverUpdate_VerifyWithData) {
78 IgnoreChecksum checksum;
79
80 EXPECT_EQ(OkStatus(), checksum.Verify(std::as_bytes(std::span(kString))));
81 }
82
TEST(IgnoreChecksum,AfterUpdate_Verify)83 TEST(IgnoreChecksum, AfterUpdate_Verify) {
84 IgnoreChecksum checksum;
85
86 checksum.Update(std::as_bytes(std::span(kString)));
87 EXPECT_EQ(OkStatus(), checksum.Verify({}));
88 }
89
90 constexpr size_t kAlignment = 10;
91
92 constexpr std::string_view kData =
93 "123456789_123456789_123456789_123456789_123456789_" // 50
94 "123456789_123456789_123456789_123456789_123456789_"; // 100
95 const std::span<const byte> kBytes = std::as_bytes(std::span(kData));
96
97 class PickyChecksum final : public AlignedChecksum<kAlignment, 32> {
98 public:
PickyChecksum()99 PickyChecksum() : AlignedChecksum(data_), data_{}, size_(0) {}
100
Reset()101 void Reset() override {}
102
FinalizeAligned()103 void FinalizeAligned() override { EXPECT_EQ(kData.size(), size_); }
104
UpdateAligned(std::span<const std::byte> data)105 void UpdateAligned(std::span<const std::byte> data) override {
106 ASSERT_EQ(data.size() % kAlignment, 0u);
107 EXPECT_EQ(kData.substr(0, data.size()),
108 std::string_view(reinterpret_cast<const char*>(data.data()),
109 data.size()));
110
111 std::memcpy(&data_[size_], data.data(), data.size());
112 size_ += data.size();
113 }
114
115 private:
116 std::byte data_[kData.size()];
117 size_t size_;
118 };
119
TEST(AlignedChecksum,MaintainsAlignment)120 TEST(AlignedChecksum, MaintainsAlignment) {
121 PickyChecksum checksum;
122
123 // Write values smaller than the alignment.
124 checksum.Update(kBytes.subspan(0, 1));
125 checksum.Update(kBytes.subspan(1, 9));
126
127 // Write values larger than the alignment but smaller than the buffer.
128 checksum.Update(kBytes.subspan(10, 11));
129
130 // Exactly fill the remainder of the buffer.
131 checksum.Update(kBytes.subspan(21, 11));
132
133 // Fill the buffer more than once.
134 checksum.Update(kBytes.subspan(32, 66));
135
136 // Write nothing.
137 checksum.Update(kBytes.subspan(98, 0));
138
139 // Write the remaining data.
140 checksum.Update(kBytes.subspan(98, 2));
141
142 auto state = checksum.Finish();
143 EXPECT_EQ(std::string_view(reinterpret_cast<const char*>(state.data()),
144 state.size()),
145 kData);
146 EXPECT_EQ(OkStatus(), checksum.Verify(kBytes));
147 }
148
149 } // namespace
150 } // namespace pw::kvs
151