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/alignment.h"
16 
17 #include <cstring>
18 #include <string_view>
19 
20 #include "gtest/gtest.h"
21 #include "pw_status/status_with_size.h"
22 
23 namespace pw::kvs {
24 namespace {
25 
26 using namespace std::string_view_literals;
27 using std::byte;
28 
TEST(AlignUp,Zero)29 TEST(AlignUp, Zero) {
30   EXPECT_EQ(0u, AlignUp(0, 1));
31   EXPECT_EQ(0u, AlignUp(0, 2));
32   EXPECT_EQ(0u, AlignUp(0, 15));
33 }
34 
TEST(AlignUp,Aligned)35 TEST(AlignUp, Aligned) {
36   for (size_t i = 1; i < 130; ++i) {
37     EXPECT_EQ(i, AlignUp(i, i));
38     EXPECT_EQ(2 * i, AlignUp(2 * i, i));
39     EXPECT_EQ(3 * i, AlignUp(3 * i, i));
40   }
41 }
42 
TEST(AlignUp,NonAligned_PowerOf2)43 TEST(AlignUp, NonAligned_PowerOf2) {
44   EXPECT_EQ(32u, AlignUp(1, 32));
45   EXPECT_EQ(32u, AlignUp(31, 32));
46   EXPECT_EQ(64u, AlignUp(33, 32));
47   EXPECT_EQ(64u, AlignUp(45, 32));
48   EXPECT_EQ(64u, AlignUp(63, 32));
49   EXPECT_EQ(128u, AlignUp(127, 32));
50 }
51 
TEST(AlignUp,NonAligned_NonPowerOf2)52 TEST(AlignUp, NonAligned_NonPowerOf2) {
53   EXPECT_EQ(2u, AlignUp(1, 2));
54 
55   EXPECT_EQ(15u, AlignUp(1, 15));
56   EXPECT_EQ(15u, AlignUp(14, 15));
57   EXPECT_EQ(30u, AlignUp(16, 15));
58 }
59 
TEST(AlignDown,Zero)60 TEST(AlignDown, Zero) {
61   EXPECT_EQ(0u, AlignDown(0, 1));
62   EXPECT_EQ(0u, AlignDown(0, 2));
63   EXPECT_EQ(0u, AlignDown(0, 15));
64 }
65 
TEST(AlignDown,Aligned)66 TEST(AlignDown, Aligned) {
67   for (size_t i = 1; i < 130; ++i) {
68     EXPECT_EQ(i, AlignDown(i, i));
69     EXPECT_EQ(2 * i, AlignDown(2 * i, i));
70     EXPECT_EQ(3 * i, AlignDown(3 * i, i));
71   }
72 }
73 
TEST(AlignDown,NonAligned_PowerOf2)74 TEST(AlignDown, NonAligned_PowerOf2) {
75   EXPECT_EQ(0u, AlignDown(1, 32));
76   EXPECT_EQ(0u, AlignDown(31, 32));
77   EXPECT_EQ(32u, AlignDown(33, 32));
78   EXPECT_EQ(32u, AlignDown(45, 32));
79   EXPECT_EQ(32u, AlignDown(63, 32));
80   EXPECT_EQ(96u, AlignDown(127, 32));
81 }
82 
TEST(AlignDown,NonAligned_NonPowerOf2)83 TEST(AlignDown, NonAligned_NonPowerOf2) {
84   EXPECT_EQ(0u, AlignDown(1, 2));
85 
86   EXPECT_EQ(0u, AlignDown(1, 15));
87   EXPECT_EQ(0u, AlignDown(14, 15));
88   EXPECT_EQ(15u, AlignDown(16, 15));
89 }
90 
TEST(Padding,Zero)91 TEST(Padding, Zero) {
92   EXPECT_EQ(0u, Padding(0, 1));
93   EXPECT_EQ(0u, Padding(0, 2));
94   EXPECT_EQ(0u, Padding(0, 15));
95 }
96 
TEST(Padding,Aligned)97 TEST(Padding, Aligned) {
98   for (size_t i = 1; i < 130; ++i) {
99     EXPECT_EQ(0u, Padding(i, i));
100     EXPECT_EQ(0u, Padding(2 * i, i));
101     EXPECT_EQ(0u, Padding(3 * i, i));
102   }
103 }
104 
TEST(Padding,NonAligned_PowerOf2)105 TEST(Padding, NonAligned_PowerOf2) {
106   EXPECT_EQ(31u, Padding(1, 32));
107   EXPECT_EQ(1u, Padding(31, 32));
108   EXPECT_EQ(31u, Padding(33, 32));
109   EXPECT_EQ(19u, Padding(45, 32));
110   EXPECT_EQ(1u, Padding(63, 32));
111   EXPECT_EQ(1u, Padding(127, 32));
112 }
113 
TEST(Padding,NonAligned_NonPowerOf2)114 TEST(Padding, NonAligned_NonPowerOf2) {
115   EXPECT_EQ(1u, Padding(1, 2));
116 
117   EXPECT_EQ(14u, Padding(1, 15));
118   EXPECT_EQ(1u, Padding(14, 15));
119   EXPECT_EQ(14u, Padding(16, 15));
120 }
121 
122 constexpr size_t kAlignment = 10;
123 
124 constexpr std::string_view kData =
125     "123456789_123456789_123456789_123456789_123456789_"   //  50
126     "123456789_123456789_123456789_123456789_123456789_";  // 100
127 
128 const std::span<const byte> kBytes = std::as_bytes(std::span(kData));
129 
130 // The output function checks that the data is properly aligned and matches
131 // the expected value (should always be 123456789_...).
__anon09f571600202(std::span<const byte> data) 132 OutputToFunction check_against_data([](std::span<const byte> data) {
133   EXPECT_EQ(data.size() % kAlignment, 0u);
134   EXPECT_EQ(kData.substr(0, data.size()),
135             std::string_view(reinterpret_cast<const char*>(data.data()),
136                              data.size()));
137   return StatusWithSize(data.size());
138 });
139 
TEST(AlignedWriter,Write_VaryingLengths)140 TEST(AlignedWriter, Write_VaryingLengths) {
141   AlignedWriterBuffer<32> writer(kAlignment, check_against_data);
142 
143   // Write values smaller than the alignment.
144   EXPECT_EQ(OkStatus(), writer.Write(kBytes.subspan(0, 1)).status());
145   EXPECT_EQ(OkStatus(), writer.Write(kBytes.subspan(1, 9)).status());
146 
147   // Write values larger than the alignment but smaller than the buffer.
148   EXPECT_EQ(OkStatus(), writer.Write(kBytes.subspan(10, 11)).status());
149 
150   // Exactly fill the remainder of the buffer.
151   EXPECT_EQ(OkStatus(), writer.Write(kBytes.subspan(21, 11)).status());
152 
153   // Fill the buffer more than once.
154   EXPECT_EQ(OkStatus(), writer.Write(kBytes.subspan(32, 66)).status());
155 
156   // Write nothing.
157   EXPECT_EQ(OkStatus(), writer.Write(kBytes.subspan(98, 0)).status());
158 
159   // Write the remaining data.
160   EXPECT_EQ(OkStatus(), writer.Write(kBytes.subspan(98, 2)).status());
161 
162   auto result = writer.Flush();
163   EXPECT_EQ(OkStatus(), result.status());
164   EXPECT_EQ(kData.size(), result.size());
165 }
166 
TEST(AlignedWriter,DestructorFlushes)167 TEST(AlignedWriter, DestructorFlushes) {
168   static size_t called_with_bytes;
169   called_with_bytes = 0;
170 
171   OutputToFunction output([](std::span<const byte> data) {
172     called_with_bytes += data.size();
173     return StatusWithSize(data.size());
174   });
175 
176   {
177     AlignedWriterBuffer<64> writer(3, output);
178     writer.Write(std::as_bytes(std::span("What is this?")));
179     EXPECT_EQ(called_with_bytes, 0u);  // Buffer not full; no output yet.
180   }
181 
182   EXPECT_EQ(called_with_bytes, AlignUp(sizeof("What is this?"), 3));
183 }
184 
185 // Output class that can be programmed to fail for testing purposes.
186 // TODO(hepler): If we create a general pw_io / pw_stream module, this and
187 // InputWithErrorInjection should be made into generic test utility classes,
188 // similar to FakeFlashMemory.
189 struct OutputWithErrorInjection final : public Output {
190  public:
191   enum { kKeepGoing, kBreakOnNext, kBroken } state = kKeepGoing;
192 
193  private:
DoWritepw::kvs::__anon09f571600111::OutputWithErrorInjection194   StatusWithSize DoWrite(std::span<const byte> data) override {
195     switch (state) {
196       case kKeepGoing:
197         return StatusWithSize(data.size());
198       case kBreakOnNext:
199         state = kBroken;
200         break;
201       case kBroken:
202         ADD_FAILURE();
203         break;
204     }
205     return StatusWithSize::Unknown(data.size());
206   }
207 };
208 
TEST(AlignedWriter,Write_NoFurtherWritesOnFailure)209 TEST(AlignedWriter, Write_NoFurtherWritesOnFailure) {
210   OutputWithErrorInjection output;
211 
212   {
213     AlignedWriterBuffer<4> writer(3, output);
214     writer.Write(std::as_bytes(std::span("Everything is fine.")));
215     output.state = OutputWithErrorInjection::kBreakOnNext;
216     EXPECT_EQ(Status::Unknown(),
217               writer.Write(std::as_bytes(std::span("No more writes, okay?")))
218                   .status());
219     writer.Flush();
220   }
221 }
222 
TEST(AlignedWriter,Write_ReturnsTotalBytesWritten)223 TEST(AlignedWriter, Write_ReturnsTotalBytesWritten) {
224   static Status return_status;
225   return_status = OkStatus();
226 
227   OutputToFunction output([](std::span<const byte> data) {
228     return StatusWithSize(return_status, data.size());
229   });
230 
231   AlignedWriterBuffer<22> writer(10, output);
232 
233   StatusWithSize result =
234       writer.Write(std::as_bytes(std::span("12345678901"sv)));
235   EXPECT_EQ(OkStatus(), result.status());
236   EXPECT_EQ(0u, result.size());  // No writes; haven't filled buffer.
237 
238   result = writer.Write(std::as_bytes(std::span("2345678901"sv)));
239   EXPECT_EQ(OkStatus(), result.status());
240   EXPECT_EQ(20u, result.size());
241 
242   return_status = Status::PermissionDenied();
243 
244   result = writer.Write(std::as_bytes(std::span("2345678901234567890"sv)));
245   EXPECT_EQ(Status::PermissionDenied(), result.status());
246   EXPECT_EQ(40u, result.size());
247 }
248 
TEST(AlignedWriter,Flush_Ok_ReturnsTotalBytesWritten)249 TEST(AlignedWriter, Flush_Ok_ReturnsTotalBytesWritten) {
250   OutputToFunction output(
251       [](std::span<const byte> data) { return StatusWithSize(data.size()); });
252 
253   AlignedWriterBuffer<4> writer(2, output);
254 
255   EXPECT_EQ(OkStatus(),
256             writer.Write(std::as_bytes(std::span("12345678901"sv))).status());
257 
258   StatusWithSize result = writer.Flush();
259   EXPECT_EQ(OkStatus(), result.status());
260   EXPECT_EQ(12u, result.size());
261 }
262 
TEST(AlignedWriter,Flush_Error_ReturnsTotalBytesWritten)263 TEST(AlignedWriter, Flush_Error_ReturnsTotalBytesWritten) {
264   OutputToFunction output([](std::span<const byte> data) {
265     return StatusWithSize::Aborted(data.size());
266   });
267 
268   AlignedWriterBuffer<20> writer(10, output);
269 
270   EXPECT_EQ(0u, writer.Write(std::as_bytes(std::span("12345678901"sv))).size());
271 
272   StatusWithSize result = writer.Flush();
273   EXPECT_EQ(Status::Aborted(), result.status());
274   EXPECT_EQ(20u, result.size());
275 }
276 
277 // Input class that can be programmed to fail for testing purposes.
278 class InputWithErrorInjection final : public Input {
279  public:
BreakOnIndex(size_t index)280   void BreakOnIndex(size_t index) { break_on_index_ = index; }
281 
282  private:
DoRead(std::span<byte> data)283   StatusWithSize DoRead(std::span<byte> data) override {
284     EXPECT_LE(index_ + data.size(), kBytes.size());
285 
286     if (index_ + data.size() > kBytes.size()) {
287       return StatusWithSize::Internal();
288     }
289 
290     // Check if reading from the index that was programmed to cause an error.
291     if (index_ <= break_on_index_ && break_on_index_ <= index_ + data.size()) {
292       return StatusWithSize::Aborted();
293     }
294 
295     std::memcpy(data.data(), kBytes.data(), data.size());
296     index_ += data.size();
297     return StatusWithSize(data.size());
298   }
299 
300   size_t index_ = 0;
301   size_t break_on_index_ = size_t(-1);
302 };
303 
TEST(AlignedWriter,WriteFromInput_Successful)304 TEST(AlignedWriter, WriteFromInput_Successful) {
305   AlignedWriterBuffer<32> writer(kAlignment, check_against_data);
306 
307   InputWithErrorInjection input;
308   StatusWithSize result = writer.Write(input, kData.size());
309   EXPECT_EQ(OkStatus(), result.status());
310   EXPECT_LE(result.size(), kData.size());  // May not have written it all yet.
311 
312   result = writer.Flush();
313   EXPECT_EQ(OkStatus(), result.status());
314   EXPECT_EQ(kData.size(), result.size());
315 }
316 
TEST(AlignedWriter,WriteFromInput_InputError)317 TEST(AlignedWriter, WriteFromInput_InputError) {
318   AlignedWriterBuffer<kAlignment> writer(kAlignment, check_against_data);
319 
320   InputWithErrorInjection input;
321   input.BreakOnIndex(kAlignment + 2);
322 
323   StatusWithSize result = writer.Write(input, kData.size());
324   EXPECT_EQ(Status::Aborted(), result.status());
325   EXPECT_LE(result.size(), kAlignment);  // Wrote the first chunk, nothing more.
326 }
327 
TEST(AlignedWriter,WriteFromInput_OutputError)328 TEST(AlignedWriter, WriteFromInput_OutputError) {
329   InputWithErrorInjection input;
330   OutputWithErrorInjection output;
331 
332   AlignedWriterBuffer<4> writer(3, output);
333   output.state = OutputWithErrorInjection::kBreakOnNext;
334 
335   StatusWithSize result = writer.Write(input, kData.size());
336   EXPECT_EQ(Status::Unknown(), result.status());
337   EXPECT_EQ(3u, result.size());  // Attempted to write 3 bytes.
338 }
339 
340 }  // namespace
341 }  // namespace pw::kvs
342