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 // Always use stats, these tests depend on it.
16 #define PW_KVS_RECORD_PARTITION_STATS 1
17
18 #include "gtest/gtest.h"
19 #include "pw_kvs/fake_flash_memory.h"
20 #include "pw_kvs/flash_memory.h"
21 #include "pw_kvs/flash_partition_with_stats.h"
22 #include "pw_kvs/key_value_store.h"
23 #include "pw_log/log.h"
24
25 namespace pw::kvs {
26 namespace {
27
28 // For KVS magic value always use a random 32 bit integer rather than a
29 // human readable 4 bytes. See pw_kvs/format.h for more information.
30 constexpr EntryFormat format{.magic = 0x1bce4ad5, .checksum = nullptr};
31
32 class WearTest : public ::testing::Test {
33 protected:
WearTest()34 WearTest()
35 : flash_(internal::Entry::kMinAlignmentBytes),
36 partition_(&flash_, 0, flash_.sector_count()),
37 kvs_(&partition_, format) {
38 EXPECT_EQ(OkStatus(), kvs_.Init());
39 }
40
41 static constexpr size_t kSectors = 16;
42 static constexpr size_t kMaxEntries = 256;
43 static constexpr size_t kTestPartitionSectorSize = 512;
44
45 FakeFlashMemoryBuffer<kTestPartitionSectorSize, kSectors> flash_;
46 FlashPartitionWithStatsBuffer<kSectors> partition_;
47
48 KeyValueStoreBuffer<kMaxEntries, kSectors> kvs_;
49 };
50
51 // Block of data to use for entry value. Sized to 470 so the total entry results
52 // in using most of the 512 byte sector.
53 uint8_t test_data[470] = {1, 2, 3, 4, 5, 6};
54
55 // Write a large key (i.e. only one entry fits in each sector) enough times to
56 // fill up the KVS multiple times, and ensure every sector was garbage collected
57 // multiple additional times.
TEST_F(WearTest,RepeatedLargeEntry)58 TEST_F(WearTest, RepeatedLargeEntry) {
59 // Initialize an empty KVS, erasing flash and all tracked sector erase counts.
60 partition_.ResetCounters();
61
62 // Add enough large entries to fill the entire KVS several times.
63 for (size_t i = 0; i < kSectors * 10; ++i) {
64 // modify the value to ensure a key-value different than was previously
65 // written.
66 test_data[0]++;
67
68 EXPECT_TRUE(kvs_.Put("large_entry", std::span(test_data)).ok());
69 }
70
71 // Ensure every sector has been erased at several times due to garbage
72 // collection.
73 EXPECT_GE(partition_.min_erase_count(), 7u);
74 EXPECT_LE(partition_.max_erase_count(), partition_.min_erase_count() + 1u);
75
76 partition_.SaveStorageStats(kvs_, "WearTest RepeatedLargeEntry")
77 .IgnoreError(); // TODO(pwbug/387): Handle Status properly
78 }
79
80 // Test a KVS with a number of entries, several sectors that are nearly full
81 // of stale (reclaimable) space, and not enough writable (free) space to add a
82 // redundant copy for any of the entries. Tests that the add redundancy step of
83 // repair is able to use garbage collection to free up space needed for the new
84 // copies.
TEST_F(WearTest,TwoPassFillWithLargeAndLarger)85 TEST_F(WearTest, TwoPassFillWithLargeAndLarger) {
86 partition_.ResetCounters();
87
88 // Add a large entry that will only fit once per sector enough times to fill
89 // the KVS with mostly stale data.
90 for (size_t i = 0; i < kSectors; i++) {
91 // modify the value to ensure a key-value different than was previously
92 // written.
93 test_data[0]++;
94
95 EXPECT_EQ(
96 OkStatus(),
97 kvs_.Put("key",
98 std::as_bytes(std::span(test_data, sizeof(test_data) - 70))));
99 }
100
101 // Add many copies of a differently sized entry that is larger than the
102 // previous entry.
103 for (size_t i = 0; i < kSectors * 200; i++) {
104 // Modify the value to ensure a key-value different than was previously
105 // written.
106 test_data[0]++;
107
108 printf("Add entry %zu\n", i);
109 EXPECT_EQ(OkStatus(), kvs_.Put("big_key", test_data));
110 }
111
112 EXPECT_EQ(2u, kvs_.size());
113 EXPECT_LT(partition_.max_erase_count(),
114 2u * partition_.average_erase_count());
115 }
116
117 } // namespace
118 } // namespace pw::kvs
119