Wyatt Hepler | b760954 | 2020-01-24 10:29:54 -0800 | [diff] [blame] | 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 | |
Wyatt Hepler | b760954 | 2020-01-24 10:29:54 -0800 | [diff] [blame] | 15 | #include "pw_kvs/key_value_store.h" |
| 16 | |
Wyatt Hepler | bab0e20 | 2020-02-04 07:40:08 -0800 | [diff] [blame] | 17 | #include <algorithm> |
Wyatt Hepler | 5a33d8c | 2020-02-06 09:32:58 -0800 | [diff] [blame] | 18 | #include <cinttypes> |
Wyatt Hepler | b760954 | 2020-01-24 10:29:54 -0800 | [diff] [blame] | 19 | #include <cstring> |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 20 | #include <type_traits> |
Wyatt Hepler | b760954 | 2020-01-24 10:29:54 -0800 | [diff] [blame] | 21 | |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 22 | #define PW_LOG_USE_ULTRA_SHORT_NAMES 1 |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 23 | #include "pw_kvs_private/format.h" |
| 24 | #include "pw_kvs_private/macros.h" |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 25 | #include "pw_log/log.h" |
Wyatt Hepler | b760954 | 2020-01-24 10:29:54 -0800 | [diff] [blame] | 26 | |
Wyatt Hepler | 2ad6067 | 2020-01-21 08:00:16 -0800 | [diff] [blame] | 27 | namespace pw::kvs { |
Wyatt Hepler | b760954 | 2020-01-24 10:29:54 -0800 | [diff] [blame] | 28 | |
Wyatt Hepler | acaacf9 | 2020-01-24 10:58:30 -0800 | [diff] [blame] | 29 | using std::byte; |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 30 | using std::string_view; |
Wyatt Hepler | acaacf9 | 2020-01-24 10:58:30 -0800 | [diff] [blame] | 31 | |
Wyatt Hepler | ad0a793 | 2020-02-06 08:20:38 -0800 | [diff] [blame] | 32 | KeyValueStore::KeyValueStore(FlashPartition* partition, |
| 33 | const EntryHeaderFormat& format, |
| 34 | const Options& options) |
| 35 | : partition_(*partition), |
| 36 | entry_header_format_(format), |
| 37 | options_(options), |
| 38 | key_descriptor_list_{}, |
| 39 | key_descriptor_list_size_(0), |
| 40 | sector_map_{}, |
| 41 | sector_map_size_(partition_.sector_count()), |
| 42 | last_new_sector_(sector_map_.data()), |
| 43 | working_buffer_{} {} |
| 44 | |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 45 | Status KeyValueStore::Init() { |
Wyatt Hepler | ad0a793 | 2020-02-06 08:20:38 -0800 | [diff] [blame] | 46 | if (kMaxUsableSectors < sector_map_size_) { |
| 47 | CRT("KeyValueStore::kMaxUsableSectors must be at least as large as the " |
| 48 | "number of sectors in the flash partition"); |
| 49 | return Status::FAILED_PRECONDITION; |
| 50 | } |
| 51 | |
| 52 | if (kMaxUsableSectors > sector_map_size_) { |
| 53 | DBG("KeyValueStore::kMaxUsableSectors is %zu sectors larger than needed", |
| 54 | kMaxUsableSectors - sector_map_size_); |
| 55 | } |
| 56 | |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 57 | // Reset the number of occupied key descriptors; we will fill them later. |
| 58 | key_descriptor_list_size_ = 0; |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 59 | |
David Rogers | 8ce55cd | 2020-02-04 19:41:48 -0800 | [diff] [blame] | 60 | // TODO: init last_new_sector_ to a random sector. Since the on-flash stored |
| 61 | // information does not allow recovering the previous last_new_sector_ after |
| 62 | // clean start, random is a good second choice. |
| 63 | |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 64 | const size_t sector_size_bytes = partition_.sector_size_bytes(); |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 65 | |
David Rogers | f0a3544 | 2020-02-04 12:16:38 -0800 | [diff] [blame] | 66 | if (working_buffer_.size() < sector_size_bytes) { |
| 67 | CRT("ERROR: working_buffer_ (%zu bytes) is smaller than sector " |
| 68 | "size (%zu bytes)", |
| 69 | working_buffer_.size(), |
| 70 | sector_size_bytes); |
| 71 | return Status::INVALID_ARGUMENT; |
| 72 | } |
| 73 | |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 74 | DBG("First pass: Read all entries from all sectors"); |
Wyatt Hepler | ad0a793 | 2020-02-06 08:20:38 -0800 | [diff] [blame] | 75 | for (size_t sector_id = 0; sector_id < sector_map_size_; ++sector_id) { |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 76 | // Track writable bytes in this sector. Updated after reading each entry. |
| 77 | sector_map_[sector_id].tail_free_bytes = sector_size_bytes; |
| 78 | |
| 79 | const Address sector_address = sector_id * sector_size_bytes; |
| 80 | Address entry_address = sector_address; |
| 81 | |
| 82 | for (int num_entries_in_sector = 0;; num_entries_in_sector++) { |
| 83 | DBG("Load entry: sector=%zu, entry#=%d, address=%zu", |
| 84 | sector_id, |
| 85 | num_entries_in_sector, |
| 86 | size_t(entry_address)); |
| 87 | |
| 88 | if (!AddressInSector(sector_map_[sector_id], entry_address)) { |
| 89 | DBG("Fell off end of sector; moving to the next sector"); |
| 90 | break; |
| 91 | } |
| 92 | |
| 93 | Address next_entry_address; |
| 94 | Status status = LoadEntry(entry_address, &next_entry_address); |
| 95 | if (status == Status::NOT_FOUND) { |
| 96 | DBG("Hit un-written data in sector; moving to the next sector"); |
| 97 | break; |
| 98 | } |
| 99 | if (status == Status::DATA_LOSS) { |
| 100 | // It's not clear KVS can make a unilateral decision about what to do |
| 101 | // in corruption cases. It's an application decision, for which we |
| 102 | // should offer some configurability. For now, entirely bail out of |
| 103 | // loading and give up. |
| 104 | // |
| 105 | // Later, scan for remaining valid keys; since it's entirely possible |
| 106 | // that there is a duplicate of the key elsewhere and everything is |
| 107 | // fine. Later, we can wipe and maybe recover the sector. |
| 108 | // |
| 109 | // TODO: Implement rest-of-sector scanning for valid entries. |
| 110 | return Status::DATA_LOSS; |
| 111 | } |
| 112 | TRY(status); |
| 113 | |
| 114 | // Entry loaded successfully; so get ready to load the next one. |
| 115 | entry_address = next_entry_address; |
| 116 | |
| 117 | // Update of the number of writable bytes in this sector. |
| 118 | sector_map_[sector_id].tail_free_bytes = |
| 119 | sector_size_bytes - (entry_address - sector_address); |
| 120 | } |
| 121 | } |
| 122 | |
| 123 | DBG("Second pass: Count valid bytes in each sector"); |
| 124 | // Initialize the sector sizes. |
Wyatt Hepler | ad0a793 | 2020-02-06 08:20:38 -0800 | [diff] [blame] | 125 | for (size_t sector_id = 0; sector_id < sector_map_size_; ++sector_id) { |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 126 | sector_map_[sector_id].valid_bytes = 0; |
| 127 | } |
| 128 | // For every valid key, increment the valid bytes for that sector. |
| 129 | for (size_t key_id = 0; key_id < key_descriptor_list_size_; ++key_id) { |
| 130 | uint32_t sector_id = |
| 131 | key_descriptor_list_[key_id].address / sector_size_bytes; |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 132 | EntryHeader header; |
Wyatt Hepler | 4d78cd6 | 2020-02-05 13:05:58 -0800 | [diff] [blame] | 133 | TRY(ReadEntryHeader(key_descriptor_list_[key_id].address, &header)); |
Wyatt Hepler | 93b889d | 2020-02-05 09:01:18 -0800 | [diff] [blame] | 134 | sector_map_[sector_id].valid_bytes += header.size(); |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 135 | } |
Wyatt Hepler | 729f28c | 2020-02-05 09:46:00 -0800 | [diff] [blame] | 136 | initialized_ = true; |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 137 | return Status::OK; |
| 138 | } |
| 139 | |
| 140 | Status KeyValueStore::LoadEntry(Address entry_address, |
| 141 | Address* next_entry_address) { |
| 142 | const size_t alignment_bytes = partition_.alignment_bytes(); |
| 143 | |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 144 | EntryHeader header; |
Wyatt Hepler | 4d78cd6 | 2020-02-05 13:05:58 -0800 | [diff] [blame] | 145 | TRY(ReadEntryHeader(entry_address, &header)); |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 146 | // TODO: Should likely add a "LogHeader" method or similar. |
| 147 | DBG("Header: "); |
| 148 | DBG(" Address = 0x%zx", size_t(entry_address)); |
| 149 | DBG(" Magic = 0x%zx", size_t(header.magic())); |
Wyatt Hepler | 6e3a83b | 2020-02-04 07:36:45 -0800 | [diff] [blame] | 150 | DBG(" Checksum = 0x%zx", size_t(header.checksum())); |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 151 | DBG(" Key length = 0x%zx", size_t(header.key_length())); |
| 152 | DBG(" Value length = 0x%zx", size_t(header.value_length())); |
Wyatt Hepler | 93b889d | 2020-02-05 09:01:18 -0800 | [diff] [blame] | 153 | DBG(" Entry size = 0x%zx", size_t(header.size())); |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 154 | DBG(" Padded size = 0x%zx", |
Wyatt Hepler | 93b889d | 2020-02-05 09:01:18 -0800 | [diff] [blame] | 155 | size_t(AlignUp(header.size(), alignment_bytes))); |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 156 | |
| 157 | if (HeaderLooksLikeUnwrittenData(header)) { |
| 158 | return Status::NOT_FOUND; |
| 159 | } |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 160 | |
| 161 | // TODO: Handle multiple magics for formats that have changed. |
| 162 | if (header.magic() != entry_header_format_.magic) { |
| 163 | // TODO: It may be cleaner to have some logging helpers for these cases. |
| 164 | CRT("Found corrupt magic: %zx; expecting %zx; at address %zx", |
| 165 | size_t(header.magic()), |
| 166 | size_t(entry_header_format_.magic), |
| 167 | size_t(entry_address)); |
| 168 | return Status::DATA_LOSS; |
| 169 | } |
| 170 | |
| 171 | // Read the key from flash & validate the entry (which reads the value). |
| 172 | KeyBuffer key_buffer; |
Wyatt Hepler | 4d78cd6 | 2020-02-05 13:05:58 -0800 | [diff] [blame] | 173 | TRY(ReadEntryKey(entry_address, header.key_length(), key_buffer.data())); |
Wyatt Hepler | bab0e20 | 2020-02-04 07:40:08 -0800 | [diff] [blame] | 174 | const string_view key(key_buffer.data(), header.key_length()); |
| 175 | |
Wyatt Hepler | 6e3a83b | 2020-02-04 07:36:45 -0800 | [diff] [blame] | 176 | TRY(header.VerifyChecksumInFlash( |
Wyatt Hepler | 4d78cd6 | 2020-02-05 13:05:58 -0800 | [diff] [blame] | 177 | &partition_, entry_address, entry_header_format_.checksum)); |
| 178 | |
Wyatt Hepler | 6c24c06 | 2020-02-05 15:30:49 -0800 | [diff] [blame] | 179 | KeyDescriptor key_descriptor( |
| 180 | key, |
| 181 | header.key_version(), |
| 182 | entry_address, |
| 183 | header.deleted() ? KeyDescriptor::kDeleted : KeyDescriptor::kValid); |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 184 | |
| 185 | DBG("Key hash: %zx (%zu)", |
| 186 | size_t(key_descriptor.key_hash), |
| 187 | size_t(key_descriptor.key_hash)); |
| 188 | |
| 189 | TRY(AppendNewOrOverwriteStaleExistingDescriptor(key_descriptor)); |
| 190 | |
| 191 | // TODO: Extract this to something like "NextValidEntryAddress". |
| 192 | *next_entry_address = |
Wyatt Hepler | 93b889d | 2020-02-05 09:01:18 -0800 | [diff] [blame] | 193 | AlignUp(key_descriptor.address + header.size(), alignment_bytes); |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 194 | |
| 195 | return Status::OK; |
| 196 | } |
| 197 | |
| 198 | // TODO: This method is the trigger of the O(valid_entries * all_entries) time |
| 199 | // complexity for reading. At some cost to memory, this could be optimized by |
| 200 | // using a hash table instead of scanning, but in practice this should be fine |
| 201 | // for a small number of keys |
| 202 | Status KeyValueStore::AppendNewOrOverwriteStaleExistingDescriptor( |
| 203 | const KeyDescriptor& key_descriptor) { |
| 204 | // With the new key descriptor, either add it to the descriptor table or |
| 205 | // overwrite an existing entry with an older version of the key. |
| 206 | KeyDescriptor* existing_descriptor = FindDescriptor(key_descriptor.key_hash); |
| 207 | if (existing_descriptor) { |
| 208 | if (existing_descriptor->key_version < key_descriptor.key_version) { |
| 209 | // Existing entry is old; replace the existing entry with the new one. |
| 210 | *existing_descriptor = key_descriptor; |
| 211 | } else { |
| 212 | // Otherwise, check for data integrity and leave the existing entry. |
| 213 | if (existing_descriptor->key_version == key_descriptor.key_version) { |
| 214 | ERR("Data loss: Duplicated old(=%zu) and new(=%zu) version", |
| 215 | size_t(existing_descriptor->key_version), |
| 216 | size_t(key_descriptor.key_version)); |
| 217 | return Status::DATA_LOSS; |
| 218 | } |
| 219 | DBG("Found stale entry when appending; ignoring"); |
| 220 | } |
| 221 | return Status::OK; |
| 222 | } |
| 223 | // Write new entry. |
| 224 | KeyDescriptor* newly_allocated_key_descriptor; |
| 225 | TRY(AppendEmptyDescriptor(&newly_allocated_key_descriptor)); |
| 226 | *newly_allocated_key_descriptor = key_descriptor; |
| 227 | return Status::OK; |
| 228 | } |
| 229 | |
| 230 | // TODO: Need a better name. |
| 231 | Status KeyValueStore::AppendEmptyDescriptor(KeyDescriptor** new_descriptor) { |
| 232 | if (KeyListFull()) { |
| 233 | // TODO: Is this the right return code? |
| 234 | return Status::RESOURCE_EXHAUSTED; |
| 235 | } |
| 236 | *new_descriptor = &key_descriptor_list_[key_descriptor_list_size_++]; |
| 237 | return Status::OK; |
| 238 | } |
| 239 | |
| 240 | // TODO: Finish. |
| 241 | bool KeyValueStore::HeaderLooksLikeUnwrittenData( |
| 242 | const EntryHeader& header) const { |
| 243 | // TODO: This is not correct; it should call through to flash memory. |
| 244 | return header.magic() == 0xffffffff; |
| 245 | } |
| 246 | |
| 247 | KeyValueStore::KeyDescriptor* KeyValueStore::FindDescriptor(uint32_t hash) { |
| 248 | for (size_t key_id = 0; key_id < key_descriptor_list_size_; key_id++) { |
| 249 | if (key_descriptor_list_[key_id].key_hash == hash) { |
| 250 | return &(key_descriptor_list_[key_id]); |
| 251 | } |
| 252 | } |
| 253 | return nullptr; |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 254 | } |
| 255 | |
| 256 | StatusWithSize KeyValueStore::Get(string_view key, |
| 257 | span<byte> value_buffer) const { |
Wyatt Hepler | 729f28c | 2020-02-05 09:46:00 -0800 | [diff] [blame] | 258 | TRY(CheckOperation(key)); |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 259 | |
David Rogers | 2761aeb | 2020-01-31 17:09:00 -0800 | [diff] [blame] | 260 | const KeyDescriptor* key_descriptor; |
| 261 | TRY(FindKeyDescriptor(key, &key_descriptor)); |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 262 | |
Wyatt Hepler | 6c24c06 | 2020-02-05 15:30:49 -0800 | [diff] [blame] | 263 | if (key_descriptor->deleted()) { |
| 264 | return Status::NOT_FOUND; |
| 265 | } |
| 266 | |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 267 | EntryHeader header; |
Wyatt Hepler | 4d78cd6 | 2020-02-05 13:05:58 -0800 | [diff] [blame] | 268 | TRY(ReadEntryHeader(key_descriptor->address, &header)); |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 269 | |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 270 | StatusWithSize result = ReadEntryValue(*key_descriptor, header, value_buffer); |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 271 | if (result.ok() && options_.verify_on_read) { |
Wyatt Hepler | 6e3a83b | 2020-02-04 07:36:45 -0800 | [diff] [blame] | 272 | return header.VerifyChecksum(entry_header_format_.checksum, |
| 273 | key, |
| 274 | value_buffer.subspan(0, result.size())); |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 275 | } |
| 276 | return result; |
| 277 | } |
| 278 | |
| 279 | Status KeyValueStore::Put(string_view key, span<const byte> value) { |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 280 | DBG("Writing key/value; key length=%zu, value length=%zu", |
| 281 | key.size(), |
| 282 | value.size()); |
Wyatt Hepler | 729f28c | 2020-02-05 09:46:00 -0800 | [diff] [blame] | 283 | |
| 284 | TRY(CheckOperation(key)); |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 285 | |
| 286 | if (value.size() > (1 << 24)) { |
| 287 | // TODO: Reject sizes that are larger than the maximum? |
| 288 | } |
| 289 | |
David Rogers | 2761aeb | 2020-01-31 17:09:00 -0800 | [diff] [blame] | 290 | KeyDescriptor* key_descriptor; |
| 291 | if (FindKeyDescriptor(key, &key_descriptor).ok()) { |
Wyatt Hepler | 5a33d8c | 2020-02-06 09:32:58 -0800 | [diff] [blame] | 292 | DBG("Writing over existing entry for key 0x%08" PRIx32, |
| 293 | key_descriptor->key_hash); |
| 294 | return WriteEntryForExistingKey( |
| 295 | key_descriptor, KeyDescriptor::kValid, key, value); |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 296 | } |
David Rogers | 2761aeb | 2020-01-31 17:09:00 -0800 | [diff] [blame] | 297 | |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 298 | return WriteEntryForNewKey(key, value); |
| 299 | } |
| 300 | |
| 301 | Status KeyValueStore::Delete(string_view key) { |
Wyatt Hepler | 729f28c | 2020-02-05 09:46:00 -0800 | [diff] [blame] | 302 | TRY(CheckOperation(key)); |
| 303 | |
Wyatt Hepler | 6c24c06 | 2020-02-05 15:30:49 -0800 | [diff] [blame] | 304 | KeyDescriptor* key_descriptor; |
| 305 | TRY(FindKeyDescriptor(key, &key_descriptor)); |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 306 | |
Wyatt Hepler | 6c24c06 | 2020-02-05 15:30:49 -0800 | [diff] [blame] | 307 | if (key_descriptor->deleted()) { |
| 308 | return Status::NOT_FOUND; |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 309 | } |
| 310 | |
Wyatt Hepler | 5a33d8c | 2020-02-06 09:32:58 -0800 | [diff] [blame] | 311 | DBG("Writing tombstone for key 0x%08" PRIx32, key_descriptor->key_hash); |
| 312 | return WriteEntryForExistingKey( |
| 313 | key_descriptor, KeyDescriptor::kDeleted, key, {}); |
Wyatt Hepler | 6c24c06 | 2020-02-05 15:30:49 -0800 | [diff] [blame] | 314 | } |
| 315 | |
| 316 | KeyValueStore::iterator& KeyValueStore::iterator::operator++() { |
| 317 | // Skip to the next entry that is valid (not deleted). |
| 318 | while (++index_ < item_.kvs_.key_descriptor_list_size_ && |
| 319 | descriptor().deleted()) { |
| 320 | } |
| 321 | return *this; |
| 322 | } |
| 323 | |
| 324 | const KeyValueStore::Item& KeyValueStore::iterator::operator*() { |
| 325 | std::memset(item_.key_buffer_.data(), 0, item_.key_buffer_.size()); |
| 326 | |
| 327 | EntryHeader header; |
| 328 | if (item_.kvs_.ReadEntryHeader(descriptor().address, &header).ok()) { |
| 329 | item_.kvs_.ReadEntryKey( |
| 330 | descriptor().address, header.key_length(), item_.key_buffer_.data()); |
| 331 | } |
| 332 | |
| 333 | return item_; |
| 334 | } |
| 335 | |
| 336 | KeyValueStore::iterator KeyValueStore::begin() const { |
| 337 | size_t i = 0; |
| 338 | // Skip over any deleted entries at the start of the descriptor list. |
| 339 | while (i < key_descriptor_list_size_ && key_descriptor_list_[i].deleted()) { |
| 340 | i += 1; |
| 341 | } |
| 342 | return iterator(*this, i); |
| 343 | } |
| 344 | |
| 345 | // TODO(hepler): The valid entry count could be tracked in the KVS to avoid the |
| 346 | // need for this for-loop. |
| 347 | size_t KeyValueStore::size() const { |
| 348 | size_t valid_entries = 0; |
| 349 | |
| 350 | for (size_t i = 0; i < key_descriptor_list_size_; ++i) { |
| 351 | if (!key_descriptor_list_[i].deleted()) { |
| 352 | valid_entries += 1; |
| 353 | } |
| 354 | } |
| 355 | |
| 356 | return valid_entries; |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 357 | } |
| 358 | |
Wyatt Hepler | ed163b0 | 2020-02-03 17:49:32 -0800 | [diff] [blame] | 359 | StatusWithSize KeyValueStore::ValueSize(std::string_view key) const { |
Wyatt Hepler | 729f28c | 2020-02-05 09:46:00 -0800 | [diff] [blame] | 360 | TRY(CheckOperation(key)); |
Wyatt Hepler | ed163b0 | 2020-02-03 17:49:32 -0800 | [diff] [blame] | 361 | |
| 362 | const KeyDescriptor* key_descriptor; |
| 363 | TRY(FindKeyDescriptor(key, &key_descriptor)); |
| 364 | |
Wyatt Hepler | 6c24c06 | 2020-02-05 15:30:49 -0800 | [diff] [blame] | 365 | if (key_descriptor->deleted()) { |
| 366 | return Status::NOT_FOUND; |
| 367 | } |
| 368 | |
Wyatt Hepler | ed163b0 | 2020-02-03 17:49:32 -0800 | [diff] [blame] | 369 | EntryHeader header; |
Wyatt Hepler | 4d78cd6 | 2020-02-05 13:05:58 -0800 | [diff] [blame] | 370 | TRY(ReadEntryHeader(key_descriptor->address, &header)); |
Wyatt Hepler | ed163b0 | 2020-02-03 17:49:32 -0800 | [diff] [blame] | 371 | |
| 372 | return StatusWithSize(header.value_length()); |
| 373 | } |
| 374 | |
Wyatt Hepler | 4d78cd6 | 2020-02-05 13:05:58 -0800 | [diff] [blame] | 375 | uint32_t KeyValueStore::HashKey(string_view string) { |
| 376 | uint32_t hash = 0; |
| 377 | uint32_t coefficient = 65599u; |
| 378 | |
| 379 | for (char ch : string) { |
| 380 | hash += coefficient * unsigned(ch); |
| 381 | coefficient *= 65599u; |
| 382 | } |
| 383 | |
| 384 | return hash; |
| 385 | } |
| 386 | |
Wyatt Hepler | 6e3a83b | 2020-02-04 07:36:45 -0800 | [diff] [blame] | 387 | Status KeyValueStore::FixedSizeGet(std::string_view key, |
| 388 | byte* value, |
| 389 | size_t size_bytes) const { |
| 390 | // Ensure that the size of the stored value matches the size of the type. |
| 391 | // Otherwise, report error. This check avoids potential memory corruption. |
| 392 | StatusWithSize result = ValueSize(key); |
| 393 | if (!result.ok()) { |
| 394 | return result.status(); |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 395 | } |
Wyatt Hepler | 6e3a83b | 2020-02-04 07:36:45 -0800 | [diff] [blame] | 396 | if (result.size() != size_bytes) { |
Wyatt Hepler | 6c24c06 | 2020-02-05 15:30:49 -0800 | [diff] [blame] | 397 | DBG("Requested %zu B read, but value is %zu B", size_bytes, result.size()); |
Wyatt Hepler | 6e3a83b | 2020-02-04 07:36:45 -0800 | [diff] [blame] | 398 | return Status::INVALID_ARGUMENT; |
Wyatt Hepler | bab0e20 | 2020-02-04 07:40:08 -0800 | [diff] [blame] | 399 | } |
Wyatt Hepler | 6e3a83b | 2020-02-04 07:36:45 -0800 | [diff] [blame] | 400 | return Get(key, span(value, size_bytes)).status(); |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 401 | } |
| 402 | |
Wyatt Hepler | 729f28c | 2020-02-05 09:46:00 -0800 | [diff] [blame] | 403 | Status KeyValueStore::CheckOperation(string_view key) const { |
Wyatt Hepler | acaacf9 | 2020-01-24 10:58:30 -0800 | [diff] [blame] | 404 | if (InvalidKey(key)) { |
Wyatt Hepler | b760954 | 2020-01-24 10:29:54 -0800 | [diff] [blame] | 405 | return Status::INVALID_ARGUMENT; |
| 406 | } |
Wyatt Hepler | 729f28c | 2020-02-05 09:46:00 -0800 | [diff] [blame] | 407 | if (!initialized_) { |
Wyatt Hepler | b760954 | 2020-01-24 10:29:54 -0800 | [diff] [blame] | 408 | return Status::FAILED_PRECONDITION; |
| 409 | } |
Wyatt Hepler | b760954 | 2020-01-24 10:29:54 -0800 | [diff] [blame] | 410 | return Status::OK; |
| 411 | } |
| 412 | |
David Rogers | 2761aeb | 2020-01-31 17:09:00 -0800 | [diff] [blame] | 413 | Status KeyValueStore::FindKeyDescriptor(string_view key, |
| 414 | const KeyDescriptor** result) const { |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 415 | char key_buffer[kMaxKeyLength]; |
| 416 | const uint32_t hash = HashKey(key); |
Wyatt Hepler | b760954 | 2020-01-24 10:29:54 -0800 | [diff] [blame] | 417 | |
David Rogers | 2761aeb | 2020-01-31 17:09:00 -0800 | [diff] [blame] | 418 | for (auto& descriptor : key_descriptors()) { |
| 419 | if (descriptor.key_hash == hash) { |
Wyatt Hepler | 4d78cd6 | 2020-02-05 13:05:58 -0800 | [diff] [blame] | 420 | TRY(ReadEntryKey(descriptor.address, key.size(), key_buffer)); |
Wyatt Hepler | b760954 | 2020-01-24 10:29:54 -0800 | [diff] [blame] | 421 | |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 422 | if (key == string_view(key_buffer, key.size())) { |
Wyatt Hepler | 5a33d8c | 2020-02-06 09:32:58 -0800 | [diff] [blame] | 423 | DBG("Found match for key hash 0x%08" PRIx32, hash); |
David Rogers | 2761aeb | 2020-01-31 17:09:00 -0800 | [diff] [blame] | 424 | *result = &descriptor; |
Wyatt Hepler | b760954 | 2020-01-24 10:29:54 -0800 | [diff] [blame] | 425 | return Status::OK; |
| 426 | } |
Wyatt Hepler | b760954 | 2020-01-24 10:29:54 -0800 | [diff] [blame] | 427 | } |
| 428 | } |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 429 | return Status::NOT_FOUND; |
| 430 | } |
| 431 | |
Wyatt Hepler | 4d78cd6 | 2020-02-05 13:05:58 -0800 | [diff] [blame] | 432 | Status KeyValueStore::ReadEntryHeader(Address address, |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 433 | EntryHeader* header) const { |
Wyatt Hepler | 4d78cd6 | 2020-02-05 13:05:58 -0800 | [diff] [blame] | 434 | return partition_.Read(address, sizeof(*header), header).status(); |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 435 | } |
| 436 | |
Wyatt Hepler | 4d78cd6 | 2020-02-05 13:05:58 -0800 | [diff] [blame] | 437 | Status KeyValueStore::ReadEntryKey(Address address, |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 438 | size_t key_length, |
| 439 | char* key) const { |
| 440 | // TODO: This check probably shouldn't be here; this is like |
| 441 | // checking that the Cortex M's RAM isn't corrupt. This should be |
| 442 | // done at boot time. |
| 443 | // ^^ This argument sometimes comes from EntryHeader::key_value_len, |
| 444 | // which is read directly from flash. If it's corrupted, we shouldn't try |
| 445 | // to read a bunch of extra data. |
| 446 | if (key_length == 0u || key_length > kMaxKeyLength) { |
| 447 | return Status::DATA_LOSS; |
| 448 | } |
| 449 | // The key is immediately after the entry header. |
Wyatt Hepler | 4d78cd6 | 2020-02-05 13:05:58 -0800 | [diff] [blame] | 450 | return partition_.Read(address + sizeof(EntryHeader), key_length, key) |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 451 | .status(); |
| 452 | } |
| 453 | |
David Rogers | 2761aeb | 2020-01-31 17:09:00 -0800 | [diff] [blame] | 454 | StatusWithSize KeyValueStore::ReadEntryValue( |
| 455 | const KeyDescriptor& key_descriptor, |
| 456 | const EntryHeader& header, |
| 457 | span<byte> value) const { |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 458 | const size_t read_size = std::min(header.value_length(), value.size()); |
David Rogers | 2761aeb | 2020-01-31 17:09:00 -0800 | [diff] [blame] | 459 | StatusWithSize result = partition_.Read( |
| 460 | key_descriptor.address + sizeof(header) + header.key_length(), |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 461 | value.subspan(0, read_size)); |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 462 | TRY(result); |
| 463 | if (read_size != header.value_length()) { |
| 464 | return StatusWithSize(Status::RESOURCE_EXHAUSTED, read_size); |
| 465 | } |
| 466 | return StatusWithSize(read_size); |
| 467 | } |
| 468 | |
David Rogers | 2761aeb | 2020-01-31 17:09:00 -0800 | [diff] [blame] | 469 | Status KeyValueStore::WriteEntryForExistingKey(KeyDescriptor* key_descriptor, |
Wyatt Hepler | 5a33d8c | 2020-02-06 09:32:58 -0800 | [diff] [blame] | 470 | KeyDescriptor::State new_state, |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 471 | string_view key, |
| 472 | span<const byte> value) { |
Wyatt Hepler | 5a33d8c | 2020-02-06 09:32:58 -0800 | [diff] [blame] | 473 | // Find the original entry and sector to update the sector's valid_bytes. |
| 474 | EntryHeader original_entry; |
| 475 | TRY(ReadEntryHeader(key_descriptor->address, &original_entry)); |
| 476 | SectorDescriptor& old_sector = SectorFromAddress(key_descriptor->address); |
Wyatt Hepler | 6c24c06 | 2020-02-05 15:30:49 -0800 | [diff] [blame] | 477 | |
David Rogers | 2761aeb | 2020-01-31 17:09:00 -0800 | [diff] [blame] | 478 | SectorDescriptor* sector; |
Wyatt Hepler | 93b889d | 2020-02-05 09:01:18 -0800 | [diff] [blame] | 479 | TRY(FindOrRecoverSectorWithSpace(§or, EntryHeader::size(key, value))); |
Wyatt Hepler | 5a33d8c | 2020-02-06 09:32:58 -0800 | [diff] [blame] | 480 | |
David Rogers | 8ce55cd | 2020-02-04 19:41:48 -0800 | [diff] [blame] | 481 | DBG("Writing existing entry; found sector: %zu", SectorIndex(sector)); |
Wyatt Hepler | 5a33d8c | 2020-02-06 09:32:58 -0800 | [diff] [blame] | 482 | TRY(AppendEntry(sector, key_descriptor, key, value, new_state)); |
| 483 | |
| 484 | old_sector.valid_bytes -= original_entry.size(); |
| 485 | return Status::OK; |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 486 | } |
| 487 | |
| 488 | Status KeyValueStore::WriteEntryForNewKey(string_view key, |
| 489 | span<const byte> value) { |
David Rogers | 2761aeb | 2020-01-31 17:09:00 -0800 | [diff] [blame] | 490 | if (KeyListFull()) { |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 491 | WRN("KVS full: trying to store a new entry, but can't. Have %zu entries", |
| 492 | key_descriptor_list_size_); |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 493 | return Status::RESOURCE_EXHAUSTED; |
| 494 | } |
| 495 | |
David Rogers | 2761aeb | 2020-01-31 17:09:00 -0800 | [diff] [blame] | 496 | // Modify the key descriptor at the end of the array, without bumping the map |
| 497 | // size so the key descriptor is prepared and written without committing |
| 498 | // first. |
| 499 | KeyDescriptor& key_descriptor = |
| 500 | key_descriptor_list_[key_descriptor_list_size_]; |
| 501 | key_descriptor.key_hash = HashKey(key); |
| 502 | key_descriptor.key_version = 0; // will be incremented by AppendEntry() |
Wyatt Hepler | 6c24c06 | 2020-02-05 15:30:49 -0800 | [diff] [blame] | 503 | key_descriptor.state = KeyDescriptor::kValid; |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 504 | |
David Rogers | 2761aeb | 2020-01-31 17:09:00 -0800 | [diff] [blame] | 505 | SectorDescriptor* sector; |
Wyatt Hepler | 93b889d | 2020-02-05 09:01:18 -0800 | [diff] [blame] | 506 | TRY(FindOrRecoverSectorWithSpace(§or, EntryHeader::size(key, value))); |
David Rogers | 8ce55cd | 2020-02-04 19:41:48 -0800 | [diff] [blame] | 507 | DBG("Writing new entry; found sector: %zu", SectorIndex(sector)); |
David Rogers | 2761aeb | 2020-01-31 17:09:00 -0800 | [diff] [blame] | 508 | TRY(AppendEntry(sector, &key_descriptor, key, value)); |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 509 | |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 510 | // Only increment bump our size when we are certain the write succeeded. |
David Rogers | 2761aeb | 2020-01-31 17:09:00 -0800 | [diff] [blame] | 511 | key_descriptor_list_size_ += 1; |
Wyatt Hepler | b760954 | 2020-01-24 10:29:54 -0800 | [diff] [blame] | 512 | return Status::OK; |
| 513 | } |
| 514 | |
David Rogers | 2761aeb | 2020-01-31 17:09:00 -0800 | [diff] [blame] | 515 | Status KeyValueStore::RelocateEntry(KeyDescriptor& key_descriptor) { |
David Rogers | f0a3544 | 2020-02-04 12:16:38 -0800 | [diff] [blame] | 516 | struct TempEntry { |
| 517 | std::array<char, kMaxKeyLength + 1> key; |
| 518 | std::array<char, sizeof(working_buffer_) - sizeof(key)> value; |
| 519 | }; |
| 520 | TempEntry* entry = reinterpret_cast<TempEntry*>(working_buffer_.data()); |
| 521 | |
| 522 | // Read the entry to be relocated. Store the header in a local variable and |
| 523 | // store the key and value in the TempEntry stored in the static allocated |
| 524 | // working_buffer_. |
| 525 | EntryHeader header; |
Wyatt Hepler | 4d78cd6 | 2020-02-05 13:05:58 -0800 | [diff] [blame] | 526 | TRY(ReadEntryHeader(key_descriptor.address, &header)); |
| 527 | TRY(ReadEntryKey( |
| 528 | key_descriptor.address, header.key_length(), entry->key.data())); |
David Rogers | f0a3544 | 2020-02-04 12:16:38 -0800 | [diff] [blame] | 529 | string_view key = string_view(entry->key.data(), header.key_length()); |
| 530 | StatusWithSize result = ReadEntryValue( |
| 531 | key_descriptor, header, as_writable_bytes(span(entry->value))); |
| 532 | if (!result.status().ok()) { |
| 533 | return Status::INTERNAL; |
| 534 | } |
| 535 | |
| 536 | auto value = span(entry->value.data(), result.size()); |
| 537 | |
| 538 | TRY(header.VerifyChecksum( |
| 539 | entry_header_format_.checksum, key, as_bytes(value))); |
| 540 | |
Wyatt Hepler | 5a33d8c | 2020-02-06 09:32:58 -0800 | [diff] [blame] | 541 | SectorDescriptor& old_sector = SectorFromAddress(key_descriptor.address); |
David Rogers | f0a3544 | 2020-02-04 12:16:38 -0800 | [diff] [blame] | 542 | |
| 543 | // Find a new sector for the entry and write it to the new location. |
David Rogers | 8ce55cd | 2020-02-04 19:41:48 -0800 | [diff] [blame] | 544 | SectorDescriptor* new_sector; |
Wyatt Hepler | 5a33d8c | 2020-02-06 09:32:58 -0800 | [diff] [blame] | 545 | TRY(FindSectorWithSpace(&new_sector, header.size(), &old_sector, true)); |
David Rogers | f0a3544 | 2020-02-04 12:16:38 -0800 | [diff] [blame] | 546 | return AppendEntry(new_sector, &key_descriptor, key, as_bytes(value)); |
David Rogers | a12786b | 2020-01-31 16:02:33 -0800 | [diff] [blame] | 547 | } |
| 548 | |
David Rogers | 8db5a72 | 2020-02-03 18:28:34 -0800 | [diff] [blame] | 549 | // Find either an existing sector with enough space that is not the sector to |
| 550 | // skip, or an empty sector. Maintains the invariant that there is always at |
| 551 | // least 1 empty sector unless set to bypass the rule. |
Wyatt Hepler | 5a33d8c | 2020-02-06 09:32:58 -0800 | [diff] [blame] | 552 | Status KeyValueStore::FindSectorWithSpace( |
| 553 | SectorDescriptor** found_sector, |
| 554 | size_t size, |
| 555 | const SectorDescriptor* sector_to_skip, |
| 556 | bool bypass_empty_sector_rule) { |
David Rogers | 8ce55cd | 2020-02-04 19:41:48 -0800 | [diff] [blame] | 557 | // The last_new_sector_ is the sector that was last selected as the "new empty |
| 558 | // sector" to write to. This last new sector is used as the starting point for |
| 559 | // the next "find a new empty sector to write to" operation. By using the last |
| 560 | // new sector as the start point we will cycle which empty sector is selected |
| 561 | // next, spreading the wear across all the empty sectors and get a wear |
| 562 | // leveling benefit, rather than putting more wear on the lower number |
| 563 | // sectors. |
| 564 | // |
| 565 | // Locally use the sector index for ease of iterating through the sectors. For |
| 566 | // the persistent storage use SectorDescriptor* rather than sector index |
| 567 | // because SectorDescriptor* is the standard way to identify a sector. |
| 568 | size_t last_new_sector_index_ = SectorIndex(last_new_sector_); |
Wyatt Hepler | ad0a793 | 2020-02-06 08:20:38 -0800 | [diff] [blame] | 569 | size_t start = (last_new_sector_index_ + 1) % sector_map_size_; |
David Rogers | 2761aeb | 2020-01-31 17:09:00 -0800 | [diff] [blame] | 570 | SectorDescriptor* first_empty_sector = nullptr; |
David Rogers | 8db5a72 | 2020-02-03 18:28:34 -0800 | [diff] [blame] | 571 | bool at_least_two_empty_sectors = bypass_empty_sector_rule; |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 572 | |
David Rogers | 67f4b6c | 2020-02-06 16:17:09 -0800 | [diff] [blame^] | 573 | DBG("Find sector with %zu bytes available", size); |
| 574 | if (sector_to_skip != nullptr) { |
| 575 | DBG(" Skip sector %zu", SectorIndex(sector_to_skip)); |
| 576 | } |
| 577 | if (bypass_empty_sector_rule) { |
| 578 | DBG(" Bypassing empty sector rule"); |
| 579 | } |
| 580 | |
David Rogers | 8ce55cd | 2020-02-04 19:41:48 -0800 | [diff] [blame] | 581 | // Look for a partial sector to use with enough space. Immediately use the |
| 582 | // first one of those that is found. While scanning for a partial sector, keep |
| 583 | // track of the first empty sector and if a second sector was seen. |
| 584 | for (size_t i = start; i != last_new_sector_index_; |
Wyatt Hepler | ad0a793 | 2020-02-06 08:20:38 -0800 | [diff] [blame] | 585 | i = (i + 1) % sector_map_size_) { |
David Rogers | 2761aeb | 2020-01-31 17:09:00 -0800 | [diff] [blame] | 586 | SectorDescriptor& sector = sector_map_[i]; |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 587 | |
David Rogers | 8db5a72 | 2020-02-03 18:28:34 -0800 | [diff] [blame] | 588 | if (sector_to_skip == §or) { |
David Rogers | 67f4b6c | 2020-02-06 16:17:09 -0800 | [diff] [blame^] | 589 | DBG(" Skipping the skip sector %zu", i); |
David Rogers | 8db5a72 | 2020-02-03 18:28:34 -0800 | [diff] [blame] | 590 | continue; |
| 591 | } |
| 592 | |
David Rogers | 67f4b6c | 2020-02-06 16:17:09 -0800 | [diff] [blame^] | 593 | DBG(" Examining sector %zu with %hu bytes available", |
| 594 | i, |
| 595 | sector.tail_free_bytes); |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 596 | if (!SectorEmpty(sector) && sector.HasSpace(size)) { |
David Rogers | 67f4b6c | 2020-02-06 16:17:09 -0800 | [diff] [blame^] | 597 | DBG(" Partially occupied sector %zu with enough space; done!", i); |
David Rogers | 8ce55cd | 2020-02-04 19:41:48 -0800 | [diff] [blame] | 598 | *found_sector = §or; |
| 599 | return Status::OK; |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 600 | } |
| 601 | |
| 602 | if (SectorEmpty(sector)) { |
| 603 | if (first_empty_sector == nullptr) { |
| 604 | first_empty_sector = §or; |
| 605 | } else { |
| 606 | at_least_two_empty_sectors = true; |
Wyatt Hepler | 2ad6067 | 2020-01-21 08:00:16 -0800 | [diff] [blame] | 607 | } |
Wyatt Hepler | b760954 | 2020-01-24 10:29:54 -0800 | [diff] [blame] | 608 | } |
| 609 | } |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 610 | |
David Rogers | 8ce55cd | 2020-02-04 19:41:48 -0800 | [diff] [blame] | 611 | // If the scan for a partial sector does not find a suitable sector, use the |
| 612 | // first empty sector that was found. Normally it is required to keep 1 empty |
| 613 | // sector after the sector found here, but that rule can be bypassed in |
| 614 | // special circumstances (such as during garbage collection). |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 615 | if (at_least_two_empty_sectors) { |
David Rogers | 67f4b6c | 2020-02-06 16:17:09 -0800 | [diff] [blame^] | 616 | DBG(" Found a usable empty sector; returning the first found (%zu)", |
David Rogers | 8ce55cd | 2020-02-04 19:41:48 -0800 | [diff] [blame] | 617 | SectorIndex(first_empty_sector)); |
| 618 | last_new_sector_ = first_empty_sector; |
| 619 | *found_sector = first_empty_sector; |
| 620 | return Status::OK; |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 621 | } |
David Rogers | 8ce55cd | 2020-02-04 19:41:48 -0800 | [diff] [blame] | 622 | |
| 623 | // No sector was found. |
David Rogers | 67f4b6c | 2020-02-06 16:17:09 -0800 | [diff] [blame^] | 624 | DBG(" Unable to find a usable sector"); |
David Rogers | 8ce55cd | 2020-02-04 19:41:48 -0800 | [diff] [blame] | 625 | *found_sector = nullptr; |
| 626 | return Status::RESOURCE_EXHAUSTED; |
Wyatt Hepler | b760954 | 2020-01-24 10:29:54 -0800 | [diff] [blame] | 627 | } |
| 628 | |
David Rogers | 2761aeb | 2020-01-31 17:09:00 -0800 | [diff] [blame] | 629 | Status KeyValueStore::FindOrRecoverSectorWithSpace(SectorDescriptor** sector, |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 630 | size_t size) { |
David Rogers | 8ce55cd | 2020-02-04 19:41:48 -0800 | [diff] [blame] | 631 | Status result = FindSectorWithSpace(sector, size); |
| 632 | if (result.ok()) { |
| 633 | return result; |
Wyatt Hepler | b760954 | 2020-01-24 10:29:54 -0800 | [diff] [blame] | 634 | } |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 635 | if (options_.partial_gc_on_write) { |
| 636 | return GarbageCollectOneSector(sector); |
| 637 | } |
David Rogers | 8ce55cd | 2020-02-04 19:41:48 -0800 | [diff] [blame] | 638 | return result; |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 639 | } |
| 640 | |
David Rogers | 2761aeb | 2020-01-31 17:09:00 -0800 | [diff] [blame] | 641 | KeyValueStore::SectorDescriptor* KeyValueStore::FindSectorToGarbageCollect() { |
| 642 | SectorDescriptor* sector_candidate = nullptr; |
David Rogers | a12786b | 2020-01-31 16:02:33 -0800 | [diff] [blame] | 643 | size_t candidate_bytes = 0; |
| 644 | |
| 645 | // Step 1: Try to find a sectors with stale keys and no valid keys (no |
| 646 | // relocation needed). If any such sectors are found, use the sector with the |
| 647 | // most reclaimable bytes. |
Wyatt Hepler | ad0a793 | 2020-02-06 08:20:38 -0800 | [diff] [blame] | 648 | for (auto& sector : sectors()) { |
David Rogers | a12786b | 2020-01-31 16:02:33 -0800 | [diff] [blame] | 649 | if ((sector.valid_bytes == 0) && |
| 650 | (RecoverableBytes(sector) > candidate_bytes)) { |
| 651 | sector_candidate = §or; |
| 652 | candidate_bytes = RecoverableBytes(sector); |
| 653 | } |
| 654 | } |
| 655 | |
| 656 | // Step 2: If step 1 yields no sectors, just find the sector with the most |
| 657 | // reclaimable bytes. |
| 658 | if (sector_candidate == nullptr) { |
Wyatt Hepler | ad0a793 | 2020-02-06 08:20:38 -0800 | [diff] [blame] | 659 | for (auto& sector : sectors()) { |
David Rogers | a12786b | 2020-01-31 16:02:33 -0800 | [diff] [blame] | 660 | if (RecoverableBytes(sector) > candidate_bytes) { |
| 661 | sector_candidate = §or; |
| 662 | candidate_bytes = RecoverableBytes(sector); |
| 663 | } |
| 664 | } |
| 665 | } |
| 666 | |
David Rogers | 67f4b6c | 2020-02-06 16:17:09 -0800 | [diff] [blame^] | 667 | DBG("Found sector %zu to Garbage Collect, %zu recoverable bytes", |
| 668 | SectorIndex(sector_candidate), |
| 669 | RecoverableBytes(*sector_candidate)); |
David Rogers | a12786b | 2020-01-31 16:02:33 -0800 | [diff] [blame] | 670 | return sector_candidate; |
| 671 | } |
| 672 | |
David Rogers | 2761aeb | 2020-01-31 17:09:00 -0800 | [diff] [blame] | 673 | Status KeyValueStore::GarbageCollectOneSector(SectorDescriptor** sector) { |
David Rogers | 67f4b6c | 2020-02-06 16:17:09 -0800 | [diff] [blame^] | 674 | DBG("Garbage Collect a single sector"); |
| 675 | |
David Rogers | a12786b | 2020-01-31 16:02:33 -0800 | [diff] [blame] | 676 | // Step 1: Find the sector to garbage collect |
David Rogers | 2761aeb | 2020-01-31 17:09:00 -0800 | [diff] [blame] | 677 | SectorDescriptor* sector_to_gc = FindSectorToGarbageCollect(); |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 678 | |
David Rogers | a12786b | 2020-01-31 16:02:33 -0800 | [diff] [blame] | 679 | if (sector_to_gc == nullptr) { |
| 680 | return Status::RESOURCE_EXHAUSTED; |
| 681 | } |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 682 | |
David Rogers | a12786b | 2020-01-31 16:02:33 -0800 | [diff] [blame] | 683 | // Step 2: Move any valid entries in the GC sector to other sectors |
| 684 | if (sector_to_gc->valid_bytes != 0) { |
David Rogers | 2761aeb | 2020-01-31 17:09:00 -0800 | [diff] [blame] | 685 | for (auto& descriptor : key_descriptors()) { |
| 686 | if (AddressInSector(*sector_to_gc, descriptor.address)) { |
David Rogers | 67f4b6c | 2020-02-06 16:17:09 -0800 | [diff] [blame^] | 687 | DBG(" Relocate entry"); |
David Rogers | 2761aeb | 2020-01-31 17:09:00 -0800 | [diff] [blame] | 688 | TRY(RelocateEntry(descriptor)); |
David Rogers | a12786b | 2020-01-31 16:02:33 -0800 | [diff] [blame] | 689 | } |
Wyatt Hepler | b760954 | 2020-01-24 10:29:54 -0800 | [diff] [blame] | 690 | } |
| 691 | } |
Wyatt Hepler | b760954 | 2020-01-24 10:29:54 -0800 | [diff] [blame] | 692 | |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 693 | if (sector_to_gc->valid_bytes != 0) { |
David Rogers | 67f4b6c | 2020-02-06 16:17:09 -0800 | [diff] [blame^] | 694 | ERR(" Failed to relocate valid entries from sector being garbage " |
| 695 | "collected, %hu valid bytes remain", |
| 696 | sector_to_gc->valid_bytes); |
Wyatt Hepler | b760954 | 2020-01-24 10:29:54 -0800 | [diff] [blame] | 697 | return Status::INTERNAL; |
| 698 | } |
| 699 | |
David Rogers | a12786b | 2020-01-31 16:02:33 -0800 | [diff] [blame] | 700 | // Step 3: Reinitialize the sector |
| 701 | sector_to_gc->tail_free_bytes = 0; |
| 702 | TRY(partition_.Erase(SectorBaseAddress(sector_to_gc), 1)); |
| 703 | sector_to_gc->tail_free_bytes = partition_.sector_size_bytes(); |
Wyatt Hepler | b760954 | 2020-01-24 10:29:54 -0800 | [diff] [blame] | 704 | |
David Rogers | 67f4b6c | 2020-02-06 16:17:09 -0800 | [diff] [blame^] | 705 | DBG(" Garbage Collect complete"); |
David Rogers | a12786b | 2020-01-31 16:02:33 -0800 | [diff] [blame] | 706 | *sector = sector_to_gc; |
| 707 | return Status::OK; |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 708 | } |
| 709 | |
David Rogers | 2761aeb | 2020-01-31 17:09:00 -0800 | [diff] [blame] | 710 | Status KeyValueStore::AppendEntry(SectorDescriptor* sector, |
| 711 | KeyDescriptor* key_descriptor, |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 712 | const string_view key, |
Wyatt Hepler | 5a33d8c | 2020-02-06 09:32:58 -0800 | [diff] [blame] | 713 | span<const byte> value, |
| 714 | KeyDescriptor::State new_state) { |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 715 | // write header, key, and value |
Wyatt Hepler | 6c24c06 | 2020-02-05 15:30:49 -0800 | [diff] [blame] | 716 | EntryHeader header; |
| 717 | |
Wyatt Hepler | 5a33d8c | 2020-02-06 09:32:58 -0800 | [diff] [blame] | 718 | if (new_state == KeyDescriptor::kDeleted) { |
Wyatt Hepler | 6c24c06 | 2020-02-05 15:30:49 -0800 | [diff] [blame] | 719 | header = EntryHeader::Tombstone(entry_header_format_.magic, |
| 720 | entry_header_format_.checksum, |
| 721 | key, |
| 722 | key_descriptor->key_version + 1); |
| 723 | } else { |
| 724 | header = EntryHeader::Valid(entry_header_format_.magic, |
| 725 | entry_header_format_.checksum, |
| 726 | key, |
| 727 | value, |
| 728 | key_descriptor->key_version + 1); |
| 729 | } |
| 730 | |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 731 | DBG("Appending entry with key version: %zx", size_t(header.key_version())); |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 732 | |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 733 | Address address = NextWritableAddress(sector); |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 734 | DBG("Appending to address: %zx", size_t(address)); |
Wyatt Hepler | 5a33d8c | 2020-02-06 09:32:58 -0800 | [diff] [blame] | 735 | |
| 736 | // Handles writing multiple concatenated buffers, while breaking up the writes |
| 737 | // into alignment-sized blocks. |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 738 | TRY_ASSIGN( |
| 739 | size_t written, |
| 740 | partition_.Write( |
| 741 | address, {as_bytes(span(&header, 1)), as_bytes(span(key)), value})); |
| 742 | |
| 743 | if (options_.verify_on_write) { |
Wyatt Hepler | 0a22358 | 2020-02-04 17:47:40 -0800 | [diff] [blame] | 744 | TRY(header.VerifyChecksumInFlash( |
| 745 | &partition_, address, entry_header_format_.checksum)); |
Wyatt Hepler | b760954 | 2020-01-24 10:29:54 -0800 | [diff] [blame] | 746 | } |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 747 | |
David Rogers | 2761aeb | 2020-01-31 17:09:00 -0800 | [diff] [blame] | 748 | key_descriptor->address = address; |
| 749 | key_descriptor->key_version = header.key_version(); |
Wyatt Hepler | 5a33d8c | 2020-02-06 09:32:58 -0800 | [diff] [blame] | 750 | key_descriptor->state = new_state; |
| 751 | |
Wyatt Hepler | 4da1fcb | 2020-01-30 17:32:18 -0800 | [diff] [blame] | 752 | sector->valid_bytes += written; |
| 753 | sector->tail_free_bytes -= written; |
| 754 | return Status::OK; |
Wyatt Hepler | b760954 | 2020-01-24 10:29:54 -0800 | [diff] [blame] | 755 | } |
| 756 | |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 757 | void KeyValueStore::LogDebugInfo() { |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 758 | const size_t sector_size_bytes = partition_.sector_size_bytes(); |
| 759 | DBG("====================== KEY VALUE STORE DUMP ========================="); |
| 760 | DBG(" "); |
| 761 | DBG("Flash partition:"); |
Wyatt Hepler | ad0a793 | 2020-02-06 08:20:38 -0800 | [diff] [blame] | 762 | DBG(" Sector count = %zu", partition_.sector_count()); |
| 763 | DBG(" Sector max count = %zu", kMaxUsableSectors); |
| 764 | DBG(" Sectors in use = %zu", sector_map_size_); |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 765 | DBG(" Sector size = %zu", sector_size_bytes); |
| 766 | DBG(" Total size = %zu", partition_.size_bytes()); |
| 767 | DBG(" Alignment = %zu", partition_.alignment_bytes()); |
| 768 | DBG(" "); |
| 769 | DBG("Key descriptors:"); |
| 770 | DBG(" Entry count = %zu", key_descriptor_list_size_); |
| 771 | DBG(" Max entry count = %zu", kMaxEntries); |
| 772 | DBG(" "); |
| 773 | DBG(" # hash version address address (hex)"); |
| 774 | for (size_t i = 0; i < key_descriptor_list_size_; ++i) { |
| 775 | const KeyDescriptor& kd = key_descriptor_list_[i]; |
| 776 | DBG(" |%3zu: | %8zx |%8zu | %8zu | %8zx", |
| 777 | i, |
| 778 | size_t(kd.key_hash), |
| 779 | size_t(kd.key_version), |
| 780 | size_t(kd.address), |
| 781 | size_t(kd.address)); |
| 782 | } |
| 783 | DBG(" "); |
| 784 | |
| 785 | DBG("Sector descriptors:"); |
| 786 | DBG(" # tail free valid has_space"); |
Wyatt Hepler | ad0a793 | 2020-02-06 08:20:38 -0800 | [diff] [blame] | 787 | for (size_t sector_id = 0; sector_id < sector_map_size_; ++sector_id) { |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 788 | const SectorDescriptor& sd = sector_map_[sector_id]; |
| 789 | DBG(" |%3zu: | %8zu |%8zu | %s", |
| 790 | sector_id, |
| 791 | size_t(sd.tail_free_bytes), |
| 792 | size_t(sd.valid_bytes), |
| 793 | sd.tail_free_bytes ? "YES" : ""); |
| 794 | } |
| 795 | DBG(" "); |
| 796 | |
| 797 | // TODO: This should stop logging after some threshold. |
| 798 | // size_t dumped_bytes = 0; |
| 799 | DBG("Sector raw data:"); |
Wyatt Hepler | ad0a793 | 2020-02-06 08:20:38 -0800 | [diff] [blame] | 800 | for (size_t sector_id = 0; sector_id < sector_map_size_; ++sector_id) { |
Keir Mierle | 8c352dc | 2020-02-02 13:58:19 -0800 | [diff] [blame] | 801 | // Read sector data. Yes, this will blow the stack on embedded. |
| 802 | std::array<byte, 500> raw_sector_data; // TODO |
| 803 | StatusWithSize sws = |
| 804 | partition_.Read(sector_id * sector_size_bytes, raw_sector_data); |
| 805 | DBG("Read: %zu bytes", sws.size()); |
| 806 | |
| 807 | DBG(" base addr offs 0 1 2 3 4 5 6 7"); |
| 808 | for (size_t i = 0; i < sector_size_bytes; i += 8) { |
| 809 | DBG(" %3zu %8zx %5zu | %02x %02x %02x %02x %02x %02x %02x %02x", |
| 810 | sector_id, |
| 811 | (sector_id * sector_size_bytes) + i, |
| 812 | i, |
| 813 | static_cast<unsigned int>(raw_sector_data[i + 0]), |
| 814 | static_cast<unsigned int>(raw_sector_data[i + 1]), |
| 815 | static_cast<unsigned int>(raw_sector_data[i + 2]), |
| 816 | static_cast<unsigned int>(raw_sector_data[i + 3]), |
| 817 | static_cast<unsigned int>(raw_sector_data[i + 4]), |
| 818 | static_cast<unsigned int>(raw_sector_data[i + 5]), |
| 819 | static_cast<unsigned int>(raw_sector_data[i + 6]), |
| 820 | static_cast<unsigned int>(raw_sector_data[i + 7])); |
| 821 | |
| 822 | // TODO: Fix exit condition. |
| 823 | if (i > 128) { |
| 824 | break; |
| 825 | } |
| 826 | } |
| 827 | DBG(" "); |
| 828 | } |
| 829 | |
| 830 | DBG("////////////////////// KEY VALUE STORE DUMP END /////////////////////"); |
| 831 | } |
| 832 | |
Wyatt Hepler | 2ad6067 | 2020-01-21 08:00:16 -0800 | [diff] [blame] | 833 | } // namespace pw::kvs |