mirror of
https://fuchsia.googlesource.com/third_party/pigweed.googlesource.com/pigweed/pigweed
synced 2024-09-21 14:16:26 +00:00
88adfe8b91
- Move EntryHeaderFormat and the EntryHeader struct to pw_kvs/format.h. - Rename EntryHeaderFormat to EntryFormat. Change-Id: Ic5e53c688cd3a483101c7985def6e4bef9c3cbaf
210 lines
6.6 KiB
C++
210 lines
6.6 KiB
C++
// Copyright 2020 The Pigweed Authors
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License"); you may not
|
|
// use this file except in compliance with the License. You may obtain a copy of
|
|
// the License at
|
|
//
|
|
// https://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
|
// License for the specific language governing permissions and limitations under
|
|
// the License.
|
|
|
|
#include "pw_kvs/internal/entry.h"
|
|
|
|
#include <cinttypes>
|
|
#include <cstring>
|
|
|
|
#include "pw_kvs_private/macros.h"
|
|
#include "pw_log/log.h"
|
|
|
|
namespace pw::kvs::internal {
|
|
|
|
using std::byte;
|
|
using std::string_view;
|
|
|
|
Status Entry::Read(FlashPartition& partition, Address address, Entry* entry) {
|
|
EntryHeader header;
|
|
TRY(partition.Read(address, sizeof(header), &header));
|
|
|
|
if (partition.AppearsErased(as_bytes(span(&header.magic, 1)))) {
|
|
return Status::NOT_FOUND;
|
|
}
|
|
if (header.key_length_bytes > kMaxKeyLength) {
|
|
return Status::DATA_LOSS;
|
|
}
|
|
|
|
*entry = Entry(&partition, address, header);
|
|
return Status::OK;
|
|
}
|
|
|
|
Status Entry::ReadKey(FlashPartition& partition,
|
|
Address address,
|
|
size_t key_length,
|
|
char* key) {
|
|
if (key_length == 0u || key_length > kMaxKeyLength) {
|
|
return Status::DATA_LOSS;
|
|
}
|
|
|
|
return partition.Read(address + sizeof(EntryHeader), key_length, key)
|
|
.status();
|
|
}
|
|
|
|
Entry::Entry(FlashPartition& partition,
|
|
Address address,
|
|
const EntryFormat& format,
|
|
string_view key,
|
|
span<const byte> value,
|
|
uint16_t value_size_bytes,
|
|
size_t alignment_bytes,
|
|
uint32_t transaction_id)
|
|
: Entry(&partition,
|
|
address,
|
|
{.magic = format.magic,
|
|
.checksum = 0,
|
|
.alignment_units = alignment_bytes_to_units(alignment_bytes),
|
|
.key_length_bytes = static_cast<uint8_t>(key.size()),
|
|
.value_size_bytes = value_size_bytes,
|
|
.transaction_id = transaction_id}) {
|
|
if (format.checksum != nullptr) {
|
|
span<const byte> checksum = CalculateChecksum(format.checksum, key, value);
|
|
std::memcpy(&header_.checksum,
|
|
checksum.data(),
|
|
std::min(checksum.size(), sizeof(header_.checksum)));
|
|
}
|
|
|
|
// TODO: 0 is an invalid alignment value. There should be an assert for this.
|
|
// DCHECK_NE(alignment_bytes, 0);
|
|
}
|
|
|
|
StatusWithSize Entry::Write(const string_view key,
|
|
span<const byte> value) const {
|
|
FlashPartition::Output flash(partition(), address_);
|
|
return AlignedWrite<64>(
|
|
flash,
|
|
alignment_bytes(),
|
|
{as_bytes(span(&header_, 1)), as_bytes(span(key)), value});
|
|
}
|
|
|
|
StatusWithSize Entry::ReadValue(span<byte> buffer, size_t offset_bytes) const {
|
|
if (offset_bytes > value_size()) {
|
|
return StatusWithSize(Status::OUT_OF_RANGE);
|
|
}
|
|
|
|
const size_t remaining_bytes = value_size() - offset_bytes;
|
|
const size_t read_size = std::min(buffer.size(), remaining_bytes);
|
|
|
|
StatusWithSize result = partition().Read(
|
|
address_ + sizeof(EntryHeader) + key_length() + offset_bytes,
|
|
buffer.subspan(0, read_size));
|
|
TRY_WITH_SIZE(result);
|
|
|
|
if (read_size != remaining_bytes) {
|
|
return StatusWithSize(Status::RESOURCE_EXHAUSTED, read_size);
|
|
}
|
|
return StatusWithSize(read_size);
|
|
}
|
|
|
|
Status Entry::VerifyChecksum(ChecksumAlgorithm* algorithm,
|
|
string_view key,
|
|
span<const byte> value) const {
|
|
if (algorithm == nullptr) {
|
|
return checksum() == 0 ? Status::OK : Status::DATA_LOSS;
|
|
}
|
|
CalculateChecksum(algorithm, key, value);
|
|
return algorithm->Verify(checksum_bytes());
|
|
}
|
|
|
|
Status Entry::VerifyChecksumInFlash(ChecksumAlgorithm* algorithm) const {
|
|
// Read the entire entry piece-by-piece into a small buffer. If the entry is
|
|
// 32 B or less, only one read is required.
|
|
union {
|
|
EntryHeader header_to_verify;
|
|
byte buffer[sizeof(EntryHeader) * 2];
|
|
};
|
|
|
|
size_t bytes_to_read = size();
|
|
size_t read_size = std::min(sizeof(buffer), bytes_to_read);
|
|
|
|
Address read_address = address_;
|
|
|
|
// Read the first chunk, which includes the header, and compare the checksum.
|
|
TRY(partition().Read(read_address, read_size, buffer));
|
|
|
|
if (header_to_verify.checksum != checksum()) {
|
|
PW_LOG_ERROR("Expected checksum %08" PRIx32 ", found %08" PRIx32,
|
|
checksum(),
|
|
header_to_verify.checksum);
|
|
return Status::DATA_LOSS;
|
|
}
|
|
|
|
if (algorithm == nullptr) {
|
|
return checksum() == 0 ? Status::OK : Status::DATA_LOSS;
|
|
}
|
|
|
|
// The checksum is calculated as if the header's checksum field were 0.
|
|
header_to_verify.checksum = 0;
|
|
|
|
algorithm->Reset();
|
|
|
|
while (true) {
|
|
// Add the chunk in the buffer to the checksum.
|
|
algorithm->Update(buffer, read_size);
|
|
|
|
bytes_to_read -= read_size;
|
|
if (bytes_to_read == 0u) {
|
|
break;
|
|
}
|
|
|
|
// Read the next chunk into the buffer.
|
|
read_address += read_size;
|
|
read_size = std::min(sizeof(buffer), bytes_to_read);
|
|
TRY(partition().Read(read_address, read_size, buffer));
|
|
}
|
|
|
|
algorithm->Finish();
|
|
return algorithm->Verify(checksum_bytes());
|
|
}
|
|
|
|
void Entry::DebugLog() {
|
|
PW_LOG_DEBUG("Header: ");
|
|
PW_LOG_DEBUG(" Address = 0x%zx", size_t(address_));
|
|
PW_LOG_DEBUG(" Magic = 0x%zx", size_t(magic()));
|
|
PW_LOG_DEBUG(" Checksum = 0x%zx", size_t(checksum()));
|
|
PW_LOG_DEBUG(" Key length = 0x%zx", size_t(key_length()));
|
|
PW_LOG_DEBUG(" Value length = 0x%zx", size_t(value_size()));
|
|
PW_LOG_DEBUG(" Entry size = 0x%zx", size_t(size()));
|
|
PW_LOG_DEBUG(" Alignment = 0x%zx", size_t(alignment_bytes()));
|
|
}
|
|
|
|
span<const byte> Entry::CalculateChecksum(ChecksumAlgorithm* algorithm,
|
|
const string_view key,
|
|
span<const byte> value) const {
|
|
algorithm->Reset();
|
|
|
|
{
|
|
EntryHeader header_for_checksum = header_;
|
|
header_for_checksum.checksum = 0;
|
|
|
|
algorithm->Update(&header_for_checksum, sizeof(header_for_checksum));
|
|
algorithm->Update(as_bytes(span(key)));
|
|
algorithm->Update(value);
|
|
}
|
|
|
|
// Update the checksum with 0s to pad the entry to its alignment boundary.
|
|
constexpr byte padding[kMinAlignmentBytes - 1] = {};
|
|
size_t padding_to_add = Padding(content_size(), alignment_bytes());
|
|
|
|
while (padding_to_add > 0u) {
|
|
const size_t chunk_size = std::min(padding_to_add, sizeof(padding));
|
|
algorithm->Update(padding, chunk_size);
|
|
padding_to_add -= chunk_size;
|
|
}
|
|
|
|
return algorithm->Finish();
|
|
}
|
|
|
|
} // namespace pw::kvs::internal
|