pw_kvs: FlashMemory updates; test utilities
- Update comments for FlashMemory class.
- Split InMemoryFakeFlash to move the fixed-size buffer into the
derived FakeFlashBuffer class.
- Support initializing FakeFlashBuffer to data provided at construction.
- Allow direct access to the underlying fake flash buffer for testing.
- Create utilities for working with byte arrays in byte_utils.h.
Change-Id: I90d33621cb91da079d7213fe7d33823494120e48
diff --git a/pw_kvs/public/pw_kvs/flash_memory.h b/pw_kvs/public/pw_kvs/flash_memory.h
index 5d8f558..93ee1eb 100644
--- a/pw_kvs/public/pw_kvs/flash_memory.h
+++ b/pw_kvs/public/pw_kvs/flash_memory.h
@@ -58,17 +58,19 @@
// Erase num_sectors starting at a given address. Blocking call.
// Address should be on a sector boundary.
- // Returns: OK, on success.
- // TIMEOUT, on timeout.
- // INVALID_ARGUMENT, if address or sector count is invalid.
- // UNKNOWN, on HAL error
+ //
+ // OK: success
+ // DEADLINE_EXCEEDED: timeout
+ // INVALID_ARGUMENT: address is not sector-aligned
+ // OUT_OF_RANGE: erases past the end of the memory
+ //
virtual Status Erase(Address flash_address, size_t num_sectors) = 0;
// Reads bytes from flash into buffer. Blocking call.
- // Returns: OK, on success.
- // TIMEOUT, on timeout.
- // INVALID_ARGUMENT, if address or length is invalid.
- // UNKNOWN, on HAL error
+ //
+ // OK: success
+ // DEADLINE_EXCEEDED: timeout
+ // OUT_OF_RANGE: write does not fit in the flash memory
virtual StatusWithSize Read(Address address, span<std::byte> output) = 0;
StatusWithSize Read(Address address, void* buffer, size_t len) {
@@ -76,10 +78,12 @@
}
// Writes bytes to flash. Blocking call.
- // Returns: OK, on success.
- // TIMEOUT, on timeout.
- // INVALID_ARGUMENT, if address or length is invalid.
- // UNKNOWN, on HAL error
+ //
+ // OK: success
+ // DEADLINE_EXCEEDED: timeout
+ // INVALID_ARGUMENT: address or data size are not aligned
+ // OUT_OF_RANGE: write does not fit in the memory
+ //
virtual StatusWithSize Write(Address destination_flash_address,
span<const std::byte> data) = 0;
@@ -150,6 +154,11 @@
: alignment_bytes),
permission_(permission) {}
+ // Creates a FlashPartition that uses the entire flash with its alignment.
+ constexpr FlashPartition(FlashMemory* flash)
+ : FlashPartition(
+ flash, 0, flash->sector_count(), flash->alignment_bytes()) {}
+
FlashPartition(const FlashPartition&) = delete;
FlashPartition& operator=(const FlashPartition&) = delete;
diff --git a/pw_kvs/public/pw_kvs/in_memory_fake_flash.h b/pw_kvs/public/pw_kvs/in_memory_fake_flash.h
index 4037161..761e57c 100644
--- a/pw_kvs/public/pw_kvs/in_memory_fake_flash.h
+++ b/pw_kvs/public/pw_kvs/in_memory_fake_flash.h
@@ -13,94 +13,80 @@
// the License.
#pragma once
+#include <algorithm>
#include <array>
+#include <cstddef>
#include <cstring>
-// TODO: Push/pop log module name due to logging in header.
-// Alternately: Push implementation into .cc
#include "pw_kvs/flash_memory.h"
-#include "pw_log/log.h"
+#include "pw_span/span.h"
#include "pw_status/status.h"
namespace pw::kvs {
-// This creates a buffer which mimics the behaviour of flash (requires erase,
-// before write, checks alignments, and is addressed in sectors).
-template <uint32_t kSectorSize, uint16_t kSectorCount>
+// This uses a buffer to mimic the behaviour of flash (requires erase before
+// write, checks alignments, and is addressed in sectors). The underlying buffer
+// is not initialized.
class InMemoryFakeFlash : public FlashMemory {
public:
- InMemoryFakeFlash(uint8_t alignment_bytes = 1) // default 8 bit alignment
- : FlashMemory(kSectorSize, kSectorCount, alignment_bytes) {}
+ // Default to 8-bit alignment.
+ static constexpr size_t kDefaultAlignmentBytes = 1;
- // Always enabled
+ static constexpr std::byte kErasedValue = std::byte{0xff};
+
+ InMemoryFakeFlash(span<std::byte> buffer,
+ size_t sector_size,
+ size_t sector_count,
+ size_t alignment_bytes = kDefaultAlignmentBytes)
+ : FlashMemory(sector_size, sector_count, alignment_bytes),
+ buffer_(buffer) {}
+
+ // The fake flash is always enabled.
Status Enable() override { return Status::OK; }
+
Status Disable() override { return Status::OK; }
+
bool IsEnabled() const override { return true; }
- // Erase num_sectors starting at a given address. Blocking call.
- // Address should be on a sector boundary.
- // Returns: OK, on success.
- // INVALID_ARGUMENT, if address or sector count is invalid.
- // UNKNOWN, on HAL error
- Status Erase(Address address, size_t num_sectors) override {
- if (address % sector_size_bytes() != 0) {
- PW_LOG_ERROR(
- "Attempted to erase sector at non-sector aligned boundary: %zx",
- size_t(address));
- return Status::INVALID_ARGUMENT;
- }
- size_t sector_id = address / sector_size_bytes();
- if (address / sector_size_bytes() + num_sectors > sector_count()) {
- PW_LOG_ERROR(
- "Tried to erase a sector at an address past partition end; "
- "address: %zx, sector implied: %zu",
- size_t(address),
- sector_id);
- return Status::UNKNOWN;
- }
- if (address % alignment_bytes() != 0) {
- return Status::INVALID_ARGUMENT;
- }
- std::memset(&buffer_[address], 0xFF, sector_size_bytes() * num_sectors);
- return Status::OK;
- }
+ // Erase num_sectors starting at a given address.
+ Status Erase(Address address, size_t num_sectors) override;
- // Reads bytes from flash into buffer. Blocking call.
- // Returns: OK, on success.
- // INVALID_ARGUMENT, if address or length is invalid.
- // UNKNOWN, on HAL error
- StatusWithSize Read(Address address, span<std::byte> output) override {
- if (address + output.size() >= sector_count() * size_bytes()) {
- return StatusWithSize(Status::INVALID_ARGUMENT);
- }
- std::memcpy(output.data(), &buffer_[address], output.size());
- return StatusWithSize(output.size());
- }
+ // Reads bytes from flash into buffer.
+ StatusWithSize Read(Address address, span<std::byte> output) override;
- // Writes bytes to flash. Blocking call.
- // Returns: OK, on success.
- // INVALID_ARGUMENT, if address or length is invalid.
- // UNKNOWN, on HAL error
- StatusWithSize Write(Address address, span<const std::byte> data) override {
- if ((address + data.size()) >= sector_count() * size_bytes() ||
- address % alignment_bytes() != 0 ||
- data.size() % alignment_bytes() != 0) {
- return StatusWithSize(Status::INVALID_ARGUMENT);
- }
- // Check in erased state
- for (unsigned i = 0; i < data.size(); i++) {
- if (buffer_[address + i] != 0xFF) {
- PW_LOG_ERROR("Writing to previously written address: %zx",
- size_t(address));
- return StatusWithSize(Status::UNKNOWN);
- }
- }
- std::memcpy(&buffer_[address], data.data(), data.size());
- return StatusWithSize(data.size());
+ // Writes bytes to flash.
+ StatusWithSize Write(Address address, span<const std::byte> data) override;
+
+ // Access the underlying buffer for testing purposes. Not part of the
+ // FlashMemory API.
+ span<std::byte> buffer() const { return buffer_; }
+
+ private:
+ const span<std::byte> buffer_;
+};
+
+// Creates an InMemoryFakeFlash backed by a std::array. The array is initialized
+// to the erased value. A byte array to which to initialize the memory may be
+// provided.
+template <size_t kSectorSize, size_t kSectorCount>
+class FakeFlashBuffer : public InMemoryFakeFlash {
+ public:
+ // Creates a flash memory with no data written.
+ FakeFlashBuffer(size_t alignment_bytes = kDefaultAlignmentBytes)
+ : FakeFlashBuffer(std::array<std::byte, 0>{}, alignment_bytes) {}
+
+ // Creates a flash memory initialized to the provided contents.
+ FakeFlashBuffer(span<const std::byte> contents,
+ size_t alignment_bytes = kDefaultAlignmentBytes)
+ : InMemoryFakeFlash(buffer_, kSectorSize, kSectorCount, alignment_bytes) {
+ std::memset(buffer_.data(), int(kErasedValue), buffer_.size());
+ std::memcpy(buffer_.data(),
+ contents.data(),
+ std::min(contents.size(), buffer_.size()));
}
private:
- std::array<uint8_t, kSectorCount * kSectorSize> buffer_;
+ std::array<std::byte, kSectorCount * kSectorSize> buffer_;
};
} // namespace pw::kvs
