Since read cache was introduced at page level, search cache became
useless in terms of reducing the number of flash read operations.
In addition to that, search cache used an assumption that if pointers to
keys are identical, the keys are also identical, which was proven wrong
by applications which generate key names dynamically.
This change removes CachedFindInfo, and all its uses. This is done at
expense of a small extra number of CPU operations (looking up a value in
the read cache is slightly more expensive) but no extra flash read
operations.
Ref TW12505
Ref https://github.com/espressif/arduino-esp32/issues/365
This change adds a check for the free page count to nvs_flash_init.
Under normal operation, NVS keeps at least one free page available,
except for transient states such as freeing up new page. Due to external
factors (such as NVS partition size reduction) this free page could be
lost, making NVS operation impossible. Previously this would cause an
error when performing any nvs_set operation or opening a new namespace.
With this change, an error is returned from nvs_flash_init to indicate
that NVS partition is in such a state.
One common pattern of using assert function looks as follows:
int ret = do_foo();
assert(ret == 0); // which reads as: “do_foo should never fail here, by design”
The problem with such code is that if ‘assert’ is removed by the preprocessor in release build,
variable ret is no longer used, and the compiler issues a warning about this.
Changing assert definition in the way done here make the variable used, from language syntax perspective.
Semantically, the variable is still unused at run time (as sizeof can be evaluated at compile time), so the compiler
can optimize things away if possible.
When read caching was added, Page::findItem started modifying itemIndex reference argument even if item wasn't found.
Incidentally, Storage::findItem reused itemIndex when starting search at next page.
So,
- if the first page had a cached index (findItem was called for that page), and it pointed to a non-zero index,
- first page has a few empty items at the end (but is marked full),
- next search looked up the item on the second page,
- index of the item on the second page was less than the cached index on the first page,
then the search would fail because cached starting index was reused.
This change fixes both sides of the problem:
- Page::findItem shouldn't modify itemIndex argument if item is not found
- Storage::findItem should not reuse itemIndex between pages
Two tests have been added.
Due to previous flash write bug it was possible to create multiple duplicate entries in a single page.
Recovery logic detected that case and bailed out with an assert.
This change adds graceful recovery from this condition.
Tests included.
Currently a restart is required to recover a page from invalid state.
The long-term solution is to detect such a condition and recover automatically (without a restart). This will be implemented in a separate change set.
nvs: fix memory leaks in HashList and nvs_close
Fixes TW8162.
Associated test case is run under Instruments on macOS, until I set up valgrind to test this automatically on Linux.
See merge request !150
spi_flash_read and spi_flash_write currently have a limitation that source and destination must be word-aligned.
This can be fixed by adding code paths for various unaligned scenarios, but function signatures also need to be adjusted.
As a first step (since we are pre-1.0 and can still change function signatures) alignment checks are added, and pointer types are relaxed to uint8_t.
Later we will add handling of unaligned operations.
This change also introduces spi_flash_erase_range and spi_flash_get_chip_size functions.
We probably need something like spi_flash_chip_size_detect which will detect actual chip size.
This is to allow single application binary to be used on a variety of boards and modules.
Introduces new internal function, Page::alterEntryRangeState, which gathers changes to multiple elements of entry state table into a single write, provided that these changes fall into a single word. This allows changing state of up to 16 entries in a single write.
Also adds new function, writeEntryData, which writes the whole payload of SZ and BLOB type entries in one go, instead of splitting it into multiple 32-byte writes.
This reduces number of writes required for SZ and BLOB entries.
This commit fixes several issues with state handling in nvs::Page. It also adds extra consistency checks in nvs::PageManger initialization.
These changes were verified with a new long-running test ("test recovery from sudden poweroff"). This test works by repeatedly performing same pseudorandom sequence of calls to nvs_ APIs. Each time it repeats the sequence, it introduces a failure into one of flash operations (write or erase). So if one iteration of this test needs, say, 25000 flash operations, then this test will run 25000 iterations, each time introducing the failure point at different location.
