This prevents wear and tear on the flash, and it also is faster in some
cases since the read-out of flash is a cheaper operation than the erasure
of flash. Some library modules (such as the esp_wifi) write out to NVS
upon every initialization without checking first that the existing value
is the same, and this speeds up initialization of modules that make
these design choices and moves it into a centralized place.
The comparison functions are based on the read-out functions of the same
name, and changes out the memcpy(...) operations for memcmp(...)
operations.
Signed-off-by: Tim Nordell <tim.nordell@nimbelink.com>
This change adds a check for compatibility between the nvs version
found on nvs flash and the one assumed by running code during nvs
initialization. Any mismatch is reported to the user using new error
code ESP_ERR_NVS_NEW_VERSION_FOUND.
Users needs functions to count the number of free and used entries.
1. `nvs_get_stats()` This function return structure of statistic about the uspace NVS.
(Struct: used_entries, free_entries, total_entries and namespace_count)
2. `nvs_get_used_entry_count()` The second function return amount of entries in the namespace (by handler)
3. Added unit tests.
Closes TW<12282>
This commit adds support for multiple NVS partitions. This provides application a flexibility to have multiple NVS
partitions such as separate partition with read-only manufacturing data and read-write partition with configuration.
Application can also use this to separate out application's configuration storage from system configuration.
This feature does not change any of the basic property of NVS subsystem. The same-named namespaces across partitions are
considered to be different namespaces. The original NVS API available for the applications remains unchanged. The only
difference is that instead of first NVS partition in the partition table, it now operates on the partition with label
"nvs" (which is default in the IDF provided partition table files). Additional APIs are provided to open a handle and
erase NVS with partition name as a parameter.
A test case is added in the host tests and it is made sure that all the host tests pass. nvs_rw_value app is also tested
with multiple partitions.
Signed-off-by: Amey Inamdar <amey.inamdar@gmail.com>
Writing values longer than half of the page size (with header taken into
account) causes fragmentation issues. Previously it was suggested on the
forum that using long values may cause issues, but this wasn’t checked
in the library itself, and wasn’t documented. This change adds necessary
checks and introduces the new error code.
Documentation is also fixed to reflect the fact that the maximum length
of the key is 15 characters, not 16.
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.
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.
