Issue:
When the setting nvs cache is disabled and `settings_nvs_save` is
called, the function reads all stored setting name entries from NVS
until either finds the desired setting name entry or reaches the last
stored setting name entry.
With the settings nvs cache enabled, `settings_nvs_save` runs through
the cached setting name entries first. If the cached entry matches with
the desired one, it immediately writes the new setting value to NVS
that corresponds to the cached setting name entry.
However, if the setting name entry is not found in the cache (which is
the case for a new entry), `settings_nvs_save` reads all stored setting
name entries from NVS again. This means that even if the number of
stored entries in the settings is less than the cache size, for each
new setting entry to be stored `settings_nvs_save` will first run
through the cache, then read all stored setting name entries from NVS
and only then will pick the next free name id for this new setting name
entry and will finally store the new setting entry.
This makes the cache ineffiсient for every new entry to be stored even
when the cache size is always able to keep all setting entries that will
be stored in NVS.
Use-case:
In the Bluetooth mesh there is a Replay Protection List which keeps
sequence numbers of all nodes it received messages from. The RPL is
stored persistently in NVS. The setting name entry is the source
address of the node and the setting value entry is the sequence number.
The common use case is when RPL is quite big (for example, 255 entries).
With the current settings nvs cache implementation, every time the node
stores a new RPL entry in settings (which is the first received message
from a particular source address), `settings_nvs_save` will always check
the cache first, then also read all stored entries in NVS and only then
will figure out that this is a new entry. With every new RPL entry to be
stored this search time increases. This behavior results in much worse
performance in comparison with when the corresponding entry was already
stored. E.g. on nRF52840, with bare minimal mesh stack configuration,
when the cache is bigger than number of stored entries or close to it,
storing of 255 RPL entries takes ~25 seconds. The time of subsequent
store of 255 RPL entires is ~2 seconds with the cache.
Solution:
This commit improves the behavior of the first write by bypassing the
reading from NVS if the following conditions are met:
1. `settings_nvs_load` was called,
2. the cache was not overflowed (bigger than the number of stored
entries).
As long as these 2 conditiones are met, it is safe to skip reading from
NVS, pick the next free name id and write the value immediately.
Signed-off-by: Pavel Vasilyev <pavel.vasilyev@nordicsemi.no>
Currently there is inconsistency in repository file names, APIs, Kconfig
options and documentation around file / file-system backend for settings
storage, as both "file" and "FS (file system)" are used. As an example,
there is `CONFIG_SETTINGS_FS` Kconfig option, but the file that implements
this settings backend is called `settings_file.c`. Another example are
names of static functions that implement settings storage API:
`settings_file_load()`, `settings_file_save()` and
`settings_fs_storage_get()`.
This backend is actually storing all settings in a single file, so it makes
sense to use "File" as the name of backend, instead of a more general
"FS" (which would make sense if several files would be used to store
settings).
Fix inconsistency in used wording in the tree and unify it to "settings
file backend". This naming is more precise to how the implementation looks.
It will also make it easier to grep through the codebase and analyze
existing code.
Deprecate settings_mount_fs_backend() function and all Kconfig options
starting with `CONFIG_SETTINGS_FS`.
Signed-off-by: Marcin Niestroj <m.niestroj@emb.dev>
Adds few missing zephyr/ prefixes to leftover #include statements that
either got added recently or were using double quote format.
Signed-off-by: Fabio Baltieri <fabiobaltieri@google.com>
In order to bring consistency in-tree, migrate all subsystems code to
the new prefix <zephyr/...>. Note that the conversion has been scripted,
refer to zephyrproject-rtos#45388 for more details.
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
move fcb.h to fs/fcb.h and
create a shim for backward-compatibility.
No functional changes to the headers.
A warning in the shim can be controlled with CONFIG_COMPAT_INCLUDES.
Related to #16539
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
This patch reworks routines used to store and read the settings data.
Provide stream-style encoding and decoding to/from flash, so the the
API only requires a pointer to binary data, and the settings
implementation takes care of encoding/decoding to/from base64 and
writing/reading to/from flash on the fly. This would eliminate the
need of a separate base64 value buffer on the application-side, thereby
further contributing to the stack footprint reduction.
Above changes allows to remove:
256-byte value length limitation.
removing enum settings_type usage so all settings data are treated
now as a byte array (i.e. what's previously SETTINGS_BYTES)
Introduced routine settings_val_read_cb for read and decode the
settings data from storage inside h_set handler implementations.
h_set settings handler now provide persistent value's context
used along with read routine instead of immediately value.
Signed-off-by: Andrzej Puzdrowski <andrzej.puzdrowski@nordicsemi.no>
Adapt the MyNewt non-volatile configuration system to become a settings
system in Zephyr.
The original code was modifed in the following ways:
* Renamed from config to settings
* Use the zephyr FCB, FS API, and base64 subsystems
* lltoa like function was added to sources as it was required but not
included in Zephyr itself.
* The original code was modified to use Zephyr's slist.h as single
linked list implementation.
* Reworked code which was using strtok_r, added function
for decoding a string to a s64_t value.
* Thank to the above the settings subsys doesn't require newlibc anymore.
Signed-off-by: Andrzej Puzdrowski <andrzej.puzdrowski@nordicsemi.no>
Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>
