pw_kvs: Add space reporting methods
This change adds KVS methods to retrieve the total available, used, and
reclaimable storage space.
Change-Id: I5461304d6c25780a3cdc3eb20f480006ae7afa92
diff --git a/pw_kvs/key_value_store.cc b/pw_kvs/key_value_store.cc
index f7fda90..306ad82 100644
--- a/pw_kvs/key_value_store.cc
+++ b/pw_kvs/key_value_store.cc
@@ -199,6 +199,31 @@
return Status::OK;
}
+KeyValueStore::StorageStats KeyValueStore::GetStorageStats() const {
+ StorageStats stats{0, 0, 0};
+ const size_t sector_size = partition_.sector_size_bytes();
+ bool found_empty_sector = false;
+
+ for (const SectorDescriptor& sector : sectors_) {
+ stats.in_use_bytes += sector.valid_bytes();
+ stats.reclaimable_bytes += sector.RecoverableBytes(sector_size);
+
+ if (!found_empty_sector && sector.Empty(sector_size)) {
+ // The KVS tries to always keep an empty sector for GC, so don't count
+ // the first empty sector seen as writable space. However, a free sector
+ // cannot always be assumed to exist; if a GC operation fails, all sectors
+ // may be partially written, in which case the space reported might be
+ // inaccurate.
+ found_empty_sector = true;
+ continue;
+ }
+
+ stats.writable_bytes += sector.writable_bytes();
+ }
+
+ return stats;
+}
+
Status KeyValueStore::LoadEntry(Address entry_address,
Address* next_entry_address) {
Entry entry;
diff --git a/pw_kvs/public/pw_kvs/key_value_store.h b/pw_kvs/public/pw_kvs/key_value_store.h
index aa9d431..1cf60d7 100644
--- a/pw_kvs/public/pw_kvs/key_value_store.h
+++ b/pw_kvs/public/pw_kvs/key_value_store.h
@@ -212,6 +212,14 @@
// the underlying flash is erased.
uint32_t transaction_count() const { return last_transaction_id_; }
+ struct StorageStats {
+ size_t writable_bytes;
+ size_t in_use_bytes;
+ size_t reclaimable_bytes;
+ };
+
+ StorageStats GetStorageStats() const;
+
protected:
using Address = FlashPartition::Address;
using Entry = internal::Entry;
