[−][src]Module sp_io::storage

Interface for accessing the storage from within the runtime.

Structs

Provides implementations for the extern host functions.

append	Append the encoded `value` to the storage item at `key`.
changes_root	"Commit" all existing operations and get the resulting storage change root. `parent_hash` is a SCALE encoded hash.
clear	Clear the storage of the given `key` and its value.
clear_prefix	Clear the storage of each key-value pair where the key starts with the given `prefix`.
commit_transaction	Commit the last transaction started by `start_transaction`.
exists	Check whether the given `key` exists in storage.
get	Returns the data for `key` in the storage or `None` if the key can not be found.
next_key	Get the next key in storage after the given one in lexicographic order.
read	Get `key` from storage, placing the value into `value_out` and return the number of bytes that the entry in storage has beyond the offset or `None` if the storage entry doesn't exist at all. If `value_out` length is smaller than the returned length, only `value_out` length bytes are copied into `value_out`.
rollback_transaction	Rollback the last transaction started by `start_transaction`.
root	"Commit" all existing operations and compute the resulting storage root.
set	Set `key` to `value` in the storage.
start_transaction	Start a new nested transaction.