[−][src]Trait sp_core::traits::Externalities

pub trait Externalities: ExtensionStore {
    fn set_offchain_storage(&mut self, key: &[u8], value: Option<&[u8]>);
    fn storage(&self, key: &[u8]) -> Option<Vec<u8>>;
    fn storage_hash(&self, key: &[u8]) -> Option<Vec<u8>>;
    fn child_storage_hash(
        &self, 
        child_info: &ChildInfo, 
        key: &[u8]
    ) -> Option<Vec<u8>>;
    fn child_storage(
        &self, 
        child_info: &ChildInfo, 
        key: &[u8]
    ) -> Option<Vec<u8>>;
    fn next_storage_key(&self, key: &[u8]) -> Option<Vec<u8>>;
    fn next_child_storage_key(
        &self, 
        child_info: &ChildInfo, 
        key: &[u8]
    ) -> Option<Vec<u8>>;
    fn kill_child_storage(&mut self, child_info: &ChildInfo);
    fn clear_prefix(&mut self, prefix: &[u8]);
    fn clear_child_prefix(&mut self, child_info: &ChildInfo, prefix: &[u8]);
    fn place_storage(&mut self, key: Vec<u8>, value: Option<Vec<u8>>);
    fn place_child_storage(
        &mut self, 
        child_info: &ChildInfo, 
        key: Vec<u8>, 
        value: Option<Vec<u8>>
    );
    fn chain_id(&self) -> u64;
    fn storage_root(&mut self) -> Vec<u8>;
    fn child_storage_root(&mut self, child_info: &ChildInfo) -> Vec<u8>;
    fn storage_append(&mut self, key: Vec<u8>, value: Vec<u8>);
    fn storage_changes_root(
        &mut self, 
        parent: &[u8]
    ) -> Result<Option<Vec<u8>>, ()>;
    fn storage_start_transaction(&mut self);
    fn storage_rollback_transaction(&mut self) -> Result<(), ()>;
    fn storage_commit_transaction(&mut self) -> Result<(), ()>;
    fn wipe(&mut self);
    fn commit(&mut self);
    fn read_write_count(&self) -> (u32, u32, u32, u32);
    fn reset_read_write_count(&mut self);
    fn set_whitelist(&mut self, new: Vec<Vec<u8>>);

    fn set_storage(&mut self, key: Vec<u8>, value: Vec<u8>) { ... }
    fn set_child_storage(
        &mut self, 
        child_info: &ChildInfo, 
        key: Vec<u8>, 
        value: Vec<u8>
    ) { ... }
    fn clear_storage(&mut self, key: &[u8]) { ... }
    fn clear_child_storage(&mut self, child_info: &ChildInfo, key: &[u8]) { ... }
    fn exists_storage(&self, key: &[u8]) -> bool { ... }
    fn exists_child_storage(&self, child_info: &ChildInfo, key: &[u8]) -> bool { ... }
}

The Substrate externalities.

Provides access to the storage and to other registered extensions.

Required methods

`fn set_offchain_storage(&mut self, key: &[u8], value: Option<&[u8]>)`

Write a key value pair to the offchain storage database.

`fn storage(&self, key: &[u8]) -> Option<Vec<u8>>`

Read runtime storage.

`fn storage_hash(&self, key: &[u8]) -> Option<Vec<u8>>`

Get storage value hash.

This may be optimized for large values.

`fn child_storage_hash( &self, child_info: &ChildInfo, key: &[u8] ) -> Option<Vec<u8>>`

Get child storage value hash.

This may be optimized for large values.

Returns an Option that holds the SCALE encoded hash.

`fn child_storage(&self, child_info: &ChildInfo, key: &[u8]) -> Option<Vec<u8>>`

Read child runtime storage.

Returns an Option that holds the SCALE encoded hash.

`fn next_storage_key(&self, key: &[u8]) -> Option<Vec<u8>>`

Returns the key immediately following the given key, if it exists.

`fn next_child_storage_key( &self, child_info: &ChildInfo, key: &[u8] ) -> Option<Vec<u8>>`

Returns the key immediately following the given key, if it exists, in child storage.

`fn kill_child_storage(&mut self, child_info: &ChildInfo)`

Clear an entire child storage.

`fn clear_prefix(&mut self, prefix: &[u8])`

Clear storage entries which keys are start with the given prefix.

`fn clear_child_prefix(&mut self, child_info: &ChildInfo, prefix: &[u8])`

Clear child storage entries which keys are start with the given prefix.

`fn place_storage(&mut self, key: Vec<u8>, value: Option<Vec<u8>>)`

Set or clear a storage entry (key) of current contract being called (effective immediately).

`fn place_child_storage( &mut self, child_info: &ChildInfo, key: Vec<u8>, value: Option<Vec<u8>> )`

Set or clear a child storage entry.

`fn chain_id(&self) -> u64`

Get the identity of the chain.

`fn storage_root(&mut self) -> Vec<u8>`

Get the trie root of the current storage map.

This will also update all child storage keys in the top-level storage map.

The returned hash is defined by the Block and is SCALE encoded.

`fn child_storage_root(&mut self, child_info: &ChildInfo) -> Vec<u8>`

Get the trie root of a child storage map.

This will also update the value of the child storage keys in the top-level storage map.

If the storage root equals the default hash as defined by the trie, the key in the top-level storage map will be removed.

`fn storage_append(&mut self, key: Vec<u8>, value: Vec<u8>)`

Append storage item.

This assumes specific format of the storage item. Also there is no way to undo this operation.

`fn storage_changes_root(&mut self, parent: &[u8]) -> Result<Option<Vec<u8>>, ()>`

Get the changes trie root of the current storage overlay at a block with given parent.

parent expects a SCALE encoded hash.

The returned hash is defined by the Block and is SCALE encoded.

`fn storage_start_transaction(&mut self)`

Start a new nested transaction.

This allows to either commit or roll back all changes made after this call to the top changes or the default child changes. For every transaction there cam be a matching call to either storage_rollback_transaction or storage_commit_transaction. Any transactions that are still open after returning from runtime are committed automatically.

Changes made without any open transaction are committed immediately.

`fn storage_rollback_transaction(&mut self) -> Result<(), ()>`

Rollback the last transaction started by storage_start_transaction.

Any changes made during that storage transaction are discarded. Returns an error when no transaction is open that can be closed.

`fn storage_commit_transaction(&mut self) -> Result<(), ()>`

Commit the last transaction started by storage_start_transaction.

Any changes made during that storage transaction are committed. Returns an error when no transaction is open that can be closed.