Struct near_store::TrieChanges

pub struct TrieChanges {
    pub old_root: StateRoot,
    pub new_root: StateRoot,
    // some fields omitted
}

TrieChanges stores delta for refcount. Multiple versions of the state work the following way: __changes1___state1 state0 / __changes2___state2

To store state0, state1 and state2, apply insertions from changes1 and changes2

Then, to discard state2, apply insertions from changes2 as deletions

Then, to discard state0, apply deletions from changes1. deleting state0 while both state1 and state2 exist is not possible. Applying deletions from changes1 while state2 exists makes accessing state2 invalid.

create a fork -> apply insertions resolve a fork -> apply opposite of insertions discard old parent which has no forks from it -> apply deletions

Having old_root and values in deletions allows to apply TrieChanges in reverse

StoreUpdate are the changes from current state refcount to refcount + delta.

Fields

old_root: StateRoot

new_root: StateRoot

Implementations

impl TrieChanges

pub fn empty(old_root: StateRoot) -> Self

Trait Implementations

impl BorshDeserialize for TrieChanges where
    StateRoot: BorshDeserialize,
    StateRoot: BorshDeserialize,
    Vec<(CryptoHash, Vec<u8>, u32)>: BorshDeserialize,
    Vec<(CryptoHash, Vec<u8>, u32)>: BorshDeserialize, 

fn deserialize(buf: &mut &[u8]) -> Result<Self, Error>

Deserializes this instance from a given slice of bytes. Updates the buffer to point at the remaining bytes.

pub fn try_from_slice(v: &[u8]) -> Result<Self, Error>

Deserialize this instance from a slice of bytes.

pub fn is_u8() -> bool

Whether Self is u8. NOTE: Vec<u8> is the most common use-case for serialization and deserialization, it’s worth handling it as a special case to improve performance. It’s a workaround for specific Vec<u8> implementation versus generic Vec<T> implementation. See https://github.com/rust-lang/rfcs/pull/1210 for details.

impl BorshSerialize for TrieChanges where
    StateRoot: BorshSerialize,
    StateRoot: BorshSerialize,
    Vec<(CryptoHash, Vec<u8>, u32)>: BorshSerialize,
    Vec<(CryptoHash, Vec<u8>, u32)>: BorshSerialize, 

fn serialize<W: Write>(&self, writer: &mut W) -> Result<(), Error>

pub fn try_to_vec(&self) -> Result<Vec<u8, Global>, Error>

Serialize this instance into a vector of bytes.

pub fn is_u8() -> bool

Whether Self is u8. NOTE: Vec<u8> is the most common use-case for serialization and deserialization, it’s worth handling it as a special case to improve performance. It’s a workaround for specific Vec<u8> implementation versus generic Vec<T> implementation. See https://github.com/rust-lang/rfcs/pull/1210 for details.

impl Clone for TrieChanges

fn clone(&self) -> TrieChanges

Returns a copy of the value.

pub fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for TrieChanges

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for TrieChanges

impl PartialEq<TrieChanges> for TrieChanges

fn eq(&self, other: &TrieChanges) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &TrieChanges) -> bool

This method tests for !=.

impl StructuralEq for TrieChanges

impl StructuralPartialEq for TrieChanges