Enum Diff 

pub enum Diff {
    Insert {
        post: Arc<Columns>,
    },
    Update {
        pre: Arc<Columns>,
        post: Arc<Columns>,
    },
    Remove {
        pre: Arc<Columns>,
    },
}

Represents a single diff.

Carries Arc<Columns> so that cloning a Diff (or the enclosing Change) is a refcount bump rather than a deep copy of every column, and so that producers (e.g. CdcProducerActor) can hold onto a slab pool of Arc<Columns> and reuse them across calls when strong_count drops back to 1 after dispatch.

Variants

Insert

Fields

post: Arc<Columns>

Update

Fields

pre: Arc<Columns>

post: Arc<Columns>

Remove

Fields

pre: Arc<Columns>

Implementations

impl Diff

pub fn insert(post: Columns) -> Self

Build an insert diff from an owned Columns. Wraps internally.

pub fn update(pre: Columns, post: Columns) -> Self

Build an update diff from owned Columns. Wraps internally.

pub fn remove(pre: Columns) -> Self

Build a remove diff from an owned Columns. Wraps internally.

pub fn insert_arc(post: Arc<Columns>) -> Self

Build an insert diff from an already-Arc’d Columns. Used by the CdcProducerActor slab pool to avoid an extra Arc::new.

pub fn update_arc(pre: Arc<Columns>, post: Arc<Columns>) -> Self

Build an update diff from already-Arc’d Columns.

pub fn remove_arc(pre: Arc<Columns>) -> Self

Build a remove diff from an already-Arc’d Columns.

pub fn pre(&self) -> Option<&Columns>

Pre-image columns (None for Insert).

pub fn post(&self) -> Option<&Columns>

Post-image columns (None for Remove).

pub fn kind(&self) -> DiffType

Kind tag; parity with BorrowedDiff::kind.

Trait Implementations

impl Clone for Diff

fn clone(&self) -> Diff

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Diff

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Diff

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for Diff

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.