Struct Session 

pub struct Session { /* private fields */ }

A session that records database changes for later extraction as a changeset or patchset.

In a real database engine this would hook into the DML pipeline. For now it provides a programmatic API for recording changes and generating the binary changeset/patchset encoding.

Implementations

impl Session

pub fn new() -> Self

Create a new, empty session.

pub fn attach_table( &mut self, name: &str, column_count: usize, pk_flags: Vec<bool>, )

Attach a table for change tracking.

pk_flags indicates which columns are part of the primary key.

pub fn record_insert(&mut self, table: &str, new_values: Vec<ChangesetValue>)

Record an INSERT operation.

pub fn record_delete(&mut self, table: &str, old_values: Vec<ChangesetValue>)

Record a DELETE operation.

pub fn record_update( &mut self, table: &str, old_values: Vec<ChangesetValue>, new_values: Vec<ChangesetValue>, )

Record an UPDATE operation.

old_values and new_values must have the same length. Use ChangesetValue::Undefined for columns that did not change.

pub fn changeset(&self) -> Changeset

Generate a Changeset from all recorded changes.

pub fn patchset(&self) -> Vec<u8>

Generate a patchset (compact binary format).

Trait Implementations

impl Debug for Session

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

Formats the value using the given formatter.

impl Default for Session

fn default() -> Self

Returns the “default value” for a type.