Struct TransactionContext 

pub struct TransactionContext<'g> { /* private fields */ }

Orchestrates transactions across graph mutations, change logging, and rollback

Implementations

impl<'g> TransactionContext<'g>

pub fn new(graph: &'g mut DependencyGraph) -> Self

Create a new transaction context for the given graph

pub fn with_max_size(graph: &'g mut DependencyGraph, max_size: usize) -> Self

Create a transaction context with custom max transaction size

pub fn begin(&mut self) -> Result<TransactionId, TransactionError>

Begin a new transaction

Returns

The ID of the newly created transaction

Errors

Returns AlreadyActive if a transaction is already in progress

pub fn editor(&mut self) -> VertexEditor<'_>

Create an editor that logs changes to this context

Safety

This uses unsafe code to work around the borrow checker. It’s safe because:

1. We control the lifetime of both the graph and change_log
2. The editor’s lifetime is tied to the TransactionContext
3. We ensure no aliasing occurs

pub fn commit(&mut self) -> Result<TransactionId, TransactionError>

Commit the current transaction

Returns

The ID of the committed transaction

Errors

Returns NoActiveTransaction if no transaction is active

pub fn rollback(&mut self) -> Result<(), TransactionError>

Rollback the current transaction

Errors

Returns NoActiveTransaction if no transaction is active Returns RollbackFailed if the rollback operation fails

pub fn savepoint(&mut self, name: &str) -> Result<(), TransactionError>

Add a named savepoint to the current transaction

Arguments

• name - Name for the savepoint

Errors

Returns NoActiveTransaction if no transaction is active

pub fn rollback_to_savepoint( &mut self, name: &str, ) -> Result<(), TransactionError>

Rollback to a named savepoint

Arguments

• name - Name of the savepoint to rollback to

Errors

Returns NoActiveTransaction if no transaction is active Returns SavepointNotFound if the savepoint doesn’t exist Returns RollbackFailed if the rollback operation fails

pub fn is_active(&self) -> bool

Check if a transaction is currently active

pub fn active_id(&self) -> Option<TransactionId>

Get the ID of the active transaction if any

pub fn change_count(&self) -> usize

Get the current size of the change log

pub fn change_log(&self) -> &ChangeLog

Get reference to the change log (for testing/debugging)

pub fn clear_change_log(&mut self)

Clear the change log (useful between transactions)