Struct ChangeLog 

pub struct ChangeLog { /* private fields */ }

A thread-safe, cloneable transaction log for collecting database operations.

This struct acts as a “Unit of Work,” allowing multiple threads to concurrently record operations without directly mutating the Database. The collected changes can then be applied later in a single batch operation. This pattern avoids lock contention on the main database during processing.

Implementations

impl ChangeLog

pub fn new() -> Self

Creates a new, empty ChangeLog.

pub fn add(&self, file: File) -> Result<(), DatabaseError>

Records a request to add a new file.

Errors

Returns a DatabaseError::PoisonedLogMutex if another thread panicked while holding the lock, leaving the change log in an unusable state.

pub fn update( &self, id: FileId, new_contents: Cow<'static, str>, ) -> Result<(), DatabaseError>

Records a request to update an existing file’s content by its FileId.

Errors

Returns a DatabaseError::PoisonedLogMutex if another thread panicked while holding the lock, leaving the change log in an unusable state.

pub fn delete(&self, id: FileId) -> Result<(), DatabaseError>

Records a request to delete a file by its FileId.

Errors

Returns a DatabaseError::PoisonedLogMutex if another thread panicked while holding the lock, leaving the change log in an unusable state.

pub fn changed_file_ids(&self) -> Result<Vec<FileId>, DatabaseError>

Returns a vector of all FileIds affected by the recorded changes.

This includes IDs for files being added, updated, or deleted.

Errors

• DatabaseError::PoisonedLogMutex: Returned if the internal lock was poisoned

pub fn into_inner(self) -> Result<Vec<Change>, DatabaseError>

Consumes the change log and returns the vector of collected changes.

This operation safely unwraps the underlying list of changes. It will only succeed if called on the last remaining reference to the change log, which guarantees that no other threads can be modifying the list.

Errors

• DatabaseError::ChangeLogInUse: Returned if other Arc references to this change log still exist.
• DatabaseError::PoisonedLogMutex: Returned if the internal lock was poisoned because another thread panicked while holding it.

Trait Implementations

impl Clone for ChangeLog

fn clone(&self) -> ChangeLog

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ChangeLog

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

Formats the value using the given formatter.

impl Default for ChangeLog

fn default() -> Self

Returns the “default value” for a type.