Struct FileChangeCounter

pub struct FileChangeCounter(/* private fields */);

File change counter (4 Bytes)

The file change counter is a 4-byte big-endian integer at offset 24 that is incremented whenever the database file is unlocked after having been modified. When two or more processes are reading the same database file, each process can detect database changes from other processes by monitoring the change counter. A process will normally want to flush its database page cache when another process modified the database, since the cache has become stale. The file change counter facilitates this.

In WAL mode, changes to the database are detected using the wal-index and so the change counter is not needed. Hence, the change counter might not be incremented on each transaction in WAL mode.

Methods from Deref<Target = u32>

pub const MIN: u32 = 0u32

pub const MAX: u32 = 4_294_967_295u32

pub const BITS: u32 = 32u32

Trait Implementations

impl Debug for FileChangeCounter

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

Formats the value using the given formatter.

impl Default for FileChangeCounter

fn default() -> FileChangeCounter

Returns the “default value” for a type.

impl Deref for FileChangeCounter

type Target = u32

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl Name for FileChangeCounter

const NAME: &'static str = "FileChangeCounter"