Enum AccessMode 

pub enum AccessMode {
    ReadWrite,
    ReadOnly,
}

How a Pager (or Wal) intends to use the file: mutating writes vs. consistent-snapshot reads. Drives the OS-level lock mode, and the Pager uses it to reject mutation attempts on read-only openers.

• ReadWrite takes flock(LOCK_EX) — one writer, no other openers.
• ReadOnly takes flock(LOCK_SH) — multiple readers can coexist; a writer is excluded.

This is POSIX-flock semantics, so “multiple readers AND one writer” isn’t supported yet. True concurrent reader-writer access would need a shared-memory coordination file and read marks — that’s deferred.

Variants

ReadWrite

ReadOnly

Trait Implementations

impl Clone for AccessMode

fn clone(&self) -> AccessMode

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for AccessMode

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

Formats the value using the given formatter.

impl PartialEq for AccessMode

fn eq(&self, other: &AccessMode) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for AccessMode

impl Eq for AccessMode

impl StructuralPartialEq for AccessMode