Struct Rules 

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

Which switches are on, as the statements have left them.

A bitset rather than a map, because there are ten of them, because a session copies this once per statement, and because the set is fixed at compile time.

Implementations

impl Rules

pub const fn new() -> Self

What a fresh database has, which is every statistics rule on and the graph sections off.

The statistics rules are on because their whole point is that they change no answer, so a database that had to be told to use them would be a database where nobody used them. The graph sections are off because they are a stored structure that nothing writes yet and a new path through the executor when they arrive, and a new path is worth having on by default only once the measurement says it is better. G3 in tamnd/rudb#763 is where that is decided.

pub fn enabled(self, rule: Rule) -> bool

Whether this rule may fire, which is its own switch and its master’s.

pub fn is_set(self, rule: Rule) -> bool

Whether this rule’s own switch is on, ignoring its master.

What a setting reads back as, because a settings surface that does not round trip is a settings surface somebody reports as a bug. Rules::enabled is what is in effect.

pub fn set(&mut self, rule: Rule, enabled: bool)

Turns one rule on or off.

pub fn set_named(&mut self, key: &str, enabled: bool) -> Result<()>

Turns one rule on or off by name.

Errors

ErrorCode::Catalog when nothing is called that, with the list of rules in the message.

pub fn reset_named(&mut self, key: &str) -> Result<()>

Puts one rule back where a fresh database has it, which is what RESET means.

Not the same as setting it on, because Rule::GraphSections starts off and a reset that turned it on would be a reset that left the database somewhere it has never been.

Errors

ErrorCode::Catalog when nothing is called that, with the list of rules in the message.

pub fn named(self, key: &str) -> Option<bool>

What one rule’s setting reads back as, or None when nothing is called that.

pub fn states(self) -> impl Iterator<Item = (&'static str, bool)>

Every rule and its own switch, in report order.

spec/stats/09-measurement.md section 9.7 requires a statistics report to carry the settings state for every rule, which is this.

pub fn changed(self) -> impl Iterator<Item = (&'static str, bool)>

The rules that are not where a fresh database left them, which is what a run records when it says what it measured.

Trait Implementations

impl Clone for Rules

fn clone(&self) -> Rules

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Rules

impl Debug for Rules

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

Formats the value using the given formatter.

impl Default for Rules

fn default() -> Self

Returns the “default value” for a type.

impl Eq for Rules

impl PartialEq for Rules

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Rules