Struct MfpPlan

pub struct MfpPlan {
    pub(crate) mfp: SafeMfpPlan,
    pub(crate) lower_bounds: Vec<ScalarExpr>,
    pub(crate) upper_bounds: Vec<ScalarExpr>,
}

Predicates partitioned into temporal and non-temporal.

Temporal predicates require some recognition to determine their structure, and it is best to do that once and re-use the results.

There are restrictions on the temporal predicates we currently support. They must directly constrain MzNow from below or above, by expressions that do not themselves contain MzNow. Conjunctions of such constraints are also ok.

Fields

mfp: SafeMfpPlan

Normal predicates to evaluate on &[Datum] and expect Ok(Datum::True).

lower_bounds: Vec<ScalarExpr>

TODO(discord9): impl temporal filter later Expressions that when evaluated lower-bound MzNow.

upper_bounds: Vec<ScalarExpr>

Expressions that when evaluated upper-bound MzNow.

Implementations

impl MfpPlan

pub fn is_temporal(&self) -> bool

Indicates if the MfpPlan contains temporal predicates. That is have outputs that may occur in future.

pub fn create_from(mfp: MapFilterProject) -> Result<Self, Error>

find now in predicates and put them into lower/upper temporal bounds for temporal filter to use

pub fn is_identity(&self) -> bool

Indicates if the planned MapFilterProject emits exactly its inputs as outputs.

pub fn evaluate<E: From<EvalError>>( &self, values: &mut Vec<Value>, sys_time: i64, diff: i64, ) -> impl Iterator<Item = Result<(Row, i64, i64), (E, i64, i64)>>

if lower_bound <= sys_time < upper_bound, return [(data, sys_time, +1), (data, min_upper_bound, -1)]

else if sys_time < lower_bound, return [(data, lower_bound, +1), (data, min_upper_bound, -1)]

else if sys_time >= upper_bound, return [None, None]

if eval error appeal in any of those process, corresponding result will be Err

Trait Implementations

impl Clone for MfpPlan

fn clone(&self) -> MfpPlan

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for MfpPlan

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

Formats the value using the given formatter.

impl PartialEq for MfpPlan

fn eq(&self, other: &MfpPlan) -> 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 StructuralPartialEq for MfpPlan