Crate psmatcher 

PSMatcher

A pub/sub matcher algorithm implementation that efficiently matches events against subscriptions. The algorithm pre-processes subscriptions into a matching tree for optimized event matching.

Overview

This crate provides a pub/sub matching system where:

• Subscriptions are conjunctions of elementary predicates
• Events must have at least one string attribute called “topic”
• The matching tree is built during pre-processing for efficient matching

Example

use psmatcher::{Matcher, Subscription, ElementaryPredicate, ElementaryTest};
use psmatcher::event_types::{DefaultEvent, AttributeValue};

// Create a matcher
let mut matcher = Matcher::new();

// Create a subscription for weather updates in San Francisco
let subscription = Subscription::new("weather-sf")
    .with_predicate(ElementaryPredicate::new(
        ElementaryTest::Equals {
            attribute: "topic".to_string(),
            value: AttributeValue::String("weather".to_string()),
        },
        false,
    ))
    .with_predicate(ElementaryPredicate::new(
        ElementaryTest::Equals {
            attribute: "city".to_string(),
            value: AttributeValue::String("San Francisco".to_string()),
        },
        false,
    ));

// Add the subscription to the matcher
matcher.add_subscription(subscription);

// Create a subscription using regex pattern matching
let regex_subscription = Subscription::new("california-cities")
    .with_predicate(ElementaryPredicate::new(
        ElementaryTest::regex("topic".to_string(), "weather|forecast").unwrap(),
        false,
    ))
    .with_predicate(ElementaryPredicate::new(
        ElementaryTest::regex("city".to_string(), "San (Francisco|Jose|Diego)").unwrap(),
        false,
    ));

// Add the regex subscription to the matcher
matcher.add_subscription(regex_subscription);

// Create an event
let event = DefaultEvent::new("weather")
    .with_attribute("city", AttributeValue::String("San Francisco".to_string()))
    .with_attribute("temperature", AttributeValue::Float(72.5));

// Match the event against subscriptions
let matches = matcher.match_event(&event).unwrap();

// Check if our subscriptions matched
assert!(matches.contains("weather-sf"));
assert!(matches.contains("california-cities"));

For more examples and detailed documentation, see the README module.

Modules

collections

Deterministic collection aliases for simulation testing.

event_types

helpers

readme

README Documentation

traits

Macros

attr_map

list_from_attr_values

list_from_bools

list_from_floats

list_from_ints

list_from_strs

map_from_attr_values

Structs

ElementaryPredicate

Represents an elementary predicate, which is the result of an elementary test

Matcher

The main matcher API for pub/sub matching

MatchingTree

The matching tree for efficient event matching

Subscription

A subscription is a conjunction of elementary predicates

Enums

ElementaryTest

Represents an elementary test that can be performed on an event attribute

MatcherError

Errors that can occur during pub/sub matching operations

Constants

TOPIC_STR