Struct NamespaceValidator 

pub struct NamespaceValidator {
    pub service_prefix: String,
    pub device_namespace: String,
    pub device_id: Option<String>,
    pub allow_system_topics: bool,
    pub additional_reserved_prefixes: Vec<String>,
}

Namespace-based topic validator for hierarchical topic isolation

This validator implements namespace-based topic validation patterns that enforce hierarchical isolation of topics, commonly used in cloud IoT platforms and enterprise systems.

The validator enforces:

• Service-reserved topic prefixes (e.g., $aws/, $azure/, $company/)
• Device-specific namespaces (e.g., {prefix}/thing/{device}/, {prefix}/device/{device}/)
• System topics (e.g., $SYS/)

Examples:

• AWS IoT: NamespaceValidator::new("$aws", "thing")
• Azure IoT: NamespaceValidator::new("$azure", "device")
• Enterprise: NamespaceValidator::new("$company", "asset")

Fields

service_prefix: String

Service prefix for reserved topics (e.g., “$aws”, “$azure”, “$company”)

device_namespace: String

Device namespace identifier (e.g., “thing”, “device”, “asset”)

device_id: Option<String>

Optional device identifier for device-specific validation If set, allows {service_prefix}/{device_namespace}/{device_id}/* topics

allow_system_topics: bool

Whether to allow system topics ($SYS/*)

additional_reserved_prefixes: Vec<String>

Additional reserved prefixes beyond the service prefix

Implementations

impl NamespaceValidator

pub fn new( service_prefix: impl Into<String>, device_namespace: impl Into<String>, ) -> Self

Creates a new namespace validator

Arguments

• service_prefix - The service prefix (e.g., “$aws”, “$azure”)
• device_namespace - The device namespace pattern (e.g., “thing”, “device”)

pub fn aws_iot() -> Self

Creates a validator configured for AWS IoT Core

pub fn azure_iot() -> Self

Creates a validator configured for Azure IoT Hub

pub fn google_cloud_iot() -> Self

Creates a validator configured for Google Cloud IoT

pub fn with_device_id(self, device_id: impl Into<String>) -> Self

Sets the device identifier for device-specific topic validation

When set, allows topics like {prefix}/{namespace}/{device_id}/* while rejecting {prefix}/{namespace}/{other_device}/*

pub fn with_system_topics(self, allow: bool) -> Self

Enables system topics ($SYS/*)

pub fn with_reserved_prefix(self, prefix: impl Into<String>) -> Self

Adds an additional reserved prefix

Trait Implementations

impl Clone for NamespaceValidator

fn clone(&self) -> NamespaceValidator

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for NamespaceValidator

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

Formats the value using the given formatter.

impl TopicValidator for NamespaceValidator

fn validate_topic_name(&self, topic: &str) -> Result<()>

Validates a topic name for publishing

fn validate_topic_filter(&self, filter: &str) -> Result<()>

Validates a topic filter for subscriptions

fn is_reserved_topic(&self, topic: &str) -> bool

Checks if a topic is reserved and should be restricted

fn description(&self) -> &'static str

Gets a human-readable description of the validator