bacnet-server 0.15.0

//! AuditLogQuery service handler (Clause 13.19).

use bacnet_objects::audit::AuditLogQueryPage;
use bacnet_objects::database::ObjectDatabase;
use bacnet_services::audit::AuditLogQueryRequest;
use bacnet_types::enums::{ErrorClass, ErrorCode, ObjectType};
use bacnet_types::error::Error;
use bacnet_types::primitives::ObjectIdentifier;

fn unknown_object() -> Error {
    Error::protocol(ErrorClass::OBJECT, ErrorCode::UNKNOWN_OBJECT)
}

fn optional_functionality_not_supported() -> Error {
    Error::protocol(
        ErrorClass::SERVICES,
        ErrorCode::OPTIONAL_FUNCTIONALITY_NOT_SUPPORTED,
    )
}

/// Decode and execute one AuditLogQuery against the object's retained state.
///
/// Decoding completes before object lookup or capability access. The returned
/// page owns its records, allowing the dispatcher to release the database read
/// guard before constructing and encoding the acknowledgment.
pub fn handle_audit_log_query(
    db: &ObjectDatabase,
    service_data: &[u8],
) -> Result<(ObjectIdentifier, AuditLogQueryPage), Error> {
    handle_audit_log_query_observed(db, service_data, |_, _| {})
}

/// Observe decoded execution once, without exposing criteria or rereading the
/// log. The caller must discard the provisional observation if ACK construction
/// fails or the response takes the outbound segmentation path.
pub(crate) fn handle_audit_log_query_observed(
    db: &ObjectDatabase,
    service_data: &[u8],
    completed: impl FnOnce(ObjectIdentifier, &Result<AuditLogQueryPage, Error>),
) -> Result<(ObjectIdentifier, AuditLogQueryPage), Error> {
    let request = AuditLogQueryRequest::decode(service_data).map_err(Error::into_request_reject)?;
    let result = query(db, &request);
    completed(request.audit_log, &result);
    result.map(|page| (request.audit_log, page))
}

fn query(db: &ObjectDatabase, request: &AuditLogQueryRequest) -> Result<AuditLogQueryPage, Error> {
    // Clause 13.19 specifies OBJECT / UNKNOWN_OBJECT for an Audit Log that
    // does not exist. A non-Audit identifier cannot designate the requested
    // Audit Log and follows the same public result instead of exposing an
    // object-type distinction.
    if request.audit_log.object_type() != ObjectType::AUDIT_LOG {
        return Err(unknown_object());
    }
    let object = db.get(&request.audit_log).ok_or_else(unknown_object)?;
    let storage = object
        .audit_log_storage_internal()
        .ok_or_else(optional_functionality_not_supported)?;
    let page = storage.query(
        &request.query_parameters,
        request.start_at_sequence_number,
        request.requested_count,
    );
    Ok(page)
}