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ops: add tasks with resource requirements and windows

This commit is contained in:
ApsisRS contributors 2026-09-26 16:59:48 +08:00
parent 72640083af
commit b3808d9a2a
6 changed files with 1013 additions and 0 deletions
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4
Cargo.lock generated
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@ -292,6 +292,10 @@ version = "0.1.0"
[[package]] [[package]]
name = "apsis-task" name = "apsis-task"
version = "0.1.0" version = "0.1.0"
dependencies = [
"apsis-core",
"apsis-resource",
]
[[package]] [[package]]
name = "apsis-time" name = "apsis-time"

2
crates/ops/apsis-task/Cargo.toml
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@ -11,3 +11,5 @@ publish = false
workspace = true workspace = true
[dependencies] [dependencies]
apsis-core.workspace = true
apsis-resource.workspace = true

82
crates/ops/apsis-task/src/error.rs Normal file
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@ -0,0 +1,82 @@
//! Errors reported while building or querying a task.
use core::fmt;
/// The category of a task error.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
#[non_exhaustive]
pub enum TaskErrorKind {
/// The duration is not finite, or is negative.
InvalidDuration,
/// A time window is not finite or ends before it starts.
InvalidWindow,
/// The window is shorter than the task duration.
WindowTooShort,
/// A resource demand is not positive and finite.
InvalidDemand,
/// The same resource is required more than once.
DuplicateRequirement,
/// A priority or value is not finite.
InvalidWeight,
/// No task has the requested identifier.
NoSuchTask,
/// A task with the identifier already exists.
DuplicateTask,
}
impl fmt::Display for TaskErrorKind {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let text = match self {
Self::InvalidDuration => "the duration is not usable",
Self::InvalidWindow => "the time window is not usable",
Self::WindowTooShort => "the window is shorter than the task",
Self::InvalidDemand => "a resource demand is not usable",
Self::DuplicateRequirement => "a resource is required more than once",
Self::InvalidWeight => "a priority or value is not finite",
Self::NoSuchTask => "no such task",
Self::DuplicateTask => "a task with that identifier exists",
};
f.write_str(text)
}
}
/// A failure while building or querying a task.
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct TaskError {
kind: TaskErrorKind,
detail: Option<String>,
}
impl TaskError {
/// Creates an error with the given category.
pub fn new(kind: TaskErrorKind) -> Self {
Self { kind, detail: None }
}
/// Attaches a description of the values that caused the failure.
pub fn with_detail(mut self, detail: impl Into<String>) -> Self {
self.detail = Some(detail.into());
self
}
/// Returns the category of this failure.
pub fn kind(&self) -> TaskErrorKind {
self.kind
}
/// Returns the detail text attached to this error, if any.
pub fn detail(&self) -> Option<&str> {
self.detail.as_deref()
}
}
impl fmt::Display for TaskError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match &self.detail {
Some(detail) => write!(f, "{}: {detail}", self.kind),
None => write!(f, "{}", self.kind),
}
}
}
impl core::error::Error for TaskError {}

44
crates/ops/apsis-task/src/lib.rs
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@ -1 +1,45 @@
//! Task modeling for satellite operations. //! Task modeling for satellite operations.
//!
//! A task is a unit of work that a scheduler places on a set of resources. It
//! carries everything a scheduler needs to decide whether and where to run
//! it: how long it takes, when it may run, which resources it needs and in
//! what amount, and what it is worth.
//!
//! A task requires all of its resources at the same time, for its whole
//! duration. That is the model an observation has: the satellite and the
//! ground station must both be available while the data is taken. A task that
//! needs resources in sequence is expressed as two tasks with a
//! precedence constraint, which the scheduling layer provides.
//!
//! Tasks are immutable once built. The state a scheduler assigns to one is
//! kept separately, in the schedule, so that the same task can be considered
//! for several placements without being modified.
//!
//! ```
//! use apsis_resource::ResourceId;
//! use apsis_task::{Requirement, Task, TaskId};
//!
//! // An observation of sixty seconds that needs a satellite and a station.
//! let task = Task::new(TaskId::new(0), 60.0)
//! .with_window(100.0, 1_000.0)
//! .with_priority(5.0)
//! .try_require(ResourceId::new(0), 1.0)
//! .expect("the satellite is not yet required")
//! .try_require(ResourceId::new(1), 1.0)
//! .expect("the station is not yet required");
//!
//! assert_eq!(task.duration, 60.0);
//! assert_eq!(task.requirements.len(), 2);
//! assert!(task.is_valid());
//! ```
#![forbid(unsafe_code)]
#![deny(missing_docs)]
mod error;
mod task;
pub use error::{TaskError, TaskErrorKind};
pub use task::{Requirement, Task, TaskId, TaskSet, TaskState, task_order};
pub use apsis_resource::ResourceId;

505
crates/ops/apsis-task/src/task.rs Normal file
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@ -0,0 +1,505 @@
//! Tasks, their requirements, and the set that holds them.
use crate::error::{TaskError, TaskErrorKind};
use apsis_resource::ResourceId;
/// An identifier for a task.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord)]
pub struct TaskId(pub usize);
impl TaskId {
/// Creates an identifier.
pub const fn new(index: usize) -> Self {
Self(index)
}
/// Returns the index.
pub const fn index(self) -> usize {
self.0
}
}
impl core::fmt::Display for TaskId {
fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
write!(f, "task {}", self.0)
}
}
/// A demand that a task makes on one resource.
///
/// The demand is the amount of the resource's capacity the task consumes
/// while it runs. A demand that exceeds the resource's capacity makes the
/// task impossible to schedule there, which a scheduler discovers by
/// comparing the two.
#[derive(Debug, Clone, Copy, PartialEq)]
pub struct Requirement {
/// The resource required.
pub resource: ResourceId,
/// The amount of the resource consumed.
pub demand: f64,
}
impl Requirement {
/// Creates a requirement.
pub const fn new(resource: ResourceId, demand: f64) -> Self {
Self { resource, demand }
}
/// Returns `true` when the demand is positive and finite.
pub fn is_valid(&self) -> bool {
self.demand.is_finite() && self.demand > 0.0
}
}
/// A unit of work to be scheduled.
///
/// A task is immutable after construction. The builder methods take `self` by
/// value and return a new task, so a caller can share a base task and derive
/// variants from it without the variants interfering.
#[derive(Debug, Clone, PartialEq)]
pub struct Task {
/// The identifier of this task.
pub id: TaskId,
/// The duration of the task, in seconds.
pub duration: f64,
/// The earliest time at which the task may start, in seconds.
///
/// This is the start of the earliest window in which the task may run.
/// A task with no window has no restriction, which is what the
/// constructors give.
pub earliest_start: f64,
/// The latest time at which the task may end, in seconds.
///
/// A task with no window has no restriction.
pub latest_end: f64,
/// The resources the task requires, in the order they were added.
pub requirements: Vec<Requirement>,
/// The priority of the task.
///
/// A larger value means the task is more important. The scale is the
/// caller's. A scheduler that maximises weighted value uses this number,
/// and one that maximises the count of scheduled tasks ignores it.
pub priority: f64,
/// Whether the task must be scheduled.
///
/// A mandatory task is scheduled even at the cost of other tasks. A
/// scheduler may still fail to place one when no placement exists, and
/// reports that rather than dropping it silently.
pub mandatory: bool,
}
impl Task {
/// Creates a task with the given duration and no requirements.
///
/// The task may start at any finite time, because it has no window. It
/// has a priority of zero and is not mandatory.
pub fn new(id: TaskId, duration: f64) -> Self {
Self {
id,
duration,
earliest_start: f64::NEG_INFINITY,
latest_end: f64::INFINITY,
requirements: Vec::new(),
priority: 0.0,
mandatory: false,
}
}
/// Returns a copy of this task with a time window.
///
/// The window is the interval in which the whole task must fit, so the
/// task may start no earlier than the window start and must end no later
/// than the window end.
pub fn with_window(mut self, start: f64, end: f64) -> Self {
self.earliest_start = start;
self.latest_end = end;
self
}
/// Returns a copy of this task with a priority.
pub fn with_priority(mut self, priority: f64) -> Self {
self.priority = priority;
self
}
/// Returns a copy of this task marked mandatory or not.
pub fn with_mandatory(mut self, mandatory: bool) -> Self {
self.mandatory = mandatory;
self
}
/// Returns a copy of this task with an additional resource requirement.
///
/// Adding the same resource twice is allowed at this point, because a
/// builder chain cannot report an error. [`Task::validate`] rejects it,
/// and [`Task::try_require`] reports it immediately.
pub fn require(mut self, resource: ResourceId, demand: f64) -> Self {
self.requirements.push(Requirement::new(resource, demand));
self
}
/// Returns a copy of this task with an additional resource requirement,
/// reporting a duplicate or an invalid demand immediately.
pub fn try_require(mut self, resource: ResourceId, demand: f64) -> Result<Self, TaskError> {
let requirement = Requirement::new(resource, demand);
if !requirement.is_valid() {
return Err(TaskError::new(TaskErrorKind::InvalidDemand)
.with_detail(format!("{resource} with demand {demand}")));
}
if self
.requirements
.iter()
.any(|existing| existing.resource == resource)
{
return Err(TaskError::new(TaskErrorKind::DuplicateRequirement)
.with_detail(format!("{resource}")));
}
self.requirements.push(requirement);
Ok(self)
}
/// Returns the demand the task makes on a resource.
///
/// Returns `None` when the task does not require the resource.
pub fn demand_for(&self, resource: ResourceId) -> Option<f64> {
self.requirements
.iter()
.find(|requirement| requirement.resource == resource)
.map(|requirement| requirement.demand)
}
/// Returns `true` when the task requires a resource.
pub fn requires(&self, resource: ResourceId) -> bool {
self.demand_for(resource).is_some()
}
/// Returns the number of resources the task requires.
pub fn requirement_count(&self) -> usize {
self.requirements.len()
}
/// Returns the identifiers of the required resources.
pub fn resources(&self) -> Vec<ResourceId> {
self.requirements
.iter()
.map(|requirement| requirement.resource)
.collect()
}
/// Returns the length of the window in which the task must fit, in
/// seconds.
///
/// Returns infinity when the task has no restriction at either end, and
/// zero or a negative value when the window cannot hold the task at all.
pub fn window_length(&self) -> f64 {
self.latest_end - self.earliest_start
}
/// Returns `true` when the window cannot hold the task.
pub fn window_is_too_short(&self) -> bool {
self.duration > self.window_length()
}
/// Returns the earliest time the task could end, given its window.
///
/// Returns infinity when the task has no upper bound, and negative
/// infinity when it has no lower bound.
pub fn earliest_possible_end(&self) -> f64 {
self.earliest_start + self.duration
}
/// Returns `true` when the task fits its window.
pub fn fits_window(&self) -> bool {
!self.window_is_too_short()
}
/// Returns `true` when the task uses any resource more than once, or
/// demands a non-positive amount.
pub fn has_duplicate_requirements(&self) -> bool {
self.requirements
.iter()
.enumerate()
.any(|(index, requirement)| {
self.requirements[..index]
.iter()
.any(|earlier| earlier.resource == requirement.resource)
})
}
/// Validates the task, returning the reason when it is not usable.
///
/// A task is usable when its duration is finite and positive, its window
/// is finite at the ends it states and holds the duration, every demand
/// is positive and finite and names a distinct resource, and the weights
/// are finite.
pub fn validate(&self) -> Result<(), TaskError> {
if !self.duration.is_finite() || self.duration <= 0.0 {
return Err(TaskError::new(TaskErrorKind::InvalidDuration)
.with_detail(format!("duration {}", self.duration)));
}
if self.earliest_start.is_nan() || self.latest_end.is_nan() {
return Err(
TaskError::new(TaskErrorKind::InvalidWindow).with_detail(format!(
"window [{}, {}]",
self.earliest_start, self.latest_end
)),
);
}
if self.latest_end < self.earliest_start {
return Err(
TaskError::new(TaskErrorKind::InvalidWindow).with_detail(format!(
"window [{}, {}] runs backwards",
self.earliest_start, self.latest_end
)),
);
}
if self.window_is_too_short() {
return Err(
TaskError::new(TaskErrorKind::WindowTooShort).with_detail(format!(
"duration {} does not fit the window [{}, {}]",
self.duration, self.earliest_start, self.latest_end
)),
);
}
for requirement in &self.requirements {
if !requirement.is_valid() {
return Err(
TaskError::new(TaskErrorKind::InvalidDemand).with_detail(format!(
"{} with demand {}",
requirement.resource, requirement.demand
)),
);
}
}
if self.has_duplicate_requirements() {
return Err(TaskError::new(TaskErrorKind::DuplicateRequirement));
}
if !self.priority.is_finite() {
return Err(TaskError::new(TaskErrorKind::InvalidWeight)
.with_detail(format!("priority {}", self.priority)));
}
Ok(())
}
/// Returns `true` when the task is usable.
pub fn is_valid(&self) -> bool {
self.validate().is_ok()
}
/// Returns the value of the task, which is its priority weighted by its
/// duration.
///
/// This is the quantity a scheduler maximises when it is asked to make
/// the most of the available time: a long task of high priority is worth
/// more than a short one of the same priority.
pub fn weighted_value(&self) -> f64 {
self.priority * self.duration
}
}
impl core::fmt::Display for Task {
fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
write!(
f,
"{} of {} s requiring {} resource(s)",
self.id,
self.duration,
self.requirements.len()
)
}
}
/// The state a scheduler has assigned to a task.
///
/// The state is kept apart from the task so that the same task can be
/// considered for several placements without being modified. A task that has
/// been placed records when and where, so that a schedule can be examined
/// without a second lookup.
#[derive(Debug, Clone, PartialEq)]
pub enum TaskState {
/// The task has not been placed and is still being considered.
Pending,
/// The task has been placed at a time.
Scheduled {
/// The start time of the placement, in seconds.
start: f64,
},
/// The task was deliberately left out.
///
/// A scheduler reports this rather than silently dropping a task, so that
/// an operator can see what was given up and why.
Deferred,
/// The task cannot be scheduled at all.
///
/// A task is infeasible when its window is too short, when it demands
/// more of a resource than the resource has, or when a resource it needs
/// does not exist.
Infeasible {
/// A description of why the task cannot be scheduled.
reason: String,
},
}
impl TaskState {
/// Returns `true` when the task has been placed.
pub const fn is_scheduled(&self) -> bool {
matches!(self, Self::Scheduled { .. })
}
/// Returns the start time of the placement, if there is one.
pub const fn start(&self) -> Option<f64> {
match self {
Self::Scheduled { start } => Some(*start),
_ => None,
}
}
/// Returns the end time of the placement, if there is one.
pub fn end(&self, duration: f64) -> Option<f64> {
self.start().map(|start| start + duration)
}
/// Returns a short name for the state.
pub const fn name(&self) -> &'static str {
match self {
Self::Pending => "pending",
Self::Scheduled { .. } => "scheduled",
Self::Deferred => "deferred",
Self::Infeasible { .. } => "infeasible",
}
}
}
/// A collection of tasks, indexed by identifier.
#[derive(Debug, Clone, PartialEq, Default)]
pub struct TaskSet {
tasks: Vec<Task>,
}
impl TaskSet {
/// Creates an empty set.
pub const fn new() -> Self {
Self { tasks: Vec::new() }
}
/// Creates a set from a list of tasks.
///
/// Returns an error when two tasks share an identifier or when any task
/// is not usable.
pub fn from_tasks(tasks: Vec<Task>) -> Result<Self, TaskError> {
let mut set = Self::new();
for task in tasks {
set.insert(task)?;
}
Ok(set)
}
/// Inserts a task.
///
/// Returns an error when the identifier is already present or when the
/// task is not usable.
pub fn insert(&mut self, task: Task) -> Result<(), TaskError> {
task.validate()?;
if self.get(task.id).is_some() {
return Err(
TaskError::new(TaskErrorKind::DuplicateTask).with_detail(format!("{}", task.id))
);
}
self.tasks.push(task);
Ok(())
}
/// Returns the task with the given identifier.
pub fn get(&self, id: TaskId) -> Option<&Task> {
self.tasks.iter().find(|task| task.id == id)
}
/// Removes a task.
///
/// Returns an error when no task has the identifier.
pub fn remove(&mut self, id: TaskId) -> Result<Task, TaskError> {
let index = self
.tasks
.iter()
.position(|task| task.id == id)
.ok_or_else(|| {
TaskError::new(TaskErrorKind::NoSuchTask).with_detail(format!("{id}"))
})?;
Ok(self.tasks.remove(index))
}
/// Returns the tasks in the order they were added.
pub fn tasks(&self) -> &[Task] {
&self.tasks
}
/// Returns the number of tasks.
pub fn len(&self) -> usize {
self.tasks.len()
}
/// Returns `true` when there are no tasks.
pub fn is_empty(&self) -> bool {
self.tasks.is_empty()
}
/// Returns the total duration of every task, in seconds.
///
/// This is the load the tasks would place on the schedule if each used
/// one unit of resource for its whole duration.
pub fn total_duration(&self) -> f64 {
self.tasks.iter().map(|task| task.duration).sum()
}
/// Returns the total weighted value of every task.
pub fn total_weighted_value(&self) -> f64 {
self.tasks.iter().map(Task::weighted_value).sum()
}
/// Returns the identifiers of the tasks that require a resource.
pub fn tasks_requiring(&self, resource: ResourceId) -> Vec<TaskId> {
self.tasks
.iter()
.filter(|task| task.requires(resource))
.map(|task| task.id)
.collect()
}
/// Returns the identifiers of the mandatory tasks.
pub fn mandatory(&self) -> Vec<TaskId> {
self.tasks
.iter()
.filter(|task| task.mandatory)
.map(|task| task.id)
.collect()
}
}
/// Returns a task ordering suitable for a greedy scheduler.
///
/// The order is by decreasing weighted value, which is an efficient
/// heuristic: placing the tasks that contribute most first leaves the least
/// valuable ones to fill the gaps. Ties are broken by the earlier deadline
/// and then by the identifier, so that the order is deterministic for a given
/// set.
///
/// This is not guaranteed to find the best possible schedule. Scheduling
/// with resource constraints is intractable in general, so a heuristic is the
/// practical choice and the caller may supply its own order instead.
pub fn task_order(tasks: &[Task]) -> Vec<TaskId> {
let mut ordered: Vec<&Task> = tasks.iter().collect();
ordered.sort_by(|first, second| {
second
.weighted_value()
.partial_cmp(&first.weighted_value())
.unwrap_or(core::cmp::Ordering::Equal)
.then_with(|| {
first
.latest_end
.partial_cmp(&second.latest_end)
.unwrap_or(core::cmp::Ordering::Equal)
})
.then_with(|| first.id.cmp(&second.id))
});
ordered.into_iter().map(|task| task.id).collect()
}

376
crates/ops/apsis-task/tests/task.rs Normal file
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@ -0,0 +1,376 @@
//! Tests for tasks and the set that holds them.
use apsis_resource::ResourceId;
use apsis_task::{Requirement, Task, TaskErrorKind, TaskId, TaskSet, TaskState, task_order};
/// A sixty second task with no window and no requirements.
fn simple() -> Task {
Task::new(TaskId::new(0), 60.0)
}
/// A task requiring two resources for sixty seconds, in a window from 100 to
/// 1 000 seconds.
fn observation() -> Task {
simple()
.with_window(100.0, 1_000.0)
.with_priority(5.0)
.try_require(ResourceId::new(0), 1.0)
.expect("the resource is new")
.try_require(ResourceId::new(1), 1.0)
.expect("the resource is new")
}
#[test]
fn a_new_task_has_the_given_duration_and_nothing_else() {
let task = simple();
assert_eq!(task.duration, 60.0);
assert_eq!(task.priority, 0.0);
assert!(!task.mandatory);
assert!(task.requirements.is_empty());
assert_eq!(task.requirement_count(), 0);
// A task with no window is unbounded at both ends.
assert!(task.earliest_start.is_infinite() && task.earliest_start < 0.0);
assert!(task.latest_end.is_infinite() && task.latest_end > 0.0);
assert!(task.window_is_too_short() == false);
}
#[test]
fn a_window_restricts_the_task() {
let task = observation();
assert_eq!(task.earliest_start, 100.0);
assert_eq!(task.latest_end, 1_000.0);
assert_eq!(task.window_length(), 900.0);
assert!(task.fits_window());
assert_eq!(task.earliest_possible_end(), 160.0);
}
#[test]
fn a_window_shorter_than_the_task_is_detected() {
let task = simple().with_window(0.0, 30.0);
assert!(task.window_is_too_short());
assert!(!task.fits_window());
assert_eq!(
task.validate().expect_err("the window is too short").kind(),
TaskErrorKind::WindowTooShort
);
assert!(!task.is_valid());
}
#[test]
fn a_window_exactly_the_length_of_the_task_is_accepted() {
// The task must fit entirely inside the window, and a window of exactly
// the duration holds it.
let task = simple().with_window(0.0, 60.0);
assert!(!task.window_is_too_short());
assert!(task.is_valid());
}
#[test]
fn requiring_a_resource_records_the_demand() {
let task = observation();
assert_eq!(task.requirement_count(), 2);
assert_eq!(task.demand_for(ResourceId::new(0)), Some(1.0));
assert_eq!(task.demand_for(ResourceId::new(1)), Some(1.0));
assert_eq!(task.demand_for(ResourceId::new(9)), None);
assert!(task.requires(ResourceId::new(0)));
assert!(!task.requires(ResourceId::new(9)));
assert_eq!(
task.resources(),
vec![ResourceId::new(0), ResourceId::new(1)]
);
}
#[test]
fn a_duplicate_requirement_is_reported_immediately() {
let task = simple()
.try_require(ResourceId::new(0), 1.0)
.expect("the resource is new");
let error = task
.try_require(ResourceId::new(0), 2.0)
.expect_err("the resource is already required");
assert_eq!(error.kind(), TaskErrorKind::DuplicateRequirement);
}
#[test]
fn a_duplicate_requirement_built_by_chaining_is_rejected_on_validation() {
// The plain builder cannot report an error, so the duplicate survives
// until validation.
let task = simple()
.require(ResourceId::new(0), 1.0)
.require(ResourceId::new(0), 1.0);
assert!(task.has_duplicate_requirements());
assert_eq!(
task.validate().expect_err("duplicate").kind(),
TaskErrorKind::DuplicateRequirement
);
}
#[test]
fn an_invalid_demand_is_rejected() {
for demand in [0.0, -1.0, f64::NAN, f64::INFINITY] {
let error = simple()
.try_require(ResourceId::new(0), demand)
.expect_err("the demand is not usable");
assert_eq!(
error.kind(),
TaskErrorKind::InvalidDemand,
"demand {demand}"
);
}
}
#[test]
fn an_invalid_duration_is_rejected() {
for duration in [0.0, -1.0, f64::NAN, f64::INFINITY] {
let task = Task::new(TaskId::new(0), duration);
assert!(!task.is_valid(), "duration {duration}");
assert_eq!(
task.validate().expect_err("invalid duration").kind(),
TaskErrorKind::InvalidDuration
);
}
}
#[test]
fn a_reversed_window_is_rejected() {
let task = simple().with_window(100.0, 50.0);
assert_eq!(
task.validate().expect_err("reversed").kind(),
TaskErrorKind::InvalidWindow
);
}
#[test]
fn a_non_finite_window_is_rejected() {
assert_eq!(
simple()
.with_window(f64::NAN, 100.0)
.validate()
.expect_err("nan")
.kind(),
TaskErrorKind::InvalidWindow
);
assert_eq!(
simple()
.with_window(0.0, f64::NAN)
.validate()
.expect_err("nan")
.kind(),
TaskErrorKind::InvalidWindow
);
}
#[test]
fn a_non_finite_priority_is_rejected() {
let task = simple().with_priority(f64::NAN);
assert_eq!(
task.validate().expect_err("nan").kind(),
TaskErrorKind::InvalidWeight
);
}
#[test]
fn the_weighted_value_combines_priority_and_duration() {
let task = simple().with_priority(5.0);
assert_eq!(task.weighted_value(), 300.0);
// A task with no priority is worth nothing.
assert_eq!(simple().weighted_value(), 0.0);
}
#[test]
fn the_mandatory_flag_is_recorded() {
assert!(!simple().mandatory);
assert!(simple().with_mandatory(true).mandatory);
}
#[test]
fn the_builder_does_not_modify_the_original() {
// A builder chain returns a new value, so a base task can be shared.
let base = simple();
let first = base.clone().with_priority(1.0);
let second = base.clone().with_priority(2.0);
assert_eq!(base.priority, 0.0);
assert_eq!(first.priority, 1.0);
assert_eq!(second.priority, 2.0);
}
#[test]
fn a_task_displays_its_shape() {
let text = observation().to_string();
assert!(text.contains("task 0"), "{text}");
assert!(text.contains("60 s"), "{text}");
assert!(text.contains("2 resource"), "{text}");
}
#[test]
fn task_states_report_their_placement() {
let pending = TaskState::Pending;
assert!(!pending.is_scheduled());
assert_eq!(pending.start(), None);
assert_eq!(pending.name(), "pending");
let scheduled = TaskState::Scheduled { start: 100.0 };
assert!(scheduled.is_scheduled());
assert_eq!(scheduled.start(), Some(100.0));
assert_eq!(scheduled.end(60.0), Some(160.0));
assert_eq!(scheduled.name(), "scheduled");
let deferred = TaskState::Deferred;
assert!(!deferred.is_scheduled());
assert_eq!(deferred.name(), "deferred");
let infeasible = TaskState::Infeasible {
reason: "window too short".to_string(),
};
assert!(!infeasible.is_scheduled());
assert_eq!(infeasible.name(), "infeasible");
}
#[test]
fn a_set_holds_tasks_by_identifier() {
let mut set = TaskSet::new();
assert!(set.is_empty());
set.insert(simple()).expect("the identifier is new");
set.insert(Task::new(TaskId::new(1), 30.0))
.expect("the identifier is new");
assert_eq!(set.len(), 2);
assert_eq!(set.total_duration(), 90.0);
assert!(set.get(TaskId::new(0)).is_some());
assert!(set.get(TaskId::new(9)).is_none());
}
#[test]
fn a_duplicate_task_identifier_is_rejected() {
let mut set = TaskSet::new();
set.insert(simple()).expect("the identifier is new");
let error = set
.insert(Task::new(TaskId::new(0), 30.0))
.expect_err("the identifier is taken");
assert_eq!(error.kind(), TaskErrorKind::DuplicateTask);
assert_eq!(set.len(), 1);
}
#[test]
fn an_invalid_task_is_rejected_by_the_set() {
let mut set = TaskSet::new();
let error = set
.insert(Task::new(TaskId::new(0), -1.0))
.expect_err("the duration is invalid");
assert_eq!(error.kind(), TaskErrorKind::InvalidDuration);
assert!(set.is_empty());
}
#[test]
fn a_set_can_be_built_from_a_list() {
let set = TaskSet::from_tasks(vec![simple(), Task::new(TaskId::new(1), 30.0)])
.expect("the tasks are usable");
assert_eq!(set.len(), 2);
assert_eq!(
TaskSet::from_tasks(vec![simple(), simple()])
.expect_err("the identifiers collide")
.kind(),
TaskErrorKind::DuplicateTask
);
}
#[test]
fn a_task_can_be_removed() {
let mut set = TaskSet::new();
set.insert(simple()).expect("new");
let removed = set.remove(TaskId::new(0)).expect("the task exists");
assert_eq!(removed.id, TaskId::new(0));
assert!(set.is_empty());
assert_eq!(
set.remove(TaskId::new(0)).expect_err("gone").kind(),
TaskErrorKind::NoSuchTask
);
}
#[test]
fn the_set_reports_queries() {
let set = TaskSet::from_tasks(vec![
observation(),
Task::new(TaskId::new(1), 30.0).with_mandatory(true),
Task::new(TaskId::new(2), 10.0)
.with_priority(2.0)
.try_require(ResourceId::new(0), 0.5)
.expect("the resource is new"),
])
.expect("the tasks are usable");
assert_eq!(
set.tasks_requiring(ResourceId::new(0)),
vec![TaskId::new(0), TaskId::new(2)]
);
assert_eq!(
set.tasks_requiring(ResourceId::new(9)),
Vec::<TaskId>::new()
);
assert_eq!(set.mandatory(), vec![TaskId::new(1)]);
// The weighted value is the priority times the duration.
assert_eq!(set.total_weighted_value(), 300.0 + 0.0 + 20.0);
}
#[test]
fn the_task_order_places_the_most_valuable_first() {
let set = TaskSet::from_tasks(vec![
Task::new(TaskId::new(0), 10.0).with_priority(1.0),
Task::new(TaskId::new(1), 100.0).with_priority(5.0),
Task::new(TaskId::new(2), 50.0).with_priority(2.0),
])
.expect("the tasks are usable");
let order = task_order(set.tasks());
// The weighted values are 10, 500, and 100, so the order is 1, 2, 0.
assert_eq!(order, vec![TaskId::new(1), TaskId::new(2), TaskId::new(0)]);
}
#[test]
fn the_task_order_breaks_ties_by_deadline_then_identifier() {
let set = TaskSet::from_tasks(vec![
// The same value and no deadline.
Task::new(TaskId::new(0), 10.0).with_priority(1.0),
Task::new(TaskId::new(1), 10.0).with_priority(1.0),
// The same value but an earlier deadline.
Task::new(TaskId::new(2), 10.0)
.with_priority(1.0)
.with_window(0.0, 100.0),
Task::new(TaskId::new(3), 10.0).with_priority(1.0),
])
.expect("the tasks are usable");
let order = task_order(set.tasks());
// The task with the deadline comes first, then the others by identifier.
assert_eq!(
order,
vec![
TaskId::new(2),
TaskId::new(0),
TaskId::new(1),
TaskId::new(3)
]
);
}
#[test]
fn the_task_order_of_an_empty_set_is_empty() {
assert!(task_order(&[]).is_empty());
}
#[test]
fn a_requirement_reports_validity() {
assert!(Requirement::new(ResourceId::new(0), 1.0).is_valid());
assert!(!Requirement::new(ResourceId::new(0), 0.0).is_valid());
assert!(!Requirement::new(ResourceId::new(0), f64::NAN).is_valid());
}
#[test]
fn task_identifiers_are_ordered() {
let mut ids = [TaskId::new(2), TaskId::new(0), TaskId::new(1)];
ids.sort();
assert_eq!(ids, [TaskId::new(0), TaskId::new(1), TaskId::new(2)]);
assert_eq!(TaskId::new(3).to_string(), "task 3");
assert_eq!(TaskId::new(3).index(), 3);
}