rustlings/src/app_state.rs
2024-09-01 20:31:16 +02:00

534 lines
18 KiB
Rust

use anyhow::{bail, Context, Result};
use std::{
env,
fs::{File, OpenOptions},
io::{self, Read, Seek, StdoutLock, Write},
path::Path,
process::{Command, Stdio},
thread,
};
use crate::{
clear_terminal,
cmd::CmdRunner,
collections::hash_set_with_capacity,
embedded::EMBEDDED_FILES,
exercise::{Exercise, RunnableExercise},
info_file::ExerciseInfo,
};
const STATE_FILE_NAME: &str = ".rustlings-state.txt";
#[must_use]
pub enum ExercisesProgress {
// All exercises are done.
AllDone,
// The current exercise failed and is still pending.
CurrentPending,
// A new exercise is now pending.
NewPending,
}
pub enum StateFileStatus {
Read,
NotRead,
}
enum AllExercisesCheck {
Pending(usize),
AllDone,
CheckedUntil(usize),
}
pub struct AppState {
current_exercise_ind: usize,
exercises: Vec<Exercise>,
// Caches the number of done exercises to avoid iterating over all exercises every time.
n_done: u16,
final_message: String,
state_file: File,
// Preallocated buffer for reading and writing the state file.
file_buf: Vec<u8>,
official_exercises: bool,
cmd_runner: CmdRunner,
// Running in VS Code.
vs_code: bool,
}
impl AppState {
pub fn new(
exercise_infos: Vec<ExerciseInfo>,
final_message: String,
) -> Result<(Self, StateFileStatus)> {
let cmd_runner = CmdRunner::build()?;
let mut state_file = OpenOptions::new()
.create(true)
.read(true)
.write(true)
.truncate(false)
.open(STATE_FILE_NAME)
.with_context(|| {
format!("Failed to open or create the state file {STATE_FILE_NAME}")
})?;
let mut exercises = exercise_infos
.into_iter()
.map(|exercise_info| {
// Leaking to be able to borrow in the watch mode `Table`.
// Leaking is not a problem because the `AppState` instance lives until
// the end of the program.
let path = exercise_info.path().leak();
let name = exercise_info.name.leak();
let dir = exercise_info.dir.map(|dir| &*dir.leak());
let hint = exercise_info.hint.leak().trim_ascii();
Exercise {
dir,
name,
path,
test: exercise_info.test,
strict_clippy: exercise_info.strict_clippy,
hint,
// Updated below.
done: false,
}
})
.collect::<Vec<_>>();
let mut current_exercise_ind = 0;
let mut n_done = 0;
let mut file_buf = Vec::with_capacity(2048);
let state_file_status = 'block: {
if state_file.read_to_end(&mut file_buf).is_err() {
break 'block StateFileStatus::NotRead;
}
// See `Self::write` for more information about the file format.
let mut lines = file_buf.split(|c| *c == b'\n').skip(2);
let Some(current_exercise_name) = lines.next() else {
break 'block StateFileStatus::NotRead;
};
if current_exercise_name.is_empty() || lines.next().is_none() {
break 'block StateFileStatus::NotRead;
}
let mut done_exercises = hash_set_with_capacity(exercises.len());
for done_exerise_name in lines {
if done_exerise_name.is_empty() {
break;
}
done_exercises.insert(done_exerise_name);
}
for (ind, exercise) in exercises.iter_mut().enumerate() {
if done_exercises.contains(exercise.name.as_bytes()) {
exercise.done = true;
n_done += 1;
}
if exercise.name.as_bytes() == current_exercise_name {
current_exercise_ind = ind;
}
}
StateFileStatus::Read
};
file_buf.clear();
file_buf.extend_from_slice(STATE_FILE_HEADER);
let slf = Self {
current_exercise_ind,
exercises,
n_done,
final_message,
state_file,
file_buf,
official_exercises: !Path::new("info.toml").exists(),
cmd_runner,
vs_code: env::var_os("TERM_PROGRAM").is_some_and(|v| v == "vscode"),
};
Ok((slf, state_file_status))
}
#[inline]
pub fn current_exercise_ind(&self) -> usize {
self.current_exercise_ind
}
#[inline]
pub fn exercises(&self) -> &[Exercise] {
&self.exercises
}
#[inline]
pub fn n_done(&self) -> u16 {
self.n_done
}
#[inline]
pub fn current_exercise(&self) -> &Exercise {
&self.exercises[self.current_exercise_ind]
}
#[inline]
pub fn cmd_runner(&self) -> &CmdRunner {
&self.cmd_runner
}
#[inline]
pub fn vs_code(&self) -> bool {
self.vs_code
}
// Write the state file.
// The file's format is very simple:
// - The first line is a comment.
// - The second line is an empty line.
// - The third line is the name of the current exercise. It must end with `\n` even if there
// are no done exercises.
// - The fourth line is an empty line.
// - All remaining lines are the names of done exercises.
fn write(&mut self) -> Result<()> {
self.file_buf.truncate(STATE_FILE_HEADER.len());
self.file_buf
.extend_from_slice(self.current_exercise().name.as_bytes());
self.file_buf.push(b'\n');
for exercise in &self.exercises {
if exercise.done {
self.file_buf.push(b'\n');
self.file_buf.extend_from_slice(exercise.name.as_bytes());
}
}
self.state_file
.rewind()
.with_context(|| format!("Failed to rewind the state file {STATE_FILE_NAME}"))?;
self.state_file
.set_len(0)
.with_context(|| format!("Failed to truncate the state file {STATE_FILE_NAME}"))?;
self.state_file
.write_all(&self.file_buf)
.with_context(|| format!("Failed to write the state file {STATE_FILE_NAME}"))?;
Ok(())
}
pub fn set_current_exercise_ind(&mut self, exercise_ind: usize) -> Result<()> {
if exercise_ind == self.current_exercise_ind {
return Ok(());
}
if exercise_ind >= self.exercises.len() {
bail!(BAD_INDEX_ERR);
}
self.current_exercise_ind = exercise_ind;
self.write()
}
pub fn set_current_exercise_by_name(&mut self, name: &str) -> Result<()> {
// O(N) is fine since this method is used only once until the program exits.
// Building a hashmap would have more overhead.
self.current_exercise_ind = self
.exercises
.iter()
.position(|exercise| exercise.name == name)
.with_context(|| format!("No exercise found for '{name}'!"))?;
self.write()
}
pub fn set_pending(&mut self, exercise_ind: usize) -> Result<()> {
let exercise = self
.exercises
.get_mut(exercise_ind)
.context(BAD_INDEX_ERR)?;
if exercise.done {
exercise.done = false;
self.n_done -= 1;
self.write()?;
}
Ok(())
}
// Official exercises: Dump the original file from the binary.
// Third-party exercises: Reset the exercise file with `git stash`.
fn reset(&self, exercise_ind: usize, path: &str) -> Result<()> {
if self.official_exercises {
return EMBEDDED_FILES
.write_exercise_to_disk(exercise_ind, path)
.with_context(|| format!("Failed to reset the exercise {path}"));
}
let output = Command::new("git")
.arg("stash")
.arg("push")
.arg("--")
.arg(path)
.stdin(Stdio::null())
.stdout(Stdio::null())
.output()
.with_context(|| format!("Failed to run `git stash push -- {path}`"))?;
if !output.status.success() {
bail!(
"`git stash push -- {path}` didn't run successfully: {}",
String::from_utf8_lossy(&output.stderr),
);
}
Ok(())
}
pub fn reset_current_exercise(&mut self) -> Result<&'static str> {
self.set_pending(self.current_exercise_ind)?;
let exercise = self.current_exercise();
self.reset(self.current_exercise_ind, exercise.path)?;
Ok(exercise.path)
}
// Reset the exercise by index and return its name.
pub fn reset_exercise_by_ind(&mut self, exercise_ind: usize) -> Result<&'static str> {
if exercise_ind >= self.exercises.len() {
bail!(BAD_INDEX_ERR);
}
self.set_pending(exercise_ind)?;
let exercise = &self.exercises[exercise_ind];
self.reset(exercise_ind, exercise.path)?;
Ok(exercise.name)
}
// Return the index of the next pending exercise or `None` if all exercises are done.
fn next_pending_exercise_ind(&self) -> Option<usize> {
let next_ind = self.current_exercise_ind + 1;
self.exercises
// If the exercise done isn't the last, search for pending exercises after it.
.get(next_ind..)
.and_then(|later_exercises| {
later_exercises
.iter()
.position(|exercise| !exercise.done)
.map(|ind| next_ind + ind)
})
// Search from the start.
.or_else(|| {
self.exercises[..self.current_exercise_ind]
.iter()
.position(|exercise| !exercise.done)
})
}
/// Official exercises: Dump the solution file from the binary and return its path.
/// Third-party exercises: Check if a solution file exists and return its path in that case.
pub fn current_solution_path(&self) -> Result<Option<String>> {
if cfg!(debug_assertions) {
return Ok(None);
}
let current_exercise = self.current_exercise();
if self.official_exercises {
EMBEDDED_FILES
.write_solution_to_disk(self.current_exercise_ind, current_exercise.name)
.map(Some)
} else {
let sol_path = current_exercise.sol_path();
if Path::new(&sol_path).exists() {
return Ok(Some(sol_path));
}
Ok(None)
}
}
// Return the exercise index of the first pending exercise found.
fn check_all_exercises(&self, stdout: &mut StdoutLock) -> Result<Option<usize>> {
stdout.write_all(RERUNNING_ALL_EXERCISES_MSG)?;
let n_exercises = self.exercises.len();
let status = thread::scope(|s| {
let handles = self
.exercises
.iter()
.map(|exercise| s.spawn(|| exercise.run_exercise(None, &self.cmd_runner)))
.collect::<Vec<_>>();
for (exercise_ind, handle) in handles.into_iter().enumerate() {
write!(stdout, "\rProgress: {exercise_ind}/{n_exercises}")?;
stdout.flush()?;
let Ok(success) = handle.join().unwrap() else {
return Ok(AllExercisesCheck::CheckedUntil(exercise_ind));
};
if !success {
return Ok(AllExercisesCheck::Pending(exercise_ind));
}
}
Ok::<_, io::Error>(AllExercisesCheck::AllDone)
})?;
let mut exercise_ind = match status {
AllExercisesCheck::Pending(exercise_ind) => return Ok(Some(exercise_ind)),
AllExercisesCheck::AllDone => return Ok(None),
AllExercisesCheck::CheckedUntil(ind) => ind,
};
// We got an error while checking all exercises in parallel.
// This could be because we exceeded the limit of open file descriptors.
// Therefore, try to continue the check sequentially.
for exercise in &self.exercises[exercise_ind..] {
write!(stdout, "\rProgress: {exercise_ind}/{n_exercises}")?;
stdout.flush()?;
let success = exercise.run_exercise(None, &self.cmd_runner)?;
if !success {
return Ok(Some(exercise_ind));
}
exercise_ind += 1;
}
Ok(None)
}
/// Mark the current exercise as done and move on to the next pending exercise if one exists.
/// If all exercises are marked as done, run all of them to make sure that they are actually
/// done. If an exercise which is marked as done fails, mark it as pending and continue on it.
pub fn done_current_exercise(&mut self, stdout: &mut StdoutLock) -> Result<ExercisesProgress> {
let exercise = &mut self.exercises[self.current_exercise_ind];
if !exercise.done {
exercise.done = true;
self.n_done += 1;
}
if let Some(ind) = self.next_pending_exercise_ind() {
self.set_current_exercise_ind(ind)?;
return Ok(ExercisesProgress::NewPending);
}
if let Some(pending_exercise_ind) = self.check_all_exercises(stdout)? {
stdout.write_all(b"\n\n")?;
self.current_exercise_ind = pending_exercise_ind;
self.exercises[pending_exercise_ind].done = false;
// All exercises were marked as done.
self.n_done -= 1;
self.write()?;
return Ok(ExercisesProgress::NewPending);
}
// Write that the last exercise is done.
self.write()?;
clear_terminal(stdout)?;
stdout.write_all(FENISH_LINE.as_bytes())?;
let final_message = self.final_message.trim_ascii();
if !final_message.is_empty() {
stdout.write_all(final_message.as_bytes())?;
stdout.write_all(b"\n")?;
}
Ok(ExercisesProgress::AllDone)
}
}
const BAD_INDEX_ERR: &str = "The current exercise index is higher than the number of exercises";
const STATE_FILE_HEADER: &[u8] = b"DON'T EDIT THIS FILE!\n\n";
const RERUNNING_ALL_EXERCISES_MSG: &[u8] = b"
All exercises seem to be done.
Recompiling and running all exercises to make sure that all of them are actually done.
";
const FENISH_LINE: &str = "+----------------------------------------------------+
| You made it to the Fe-nish line! |
+-------------------------- ------------------------+
\\/\x1b[31m
▒▒ ▒▒▒▒▒▒▒▒ ▒▒▒▒▒▒▒▒ ▒▒
▒▒▒▒ ▒▒ ▒▒ ▒▒ ▒▒ ▒▒ ▒▒ ▒▒▒▒
▒▒▒▒ ▒▒ ▒▒ ▒▒ ▒▒ ▒▒ ▒▒▒▒
░░▒▒▒▒░░▒▒ ▒▒ ▒▒ ▒▒ ▒▒░░▒▒▒▒
▓▓▓▓▓▓▓▓ ▓▓ ▓▓██ ▓▓ ▓▓██ ▓▓ ▓▓▓▓▓▓▓▓
▒▒▒▒ ▒▒ ████ ▒▒ ████ ▒▒░░ ▒▒▒▒
▒▒ ▒▒▒▒▒▒ ▒▒▒▒▒▒ ▒▒▒▒▒▒ ▒▒
▒▒▒▒▒▒▒▒▒▒▓▓▓▓▓▓▒▒▒▒▒▒▒▒▓▓▓▓▓▓▒▒▒▒▒▒▒▒
▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
▒▒▒▒▒▒▒▒▒▒██▒▒▒▒▒▒██▒▒▒▒▒▒▒▒▒▒
▒▒ ▒▒▒▒▒▒▒▒▒▒██████▒▒▒▒▒▒▒▒▒▒ ▒▒
▒▒ ▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒ ▒▒
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▒▒ ▒▒ ▒▒ ▒▒ ▒▒ ▒▒
▒▒ ▒▒ ▒▒ ▒▒\x1b[0m
";
#[cfg(test)]
mod tests {
use super::*;
fn dummy_exercise() -> Exercise {
Exercise {
dir: None,
name: "0",
path: "exercises/0.rs",
test: false,
strict_clippy: false,
hint: "",
done: false,
}
}
#[test]
fn next_pending_exercise() {
let mut app_state = AppState {
current_exercise_ind: 0,
exercises: vec![dummy_exercise(), dummy_exercise(), dummy_exercise()],
n_done: 0,
final_message: String::new(),
state_file: tempfile::tempfile().unwrap(),
file_buf: Vec::new(),
official_exercises: true,
cmd_runner: CmdRunner::build().unwrap(),
vs_code: false,
};
let mut assert = |done: [bool; 3], expected: [Option<usize>; 3]| {
for (exercise, done) in app_state.exercises.iter_mut().zip(done) {
exercise.done = done;
}
for (ind, expected) in expected.into_iter().enumerate() {
app_state.current_exercise_ind = ind;
assert_eq!(
app_state.next_pending_exercise_ind(),
expected,
"done={done:?}, ind={ind}",
);
}
};
assert([true, true, true], [None, None, None]);
assert([false, false, false], [Some(1), Some(2), Some(0)]);
assert([false, true, true], [None, Some(0), Some(0)]);
assert([true, false, true], [Some(1), None, Some(1)]);
assert([true, true, false], [Some(2), Some(2), None]);
assert([true, false, false], [Some(1), Some(2), Some(1)]);
assert([false, true, false], [Some(2), Some(2), Some(0)]);
assert([false, false, true], [Some(1), Some(0), Some(0)]);
}
}