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No commits in common. "0d7b3848211fbd0f450bf3677911749c5a4fd6c1" and "2520d03d1385eef9013a4d902282248dae04f77d" have entirely different histories.

3 changed files with 24 additions and 213 deletions

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@ -1,22 +1,7 @@
const tam = require('./sources/tam');
const util = require('../util');
/**
* Comparison function between two stop passings.
*
* @param passing1 First stop passing.
* @param passing2 Second stop passing.
* @return Negative value if passing1 is sooner than passing2, positive
* otherwise, zero if they occur at the same time.
*/
const passingCompare = ({arrivalTime: time1}, {arrivalTime: time2}) => (
time1 - time2
);
// Time at which the course data needs to be updated next
let nextUpdate = null;
// Current information about courses
let currentCourses = null;
/**
@ -29,10 +14,10 @@ let currentCourses = null;
*
* - `id`: Unique identifier for the course.
* - `line`: Line number.
* - `nextStop`: Identifier of the next stop of the course.
* - `arrivalTime`: Timestamp at which the vehicle is predicted to arrive
* to the next stop.
* - `finalStop`: The final stop to which the course is headed.
* - `nextPassings`: Next passings of the vehicle, sorted by increasing
* arrival time, containing both the stop identifier (`stopId`) and the
* expected arrival timestamp (`arrivalTime`).
*
* @return Mapping from active course IDs to information about each course.
*/
@ -57,13 +42,6 @@ const getCourses = () => new Promise((res, rej) =>
if (!util.isObject(entry))
{
// End of courses information stream. Sort next stops by increasing
// arrival time in each course then save result in memory cache
for (let course of Object.values(courses))
{
course.nextPassings.sort(passingCompare);
}
currentCourses = courses;
res(currentCourses);
return;
@ -71,7 +49,6 @@ const getCourses = () => new Promise((res, rej) =>
if ('lastUpdate' in entry)
{
// Metadata header
lastUpdate = entry.lastUpdate;
nextUpdate = entry.nextUpdate;
return;
@ -80,7 +57,7 @@ const getCourses = () => new Promise((res, rej) =>
const {
course: id,
routeShortName: line,
stopId,
stopId: nextStop,
destArCode: finalStop,
} = entry;
@ -88,14 +65,14 @@ const getCourses = () => new Promise((res, rej) =>
if (!(id in courses))
{
courses[id] = {
id, line, finalStop,
nextPassings: [{stopId, arrivalTime}],
};
courses[id] = {id, line, nextStop, arrivalTime, finalStop};
}
else
else if (arrivalTime < courses[id].arrivalTime)
{
courses[id].nextPassings.push({stopId, arrivalTime});
// The stop where the next passing is soonest is assumed
// to be the next stop
courses[id].nextStop = nextStop;
courses[id].arrivalTime = arrivalTime;
}
});
});

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@ -1,195 +1,32 @@
const axios = require('axios');
const network = require('../back/data/network.json');
const server = 'http://localhost:4321';
const arriveAtStop = (course, stop) =>
{
course.state = 'stopped';
course.currentStop = stop;
delete course.departureStop;
delete course.arrivalStop;
delete course.arrivalTime;
delete course.traveledDistance;
delete course.speed;
};
const moveToStop = (course, stop, arrivalTime) =>
{
course.state = 'moving';
course.departureStop = course.currentStop;
course.arrivalStop = stop;
course.arrivalTime = arrivalTime;
course.traveledDistance = 0;
course.speed = 0;
delete course.currentStop;
const segment = `${course.departureStop}-${course.arrivalStop}`;
if (!(segment in network.segments))
{
// There is no segment between the two requested stops, jump
// directly to the arrival stop
arriveAtStop(course, course.arrivalStop);
}
else
{
updateSpeed(course);
}
};
const getCurrentSegment = course =>
{
if (course.state === 'stopped')
{
return null;
}
return network.segments[`${course.departureStop}-${course.arrivalStop}`];
};
const updateSpeed = course =>
{
const segment = getCurrentSegment(course);
const length = segment.points[segment.points.length - 1].distance;
const remainingTime = course.arrivalTime - Date.now();
const remainingDistance = length - course.traveledDistance;
if (remainingTime <= 0 || remainingDistance <= 0)
{
arriveAtStop(course, course.arrivalStop);
return;
}
course.speed = remainingDistance / remainingTime;
};
const updateFromTam = async (courses) =>
{
const currentCourses = (await axios.get(`${server}/courses`)).data;
const currentCourses = await getCurrentCourses();
for (let [id, course] of Object.entries(currentCourses))
{
// Only track selected lines
if (!['1', '2', '3', '4'].includes(course.line))
if (!(id in courses))
{
continue;
}
// Find out the next stop, ignoring the ones that are in the past
let nextStop = null;
let arrivalTime = null;
for (let {stopId, arrivalTime: time} of course.nextPassings)
{
if (time > Date.now())
{
nextStop = stopId;
arrivalTime = time;
break;
}
}
if (nextStop === null)
{
continue;
}
// Update an existing course
if (id in courses)
{
const prev = courses[id];
if (prev.state === 'stopped')
{
if (prev.currentStop !== nextStop)
{
// Start traveling from the current stop to the next
moveToStop(prev, nextStop, arrivalTime);
}
course.arrivalTime = now() + course.eta;
console.log(`${displayNow(now())} - New course ${id} @ ${course.line} departing from stop ${course.stop} at ${displayNow(course.arrivalTime)}`);
courses[id] = course;
}
else
{
// Update the ETA if were still headed to the same stop
if (prev.arrivalStop === nextStop)
{
prev.arrivalTime = arrivalTime;
updateSpeed(prev);
}
// Otherwise, we missed a stop, try to go directly to the
// next segment
else
{
arriveAtStop(prev, prev.arrivalStop);
moveToStop(prev, nextStop, arrivalTime);
}
}
}
// Create a new course
else
{
courses[id] = {
id,
line: course.line,
finalStop: course.finalStop,
};
arriveAtStop(courses[id], nextStop);
}
}
// Remove stale courses
for (let id of Object.keys(courses))
{
if (!(id in currentCourses))
{
delete courses[id];
}
}
};
const updatePositions = (courses, time) =>
{
for (let [id, course] of Object.entries(courses))
{
if (course.state === 'moving')
{
const delta = course.speed * time;
const segment = getCurrentSegment(course);
const length = segment.points[segment.points.length - 1].distance;
if (course.traveledDistance + delta >= length)
{
course.traveledDistance = length;
}
else
{
course.traveledDistance += delta;
}
course.arrivalTime = now() + course.eta;
console.log(`${displayNow(now())} - Course ${id} @ ${course.line} will arrive to stop ${course.stop} at ${displayNow(course.arrivalTime)} (previously to stop ${courses[id].stop} at ${displayNow(courses[id].arrivalTime)})`);
courses[id] = course;
}
}
};
const sleep = time => new Promise(res => setTimeout(res, time));
const courses = {};
let lastFrame = null;
let lastUpdate = null;
const loop = now =>
const loop = async (courses = {}) =>
{
const time = lastFrame === null ? 0 : now - lastFrame;
lastFrame = now;
updatePositions(courses, time);
if (lastUpdate === null || lastUpdate + 5000 <= now)
{
lastUpdate = now;
updateFromTam(courses);
}
requestAnimationFrame(loop);
await updateFromTam(courses);
await sleep(30000);
return loop(courses);
};
requestAnimationFrame(loop);
loop();

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@ -1,7 +1,4 @@
require('regenerator-runtime/runtime');
const {createMap} = require('./map');
require('./data');
createMap(/* map = */ 'map');