function isSubset (a, b) {
if (!a && b) { return true; }
return [...a].every(member => b.has(member));
}
instructionOrder = {
let out = [];
let unvisitedNodes = new Set(nodes);
while (unvisitedNodes.size) {
// Find nodes whose dependencies have all been visited
// From those, pick the one whose value comes earliest in the alphabet
const nextNode = [...unvisitedNodes].filter(
n => isSubset(dependencies[n], new Set(out))).reduce((a, b) => a < b ? a : b);
out.push(nextNode);
unvisitedNodes.delete(nextNode);
}
return out.join('');
}
timeElapsed = {
let completedTasks = [];
let secondsElapsed = 0;
let timers = new Array(numWorkers).fill(0);
let tasks = new Array(numWorkers).fill('');
let remainingTasks = new Set(nodes);
while (true) {
// Decrement worker timers and unload completed tasks
for (let w = 0; w < timers.length; w++) {
timers[w] = Math.max(0, timers[w] - 1);
if (timers[w] === 0 && tasks[w].length) {
completedTasks.push(tasks[w]);
tasks[w] = '';
}
}
// Find available tasks, as before
// Sort them in order of increasing time burden
let availableTasks = [...remainingTasks].filter(
n => isSubset(dependencies[n], new Set(completedTasks))).sort();
// If there's no new work to do and all the workers are idle, return the time elapsed
if (availableTasks.length === 0 && timers.every(t => t === 0)) {
return secondsElapsed;
}
// Assign new tasks to idle workers and adjust their timers
// Remove those tasks from the list of tasks available to claim
for (let w = 0; w < timers.length; w++) {
if (availableTasks.length) {
if (timers[w] === 0) {
tasks[w] = availableTasks.shift();
timers[w] = taskTimeFloor + tasks[w].charCodeAt(0) - 64;
remainingTasks.delete(tasks[w]);
}
}
}
secondsElapsed++;
}
}
One platform to build and deploy the best data apps
Experiment and prototype by building visualizations in live JavaScript notebooks. Collaborate with your team and decide which concepts to build out.
Use Observable Framework to build data apps locally. Use data loaders to build in any language or library, including Python, SQL, and R.
Seamlessly deploy to Observable. Test before you ship, use automatic deploy-on-commit, and ensure your projects are always up-to-date.