Files
OpenFrontIO/tests/pathfinding/playground/server.ts
T
Arkadiusz Sygulski 85def73bd9 Pathfinding Refinement (#2878)
# Pathfinding pt. 3

## Description:

This PR introduces final change to the pathfinding - path refinement. It
optimizes Line of Sight refinement by searching with for the best tile
with a binary search instead of linearly. And then spends the recovered
budget on better refinement of the first and last 50 tiles of the
journey - the place where user is most likely to look at. Additionally
this PR re-introduces magnitude check and makes the ships prefer sailing
close to the coast, but not too close.

## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [x] I have added relevant tests to the test directory
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced

## What?

| Before | After |
| :--- | :--- |
| <img width="1097" height="1117" alt="image"
src="https://github.com/user-attachments/assets/4a0b300d-10ef-4151-b6dc-33acfb49f992"
/> | <img width="1093" height="1119" alt="image"
src="https://github.com/user-attachments/assets/cf81c515-c145-40f4-91e5-a4353986907b"
/> |
| <img width="1096" height="1129" alt="image"
src="https://github.com/user-attachments/assets/21b46bce-f961-4259-88f6-fe4a66180270"
/> | <img width="1098" height="1126" alt="image"
src="https://github.com/user-attachments/assets/d92587d1-e6b6-4353-b4a4-1efe71bca43d"
/> |

## Performance

There is actually a severe performance impact of these changes. The path
initial path takes almost 2x as long to generate - this is because pre
processing can only do so much if the initial path is ugly. Luckily in
real gameplay we only need to do this calculation once per edge, so the
actual observed performance impact should be much smaller. Cache FTW.

| | No Cache | Cache |
| :--- | :--- | :--- |
| Before | 277.04ms | 208.58ms |
| After | 498.34ms | 264.27ms |

## DebugSpan

Small utility, it allows any code to be easily instrumented for
performance. The idea is the same as with [OTEL
Spans](https://opentelemetry.io/docs/concepts/signals/traces/). Produce
a span, create sub-spans, measure whatever you need. Works only when
`globalThis.__DEBUG_SPAN_ENABLED__ === true`, otherwise no-op.

Cool stuff, try it out:
```ts
// Convenient wrapper, small performance impact
return DebugSpan.wrap('add', () => a + b)

// Synchronous API, basically free
DebugSpan.start('work')
work()
DebugSpan.end()

// Create sub spans
DebugSpan.wrap('complex', () => {
  const aPlusB = DebugSpan.wrap('add', () => a + b)
  DebugSpan.set('additionResult', () => aPlusB)  // Store data
  return aPlusB * c
})

// Access spans, data and timing
const span = DebugSpan.getLast()
const compelxSpan = DebugSpan.getLast('complex')

console.log(complexSpan.duration, complexSpan.data['additionResult'])
```

These are virtually free and can be enabled on-demand **in production**
and available in the devtools. Under the hood devtools integration is
just a wrapper around [Performance
API](https://developer.mozilla.org/en-US/docs/Web/API/Performance_API).
For clarity data keys not prefixed by `$` are omitted from the
integration. Every key prefixed with `$` must be fully JSON
serializable.

<img width="977" height="799" alt="image"
src="https://github.com/user-attachments/assets/b4d43506-1639-4f78-a611-30e61de12a07"
/>
2026-01-13 12:39:54 -08:00

198 lines
5.2 KiB
TypeScript

import compression from "compression";
import express, { Request, Response } from "express";
import { dirname, join } from "path";
import { fileURLToPath } from "url";
import {
clearCache as clearMapCache,
getMapMetadata,
listMaps,
} from "./api/maps.js";
import { clearAdapterCaches, computePath } from "./api/pathfinding.js";
const app = express();
const PORT = process.env.PORT ?? 5555;
// Middleware
app.use(compression()); // gzip compression for large responses
app.use(express.json({ limit: "50mb" })); // JSON body parser with larger limit
// Serve static files from public directory
const publicDir = join(dirname(fileURLToPath(import.meta.url)), "public");
app.use(express.static(publicDir));
// API Routes
/**
* GET /api/maps
* List all available maps
*/
app.get("/api/maps", (req: Request, res: Response) => {
try {
const maps = listMaps();
res.json({ maps });
} catch (error) {
console.error("Error listing maps:", error);
res.status(500).json({
error: "Failed to list maps",
message: error instanceof Error ? error.message : String(error),
});
}
});
/**
* GET /api/maps/:name
* Get map metadata (map data, dimensions)
*/
app.get("/api/maps/:name", async (req: Request, res: Response) => {
try {
const { name } = req.params;
const metadata = await getMapMetadata(name);
res.json(metadata);
} catch (error) {
console.error(`Error loading map ${req.params.name}:`, error);
if (error instanceof Error && error.message.includes("ENOENT")) {
res.status(404).json({
error: "Map not found",
message: `Map "${req.params.name}" does not exist`,
});
} else {
res.status(500).json({
error: "Failed to load map",
message: error instanceof Error ? error.message : String(error),
});
}
}
});
/**
* GET /api/maps/:name/thumbnail
* Get map thumbnail image
*/
app.get("/api/maps/:name/thumbnail", (req: Request, res: Response) => {
try {
const { name } = req.params;
const thumbnailPath = join(
dirname(fileURLToPath(import.meta.url)),
"../../../resources/maps",
name,
"thumbnail.webp",
);
res.sendFile(thumbnailPath);
} catch (error) {
console.error(`Error loading thumbnail for ${req.params.name}:`, error);
res.status(404).json({
error: "Thumbnail not found",
message: error instanceof Error ? error.message : String(error),
});
}
});
/**
* POST /api/pathfind
* Compute pathfinding between two points
*
* Request body:
* {
* map: string,
* from: [x, y],
* to: [x, y],
* adapters?: string[] // Optional: which comparison adapters to run
* }
*
* Response:
* {
* primary: { path, length, time, debug: { nodePath, initialPath, timings } },
* comparisons: [{ adapter, path, length, time }, ...]
* }
*/
app.post("/api/pathfind", async (req: Request, res: Response) => {
try {
const { map, from, to, adapters } = req.body;
// Validate request
if (!map || !from || !to) {
return res.status(400).json({
error: "Invalid request",
message: "Missing required fields: map, from, to",
});
}
if (
!Array.isArray(from) ||
from.length !== 2 ||
!Array.isArray(to) ||
to.length !== 2
) {
return res.status(400).json({
error: "Invalid coordinates",
message: "from and to must be [x, y] coordinate arrays",
});
}
// Compute paths
const result = await computePath(
map,
from as [number, number],
to as [number, number],
{ adapters },
);
res.json(result);
} catch (error) {
console.error("Error computing path:", error);
if (error instanceof Error && error.message.includes("is not water")) {
res.status(400).json({
error: "Invalid coordinates",
message: error.message,
});
} else {
res.status(500).json({
error: "Failed to compute path",
message: error instanceof Error ? error.message : String(error),
});
}
}
});
/**
* POST /api/cache/clear
* Clear all caches (useful for development)
*/
app.post("/api/cache/clear", (req: Request, res: Response) => {
try {
clearMapCache();
clearAdapterCaches();
res.json({ message: "Caches cleared successfully" });
} catch (error) {
console.error("Error clearing caches:", error);
res.status(500).json({
error: "Failed to clear caches",
message: error instanceof Error ? error.message : String(error),
});
}
});
// Error handling middleware
app.use((err: Error, req: Request, res: Response, next: any) => {
console.error("Unhandled error:", err);
res.status(500).json({
error: "Internal server error",
message: err.message,
});
});
// Start server
app.listen(PORT, () => {
console.log(`
╔════════════════════════════════════════════════════════════╗
║ Pathfinding Playground Server ║
╚════════════════════════════════════════════════════════════╝
Server running at: http://localhost:${PORT}
Press Ctrl+C to stop
`);
});