markmental/ws4kp-linhanced
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

cache ArcGIS basemap tiles on disk for faster map loads

Browse source
This commit is contained in:
mrkmntal 2026-04-07 22:11:03 -04:00
commit 437100c433
5 changed files with 89 additions and 9 deletions
Download patch file Download diff file Expand all files Collapse all files

50
proxy/cache.mjs
View file

@ -32,10 +32,18 @@ const STALE_TIME_LIMIT_MS = 3 * 60 * 60 * 1000;
const PERSISTED_HOSTS = new Set([
'api.open-meteo.com',
'api.rainviewer.com',
'server.arcgisonline.com',
'services.arcgisonline.com',
]);
const BINARY_PERSISTED_HOSTS = new Set([
'server.arcgisonline.com',
'services.arcgisonline.com',
]);
const HOST_FALLBACK_TTLS = {
'api.open-meteo.com': 10 * 60,
'api.rainviewer.com': 2 * 60,
'server.arcgisonline.com': 7 * 24 * 60 * 60,
'services.arcgisonline.com': 7 * 24 * 60 * 60,
};
class HttpCache {
@ -55,16 +63,30 @@ class HttpCache {
return path.join(CACHE_DIR, `${HttpCache.hashKey(key)}.json`);
}
static shouldPersist(url, options, response) {
if (options?.encoding === 'binary') return false;
if (typeof response?.data !== 'string') return false;
static getCacheBodyFilePath(key) {
return path.join(CACHE_DIR, `${HttpCache.hashKey(key)}.bin`);
}
static getPersistedHost(url) {
try {
const parsedUrl = new URL(url);
return PERSISTED_HOSTS.has(parsedUrl.hostname);
return parsedUrl.hostname;
} catch {
return null;
}
}
static shouldPersist(url, options, response) {
const host = HttpCache.getPersistedHost(url);
if (!host || !PERSISTED_HOSTS.has(host)) {
return false;
}
if (options?.encoding === 'binary') {
return BINARY_PERSISTED_HOSTS.has(host) && Buffer.isBuffer(response?.data);
}
return typeof response?.data === 'string';
}
static getHostFallbackTtl(url) {
@ -96,10 +118,17 @@ class HttpCache {
}
if (now > parsed.entry.expiry + STALE_TIME_LIMIT_MS) {
if (parsed.entry.binaryBody === true) {
await unlink(HttpCache.getCacheBodyFilePath(parsed.key)).catch(() => null);
}
await unlink(filePath);
return;
}
if (parsed.entry.binaryBody === true) {
parsed.entry.data = await readFile(HttpCache.getCacheBodyFilePath(parsed.key));
}
this.cache.set(parsed.key, parsed.entry);
}));
} catch (error) {
@ -110,6 +139,18 @@ class HttpCache {
static async persistEntry(key, entry) {
try {
await mkdir(CACHE_DIR, { recursive: true });
if (Buffer.isBuffer(entry.data)) {
const metadata = {
...entry,
data: undefined,
binaryBody: true,
};
await writeFile(HttpCache.getCacheBodyFilePath(key), entry.data);
await writeFile(HttpCache.getCacheFilePath(key), JSON.stringify({ key, entry: metadata }));
return;
}
await writeFile(HttpCache.getCacheFilePath(key), JSON.stringify({ key, entry }));
} catch (error) {
console.warn(`⚠️ Cache save | Failed to persist cache entry ${key}: ${error.message}`);
@ -118,6 +159,7 @@ class HttpCache {
static async deletePersistedEntry(key) {
try {
await unlink(HttpCache.getCacheBodyFilePath(key)).catch(() => null);
await unlink(HttpCache.getCacheFilePath(key));
} catch (error) {
if (error.code !== 'ENOENT') {

16
proxy/handlers.mjs
View file

@ -64,3 +64,19 @@ export const rainViewerProxy = async (req, res) => {
skipParams: ['u'],
});
};
export const arcGisServerProxy = async (req, res) => {
await cache.handleRequest(req, res, 'https://server.arcgisonline.com', {
serviceName: 'ArcGIS Server',
skipParams: ['u'],
encoding: 'binary',
});
};
export const arcGisServicesProxy = async (req, res) => {
await cache.handleRequest(req, res, 'https://services.arcgisonline.com', {
serviceName: 'ArcGIS Services',
skipParams: ['u'],
encoding: 'binary',
});
};