system: add disk usage task

src/routes/system.js

@@ -3,8 +3,6 @@
 exports = module.exports = {
     reboot,
     getInfo,
-    getDiskUsage,
-    updateDiskUsage,
     getMemory,
     getLogs,
     getLogStream,
@@ -12,6 +10,7 @@ exports = module.exports = {
     getMetricStream,
     getBlockDevices,
     getFilesystems,
+    getFilesystemUsage,
     getCpus,
 };
 
@@ -37,20 +36,6 @@ async function getInfo(req, res, next) {
     next(new HttpSuccess(200, { info }));
 }
 
-async function getDiskUsage(req, res, next) {
-    const [error, result] = await safe(system.getDiskUsage());
-    if (error) return next(BoxError.toHttpError(error));
-
-    next(new HttpSuccess(200, { usage: result }));
-}
-
-async function updateDiskUsage(req, res, next) {
-    const [error, taskId] = await safe(system.startUpdateDiskUsage());
-    if (error) return next(BoxError.toHttpError(error));
-
-    next(new HttpSuccess(201, { taskId }));
-}
-
 async function getMemory(req, res, next) {
     const [error, result] = await safe(system.getMemory());
     if (error) return next(BoxError.toHttpError(error));
@@ -183,3 +168,34 @@ async function getFilesystems(req, res, next) {
 
     next(new HttpSuccess(200, { filesystems }));
 }
+
+async function getFilesystemUsage(req, res, next) {
+    if (typeof req.query.filesystem !== 'string') return next(new HttpError(400, 'getFilesystemUsage'));
+    if (req.headers.accept !== 'text/event-stream') return next(new HttpError(400, 'This API call requires EventStream'));
+
+    const [error, task] = await safe(system.getFilesystemUsage(req.query.filesystem));
+    if (error) return next(BoxError.toHttpError(error));
+
+    res.writeHead(200, {
+        'Content-Type': 'text/event-stream',
+        'Cache-Control': 'no-cache',
+        'Connection': 'keep-alive',
+        'X-Accel-Buffering': 'no', // disable nginx buffering
+        'Access-Control-Allow-Origin': '*'
+    });
+    res.write('retry: 30000\n'); // client should .close() to prevent reconnect within 30s
+    res.on('close', () => task.stop());
+    task.on('data', function (type, data) {
+        const obj = { type, ...data };
+        const sse = `data: ${JSON.stringify(obj)}\n\n`;
+        res.write(sse);
+    });
+    task.on('done', function (error) {
+        const obj = { type: 'done', ...error };
+        const sse = `data: ${JSON.stringify(obj)}\n\n`;
+        res.write(sse);
+        res.end();
+    });
+
+    task.start();
+}