jsl data refactor

packages/api/src/proc/jslDatastoreProcess.js

@@ -0,0 +1,57 @@
+const childProcessChecker = require('../utility/childProcessChecker');
+const JsonLinesDatastore = require('../utility/JsonLinesDatastore');
+
+let lastPing = null;
+let datastore = new JsonLinesDatastore();
+
+function handlePing() {
+  lastPing = new Date().getTime();
+}
+
+function handleOpen({file }) {
+  handlePing();
+  datastore = new JsonLinesDatastore(file);
+}
+
+async function handleRead({ msgid, offset, limit }) {
+  handlePing();
+  const rows = await datastore.getRows(offset, limit);
+  process.send({ msgtype: 'response', msgid, rows });
+}
+
+function handleNotifyChanged() {
+  datastore.notifyChanged();
+}
+
+const messageHandlers = {
+  open: handleOpen,
+  read: handleRead,
+  ping: handlePing,
+  notifyChanged: handleNotifyChanged,
+};
+
+async function handleMessage({ msgtype, ...other }) {
+  const handler = messageHandlers[msgtype];
+  await handler(other);
+}
+
+function start() {
+  childProcessChecker();
+
+  setInterval(() => {
+    const time = new Date().getTime();
+    if (time - lastPing > 60 * 1000) {
+      process.exit(0);
+    }
+  }, 60 * 1000);
+
+  process.on('message', async (message) => {
+    try {
+      await handleMessage(message);
+    } catch (e) {
+      process.send({ msgtype: 'error', error: e.message });
+    }
+  });
+}
+
+module.exports = { start };