introduced yarn workspace

packages/api/src/proc/databaseConnectionProcess.js

@@ -0,0 +1,66 @@
+const engines = require('@dbgate/engines');
+const Select = require('../dmlf/select');
+const driverConnect = require('../utility/driverConnect')
+
+let systemConnection;
+let storedConnection;
+let afterConnectCallbacks = [];
+
+async function handleFullRefresh() {
+  const driver = engines(storedConnection);
+  const structure = await driver.analyseFull(systemConnection);
+  process.send({ msgtype: 'structure', structure });
+}
+
+async function handleConnect(connection) {
+  storedConnection = connection;
+
+  const driver = engines(storedConnection);
+  systemConnection = await driverConnect(driver, storedConnection);
+  handleFullRefresh();
+  setInterval(handleFullRefresh, 30 * 1000);
+  for (const [resolve, reject] of afterConnectCallbacks) {
+    resolve();
+  }
+  afterConnectCallbacks = [];
+}
+
+function waitConnected() {
+  if (systemConnection) return Promise.resolve();
+  return new Promise((resolve, reject) => {
+    afterConnectCallbacks.push([resolve, reject]);
+  });
+}
+
+async function handleTableData({ msgid, schemaName, pureName }) {
+  await waitConnected();
+  const driver = engines(storedConnection);
+
+  const select = new Select();
+  if (driver.dialect.limitSelect) select.topRecords = 100;
+  if (driver.dialect.rangeSelect) select.range = { offset: 0, limit: 100 };
+  select.from = { schemaName, pureName };
+  select.selectAll = true;
+  const sql = select.toSql(driver);
+  const res = await driver.query(systemConnection, sql);
+
+  process.send({ msgtype: 'response', msgid, ...res });
+}
+
+const messageHandlers = {
+  connect: handleConnect,
+  tableData: handleTableData,
+};
+
+async function handleMessage({ msgtype, ...other }) {
+  const handler = messageHandlers[msgtype];
+  await handler(other);
+}
+
+process.on('message', async message => {
+  try {
+    await handleMessage(message);
+  } catch (e) {
+    process.send({ msgtype: 'error', error: e.message });
+  }
+});