added plugins

plugins/dbgate-plugin-mongo/src/backend/createBulkInsertStream.js

@@ -0,0 +1,58 @@
+export function createBulkInsertStream(driver, stream, pool, name, options) {
+  const collectionName = name.pureName;
+  const db = pool.__getDatabase();
+
+  const writable = new stream.Writable({
+    objectMode: true,
+  });
+
+  writable.buffer = [];
+  writable.wasHeader = false;
+
+  writable.addRow = (row) => {
+    if (!writable.wasHeader) {
+      writable.wasHeader = true;
+      if (row.__isStreamHeader || 
+        // TODO remove isArray test
+        Array.isArray(row.columns)) return;
+    }
+    writable.buffer.push(row);
+  };
+
+  writable.checkStructure = async () => {
+    if (options.dropIfExists || options.truncate) {
+      console.log(`Dropping collection ${collectionName}`);
+      await db.collection(collectionName).drop();
+    }
+    if (options.truncate) {
+      console.log(`Truncating collection ${collectionName}`);
+      await db.collection(collectionName).deleteMany({});
+    }
+  };
+
+  writable.send = async () => {
+    const rows = writable.buffer;
+    writable.buffer = [];
+
+    await db.collection(collectionName).insertMany(rows);
+  };
+
+  writable.sendIfFull = async () => {
+    if (writable.buffer.length > 100) {
+      await writable.send();
+    }
+  };
+
+  writable._write = async (chunk, encoding, callback) => {
+    writable.addRow(chunk);
+    await writable.sendIfFull();
+    callback();
+  };
+
+  writable._final = async (callback) => {
+    await writable.send();
+    callback();
+  };
+
+  return writable;
+}