better loading free table data

packages/api/src/shell/collectorWriter.js

@@ -0,0 +1,33 @@
+const stream = require('stream');
+
+class CollectorWriterStream extends stream.Writable {
+  constructor(options) {
+    super(options);
+    this.rows = [];
+    this.structure = null;
+    this.runid = options.runid;
+  }
+  _write(chunk, enc, next) {
+    if (!this.structure) this.structure = chunk;
+    else this.rows.push(chunk);
+    next();
+  }
+
+  _final(callback) {
+    process.send({
+      msgtype: 'freeData',
+      runid: this.runid,
+      freeData: { rows: this.rows, structure: this.structure },
+    });
+    callback();
+  }
+}
+
+async function collectorWriter({ runid }) {
+  return new CollectorWriterStream({
+    objectMode: true,
+    runid,
+  });
+}
+
+module.exports = collectorWriter;