perf(XS-51): Stream exports to disk in chunks

e2e/pages/results-page.ts

@@ -117,7 +117,7 @@ export class ResultsPage {
   }
 
   // ── Export ───────────────────────────────────────────────────────────────
-  /** The "Export as" options dialog (note: "Save to file" itself uses a native dialog). */
+  /** The export options dialog (note: "Save to file" itself uses a native dialog). */
   get exportDialog(): Locator {
     return this.page.locator('.modal').filter({ has: this.page.locator('#export-format') });
   }
@@ -130,12 +130,16 @@ export class ResultsPage {
     return this.page.locator('#export-rows-group');
   }
 
+  get exportColumnsGroup(): Locator {
+    return this.page.locator('#export-cols-group');
+  }
+
   get exportSummary(): Locator {
     return this.page.locator('.export-results-summary');
   }
 
   async openExportDialog(): Promise<void> {
-    await this.activeSet.getByRole('button', { name: 'Export as' }).click();
+    await this.activeSet.getByRole('button', { name: 'Export', exact: true }).click();
     await expect(this.exportDialog).toBeVisible();
   }
 

e2e/specs/results/export.spec.ts

@@ -1,7 +1,7 @@
 import { POSTGRES } from '@support/databases';
 import { expect, test } from '@support/fixtures';
 
-// Covers the "Export as" dialog UI only. "Save to file" (native OS dialog) and
+// Covers the export dialog UI only. "Save to file" (native OS dialog) and
 // "Copy to clipboard" (Wails clipboard) aren't driven here.
 test.describe('Export', () => {
   test('switches format and scope and reflects them in the summary', async ({ connections, editor, results }) => {
@@ -16,6 +16,11 @@ test.describe('Export', () => {
     const selectedRows = results.exportRowsGroup.getByRole('button', { name: /Selected/ });
     await expect(selectedRows).toBeDisabled();
 
+    // With no column hidden, "Visible" would duplicate "All", so only "All" is offered.
+    const colsGroup = results.exportColumnsGroup;
+    await expect(colsGroup.getByRole('button', { name: 'All (2)' })).toHaveClass(/active/);
+    await expect(colsGroup.getByRole('button', { name: /Visible/ })).toHaveCount(0);
+
     await results.setExportFormat('json');
     await expect(results.exportSummary).toContainText('JSON');
 

e2e/specs/table-view/columns.spec.ts

@@ -18,7 +18,7 @@ test.describe('Table view - column visibility', () => {
     await expect(tableView.columnsButton).toContainText('(1/2)');
 
     // The export dialog defaults to the visible-column scope.
-    await tableView.pane.getByRole('button', { name: 'Export as' }).click();
+    await tableView.pane.getByRole('button', { name: 'Export', exact: true }).click();
     const colsGroup = page.locator('#export-cols-group');
     await expect(colsGroup.getByRole('button', { name: 'All (2)' })).toBeVisible();
     await expect(colsGroup.getByRole('button', { name: 'Visible (1)' })).toHaveClass(/active/);

frontend/bindings/xensql/internal/app/app.ts

@@ -19,6 +19,14 @@ import * as storage$0 from "../storage/models.js";
 // @ts-ignore: Unused imports
 import * as $models from "./models.js";
 
+/**
+ * AppendTextFile writes one chunk, emptying the file first when truncate is set. Each chunk opens and
+ * closes the file, so nothing leaks if the caller stops part-way.
+ */
+export function AppendTextFile(path: string, chunk: string, truncate: boolean): $CancellablePromise<void> {
+    return $Call.ByID(403815492, path, chunk, truncate);
+}
+
 /**
  * BeginTransaction pins a dedicated connection to the tab and opens a transaction.
  * Subsequent ExecuteQueryStream calls for tabID will run on that connection until

frontend/src/features/results/ResultsGrid.tsx

@@ -212,7 +212,7 @@ function ResultsGridImpl({
     selectionRef,
     focusRef,
   });
-  const { copyFormat, setCopyFormat, exportBusy, copyToClipboard, exportToFile } = copyExport;
+  const { copyFormat, setCopyFormat, copyToClipboard } = copyExport;
   const copySelectionToClipboard = useCallback(() => copyToClipboard(true), [copyToClipboard]);
   const copyButtonToClipboard = useCallback(() => copyToClipboard(false), [copyToClipboard]);
 
@@ -428,10 +428,8 @@ function ResultsGridImpl({
         }
         copyFormat={copyFormat}
         onFormatChange={setCopyFormat}
-        exportBusy={exportBusy}
         onCopy={copyButtonToClipboard}
-        onExportToFile={exportToFile}
-        onExportAs={() => setExportOpen(true)}
+        onExport={() => setExportOpen(true)}
       />
 
       <GridTable

frontend/src/features/table-view/TableViewGrid.tsx

@@ -292,20 +292,10 @@ export const TableViewGrid = memo(function TableViewGrid({
       lastCopyRef.current = copied;
     },
   });
-  const { copyFormat, setCopyFormat, exportBusy, copyToClipboard, exportToFile } = copyExport;
+  const { copyFormat, setCopyFormat, copyToClipboard } = copyExport;
   const copyButtonToClipboard = useCallback(() => copyToClipboard(false), [copyToClipboard]);
   const copySelectionToClipboard = useCallback(() => copyToClipboard(true), [copyToClipboard]);
 
-  const exportAllLoaded = useCallback(async () => {
-    const saved = selectionRef.current;
-    selectionRef.current = { rows: new Set(), cols: new Set() };
-    try {
-      await exportToFile();
-    } finally {
-      selectionRef.current = saved;
-    }
-  }, [exportToFile, selectionRef]);
-
   const { selectionRowsCount, selectionColsCount, selectedSortedRows, selectedColPositions } = useGridSelectionView({
     cellRange,
     selectedRows,
@@ -467,10 +457,8 @@ export const TableViewGrid = memo(function TableViewGrid({
         }
         copyFormat={copyFormat}
         onFormatChange={setCopyFormat}
-        exportBusy={exportBusy}
         onCopy={copyButtonToClipboard}
-        onExportToFile={exportAllLoaded}
-        onExportAs={() => setExportOpen(true)}
+        onExport={() => setExportOpen(true)}
       />
 
       <GridTable

frontend/src/i18n/locales/bg.json

@@ -108,7 +108,8 @@
     "savedFile": "Запазено като {{fileName}}",
     "exportCopied": "Експортът е копиран в клипборда",
     "connectionSuccess": "Връзката е успешна!",
-    "savedQuery": "Заявката е запазена"
+    "savedQuery": "Заявката е запазена",
+    "exportStopped": "Експортирането е спряно - {{fileName}} съдържа само първите {{count}} ред(а)"
   },
   "tooltip": {
     "runStatement": "Изпълни тази заявка",
@@ -123,7 +124,6 @@
     "copyFormat": "Формат за копиране и експорт",
     "cellViewerKind": "Преглед на съдържанието като",
     "copyResults": "Копирай резултатите в клипборда",
-    "exportFile": "Запази резултатите във файл",
     "exportOptions": "Експорт с опции за редове, колони и формат",
     "showHideColumns": "Покажи или скрий колони",
     "resultsColumnHeader": "Клик за сортиране · Ctrl+клик за колона · Shift+клик за диапазон",
@@ -230,7 +230,6 @@
     "txnCommit": "Транзакцията е потвърдена",
     "txnRollback": "Транзакцията е отменена",
     "fitColumns": "Оразмери колоните",
-    "exportAs": "Експорт като",
     "export": "Експорт",
     "deleteRows": "Изтрий ({{count}})",
     "contextExportAs": "Експорт като",
@@ -266,7 +265,9 @@
     "formatCsv": "CSV",
     "formatJson": "JSON",
     "formatMarkdown": "Markdown",
-    "formatSql": "SQL INSERT"
+    "formatSql": "SQL INSERT",
+    "progress": "Експортиране… {{done}} от {{total}} реда записани",
+    "stop": "Спиране"
   },
   "sidebar": {
     "connect": "Свържи",

frontend/src/i18n/locales/de.json

@@ -108,7 +108,8 @@
     "savedFile": "Gespeichert als {{fileName}}",
     "exportCopied": "Export in Zwischenablage kopiert",
     "connectionSuccess": "Verbindung erfolgreich!",
-    "savedQuery": "Abfrage gespeichert"
+    "savedQuery": "Abfrage gespeichert",
+    "exportStopped": "Export abgebrochen - {{fileName}} enthält nur die ersten {{count}} Zeile(n)"
   },
   "tooltip": {
     "runStatement": "Diese Anweisung ausführen",
@@ -123,7 +124,6 @@
     "copyFormat": "Format für Kopieren und Export",
     "cellViewerKind": "Inhalt anzeigen als",
     "copyResults": "Ergebnisse in Zwischenablage kopieren",
-    "exportFile": "Ergebnisse in Datei speichern",
     "exportOptions": "Export mit Zeilen-, Spalten- und Formatoptionen",
     "showHideColumns": "Spalten ein- oder ausblenden",
     "resultsColumnHeader": "Klicken zum Sortieren · Strg+Klick Spalte wählen · Umschalt+Klick Bereich",
@@ -230,7 +230,6 @@
     "txnCommit": "Transaktion bestätigt",
     "txnRollback": "Transaktion zurückgerollt",
     "fitColumns": "Spalten anpassen",
-    "exportAs": "Exportieren als",
     "export": "Exportieren",
     "deleteRows": "Löschen ({{count}})",
     "contextExportAs": "Exportieren als",
@@ -266,7 +265,9 @@
     "formatCsv": "CSV",
     "formatJson": "JSON",
     "formatMarkdown": "Markdown",
-    "formatSql": "SQL INSERT"
+    "formatSql": "SQL INSERT",
+    "progress": "Exportiert… {{done}} von {{total}} Zeilen geschrieben",
+    "stop": "Stoppen"
   },
   "sidebar": {
     "connect": "Verbinden",

frontend/src/i18n/locales/en.json

@@ -108,7 +108,8 @@
     "savedFile": "Saved as {{fileName}}",
     "exportCopied": "Export copied to clipboard",
     "connectionSuccess": "Connection successful!",
-    "savedQuery": "Query saved"
+    "savedQuery": "Query saved",
+    "exportStopped": "Export stopped - {{fileName}} holds only the first {{count}} row(s)"
   },
   "tooltip": {
     "runStatement": "Run this statement",
@@ -123,7 +124,6 @@
     "copyFormat": "Format used for copy and export",
     "cellViewerKind": "View content as",
     "copyResults": "Copy results to clipboard",
-    "exportFile": "Save results to file",
     "exportOptions": "Export with row, column and format options",
     "showHideColumns": "Show or hide columns",
     "resultsColumnHeader": "Click to sort · Ctrl+click to select column · Shift+click for range",
@@ -230,7 +230,6 @@
     "txnCommit": "Transaction committed",
     "txnRollback": "Transaction rolled back",
     "fitColumns": "Fit columns",
-    "exportAs": "Export as",
     "export": "Export",
     "deleteRows": "Delete ({{count}})",
     "contextExportAs": "Export as",
@@ -266,7 +265,9 @@
     "formatCsv": "CSV",
     "formatJson": "JSON",
     "formatMarkdown": "Markdown",
-    "formatSql": "SQL INSERT"
+    "formatSql": "SQL INSERT",
+    "progress": "Exporting… {{done}} of {{total}} rows written",
+    "stop": "Stop"
   },
   "sidebar": {
     "connect": "Connect",