fix: truncate context logic

Plugins/ZShell/Llm/filetool.cpp

@@ -53,9 +53,9 @@ QJsonObject FileReadTool::parameters() const {
 	QJsonObject limit;
 	limit[QStringLiteral("type")] = QStringLiteral("integer");
 	limit[QStringLiteral("minimum")] = 1;
-	limit[QStringLiteral("description")] =
-		QStringLiteral("Maximum number of characters to return. Defaults "
-					   "to a value that fits the model's context window.");
+	limit[QStringLiteral("description")] = QStringLiteral(
+		"Maximum number of characters to return. Defaults "
+		"to a value that fits the model's context window.");
 
 	QJsonObject properties;
 	properties[QStringLiteral("path")] = path;
@@ -74,6 +74,7 @@ QJsonObject FileReadTool::parameters() const {
 void FileReadTool::execute(
 	const QString& toolCallId,
 	const QJsonObject& args,
+	int outputBudgetChars,
 	std::function<void(const QJsonObject&)> done) {
 	Q_UNUSED(toolCallId);
 	const QString path = args[QStringLiteral("path")].toString().trimmed();
@@ -82,7 +83,8 @@ void FileReadTool::execute(
 		return;
 	}
 	const int offset = qMax(0, args[QStringLiteral("offset")].toInt(0));
-	const int budget = inlineBudgetChars();
+	int budget = inlineBudgetChars();
+	if (outputBudgetChars > 0) budget = qMin(budget, outputBudgetChars);
 	const int limit =
 		qBound(1, args[QStringLiteral("limit")].toInt(budget), budget);
 
@@ -90,8 +92,9 @@ void FileReadTool::execute(
 	if (!file.open(QIODevice::ReadOnly)) {
 		const QFileInfo info(path);
 		if (info.exists() && info.isDir()) {
-			done(makeError(QStringLiteral("Path is a directory, not a "
-										   "file: %1")
+			done(makeError(QStringLiteral(
+							   "Path is a directory, not a "
+							   "file: %1")
 							   .arg(path)));
 		} else {
 			done(makeError(QStringLiteral("Cannot open file: %1").arg(path)));
@@ -106,8 +109,9 @@ void FileReadTool::execute(
 	}
 	if (offset >= fileSize) {
 		file.close();
-		done(makeError(QStringLiteral("Offset %1 is beyond the end of the "
-									   "file (%2 bytes)")
+		done(makeError(QStringLiteral(
+						   "Offset %1 is beyond the end of the "
+						   "file (%2 bytes)")
 						   .arg(offset)
 						   .arg(fileSize)));
 		return;
@@ -117,15 +121,13 @@ void FileReadTool::execute(
 		done(makeError(QStringLiteral("Cannot seek in file: %1").arg(path)));
 		return;
 	}
-	// UTF-8 uses at most 4 bytes per character, so this many bytes always
-	// cover `limit` characters.
 	const qint64 wanted = qint64(limit) * 4 + 16;
 	const QByteArray chunk = file.read(qMin(wanted, fileSize - offset));
 	file.close();
 
 	if (chunk.contains('\0')) {
-		done(makeError(QStringLiteral("Binary files are not supported: %1")
-						   .arg(path)));
+		done(makeError(
+			QStringLiteral("Binary files are not supported: %1").arg(path)));
 		return;
 	}
 	const QString content = QString::fromUtf8(chunk);