dtSearch Engine API Reference 2023.02
IIndexJob::StatusDocsInIndex Property
long * StatusDocsInIndex;

Number of documents in the index

While indexing is in process, the Status* properties provide easy access to information about the progress of the indexing job. When the indexing job was started with ExecuteInThread, the Status values will be updated each time IsThreadDone is called. These are only available when ExecuteInThread is called.