Function FlushBuffer

pg_documentdb/src/infrastructure/cursor_store.c:578–607

* Writes whatever bytes have been filed into the buffer to the * cursor file. This is called when the buffer is full or * when the cursor file is closed. */

 * when the cursor file is closed.
 */
static void
FlushBuffer(CursorFileState *cursorFileState)
{
	if (cursorFileState->pos > 0)
	{
		int bytesWritten = FileWrite(cursorFileState->bufFile,
									 cursorFileState->buffer.data, cursorFileState->pos,
									 cursorFileState->cursorState.file_offset,
									 WAIT_EVENT_BUFFILE_WRITE);

		if (bytesWritten != cursorFileState->pos)
		{
			ereport(ERROR,
					(errcode_for_file_access(),
					 errmsg("Failed to save data to file")));
		}

		cursorFileState->cursorState.file_offset += cursorFileState->pos;
		cursorFileState->pos = 0;

		Size maxFileSize = ((Size) MaxAllowedCursorIntermediateFileSizeMB) * 1024L * 1024;
		if (cursorFileState->cursorState.file_offset > maxFileSize)
		{
			ereport(ERROR, (errcode(ERRCODE_DOCUMENTDB_INTERNALERROR),
							errmsg("Cursor file size %u exceeded the limit %d MB",
								   cursorFileState->cursorState.file_offset,
								   MaxAllowedCursorIntermediateFileSizeMB)));
		}
	}
}


/*