Functions to truncate and/or close a column

src/obidmscolumn.c

@@ -948,15 +948,130 @@ OBIDMS_column_p obi_clone_column(OBIDMS_p dms, const char* column_name, obiversi
 		(new_column->header)->lines_used = nb_lines;
 	}
 
+	// close column_to_clone TODO
+
 	return new_column;
 }
 
 
 int obi_close_column(OBIDMS_column_p column)
 {
-	//munmap? TODO
-	//truncate to lines used TODO
+	size_t data_size;
+
+	// Munmap data
+	data_size = (column->header)->line_count * (column->header)->nb_elements_per_line * sizeof((column->header)->data_type);
+	if (munmap(column->data, data_size) < 0)
+	{
+		obi_set_errno(OBICOL_UNKNOWN_ERROR);
+		obidebug(1, "\nError munmapping column data");
+		return -1;
+	}
+
+	// Munmap header
+	if (munmap(column->header, (column->header)->header_size) < 0)
+	{
+		obi_set_errno(OBICOL_UNKNOWN_ERROR);
+		obidebug(1, "\nError munmapping a column header");
+		return -1;
+	}
+
 	free(column);
+
+	return 0;
+}
+
+
+int obi_truncate_column_to_lines_used(OBIDMS_column_p column)
+{
+	size_t file_size;
+	size_t data_size;
+	int column_dir_file_descriptor;
+	int column_file_descriptor;
+	char* column_file_name;
+
+	// Get the file descriptor associated to the column directory
+	column_dir_file_descriptor = dirfd((column->column_directory)->directory);
+	if (column_dir_file_descriptor < 0)
+	{
+		obi_set_errno(OBICOLDIR_UNKNOWN_ERROR);
+		obidebug(1, "\nError getting the file descriptor for a column directory");
+		return -1;
+	}
+
+	// Get the column file name
+	column_file_name = build_column_file_name((column->header)->name, (column->header)->version);
+	if (column_file_name == NULL)
+	{
+		return -1;
+	}
+
+	// Open the column file
+	column_file_descriptor = openat(column_dir_file_descriptor, column_file_name, O_RDWR | O_CREAT);
+	if (column_file_descriptor < 0)
+	{
+		obi_set_errno(OBICOL_UNKNOWN_ERROR);
+		free(column_file_name);
+		return -1;
+	}
+
+	// Unmap the data before truncating the file
+	data_size = (column->header)->line_count * (column->header)->nb_elements_per_line * sizeof((column->header)->data_type);
+	if (munmap(column->data, data_size) < 0)
+	{
+		obi_set_errno(OBICOL_UNKNOWN_ERROR);
+		obidebug(1, "\nError munmapping the data of a column before truncating");
+		free(column_file_name);
+		close(column_file_descriptor);
+		return -1;
+	}
+
+	// Truncate the column file at the number of lines used
+	data_size = (column->header)->lines_used * (column->header)->nb_elements_per_line * sizeof((column->header)->data_type);
+	file_size = (column->header)->header_size + data_size;
+	if (ftruncate(column_file_descriptor, file_size) < 0)
+	{
+		obi_set_errno(OBICOL_UNKNOWN_ERROR);
+		obidebug(1, "\nError truncating a column file at the number of lines used");
+		free(column_file_name);
+		close(column_file_descriptor);
+		return -1;
+	}
+
+	// Remap the data
+	column->data   			 = mmap(NULL,
+			                 	 	data_size,
+			                 	 	PROT_READ | PROT_WRITE,
+			                 	 	MAP_SHARED,
+			                 	 	column_file_descriptor,
+									(column->header)->header_size
+			                		);
+
+	if (column->data == MAP_FAILED)
+	{
+		obi_set_errno(OBICOL_UNKNOWN_ERROR);
+		obidebug(1, "\nError re-mmapping the data of a column after truncating");
+		free(column_file_name);
+		close(column_file_descriptor);
+		return -1;
+	}
+
+	// Set line_count to lines_used
+	(column->header)->line_count = (column->header)->lines_used;
+
+	free(column_file_name);
+	close(column_file_descriptor);
+
+	return 0;
+}
+
+
+int obi_truncate_and_close_column(OBIDMS_column_p column)
+{
+	if (obi_truncate_column_to_lines_used(column) < 0)
+		return -1;
+	if (obi_close_column(column) < 0)
+		return -1;
+
 	return 0;
 }