static USAGE: &str = r#"
Pseudonymise the value of a given column by replacing it with an
incremental identifier. See https://en.wikipedia.org/wiki/Pseudonymization
Once a value is pseudonymised, it will always be replaced with the same
identifier. This means that the same value will always be replaced with
the same identifier, even if it appears in different rows.
The incremental identifier is generated by using the given format string
and the starting number and increment.
EXAMPLE:
Pseudonymise the value of the "Name" column by replacing it with an
incremental identifier starting at 1000 and incrementing by 5:
$ qsv pseudo Name --start 1000 --increment 5 --fmtstr "ID-{}" data.csv
If run on the following CSV data:
Name,Color
Mary,yellow
John,blue
Mary,purple
Sue,orange
John,magenta
Mary,cyan
will replace the value of the "Name" column with the following values:
Name,Color
ID-1000,yellow
ID-1005,blue
ID-1000,purple
ID-1010,orange
ID-1005,magenta
ID-1000,cyan
For more examples, see https://github.com/dathere/qsv/blob/master/tests/test_pseudo.rs.
Usage:
qsv pseudo [options] <column> [<input>]
qsv pseudo --help
pseudo arguments:
<column> The column to pseudonymise. You can use the `--select`
option to select the column by name or index.
See `select` command for more details.
<input> The CSV file to read from. If not specified, then
the input will be read from stdin.
Common options:
-h, --help Display this message
--start <number> The starting number for the incremental identifier.
[default: 0]
--increment <number> The increment for the incremental identifier.
[default: 1]
--formatstr <template> The format string for the incremental identifier.
The format string must contain a single "{}" which
will be replaced with the incremental identifier.
[default: {}]
-o, --output <file> Write output to <file> instead of stdout.
-n, --no-headers When set, the first row will not be interpreted
as headers.
-d, --delimiter <arg> The field delimiter for reading CSV data.
Must be a single character. (default: ,)
"#;
use dynfmt2::Format;
use foldhash::{HashMap, HashMapExt};
use serde::Deserialize;
use crate::{
CliResult,
config::{Config, Delimiter},
select::SelectColumns,
util,
util::replace_column_value,
};
#[derive(Deserialize)]
struct Args {
arg_column: SelectColumns,
arg_input: Option<String>,
flag_start: u64,
flag_increment: u64,
flag_formatstr: String,
flag_output: Option<String>,
flag_no_headers: bool,
flag_delimiter: Option<Delimiter>,
}
type Values = HashMap<String, String>;
type ValuesNum = HashMap<String, u64>;
pub fn run(argv: &[&str]) -> CliResult<()> {
let args: Args = util::get_args(USAGE, argv)?;
let rconfig = Config::new(args.arg_input.as_ref())
.delimiter(args.flag_delimiter)
.no_headers_flag(args.flag_no_headers)
.select(args.arg_column);
let mut rdr = rconfig.reader()?;
let mut wtr = Config::new(args.flag_output.as_ref()).writer()?;
let headers = rdr.byte_headers()?.clone();
let column_index = match rconfig.selection(&headers) {
Ok(sel) => {
let sel_len = sel.len();
if sel_len > 1 {
return fail_incorrectusage_clierror!(
"{sel_len} columns selected. Only one column can be selected for \
pseudonymisation."
);
}
*sel.iter().next().unwrap()
},
Err(e) => return fail_clierror!("{e}"),
};
if !rconfig.no_headers {
wtr.write_record(&headers)?;
}
let mut record = csv::StringRecord::new();
let mut counter: u64 = args.flag_start;
let increment = args.flag_increment;
let mut curr_counter: u64 = 0;
let mut overflowed = false;
if args.flag_formatstr == "{}" {
let mut values_num = ValuesNum::with_capacity(1000);
while rdr.read_record(&mut record)? {
let value = record[column_index].to_owned();
let new_value = values_num.entry(value.clone()).or_insert_with(|| {
curr_counter = counter;
(counter, overflowed) = counter.overflowing_add(increment);
curr_counter
});
if overflowed {
return fail_incorrectusage_clierror!(
"Overflowed. The counter is larger than u64::MAX {}. The last valid counter \
is {curr_counter}.",
u64::MAX
);
}
record = replace_column_value(&record, column_index, &new_value.to_string());
wtr.write_record(&record)?;
}
} else {
if !args.flag_formatstr.contains("{}")
|| dynfmt2::SimpleCurlyFormat
.format(&args.flag_formatstr, [0])
.is_err()
{
return fail_incorrectusage_clierror!(
"Invalid format string: \"{}\". The format string must contain a single \"{{}}\" \
which will be replaced with the incremental identifier.",
args.flag_formatstr
);
}
let mut values = Values::with_capacity(1000);
while rdr.read_record(&mut record)? {
let value = record[column_index].to_owned();
let new_value = values.entry(value.clone()).or_insert_with(|| {
curr_counter = counter;
(counter, overflowed) = counter.overflowing_add(increment);
dynfmt2::SimpleCurlyFormat
.format(&args.flag_formatstr, [curr_counter])
.unwrap()
.to_string()
});
if overflowed {
return fail_incorrectusage_clierror!(
"Overflowed. The counter is larger than u64::MAX({}). The last valid counter \
is {curr_counter}.",
u64::MAX
);
}
record = replace_column_value(&record, column_index, new_value);
wtr.write_record(&record)?;
}
}
Ok(wtr.flush()?)
}