static USAGE: &str = r#"
Find the difference between two CSVs with ludicrous speed.
Note: Primary key values must be unique within each CSV file. The command will
exit with an error if duplicate keys are found.
Note that diff does not support stdin. A file path is required for both arguments.
Examples:
Find the difference between two CSVs:
qsv diff left.csv right.csv
Find the difference between two CSVs. The right CSV has no headers:
qsv diff left.csv --no-headers-right right-noheaders.csv
Find the difference between two CSVs. The left CSV uses a tab as the delimiter:
qsv diff --delimiter-left '\t' left.csv right-tab.tsv
# or ';' as the delimiter
qsv diff --delimiter-left ';' left.csv right-semicolon.csv
Find the difference between two CSVs. The output CSV uses a tab as the delimiter
and is written to a file:
qsv diff -o diff-tab.tsv --delimiter-output '\t' left.csv right.csv
# or ';' as the delimiter
qsv diff -o diff-semicolon.csv --delimiter-output ';' left.csv right.csv
Find the difference between two CSVs, comparing records that have the same values
in the first two columns:
qsv diff --key 0,1 left.csv right.csv
Find the difference between two CSVs, comparing records that have the same values
in the first two columns and sort the result by the first two columns:
qsv diff -k 0,1 --sort-columns 0,1 left.csv right.csv
Find the difference between two CSVs, but do not output equal field values
in the result (equal field values are replaced with the empty string). Key
field values _will_ appear in the output:
qsv diff --drop-equal-fields left.csv right.csv
Find the difference between two CSVs, but do not output headers in the result:
qsv diff --no-headers-output left.csv right.csv
Find the difference between two CSVs. Both CSVs have no headers, but the result should have
headers, so generic headers will be used in the form of: _col_1, _col_2, etc.:
qsv diff --no-headers-left --no-headers-right left.csv right.csv
For more examples, see https://github.com/dathere/qsv/blob/master/tests/test_diff.rs
Usage:
qsv diff [options] [<input-left>] [<input-right>]
qsv diff --help
diff options:
--no-headers-left When set, the first row will be considered as part of
the left CSV to diff. (When not set, the
first row is the header row and will be skipped during
the diff. It will always appear in the output.)
--no-headers-right When set, the first row will be considered as part of
the right CSV to diff. (When not set, the
first row is the header row and will be skipped during
the diff. It will always appear in the output.)
--no-headers-output When set, the diff result won't have a header row in
its output. If not set and both CSVs have no headers,
headers in the result will be: _col_1,_col_2, etc.
--delimiter-left <arg> The field delimiter for reading CSV data on the left.
Must be a single character. (default: ,)
--delimiter-right <arg> The field delimiter for reading CSV data on the right.
Must be a single character. (default: ,)
--delimiter-output <arg> The field delimiter for writing the CSV diff result.
Must be a single character. (default: ,)
-k, --key <arg...> The column indices that uniquely identify a record
as a comma separated list of indices, e.g. 0,1,2
or column names, e.g. name,age.
Note that when selecting columns by name, only the
left CSV's headers are used to match the column names
and it is assumed that the right CSV has the same
selected column names in the same order as the left CSV.
(default: 0)
--sort-columns <arg...> The column indices by which the diff result should be
sorted as a comma separated list of indices, e.g. 0,1,2
or column names, e.g. name,age.
Records in the diff result that are marked as "modified"
("delete" and "add" records that have the same key,
but have different content) will always be kept together
in the sorted diff result and so won't be sorted
independently from each other.
Note that when selecting columns by name, only the
left CSV's headers are used to match the column names
and it is assumed that the right CSV has the same
selected column names in the same order as the left CSV.
--drop-equal-fields Drop values of equal fields in modified rows of the CSV
diff result (and replace them with the empty string).
Key field values will not be dropped.
-j, --jobs <arg> The number of jobs to run in parallel.
When not set, the number of jobs is set to the number
of CPUs detected.
Common options:
-h, --help Display this message
-o, --output <file> Write output to <file> instead of stdout.
-d, --delimiter <arg> Set ALL delimiters to this character.
Overrides --delimiter-right, --delimiter-left
and --delimiter-output.
"#;
use std::io::{self, Write};
use csv::ByteRecord;
use csv_diff::{
csv_diff::CsvByteDiffBuilder, csv_headers::Headers, diff_result::DiffByteRecords,
diff_row::DiffByteRecord,
};
use serde::Deserialize;
use super::rename::rename_headers_all_generic;
use crate::{
clitypes::CliError,
config::{Config, Delimiter},
util, CliResult,
};
#[derive(Deserialize)]
struct Args {
arg_input_left: Option<String>,
arg_input_right: Option<String>,
flag_output: Option<String>,
flag_jobs: Option<usize>,
flag_no_headers_left: bool,
flag_no_headers_right: bool,
flag_no_headers_output: bool,
flag_delimiter_left: Option<Delimiter>,
flag_delimiter_right: Option<Delimiter>,
flag_delimiter_output: Option<Delimiter>,
flag_key: Option<String>,
flag_sort_columns: Option<String>,
flag_drop_equal_fields: bool,
flag_delimiter: Option<Delimiter>,
}
pub fn run(argv: &[&str]) -> CliResult<()> {
let mut args: Args = util::get_args(USAGE, argv)?;
if let Some(delim) = args.flag_delimiter {
[
args.flag_delimiter_left,
args.flag_delimiter_right,
args.flag_delimiter_output,
] = [Some(delim); 3];
}
let rconfig_left = Config::new(args.arg_input_left.as_ref())
.delimiter(args.flag_delimiter_left)
.no_headers(args.flag_no_headers_left);
let rconfig_right = Config::new(args.arg_input_right.as_ref())
.delimiter(args.flag_delimiter_right)
.no_headers(args.flag_no_headers_right);
if rconfig_left.is_stdin() || rconfig_right.is_stdin() {
return fail_incorrectusage_clierror!(
"diff does not support stdin. A file path is required for both arguments."
);
}
let mut csv_rdr_left = rconfig_left.reader()?;
let mut csv_rdr_right = rconfig_right.reader()?;
// Get headers but keep as references
let headers_left = csv_rdr_left.byte_headers()?;
let headers_right = csv_rdr_right.byte_headers()?;
let primary_key_cols: Vec<usize> = match args.flag_key {
None => vec![0],
Some(ref s) => {
if args.flag_no_headers_left || args.flag_no_headers_right {
util::str::parse_columns(s, ',')?
} else {
let left_key_indices = s.col_names_to_indices(',', headers_left, "left")?;
let right_key_indices = s.col_names_to_indices(',', headers_right, "right")?;
if left_key_indices != right_key_indices {
return fail_clierror!("Key columns must be the same in both files");
}
left_key_indices
}
}
};
// Check for duplicates in left CSV
{
let mut seen_keys_left = std::collections::HashSet::new();
let mut rdr = rconfig_left.reader()?;
rdr.byte_headers()?; // Skip headers
for result in rdr.byte_records() {
let record = result?;
let key: Vec<&[u8]> = primary_key_cols
.iter()
.filter_map(|&idx| record.get(idx))
.collect();
if !seen_keys_left.insert(key.clone()) {
return fail_clierror!(
"Duplicate primary key found in left CSV: {}",
String::from_utf8_lossy(&key.concat())
);
}
}
}
// Check for duplicates in right CSV
{
let mut seen_keys_right = std::collections::HashSet::new();
let mut rdr = rconfig_right.reader()?;
rdr.byte_headers()?; // Skip headers
for result in rdr.byte_records() {
let record = result?;
let key: Vec<&[u8]> = primary_key_cols
.iter()
.filter_map(|&idx| record.get(idx))
.collect();
if !seen_keys_right.insert(key.clone()) {
return fail_clierror!(
"Duplicate primary key found in right CSV: {}",
String::from_utf8_lossy(&key.concat())
);
}
}
}
// Create fresh readers for the actual diff operation
csv_rdr_left = rconfig_left.reader()?;
csv_rdr_right = rconfig_right.reader()?;
csv_rdr_left.byte_headers()?;
csv_rdr_right.byte_headers()?;
let sort_cols = args
.flag_sort_columns
.map(|s| {
// check if the sort columns are a comma separated list of numbers
if s.chars().all(|c: char| c.is_numeric() || c == ',') {
s.split(',')
.map(str::parse::<usize>)
.collect::<Result<Vec<_>, _>>()
.map_err(|err| CliError::Other(err.to_string()))
} else {
// check if the sort columns is a comma separated list of column names
let left_sort_indices = s.col_names_to_indices(',', headers_left, "left")?;
// now check if the right CSV has the same selected colnames in the same locations
let right_sort_indices = s.col_names_to_indices(',', headers_right, "right")?;
if left_sort_indices != right_sort_indices {
return fail_incorrectusage_clierror!(
"Column names on left and right CSVs do not match.\nUse `qsv select` to \
reorder the columns on the right CSV to match the order of the left \
CSV.\nThe sort column indices on the left CSV are in index \
locations:\n{left_sort_indices:?}\nand on the right CSV \
are:\n{right_sort_indices:?}",
);
}
Ok(left_sort_indices)
}
})
.transpose()?;
let wtr = Config::new(args.flag_output.as_ref())
.delimiter(args.flag_delimiter_output)
.writer()?;
util::njobs(args.flag_jobs);
let Ok(csv_diff) = CsvByteDiffBuilder::new()
.primary_key_columns(primary_key_cols.clone())
.build()
else {
return fail_clierror!("Cannot instantiate diff");
};
let mut diff_byte_records = csv_diff
.diff(csv_rdr_left.into(), csv_rdr_right.into())
.try_to_diff_byte_records()?;
match sort_cols {
Some(sort_cols) => {
diff_byte_records
.sort_by_columns(sort_cols)
.map_err(|e| CliError::Other(e.to_string()))?;
},
None => {
diff_byte_records.sort_by_line();
},
}
let mut csv_diff_writer = CsvDiffWriter::new(
wtr,
args.flag_no_headers_output,
args.flag_drop_equal_fields,
primary_key_cols,
);
Ok(csv_diff_writer.write_diff_byte_records(diff_byte_records)?)
}
trait StringExt {
fn col_names_to_indices<C: Into<char>>(
&self,
col_names_split_by: C,
headers: &ByteRecord,
msg_left_or_right: &str,
) -> Result<Vec<usize>, CliError>;
}
impl StringExt for String {
fn col_names_to_indices<C: Into<char>>(
&self,
col_names_split_by: C,
headers: &ByteRecord,
msg_left_or_right: &str,
) -> Result<Vec<usize>, CliError> {
self.split(col_names_split_by.into())
.map(|col_name| {
headers
.iter()
.position(|h| h == col_name.as_bytes())
.ok_or_else(|| {
CliError::Other(format!(
"Column name '{col_name}' not found on {msg_left_or_right} CSV"
))
})
})
.collect::<Result<Vec<usize>, _>>()
}
}
struct CsvDiffWriter<W: Write> {
csv_writer: csv::Writer<W>,
no_headers: bool,
drop_equal_fields: bool,
key_fields: Vec<usize>,
}
impl<W: Write> CsvDiffWriter<W> {
fn new(
csv_writer: csv::Writer<W>,
no_headers: bool,
drop_equal_fields: bool,
key_fields: impl IntoIterator<Item = usize>,
) -> Self {
Self {
csv_writer,
no_headers,
drop_equal_fields,
key_fields: key_fields.into_iter().collect(),
}
}
fn write_headers(&mut self, headers: &Headers, num_columns: Option<&usize>) -> csv::Result<()> {
match (headers.headers_left(), headers.headers_right()) {
(Some(lbh), Some(_rbh)) => {
// currently, `diff` can only handle two CSVs that have the same
// headers ordering, so in this case we can either choose the left
// or right headers, because both are the same
if !self.no_headers {
lbh.write_diffresult_header(&mut self.csv_writer)?;
}
},
(Some(bh), None) | (None, Some(bh)) => {
if !self.no_headers {
bh.write_diffresult_header(&mut self.csv_writer)?;
}
},
(None, None) => {
if let (Some(&num_cols), false) = (num_columns.filter(|&&c| c > 0), self.no_headers)
{
let headers_generic = rename_headers_all_generic(num_cols);
let mut new_rdr = csv::Reader::from_reader(headers_generic.as_bytes());
let new_headers = new_rdr.byte_headers()?;
new_headers.write_diffresult_header(&mut self.csv_writer)?;
}
},
}
Ok(())
}
fn write_diff_byte_records(&mut self, diff_byte_records: DiffByteRecords) -> io::Result<()> {
self.write_headers(
diff_byte_records.headers(),
diff_byte_records.num_columns().as_ref(),
)?;
for dbr in diff_byte_records {
self.write_diff_byte_record(&dbr)?;
}
self.csv_writer.flush()?;
Ok(())
}
#[inline]
fn write_diff_byte_record(&mut self, diff_byte_record: &DiffByteRecord) -> csv::Result<()> {
let add_sign: &[u8] = &b"+"[..];
let remove_sign: &[u8] = &b"-"[..];
match diff_byte_record {
DiffByteRecord::Add(add) => {
let mut vec = vec![add_sign];
vec.extend(add.byte_record());
self.csv_writer.write_record(vec)
},
DiffByteRecord::Modify {
delete,
add,
field_indices,
} => {
let vec_del = if self.drop_equal_fields {
self.fill_modified_and_drop_equal_fields(
remove_sign,
delete.byte_record(),
field_indices.as_slice(),
)
} else {
let mut tmp = vec![remove_sign];
tmp.extend(delete.byte_record());
tmp
};
self.csv_writer.write_record(vec_del)?;
let vec_add = if self.drop_equal_fields {
self.fill_modified_and_drop_equal_fields(
add_sign,
add.byte_record(),
field_indices.as_slice(),
)
} else {
let mut tmp = vec![add_sign];
tmp.extend(add.byte_record());
tmp
};
self.csv_writer.write_record(vec_add)
},
DiffByteRecord::Delete(del) => {
let mut vec = vec![remove_sign];
vec.extend(del.byte_record());
self.csv_writer.write_record(vec)
},
}
}
fn fill_modified_and_drop_equal_fields<'a>(
&self,
prefix: &'a [u8],
byte_record: &'a ByteRecord,
modified_field_indices: &[usize],
) -> Vec<&'a [u8]> {
let mut vec_to_fill = {
// We start out with all fields set to an empty byte slice
// (which end up as our equal fields).
let mut tmp = vec![&b""[..]; byte_record.len() + 1 /* + 1, because we need to store our additional prefix*/];
tmp.as_mut_slice()[0] = prefix;
tmp
};
// key field values and modified field values should appear in the output
for &key_field in self.key_fields.iter().chain(modified_field_indices) {
// + 1 here, because of the prefix value (see above)
vec_to_fill[key_field + 1] = &byte_record[key_field];
}
vec_to_fill
}
}
trait WriteDiffResultHeader {
fn write_diffresult_header<W: Write>(&self, csv_writer: &mut csv::Writer<W>)
-> csv::Result<()>;
}
impl WriteDiffResultHeader for csv::ByteRecord {
fn write_diffresult_header<W: Write>(
&self,
csv_writer: &mut csv::Writer<W>,
) -> csv::Result<()> {
if !self.is_empty() {
let mut new_header = vec![&b"diffresult"[..]];
new_header.extend(self);
csv_writer.write_record(new_header)?;
}
Ok(())
}
}