YADF — Yet Another Dupes Finder

It's fast on my machine.

Installation

Prebuilt Packages

Executable binaries for some platforms are available in the releases section.

Building from source

1. Install Rust Toolchain
2. Run cargo install yadf

Usage

yadf defaults:

• search current working directory $PWD
• output format is the same as the "standard" fdupes, newline separated groups
• descends automatically into subdirectories
• search includes every files (including empty files)

yadf # find duplicate files in current directory
yadf ~/Documents ~/Pictures # find duplicate files in two directories
yadf --depth 0 file1 file2 # compare two files
yadf --depth 1 # find duplicates in current directory without descending
fd --type d a | yadf --depth 1 # find directories with an "a" and search them for duplicates without descending
fd --type f a | yadf # find files with an "a" and check them for duplicates

Filtering

yadf --min 100M # find duplicate files of at least 100 MB
yadf --max 100M # find duplicate files below 100 MB
yadf --pattern '*.jpg' # find duplicate jpg
yadf --regex '^g' # find duplicate starting with 'g'
yadf --rfactor over:10 # find files with more than 10 copies
yadf --rfactor under:10 # find files with less than 10 copies
yadf --rfactor equal:1 # find unique files

Formatting

Look up the help for a list of output formats yadf -h.

yadf -f json
yadf -f fdupes
yadf -f csv
yadf -f ldjson

Help output.

yadf 0.13.1
Yet Another Dupes Finder

USAGE:
    yadf [FLAGS] [OPTIONS] [paths]...

FLAGS:
    -H, --hard-links    Treat hard links to same file as duplicates
    -h, --help          Prints help information
    -n, --no-empty      Excludes empty files
    -q, --quiet         Pass many times for less log output
    -V, --version       Prints version information
    -v, --verbose       Pass many times for more log output

OPTIONS:
    -a, --algorithm <algorithm>    Hashing algorithm [default: AHash]  [possible values: AHash,
                                   Highway, MetroHash, SeaHash, XxHash]
    -f, --format <format>          Output format [default: Fdupes]  [possible values: Csv, Fdupes,
                                   Json, JsonPretty, LdJson, Machine]
        --max <size>               Maximum file size
    -d, --depth <depth>            Maximum recursion depth
        --min <size>               Minimum file size
    -p, --pattern <glob>           Check files with a name matching a glob pattern, see:
                                   https://docs.rs/globset/0.4.6/globset/index.html#syntax
    -R, --regex <regex>            Check files with a name matching a Perl-style regex, see:
                                   https://docs.rs/regex/1.4.2/regex/index.html#syntax
        --rfactor <rfactor>        Replication factor [under|equal|over]:n

ARGS:
    <paths>...    Directories to search

For sizes, K/M/G/T[B|iB] suffixes can be used (case-insensitive).

Notes on the algorithm

Most¹ dupe finders follow a 3 steps algorithm:

1. group files by their size
2. group files by their first few bytes
3. group files by their entire content

yadf skips the first step, and only does the steps 2 and 3, preferring hashing rather than byte comparison. In my tests having the first step on a SSD actually slowed down the program. yadf makes heavy use of the standard library BTreeMap, it uses a cache aware implementation avoiding too many cache misses. yadf uses the parallel walker provided by ignore (disabling its ignore features) and rayon's parallel iterators to do each of these 2 steps in parallel.

¹: some need a different algorithm to support different features or different performance trade-offs

Design goals

I sought out to build a high performing artefact by assembling together libraries doing the actual work, nothing here is custom made, it's all "off-the-shelf" software.

Benchmarks

The performance of yadf is heavily tied to the hardware, specifically the NVMe SSD. I recommend fclones as it has more hardware heuristics. and in general more features.

My home directory contains upwards of 700k paths and 39 GB of data, and is probably a pathological case of file duplication with all the node_modules, python virtual environments, rust target, etc. Arguably, the most important measure here is the mean time when the filesystem cache is cold.

Program (warm filesystem cache)	Version	Mean [s]	Min [s]	Max [s]	Relative
fclones	0.8.0	4.107 ± 0.045	4.065	4.189	1.58 ± 0.04
jdupes	1.14.0	11.982 ± 0.038	11.924	12.030	4.60 ± 0.11
ddh	0.11.3	10.602 ± 0.062	10.521	10.678	4.07 ± 0.10
rmlint	2.9.0	17.640 ± 0.119	17.426	17.833	6.77 ± 0.17
dupe-krill	1.4.4	9.110 ± 0.040	9.053	9.154	3.50 ± 0.08
fddf	1.7.0	5.630 ± 0.049	5.562	5.717	2.16 ± 0.05
yadf	0.14.1	2.605 ± 0.062	2.517	2.676	1.00

Program (cold filesystem cache)	Version	Mean [s]
fclones	0.8.0	19.452
jdupes	1.14.0	129.132
ddh	0.11.3	27.241
rmlint	2.9.0	67.580
dupe-krill	1.4.4	127.860
fddf	1.7.0	32.661
yadf	0.13.1	21.554

fdupes is excluded from this benchmark because it's really slow.

The script used to benchmark can be read here.

Hardware used.

Extract from neofetch and hwinfo --disk:

• OS: Ubuntu 20.04.1 LTS x86_64
• Host: XPS 15 9570
• Kernel: 5.4.0-42-generic
• CPU: Intel i9-8950HK (12) @ 4.800GHz
• Memory: 4217MiB / 31755MiB
• Disk:
  • model: "SK hynix Disk"
  • driver: "nvme"