Create the diff -y utility, this time introducing tests and changes focused
mainly on the construction of the utility and issues related to alignment
and response tabulation. New parameters were introduced such as the size
of the total width of the output in the parameters. A new calculation was
introduced to determine the size of the output columns and the maximum
total column size. The tab and spacing mechanism has the same behavior
as the original diff, with tabs and spaces formatted in the same way.
- Introducing tests for the diff 'main' function
- Introducing fuzzing for side diff utility
- Introducing tests for internal mechanisms
- Modular functions that allow consistent changes across the entire project
- Create the function, in the utils package, limited_string that allows you to truncate a string based on a
delimiter (May break the encoding of the character where it was cut)
- Create tests for limited_string function
- Add support for -y and --side-by-side flags that enables diff output for side-by-side mode
- Create implementation of the diff -y (SideBySide) command, base command for sdiff, using the crate
diff as engine. Currently it does not fully represent GNU diff -y, some flags (|, (, ), , /) could
not be developed due to the limitation of the engine we currently use (crate diff), which did not
allow perform logic around it. Only the use of '<' and '>' were enabled.
- Create tests for SideBySide implementation
The utility should support all the arguments supported by GNU cmp and
perform slightly better.
On a "bad" scenario, ~36M files which are completely different, our
version runs in ~72% of the time of the original on my M1 Max:
> hyperfine --warmup 1 -i --output=pipe \
'cmp -l huge huge.3'
Benchmark 1: cmp -l huge huge.3
Time (mean ± σ): 3.237 s ± 0.014 s [User: 2.891 s, System: 0.341 s]
Range (min … max): 3.221 s … 3.271 s 10 runs
Warning: Ignoring non-zero exit code.
> hyperfine --warmup 1 -i --output=pipe \
'../target/release/diffutils cmp -l huge huge.3'
Benchmark 1: ../target/release/diffutils cmp -l huge huge.3
Time (mean ± σ): 2.392 s ± 0.009 s [User: 1.978 s, System: 0.406 s]
Range (min … max): 2.378 s … 2.406 s 10 runs
Warning: Ignoring non-zero exit code.
Our cmp runs in ~116% of the time when comparing libxul.so to the
chromium-browser binary with -l and -b. In a best case scenario of
comparing 2 files which are the same except for the last byte, our
tool is slightly faster.
This is in preparation for adding the other diffutils commands, cmp,
diff3, sdiff.
We use a similar strategy to uutils/coreutils, with the single binary
acting as one of the supported tools if called through a symlink with
the appropriate name. When using the multi-tool binary directly, the
utility needds to be the first parameter.
Sami Daniel (Tsoi)