* ls: Remove allocations by eliminating collect/clones
* ls: Introduce PathData structure
- PathData will hold Path related metadata / strings that are required
frequently in subsequent functions
- All data is precomputed and cached and subsequent functions just
use cached data
* ls: Cache more data related to paths
- Cache filename and sort by filename instead of full path
- Cache uid->usr and gid->grp mappings
https://github.com/uutils/coreutils/pull/2099/files
* ls: Add BENCHMARKING.md
* ls: Document PathData structure
* tests/ls: Add testcase for error paths with width option
* ls: Fix unused import warning
cached will be only used for unix currently as current use of
caching gid/uid mappings is only relevant on unix
* ls: Suggest checking syscall count in BENCHMARKING.md
* ls: Remove mentions of sort in BENCHMARKING.md
* ls: Remove dependency on cached
Implement caching using HashMap and lazy_static
* ls: Fix MSRV error related to map_or
Rust 1.40 did not support map_or for result types
Trailing separators were included at the end of the last token, but they
should not be.
This changes tokenize_with_separator as suggested by @cbjadwani.
GNU sort disallows these combinations, presumably because they are
likely not what the user really wants.
Ignoring characters would cause things to be put together that aren't
together in the input. For example, -dn would cause "0.12" or "0,12" to
be parsed as "12" which is highly unexpected and confusing.
* sort: use unstable sort when possible
This results in a very minor performance (speed) improvement.
It does however result in a memory usage reduction, because unstable
sort does not allocate auxiliary memory. There's also an improvement in
overall CPU usage.
* add benchmarking instructions
* add user time
* fix typo
* sort: implement numeric string comparison
This implements -n and -h using a string comparison algorithm instead
of parsing each number to a f64 and comparing those.
This should result in a moderate performance increase and eliminate loss
of precision.
* cache parsed f64 numbers
For general numeric comparisons we have to parse numbers as f64,
as this behavior is explicitly documented by GNU coreutils.
We can however cache the parsed value to speed up comparisons.
* fix leading zeroes for negative numbers
* use more appropriate name for exponent
* improvements to the parse function
* move checks into main loop and fix thousands separator condition
* remove unneeded checks
* rustfmt
