This commit adds a simple `.exists()` check for `.gitignore`, `.ignore`, and other similar files before actually calling `File::open(…)` in `GitIgnoreBuilder::add`. The reason is that a simple existence check via `stat` can be faster than actually trying to `open` the file, see https://stackoverflow.com/a/12774387/704831. As we typically expect(?) the number of directories *without* ignore files to be much larger than the number of directories *with* ignore files, this leads to an overall speedup. The performance gain is not huge for `rg`, but can be quite significant if more `.gitignore`-like files are added via `add_custom_ignore_filename`. The speedup is *larger* for folders with *low* files-per-directory ratios. Note though that we do not do this check on Windows until a specific analysis there suggests this is beneficial. Namely, Windows generally has slower file system operations, so it's not clear whether this speculative check is actually a benefit or not. Benchmark results ----------------- `rg --files` in my home folder (200k results, 6.5 files per directory): | Command | Mean [ms] | Min [ms] | Max [ms] | Relative | |:---|---:|---:|---:|---:| | `./rg-master --files` | 396.4 ± 3.2 | 390.9 | 400.0 | 1.05 | | `./rg-feature --files` | 376.0 ± 3.6 | 369.3 | 383.5 | 1.00 | `rg --files --hidden` in my home folder (800k results, 5.4 files per directory) | Command | Mean [s] | Min [s] | Max [s] | Relative | |:---|---:|---:|---:|---:| | `./rg-master --files --hidden` | 1.575 ± 0.012 | 1.560 | 1.597 | 1.06 | | `./rg-feature --files --hidden` | 1.479 ± 0.011 | 1.464 | 1.496 | 1.00 | `rg --files` in the chromium-79.0.3915.2 source tree (300k results, 12.7 files per directory) | Command | Mean [ms] | Min [ms] | Max [ms] | Relative | |:---|---:|---:|---:|---:| | `~/rg-master --files` | 445.2 ± 5.3 | 435.6 | 453.0 | 1.04 | | `~/rg-feature --files` | 428.9 ± 7.0 | 418.2 | 440.0 | 1.00 | `rg --files` in the linux-5.3 source tree (65k results, 15.1 files per directory) | Command | Mean [ms] | Min [ms] | Max [ms] | Relative | |:---|---:|---:|---:|---:| | `./rg-master --files` | 94.5 ± 1.9 | 89.8 | 98.5 | 1.02 | | `./rg-feature --files` | 92.6 ± 2.7 | 88.4 | 98.7 | 1.00 | Closes #1381
ignore
The ignore crate provides a fast recursive directory iterator that respects
various filters such as globs, file types and .gitignore
files. This crate
also provides lower level direct access to gitignore and file type matchers.
Dual-licensed under MIT or the UNLICENSE.
Documentation
Usage
Add this to your Cargo.toml
:
[dependencies]
ignore = "0.4"
and this to your crate root:
extern crate ignore;
Example
This example shows the most basic usage of this crate. This code will
recursively traverse the current directory while automatically filtering out
files and directories according to ignore globs found in files like
.ignore
and .gitignore
:
use ignore::Walk;
for result in Walk::new("./") {
// Each item yielded by the iterator is either a directory entry or an
// error, so either print the path or the error.
match result {
Ok(entry) => println!("{}", entry.path().display()),
Err(err) => println!("ERROR: {}", err),
}
}
Example: advanced
By default, the recursive directory iterator will ignore hidden files and
directories. This can be disabled by building the iterator with WalkBuilder
:
use ignore::WalkBuilder;
for result in WalkBuilder::new("./").hidden(false).build() {
println!("{:?}", result);
}
See the documentation for WalkBuilder
for many other options.