mirror of https://github.com/cheat/cheat.git
73 lines
2.4 KiB
Go
73 lines
2.4 KiB
Go
package sheets
|
|
|
|
import (
|
|
"fmt"
|
|
"os"
|
|
"strings"
|
|
)
|
|
|
|
// isGitDir returns `true` if `path` is within a `.git` directory, or `false`
|
|
// otherwise
|
|
func isGitDir(path string) (bool, error) {
|
|
|
|
/*
|
|
A bit of context is called for here, because this functionality has
|
|
previously caused a number of tricky, subtle bugs.
|
|
|
|
Fundamentally, here we are simply trying to avoid walking over the
|
|
contents of the `.git` directory. Doing so potentially makes
|
|
hundreds/thousands of needless syscalls, and can noticeably harm
|
|
performance on machines with slow disks.
|
|
|
|
The earliest effort to solve this problem involved simply returning
|
|
`fs.SkipDir` when the cheatsheet file path began with `.`, signifying a
|
|
hidden directory. This, however, caused two problems:
|
|
|
|
1. The `.cheat` directory was ignored
|
|
2. Cheatsheets installed by `brew` (which were by default installed to
|
|
`~/.config/cheat`) were ignored
|
|
|
|
See: https://github.com/cheat/cheat/issues/690
|
|
|
|
To remedy this, the exclusion criteria were narrowed, and the search
|
|
for a literal `.` was replaced with a search for a literal `.git`.
|
|
This, however, broke user installations that stored cheatsheets in
|
|
`git` submodules, because such an installation would contain a `.git`
|
|
file that pointed to the upstream repository.
|
|
|
|
See: https://github.com/cheat/cheat/issues/694
|
|
|
|
Accounting for all of the above, we are now searching for the presence
|
|
of a `.git` literal string in the cheatsheet file path. If it is not
|
|
found, we continue to walk the directory, as before.
|
|
|
|
If it *is* found, we determine if `.git` refers to a file or directory,
|
|
and only stop walking the path in the latter case.
|
|
*/
|
|
|
|
// determine if the literal string `.git` appears within `path`
|
|
pos := strings.Index(path, ".git")
|
|
|
|
// if it does not, we know for certain that we are not within a `.git`
|
|
// directory.
|
|
if pos == -1 {
|
|
return false, nil
|
|
}
|
|
|
|
// If `path` does contain the string `.git`, we need to determine if we're
|
|
// inside of a `.git` directory, or if `path` points to a cheatsheet that's
|
|
// stored within a `git` submodule.
|
|
//
|
|
// See: https://github.com/cheat/cheat/issues/694
|
|
|
|
// truncate `path` to the occurrence of `.git`
|
|
f, err := os.Stat(path[:pos+4])
|
|
if err != nil {
|
|
return false, fmt.Errorf("failed to stat path %s: %v", path, err)
|
|
}
|
|
|
|
// return true or false depending on whether the truncated path is a
|
|
// directory
|
|
return f.Mode().IsDir(), nil
|
|
}
|