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