diff options
Diffstat (limited to 'vendor/github.com/opencontainers/selinux/pkg')
4 files changed, 165 insertions, 2 deletions
diff --git a/vendor/github.com/opencontainers/selinux/pkg/pwalk/README.md b/vendor/github.com/opencontainers/selinux/pkg/pwalk/README.md index 16c4dfd3e..7e78dce01 100644 --- a/vendor/github.com/opencontainers/selinux/pkg/pwalk/README.md +++ b/vendor/github.com/opencontainers/selinux/pkg/pwalk/README.md @@ -8,6 +8,12 @@ By default, it utilizes 2\*runtime.NumCPU() goroutines for callbacks. This can be changed by using WalkN function which has the additional parameter, specifying the number of goroutines (concurrency). +### pwalk vs pwalkdir + +This package is deprecated in favor of +[pwalkdir](https://pkg.go.dev/github.com/opencontainers/selinux/pkg/pwalkdir), +which is faster, but requires at least Go 1.16. + ### Caveats Please note the following limitations of this code: diff --git a/vendor/github.com/opencontainers/selinux/pkg/pwalk/pwalk.go b/vendor/github.com/opencontainers/selinux/pkg/pwalk/pwalk.go index a8088a196..011fe862a 100644 --- a/vendor/github.com/opencontainers/selinux/pkg/pwalk/pwalk.go +++ b/vendor/github.com/opencontainers/selinux/pkg/pwalk/pwalk.go @@ -19,7 +19,7 @@ type WalkFunc = filepath.WalkFunc // // Note that this implementation only supports primitive error handling: // -// - no errors are ever passed to WalkFn; +// - no errors are ever passed to walkFn; // // - once a walkFn returns any error, all further processing stops // and the error is returned to the caller of Walk; @@ -95,7 +95,7 @@ func WalkN(root string, walkFn WalkFunc, num int) error { return err } -// walkArgs holds the arguments that were passed to the Walk or WalkLimit +// walkArgs holds the arguments that were passed to the Walk or WalkN // functions. type walkArgs struct { path string diff --git a/vendor/github.com/opencontainers/selinux/pkg/pwalkdir/README.md b/vendor/github.com/opencontainers/selinux/pkg/pwalkdir/README.md new file mode 100644 index 000000000..068ac4005 --- /dev/null +++ b/vendor/github.com/opencontainers/selinux/pkg/pwalkdir/README.md @@ -0,0 +1,54 @@ +## pwalkdir: parallel implementation of filepath.WalkDir + +This is a wrapper for [filepath.WalkDir](https://pkg.go.dev/path/filepath#WalkDir) +which may speed it up by calling multiple callback functions (WalkDirFunc) +in parallel, utilizing goroutines. + +By default, it utilizes 2\*runtime.NumCPU() goroutines for callbacks. +This can be changed by using WalkN function which has the additional +parameter, specifying the number of goroutines (concurrency). + +### pwalk vs pwalkdir + +This package is very similar to +[pwalk](https://pkg.go.dev/github.com/opencontainers/selinux/pkg/pwalkdir), +but utilizes `filepath.WalkDir` (added to Go 1.16), which does not call stat(2) +on every entry and is therefore faster (up to 3x, depending on usage scenario). + +Users who are OK with requiring Go 1.16+ should switch to this +implementation. + +### Caveats + +Please note the following limitations of this code: + +* Unlike filepath.WalkDir, the order of calls is non-deterministic; + +* Only primitive error handling is supported: + + * fs.SkipDir is not supported; + + * no errors are ever passed to WalkDirFunc; + + * once any error is returned from any walkDirFunc instance, no more calls + to WalkDirFunc are made, and the error is returned to the caller of WalkDir; + + * if more than one WalkDirFunc instance will return an error, only one + of such errors will be propagated to and returned by WalkDir, others + will be silently discarded. + +### Documentation + +For the official documentation, see +https://pkg.go.dev/github.com/opencontainers/selinux/pkg/pwalkdir + +### Benchmarks + +For a WalkDirFunc that consists solely of the return statement, this +implementation is about 15% slower than the standard library's +filepath.WalkDir. + +Otherwise (if a WalkDirFunc is actually doing something) this is usually +faster, except when the WalkDirN(..., 1) is used. Run `go test -bench .` +to see how different operations can benefit from it, as well as how the +level of paralellism affects the speed. diff --git a/vendor/github.com/opencontainers/selinux/pkg/pwalkdir/pwalkdir.go b/vendor/github.com/opencontainers/selinux/pkg/pwalkdir/pwalkdir.go new file mode 100644 index 000000000..222820750 --- /dev/null +++ b/vendor/github.com/opencontainers/selinux/pkg/pwalkdir/pwalkdir.go @@ -0,0 +1,103 @@ +// +build go1.16 + +package pwalkdir + +import ( + "fmt" + "io/fs" + "path/filepath" + "runtime" + "sync" +) + +// Walk is a wrapper for filepath.WalkDir which can call multiple walkFn +// in parallel, allowing to handle each item concurrently. A maximum of +// twice the runtime.NumCPU() walkFn will be called at any one time. +// If you want to change the maximum, use WalkN instead. +// +// The order of calls is non-deterministic. +// +// Note that this implementation only supports primitive error handling: +// +// - no errors are ever passed to walkFn; +// +// - once a walkFn returns any error, all further processing stops +// and the error is returned to the caller of Walk; +// +// - filepath.SkipDir is not supported; +// +// - if more than one walkFn instance will return an error, only one +// of such errors will be propagated and returned by Walk, others +// will be silently discarded. +func Walk(root string, walkFn fs.WalkDirFunc) error { + return WalkN(root, walkFn, runtime.NumCPU()*2) +} + +// WalkN is a wrapper for filepath.WalkDir which can call multiple walkFn +// in parallel, allowing to handle each item concurrently. A maximum of +// num walkFn will be called at any one time. +// +// Please see Walk documentation for caveats of using this function. +func WalkN(root string, walkFn fs.WalkDirFunc, num int) error { + // make sure limit is sensible + if num < 1 { + return fmt.Errorf("walk(%q): num must be > 0", root) + } + + files := make(chan *walkArgs, 2*num) + errCh := make(chan error, 1) // Get the first error, ignore others. + + // Start walking a tree asap. + var ( + err error + wg sync.WaitGroup + ) + wg.Add(1) + go func() { + err = filepath.WalkDir(root, func(p string, entry fs.DirEntry, err error) error { + if err != nil { + close(files) + return err + } + // Add a file to the queue unless a callback sent an error. + select { + case e := <-errCh: + close(files) + return e + default: + files <- &walkArgs{path: p, entry: entry} + return nil + } + }) + if err == nil { + close(files) + } + wg.Done() + }() + + wg.Add(num) + for i := 0; i < num; i++ { + go func() { + for file := range files { + if e := walkFn(file.path, file.entry, nil); e != nil { + select { + case errCh <- e: // sent ok + default: // buffer full + } + } + } + wg.Done() + }() + } + + wg.Wait() + + return err +} + +// walkArgs holds the arguments that were passed to the Walk or WalkN +// functions. +type walkArgs struct { + path string + entry fs.DirEntry +} |