TUN-7373: Streaming logs override for same actor

To help accommodate web browser interactions with websockets, when a
streaming logs session is requested for the same actor while already
serving a session for that user in a separate request, the original
request will be closed and the new request start streaming logs
instead. This should help with rogue sessions holding on for too long
with no client on the other side (before idle timeout or connection
close).

vendor/golang.org/x/tools/internal/imports/fix.go

@@ -697,6 +697,9 @@ func candidateImportName(pkg *pkg) string {
 
 // GetAllCandidates calls wrapped for each package whose name starts with
 // searchPrefix, and can be imported from filename with the package name filePkg.
+//
+// Beware that the wrapped function may be called multiple times concurrently.
+// TODO(adonovan): encapsulate the concurrency.
 func GetAllCandidates(ctx context.Context, wrapped func(ImportFix), searchPrefix, filename, filePkg string, env *ProcessEnv) error {
 	callback := &scanCallback{
 		rootFound: func(gopathwalk.Root) bool {
@@ -796,7 +799,7 @@ func GetPackageExports(ctx context.Context, wrapped func(PackageExport), searchP
 	return getCandidatePkgs(ctx, callback, filename, filePkg, env)
 }
 
-var RequiredGoEnvVars = []string{"GO111MODULE", "GOFLAGS", "GOINSECURE", "GOMOD", "GOMODCACHE", "GONOPROXY", "GONOSUMDB", "GOPATH", "GOPROXY", "GOROOT", "GOSUMDB", "GOWORK"}
+var requiredGoEnvVars = []string{"GO111MODULE", "GOFLAGS", "GOINSECURE", "GOMOD", "GOMODCACHE", "GONOPROXY", "GONOSUMDB", "GOPATH", "GOPROXY", "GOROOT", "GOSUMDB", "GOWORK"}
 
 // ProcessEnv contains environment variables and settings that affect the use of
 // the go command, the go/build package, etc.
@@ -807,6 +810,11 @@ type ProcessEnv struct {
 	ModFlag    string
 	ModFile    string
 
+	// SkipPathInScan returns true if the path should be skipped from scans of
+	// the RootCurrentModule root type. The function argument is a clean,
+	// absolute path.
+	SkipPathInScan func(string) bool
+
 	// Env overrides the OS environment, and can be used to specify
 	// GOPROXY, GO111MODULE, etc. PATH cannot be set here, because
 	// exec.Command will not honor it.
@@ -861,7 +869,7 @@ func (e *ProcessEnv) init() error {
 	}
 
 	foundAllRequired := true
-	for _, k := range RequiredGoEnvVars {
+	for _, k := range requiredGoEnvVars {
 		if _, ok := e.Env[k]; !ok {
 			foundAllRequired = false
 			break
@@ -877,7 +885,7 @@ func (e *ProcessEnv) init() error {
 	}
 
 	goEnv := map[string]string{}
-	stdout, err := e.invokeGo(context.TODO(), "env", append([]string{"-json"}, RequiredGoEnvVars...)...)
+	stdout, err := e.invokeGo(context.TODO(), "env", append([]string{"-json"}, requiredGoEnvVars...)...)
 	if err != nil {
 		return err
 	}
@@ -1367,9 +1375,9 @@ func (r *gopathResolver) scan(ctx context.Context, callback *scanCallback) error
 		return err
 	}
 	var roots []gopathwalk.Root
-	roots = append(roots, gopathwalk.Root{filepath.Join(goenv["GOROOT"], "src"), gopathwalk.RootGOROOT})
+	roots = append(roots, gopathwalk.Root{Path: filepath.Join(goenv["GOROOT"], "src"), Type: gopathwalk.RootGOROOT})
 	for _, p := range filepath.SplitList(goenv["GOPATH"]) {
-		roots = append(roots, gopathwalk.Root{filepath.Join(p, "src"), gopathwalk.RootGOPATH})
+		roots = append(roots, gopathwalk.Root{Path: filepath.Join(p, "src"), Type: gopathwalk.RootGOPATH})
 	}
 	// The callback is not necessarily safe to use in the goroutine below. Process roots eagerly.
 	roots = filterRoots(roots, callback.rootFound)

vendor/golang.org/x/tools/internal/imports/mod.go

@@ -129,22 +129,22 @@ func (r *ModuleResolver) init() error {
 	})
 
 	r.roots = []gopathwalk.Root{
-		{filepath.Join(goenv["GOROOT"], "/src"), gopathwalk.RootGOROOT},
+		{Path: filepath.Join(goenv["GOROOT"], "/src"), Type: gopathwalk.RootGOROOT},
 	}
 	r.mainByDir = make(map[string]*gocommand.ModuleJSON)
 	for _, main := range r.mains {
-		r.roots = append(r.roots, gopathwalk.Root{main.Dir, gopathwalk.RootCurrentModule})
+		r.roots = append(r.roots, gopathwalk.Root{Path: main.Dir, Type: gopathwalk.RootCurrentModule})
 		r.mainByDir[main.Dir] = main
 	}
 	if vendorEnabled {
-		r.roots = append(r.roots, gopathwalk.Root{r.dummyVendorMod.Dir, gopathwalk.RootOther})
+		r.roots = append(r.roots, gopathwalk.Root{Path: r.dummyVendorMod.Dir, Type: gopathwalk.RootOther})
 	} else {
 		addDep := func(mod *gocommand.ModuleJSON) {
 			if mod.Replace == nil {
 				// This is redundant with the cache, but we'll skip it cheaply enough.
-				r.roots = append(r.roots, gopathwalk.Root{mod.Dir, gopathwalk.RootModuleCache})
+				r.roots = append(r.roots, gopathwalk.Root{Path: mod.Dir, Type: gopathwalk.RootModuleCache})
 			} else {
-				r.roots = append(r.roots, gopathwalk.Root{mod.Dir, gopathwalk.RootOther})
+				r.roots = append(r.roots, gopathwalk.Root{Path: mod.Dir, Type: gopathwalk.RootOther})
 			}
 		}
 		// Walk dependent modules before scanning the full mod cache, direct deps first.
@@ -158,7 +158,7 @@ func (r *ModuleResolver) init() error {
 				addDep(mod)
 			}
 		}
-		r.roots = append(r.roots, gopathwalk.Root{r.moduleCacheDir, gopathwalk.RootModuleCache})
+		r.roots = append(r.roots, gopathwalk.Root{Path: r.moduleCacheDir, Type: gopathwalk.RootModuleCache})
 	}
 
 	r.scannedRoots = map[gopathwalk.Root]bool{}
@@ -466,6 +466,16 @@ func (r *ModuleResolver) scan(ctx context.Context, callback *scanCallback) error
 	// We assume cached directories are fully cached, including all their
 	// children, and have not changed. We can skip them.
 	skip := func(root gopathwalk.Root, dir string) bool {
+		if r.env.SkipPathInScan != nil && root.Type == gopathwalk.RootCurrentModule {
+			if root.Path == dir {
+				return false
+			}
+
+			if r.env.SkipPathInScan(filepath.Clean(dir)) {
+				return true
+			}
+		}
+
 		info, ok := r.cacheLoad(dir)
 		if !ok {
 			return false

vendor/golang.org/x/tools/internal/imports/sortimports.go

@@ -52,6 +52,7 @@ func sortImports(localPrefix string, tokFile *token.File, f *ast.File) {
 		d.Specs = specs
 
 		// Deduping can leave a blank line before the rparen; clean that up.
+		// Ignore line directives.
 		if len(d.Specs) > 0 {
 			lastSpec := d.Specs[len(d.Specs)-1]
 			lastLine := tokFile.PositionFor(lastSpec.Pos(), false).Line