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/fastwalk/fastwalk_darwin.go

@@ -0,0 +1,119 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build darwin && cgo
+// +build darwin,cgo
+
+package fastwalk
+
+/*
+#include <dirent.h>
+
+// fastwalk_readdir_r wraps readdir_r so that we don't have to pass a dirent**
+// result pointer which triggers CGO's "Go pointer to Go pointer" check unless
+// we allocat the result dirent* with malloc.
+//
+// fastwalk_readdir_r returns 0 on success, -1 upon reaching the end of the
+// directory, or a positive error number to indicate failure.
+static int fastwalk_readdir_r(DIR *fd, struct dirent *entry) {
+	struct dirent *result;
+	int ret = readdir_r(fd, entry, &result);
+	if (ret == 0 && result == NULL) {
+		ret = -1; // EOF
+	}
+	return ret;
+}
+*/
+import "C"
+
+import (
+	"os"
+	"syscall"
+	"unsafe"
+)
+
+func readDir(dirName string, fn func(dirName, entName string, typ os.FileMode) error) error {
+	fd, err := openDir(dirName)
+	if err != nil {
+		return &os.PathError{Op: "opendir", Path: dirName, Err: err}
+	}
+	defer C.closedir(fd)
+
+	skipFiles := false
+	var dirent syscall.Dirent
+	for {
+		ret := int(C.fastwalk_readdir_r(fd, (*C.struct_dirent)(unsafe.Pointer(&dirent))))
+		if ret != 0 {
+			if ret == -1 {
+				break // EOF
+			}
+			if ret == int(syscall.EINTR) {
+				continue
+			}
+			return &os.PathError{Op: "readdir", Path: dirName, Err: syscall.Errno(ret)}
+		}
+		if dirent.Ino == 0 {
+			continue
+		}
+		typ := dtToType(dirent.Type)
+		if skipFiles && typ.IsRegular() {
+			continue
+		}
+		name := (*[len(syscall.Dirent{}.Name)]byte)(unsafe.Pointer(&dirent.Name))[:]
+		name = name[:dirent.Namlen]
+		for i, c := range name {
+			if c == 0 {
+				name = name[:i]
+				break
+			}
+		}
+		// Check for useless names before allocating a string.
+		if string(name) == "." || string(name) == ".." {
+			continue
+		}
+		if err := fn(dirName, string(name), typ); err != nil {
+			if err != ErrSkipFiles {
+				return err
+			}
+			skipFiles = true
+		}
+	}
+
+	return nil
+}
+
+func dtToType(typ uint8) os.FileMode {
+	switch typ {
+	case syscall.DT_BLK:
+		return os.ModeDevice
+	case syscall.DT_CHR:
+		return os.ModeDevice | os.ModeCharDevice
+	case syscall.DT_DIR:
+		return os.ModeDir
+	case syscall.DT_FIFO:
+		return os.ModeNamedPipe
+	case syscall.DT_LNK:
+		return os.ModeSymlink
+	case syscall.DT_REG:
+		return 0
+	case syscall.DT_SOCK:
+		return os.ModeSocket
+	}
+	return ^os.FileMode(0)
+}
+
+// openDir wraps opendir(3) and handles any EINTR errors. The returned *DIR
+// needs to be closed with closedir(3).
+func openDir(path string) (*C.DIR, error) {
+	name, err := syscall.BytePtrFromString(path)
+	if err != nil {
+		return nil, err
+	}
+	for {
+		fd, err := C.opendir((*C.char)(unsafe.Pointer(name)))
+		if err != syscall.EINTR {
+			return fd, err
+		}
+	}
+}

vendor/golang.org/x/tools/internal/fastwalk/fastwalk_dirent_ino.go

@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build (linux || darwin) && !appengine
-// +build linux darwin
+//go:build (linux || (darwin && !cgo)) && !appengine
+// +build linux darwin,!cgo
 // +build !appengine
 
 package fastwalk
@@ -11,5 +11,5 @@ package fastwalk
 import "syscall"
 
 func direntInode(dirent *syscall.Dirent) uint64 {
-	return uint64(dirent.Ino)
+	return dirent.Ino
 }

vendor/golang.org/x/tools/internal/fastwalk/fastwalk_dirent_namlen_bsd.go

@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build darwin || freebsd || openbsd || netbsd
-// +build darwin freebsd openbsd netbsd
+//go:build (darwin && !cgo) || freebsd || openbsd || netbsd
+// +build darwin,!cgo freebsd openbsd netbsd
 
 package fastwalk
 

vendor/golang.org/x/tools/internal/fastwalk/fastwalk_unix.go

@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build (linux || darwin || freebsd || openbsd || netbsd) && !appengine
-// +build linux darwin freebsd openbsd netbsd
+//go:build (linux || freebsd || openbsd || netbsd || (darwin && !cgo)) && !appengine
+// +build linux freebsd openbsd netbsd darwin,!cgo
 // +build !appengine
 
 package fastwalk