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-rw-r--r--vendor/github.com/Microsoft/go-winio/internal/fs/doc.go2
-rw-r--r--vendor/github.com/Microsoft/go-winio/internal/fs/fs.go262
-rw-r--r--vendor/github.com/Microsoft/go-winio/internal/fs/security.go12
-rw-r--r--vendor/github.com/Microsoft/go-winio/internal/fs/zsyscall_windows.go61
-rw-r--r--vendor/github.com/Microsoft/go-winio/internal/socket/socket.go12
-rw-r--r--vendor/github.com/Microsoft/go-winio/internal/socket/zsyscall_windows.go9
-rw-r--r--vendor/github.com/Microsoft/go-winio/internal/stringbuffer/wstring.go132
7 files changed, 477 insertions, 13 deletions
diff --git a/vendor/github.com/Microsoft/go-winio/internal/fs/doc.go b/vendor/github.com/Microsoft/go-winio/internal/fs/doc.go
new file mode 100644
index 0000000..1f65388
--- /dev/null
+++ b/vendor/github.com/Microsoft/go-winio/internal/fs/doc.go
@@ -0,0 +1,2 @@
+// This package contains Win32 filesystem functionality.
+package fs
diff --git a/vendor/github.com/Microsoft/go-winio/internal/fs/fs.go b/vendor/github.com/Microsoft/go-winio/internal/fs/fs.go
new file mode 100644
index 0000000..0cd9621
--- /dev/null
+++ b/vendor/github.com/Microsoft/go-winio/internal/fs/fs.go
@@ -0,0 +1,262 @@
+//go:build windows
+
+package fs
+
+import (
+ "golang.org/x/sys/windows"
+
+ "github.com/Microsoft/go-winio/internal/stringbuffer"
+)
+
+//go:generate go run github.com/Microsoft/go-winio/tools/mkwinsyscall -output zsyscall_windows.go fs.go
+
+// https://learn.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfilew
+//sys CreateFile(name string, access AccessMask, mode FileShareMode, sa *windows.SecurityAttributes, createmode FileCreationDisposition, attrs FileFlagOrAttribute, templatefile windows.Handle) (handle windows.Handle, err error) [failretval==windows.InvalidHandle] = CreateFileW
+
+const NullHandle windows.Handle = 0
+
+// AccessMask defines standard, specific, and generic rights.
+//
+// Used with CreateFile and NtCreateFile (and co.).
+//
+// Bitmask:
+// 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
+// 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
+// +---------------+---------------+-------------------------------+
+// |G|G|G|G|Resvd|A| StandardRights| SpecificRights |
+// |R|W|E|A| |S| | |
+// +-+-------------+---------------+-------------------------------+
+//
+// GR Generic Read
+// GW Generic Write
+// GE Generic Exectue
+// GA Generic All
+// Resvd Reserved
+// AS Access Security System
+//
+// https://learn.microsoft.com/en-us/windows/win32/secauthz/access-mask
+//
+// https://learn.microsoft.com/en-us/windows/win32/secauthz/generic-access-rights
+//
+// https://learn.microsoft.com/en-us/windows/win32/fileio/file-access-rights-constants
+type AccessMask = windows.ACCESS_MASK
+
+//nolint:revive // SNAKE_CASE is not idiomatic in Go, but aligned with Win32 API.
+const (
+ // Not actually any.
+ //
+ // For CreateFile: "query certain metadata such as file, directory, or device attributes without accessing that file or device"
+ // https://learn.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfilew#parameters
+ FILE_ANY_ACCESS AccessMask = 0
+
+ GENERIC_READ AccessMask = 0x8000_0000
+ GENERIC_WRITE AccessMask = 0x4000_0000
+ GENERIC_EXECUTE AccessMask = 0x2000_0000
+ GENERIC_ALL AccessMask = 0x1000_0000
+ ACCESS_SYSTEM_SECURITY AccessMask = 0x0100_0000
+
+ // Specific Object Access
+ // from ntioapi.h
+
+ FILE_READ_DATA AccessMask = (0x0001) // file & pipe
+ FILE_LIST_DIRECTORY AccessMask = (0x0001) // directory
+
+ FILE_WRITE_DATA AccessMask = (0x0002) // file & pipe
+ FILE_ADD_FILE AccessMask = (0x0002) // directory
+
+ FILE_APPEND_DATA AccessMask = (0x0004) // file
+ FILE_ADD_SUBDIRECTORY AccessMask = (0x0004) // directory
+ FILE_CREATE_PIPE_INSTANCE AccessMask = (0x0004) // named pipe
+
+ FILE_READ_EA AccessMask = (0x0008) // file & directory
+ FILE_READ_PROPERTIES AccessMask = FILE_READ_EA
+
+ FILE_WRITE_EA AccessMask = (0x0010) // file & directory
+ FILE_WRITE_PROPERTIES AccessMask = FILE_WRITE_EA
+
+ FILE_EXECUTE AccessMask = (0x0020) // file
+ FILE_TRAVERSE AccessMask = (0x0020) // directory
+
+ FILE_DELETE_CHILD AccessMask = (0x0040) // directory
+
+ FILE_READ_ATTRIBUTES AccessMask = (0x0080) // all
+
+ FILE_WRITE_ATTRIBUTES AccessMask = (0x0100) // all
+
+ FILE_ALL_ACCESS AccessMask = (STANDARD_RIGHTS_REQUIRED | SYNCHRONIZE | 0x1FF)
+ FILE_GENERIC_READ AccessMask = (STANDARD_RIGHTS_READ | FILE_READ_DATA | FILE_READ_ATTRIBUTES | FILE_READ_EA | SYNCHRONIZE)
+ FILE_GENERIC_WRITE AccessMask = (STANDARD_RIGHTS_WRITE | FILE_WRITE_DATA | FILE_WRITE_ATTRIBUTES | FILE_WRITE_EA | FILE_APPEND_DATA | SYNCHRONIZE)
+ FILE_GENERIC_EXECUTE AccessMask = (STANDARD_RIGHTS_EXECUTE | FILE_READ_ATTRIBUTES | FILE_EXECUTE | SYNCHRONIZE)
+
+ SPECIFIC_RIGHTS_ALL AccessMask = 0x0000FFFF
+
+ // Standard Access
+ // from ntseapi.h
+
+ DELETE AccessMask = 0x0001_0000
+ READ_CONTROL AccessMask = 0x0002_0000
+ WRITE_DAC AccessMask = 0x0004_0000
+ WRITE_OWNER AccessMask = 0x0008_0000
+ SYNCHRONIZE AccessMask = 0x0010_0000
+
+ STANDARD_RIGHTS_REQUIRED AccessMask = 0x000F_0000
+
+ STANDARD_RIGHTS_READ AccessMask = READ_CONTROL
+ STANDARD_RIGHTS_WRITE AccessMask = READ_CONTROL
+ STANDARD_RIGHTS_EXECUTE AccessMask = READ_CONTROL
+
+ STANDARD_RIGHTS_ALL AccessMask = 0x001F_0000
+)
+
+type FileShareMode uint32
+
+//nolint:revive // SNAKE_CASE is not idiomatic in Go, but aligned with Win32 API.
+const (
+ FILE_SHARE_NONE FileShareMode = 0x00
+ FILE_SHARE_READ FileShareMode = 0x01
+ FILE_SHARE_WRITE FileShareMode = 0x02
+ FILE_SHARE_DELETE FileShareMode = 0x04
+ FILE_SHARE_VALID_FLAGS FileShareMode = 0x07
+)
+
+type FileCreationDisposition uint32
+
+//nolint:revive // SNAKE_CASE is not idiomatic in Go, but aligned with Win32 API.
+const (
+ // from winbase.h
+
+ CREATE_NEW FileCreationDisposition = 0x01
+ CREATE_ALWAYS FileCreationDisposition = 0x02
+ OPEN_EXISTING FileCreationDisposition = 0x03
+ OPEN_ALWAYS FileCreationDisposition = 0x04
+ TRUNCATE_EXISTING FileCreationDisposition = 0x05
+)
+
+// Create disposition values for NtCreate*
+type NTFileCreationDisposition uint32
+
+//nolint:revive // SNAKE_CASE is not idiomatic in Go, but aligned with Win32 API.
+const (
+ // From ntioapi.h
+
+ FILE_SUPERSEDE NTFileCreationDisposition = 0x00
+ FILE_OPEN NTFileCreationDisposition = 0x01
+ FILE_CREATE NTFileCreationDisposition = 0x02
+ FILE_OPEN_IF NTFileCreationDisposition = 0x03
+ FILE_OVERWRITE NTFileCreationDisposition = 0x04
+ FILE_OVERWRITE_IF NTFileCreationDisposition = 0x05
+ FILE_MAXIMUM_DISPOSITION NTFileCreationDisposition = 0x05
+)
+
+// CreateFile and co. take flags or attributes together as one parameter.
+// Define alias until we can use generics to allow both
+//
+// https://learn.microsoft.com/en-us/windows/win32/fileio/file-attribute-constants
+type FileFlagOrAttribute uint32
+
+//nolint:revive // SNAKE_CASE is not idiomatic in Go, but aligned with Win32 API.
+const (
+ // from winnt.h
+
+ FILE_FLAG_WRITE_THROUGH FileFlagOrAttribute = 0x8000_0000
+ FILE_FLAG_OVERLAPPED FileFlagOrAttribute = 0x4000_0000
+ FILE_FLAG_NO_BUFFERING FileFlagOrAttribute = 0x2000_0000
+ FILE_FLAG_RANDOM_ACCESS FileFlagOrAttribute = 0x1000_0000
+ FILE_FLAG_SEQUENTIAL_SCAN FileFlagOrAttribute = 0x0800_0000
+ FILE_FLAG_DELETE_ON_CLOSE FileFlagOrAttribute = 0x0400_0000
+ FILE_FLAG_BACKUP_SEMANTICS FileFlagOrAttribute = 0x0200_0000
+ FILE_FLAG_POSIX_SEMANTICS FileFlagOrAttribute = 0x0100_0000
+ FILE_FLAG_OPEN_REPARSE_POINT FileFlagOrAttribute = 0x0020_0000
+ FILE_FLAG_OPEN_NO_RECALL FileFlagOrAttribute = 0x0010_0000
+ FILE_FLAG_FIRST_PIPE_INSTANCE FileFlagOrAttribute = 0x0008_0000
+)
+
+// NtCreate* functions take a dedicated CreateOptions parameter.
+//
+// https://learn.microsoft.com/en-us/windows/win32/api/Winternl/nf-winternl-ntcreatefile
+//
+// https://learn.microsoft.com/en-us/windows/win32/devnotes/nt-create-named-pipe-file
+type NTCreateOptions uint32
+
+//nolint:revive // SNAKE_CASE is not idiomatic in Go, but aligned with Win32 API.
+const (
+ // From ntioapi.h
+
+ FILE_DIRECTORY_FILE NTCreateOptions = 0x0000_0001
+ FILE_WRITE_THROUGH NTCreateOptions = 0x0000_0002
+ FILE_SEQUENTIAL_ONLY NTCreateOptions = 0x0000_0004
+ FILE_NO_INTERMEDIATE_BUFFERING NTCreateOptions = 0x0000_0008
+
+ FILE_SYNCHRONOUS_IO_ALERT NTCreateOptions = 0x0000_0010
+ FILE_SYNCHRONOUS_IO_NONALERT NTCreateOptions = 0x0000_0020
+ FILE_NON_DIRECTORY_FILE NTCreateOptions = 0x0000_0040
+ FILE_CREATE_TREE_CONNECTION NTCreateOptions = 0x0000_0080
+
+ FILE_COMPLETE_IF_OPLOCKED NTCreateOptions = 0x0000_0100
+ FILE_NO_EA_KNOWLEDGE NTCreateOptions = 0x0000_0200
+ FILE_DISABLE_TUNNELING NTCreateOptions = 0x0000_0400
+ FILE_RANDOM_ACCESS NTCreateOptions = 0x0000_0800
+
+ FILE_DELETE_ON_CLOSE NTCreateOptions = 0x0000_1000
+ FILE_OPEN_BY_FILE_ID NTCreateOptions = 0x0000_2000
+ FILE_OPEN_FOR_BACKUP_INTENT NTCreateOptions = 0x0000_4000
+ FILE_NO_COMPRESSION NTCreateOptions = 0x0000_8000
+)
+
+type FileSQSFlag = FileFlagOrAttribute
+
+//nolint:revive // SNAKE_CASE is not idiomatic in Go, but aligned with Win32 API.
+const (
+ // from winbase.h
+
+ SECURITY_ANONYMOUS FileSQSFlag = FileSQSFlag(SecurityAnonymous << 16)
+ SECURITY_IDENTIFICATION FileSQSFlag = FileSQSFlag(SecurityIdentification << 16)
+ SECURITY_IMPERSONATION FileSQSFlag = FileSQSFlag(SecurityImpersonation << 16)
+ SECURITY_DELEGATION FileSQSFlag = FileSQSFlag(SecurityDelegation << 16)
+
+ SECURITY_SQOS_PRESENT FileSQSFlag = 0x0010_0000
+ SECURITY_VALID_SQOS_FLAGS FileSQSFlag = 0x001F_0000
+)
+
+// GetFinalPathNameByHandle flags
+//
+// https://learn.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-getfinalpathnamebyhandlew#parameters
+type GetFinalPathFlag uint32
+
+//nolint:revive // SNAKE_CASE is not idiomatic in Go, but aligned with Win32 API.
+const (
+ GetFinalPathDefaultFlag GetFinalPathFlag = 0x0
+
+ FILE_NAME_NORMALIZED GetFinalPathFlag = 0x0
+ FILE_NAME_OPENED GetFinalPathFlag = 0x8
+
+ VOLUME_NAME_DOS GetFinalPathFlag = 0x0
+ VOLUME_NAME_GUID GetFinalPathFlag = 0x1
+ VOLUME_NAME_NT GetFinalPathFlag = 0x2
+ VOLUME_NAME_NONE GetFinalPathFlag = 0x4
+)
+
+// getFinalPathNameByHandle facilitates calling the Windows API GetFinalPathNameByHandle
+// with the given handle and flags. It transparently takes care of creating a buffer of the
+// correct size for the call.
+//
+// https://learn.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-getfinalpathnamebyhandlew
+func GetFinalPathNameByHandle(h windows.Handle, flags GetFinalPathFlag) (string, error) {
+ b := stringbuffer.NewWString()
+ //TODO: can loop infinitely if Win32 keeps returning the same (or a larger) n?
+ for {
+ n, err := windows.GetFinalPathNameByHandle(h, b.Pointer(), b.Cap(), uint32(flags))
+ if err != nil {
+ return "", err
+ }
+ // If the buffer wasn't large enough, n will be the total size needed (including null terminator).
+ // Resize and try again.
+ if n > b.Cap() {
+ b.ResizeTo(n)
+ continue
+ }
+ // If the buffer is large enough, n will be the size not including the null terminator.
+ // Convert to a Go string and return.
+ return b.String(), nil
+ }
+}
diff --git a/vendor/github.com/Microsoft/go-winio/internal/fs/security.go b/vendor/github.com/Microsoft/go-winio/internal/fs/security.go
new file mode 100644
index 0000000..81760ac
--- /dev/null
+++ b/vendor/github.com/Microsoft/go-winio/internal/fs/security.go
@@ -0,0 +1,12 @@
+package fs
+
+// https://learn.microsoft.com/en-us/windows/win32/api/winnt/ne-winnt-security_impersonation_level
+type SecurityImpersonationLevel int32 // C default enums underlying type is `int`, which is Go `int32`
+
+// Impersonation levels
+const (
+ SecurityAnonymous SecurityImpersonationLevel = 0
+ SecurityIdentification SecurityImpersonationLevel = 1
+ SecurityImpersonation SecurityImpersonationLevel = 2
+ SecurityDelegation SecurityImpersonationLevel = 3
+)
diff --git a/vendor/github.com/Microsoft/go-winio/internal/fs/zsyscall_windows.go b/vendor/github.com/Microsoft/go-winio/internal/fs/zsyscall_windows.go
new file mode 100644
index 0000000..a94e234
--- /dev/null
+++ b/vendor/github.com/Microsoft/go-winio/internal/fs/zsyscall_windows.go
@@ -0,0 +1,61 @@
+//go:build windows
+
+// Code generated by 'go generate' using "github.com/Microsoft/go-winio/tools/mkwinsyscall"; DO NOT EDIT.
+
+package fs
+
+import (
+ "syscall"
+ "unsafe"
+
+ "golang.org/x/sys/windows"
+)
+
+var _ unsafe.Pointer
+
+// Do the interface allocations only once for common
+// Errno values.
+const (
+ errnoERROR_IO_PENDING = 997
+)
+
+var (
+ errERROR_IO_PENDING error = syscall.Errno(errnoERROR_IO_PENDING)
+ errERROR_EINVAL error = syscall.EINVAL
+)
+
+// errnoErr returns common boxed Errno values, to prevent
+// allocations at runtime.
+func errnoErr(e syscall.Errno) error {
+ switch e {
+ case 0:
+ return errERROR_EINVAL
+ case errnoERROR_IO_PENDING:
+ return errERROR_IO_PENDING
+ }
+ return e
+}
+
+var (
+ modkernel32 = windows.NewLazySystemDLL("kernel32.dll")
+
+ procCreateFileW = modkernel32.NewProc("CreateFileW")
+)
+
+func CreateFile(name string, access AccessMask, mode FileShareMode, sa *windows.SecurityAttributes, createmode FileCreationDisposition, attrs FileFlagOrAttribute, templatefile windows.Handle) (handle windows.Handle, err error) {
+ var _p0 *uint16
+ _p0, err = syscall.UTF16PtrFromString(name)
+ if err != nil {
+ return
+ }
+ return _CreateFile(_p0, access, mode, sa, createmode, attrs, templatefile)
+}
+
+func _CreateFile(name *uint16, access AccessMask, mode FileShareMode, sa *windows.SecurityAttributes, createmode FileCreationDisposition, attrs FileFlagOrAttribute, templatefile windows.Handle) (handle windows.Handle, err error) {
+ r0, _, e1 := syscall.SyscallN(procCreateFileW.Addr(), uintptr(unsafe.Pointer(name)), uintptr(access), uintptr(mode), uintptr(unsafe.Pointer(sa)), uintptr(createmode), uintptr(attrs), uintptr(templatefile))
+ handle = windows.Handle(r0)
+ if handle == windows.InvalidHandle {
+ err = errnoErr(e1)
+ }
+ return
+}
diff --git a/vendor/github.com/Microsoft/go-winio/internal/socket/socket.go b/vendor/github.com/Microsoft/go-winio/internal/socket/socket.go
index 39e8c05..88580d9 100644
--- a/vendor/github.com/Microsoft/go-winio/internal/socket/socket.go
+++ b/vendor/github.com/Microsoft/go-winio/internal/socket/socket.go
@@ -100,8 +100,8 @@ func (f *runtimeFunc) Load() error {
(*byte)(unsafe.Pointer(&f.addr)),
uint32(unsafe.Sizeof(f.addr)),
&n,
- nil, //overlapped
- 0, //completionRoutine
+ nil, // overlapped
+ 0, // completionRoutine
)
})
return f.err
@@ -156,9 +156,7 @@ func connectEx(
bytesSent *uint32,
overlapped *windows.Overlapped,
) (err error) {
- // todo: after upgrading to 1.18, switch from syscall.Syscall9 to syscall.SyscallN
- r1, _, e1 := syscall.Syscall9(connectExFunc.addr,
- 7,
+ r1, _, e1 := syscall.SyscallN(connectExFunc.addr,
uintptr(s),
uintptr(name),
uintptr(namelen),
@@ -166,8 +164,8 @@ func connectEx(
uintptr(sendDataLen),
uintptr(unsafe.Pointer(bytesSent)),
uintptr(unsafe.Pointer(overlapped)),
- 0,
- 0)
+ )
+
if r1 == 0 {
if e1 != 0 {
err = error(e1)
diff --git a/vendor/github.com/Microsoft/go-winio/internal/socket/zsyscall_windows.go b/vendor/github.com/Microsoft/go-winio/internal/socket/zsyscall_windows.go
index 6d2e1a9..e150412 100644
--- a/vendor/github.com/Microsoft/go-winio/internal/socket/zsyscall_windows.go
+++ b/vendor/github.com/Microsoft/go-winio/internal/socket/zsyscall_windows.go
@@ -33,9 +33,6 @@ func errnoErr(e syscall.Errno) error {
case errnoERROR_IO_PENDING:
return errERROR_IO_PENDING
}
- // TODO: add more here, after collecting data on the common
- // error values see on Windows. (perhaps when running
- // all.bat?)
return e
}
@@ -48,7 +45,7 @@ var (
)
func bind(s windows.Handle, name unsafe.Pointer, namelen int32) (err error) {
- r1, _, e1 := syscall.Syscall(procbind.Addr(), 3, uintptr(s), uintptr(name), uintptr(namelen))
+ r1, _, e1 := syscall.SyscallN(procbind.Addr(), uintptr(s), uintptr(name), uintptr(namelen))
if r1 == socketError {
err = errnoErr(e1)
}
@@ -56,7 +53,7 @@ func bind(s windows.Handle, name unsafe.Pointer, namelen int32) (err error) {
}
func getpeername(s windows.Handle, name unsafe.Pointer, namelen *int32) (err error) {
- r1, _, e1 := syscall.Syscall(procgetpeername.Addr(), 3, uintptr(s), uintptr(name), uintptr(unsafe.Pointer(namelen)))
+ r1, _, e1 := syscall.SyscallN(procgetpeername.Addr(), uintptr(s), uintptr(name), uintptr(unsafe.Pointer(namelen)))
if r1 == socketError {
err = errnoErr(e1)
}
@@ -64,7 +61,7 @@ func getpeername(s windows.Handle, name unsafe.Pointer, namelen *int32) (err err
}
func getsockname(s windows.Handle, name unsafe.Pointer, namelen *int32) (err error) {
- r1, _, e1 := syscall.Syscall(procgetsockname.Addr(), 3, uintptr(s), uintptr(name), uintptr(unsafe.Pointer(namelen)))
+ r1, _, e1 := syscall.SyscallN(procgetsockname.Addr(), uintptr(s), uintptr(name), uintptr(unsafe.Pointer(namelen)))
if r1 == socketError {
err = errnoErr(e1)
}
diff --git a/vendor/github.com/Microsoft/go-winio/internal/stringbuffer/wstring.go b/vendor/github.com/Microsoft/go-winio/internal/stringbuffer/wstring.go
new file mode 100644
index 0000000..42ebc01
--- /dev/null
+++ b/vendor/github.com/Microsoft/go-winio/internal/stringbuffer/wstring.go
@@ -0,0 +1,132 @@
+package stringbuffer
+
+import (
+ "sync"
+ "unicode/utf16"
+)
+
+// TODO: worth exporting and using in mkwinsyscall?
+
+// Uint16BufferSize is the buffer size in the pool, chosen somewhat arbitrarily to accommodate
+// large path strings:
+// MAX_PATH (260) + size of volume GUID prefix (49) + null terminator = 310.
+const MinWStringCap = 310
+
+// use *[]uint16 since []uint16 creates an extra allocation where the slice header
+// is copied to heap and then referenced via pointer in the interface header that sync.Pool
+// stores.
+var pathPool = sync.Pool{ // if go1.18+ adds Pool[T], use that to store []uint16 directly
+ New: func() interface{} {
+ b := make([]uint16, MinWStringCap)
+ return &b
+ },
+}
+
+func newBuffer() []uint16 { return *(pathPool.Get().(*[]uint16)) }
+
+// freeBuffer copies the slice header data, and puts a pointer to that in the pool.
+// This avoids taking a pointer to the slice header in WString, which can be set to nil.
+func freeBuffer(b []uint16) { pathPool.Put(&b) }
+
+// WString is a wide string buffer ([]uint16) meant for storing UTF-16 encoded strings
+// for interacting with Win32 APIs.
+// Sizes are specified as uint32 and not int.
+//
+// It is not thread safe.
+type WString struct {
+ // type-def allows casting to []uint16 directly, use struct to prevent that and allow adding fields in the future.
+
+ // raw buffer
+ b []uint16
+}
+
+// NewWString returns a [WString] allocated from a shared pool with an
+// initial capacity of at least [MinWStringCap].
+// Since the buffer may have been previously used, its contents are not guaranteed to be empty.
+//
+// The buffer should be freed via [WString.Free]
+func NewWString() *WString {
+ return &WString{
+ b: newBuffer(),
+ }
+}
+
+func (b *WString) Free() {
+ if b.empty() {
+ return
+ }
+ freeBuffer(b.b)
+ b.b = nil
+}
+
+// ResizeTo grows the buffer to at least c and returns the new capacity, freeing the
+// previous buffer back into pool.
+func (b *WString) ResizeTo(c uint32) uint32 {
+ // already sufficient (or n is 0)
+ if c <= b.Cap() {
+ return b.Cap()
+ }
+
+ if c <= MinWStringCap {
+ c = MinWStringCap
+ }
+ // allocate at-least double buffer size, as is done in [bytes.Buffer] and other places
+ if c <= 2*b.Cap() {
+ c = 2 * b.Cap()
+ }
+
+ b2 := make([]uint16, c)
+ if !b.empty() {
+ copy(b2, b.b)
+ freeBuffer(b.b)
+ }
+ b.b = b2
+ return c
+}
+
+// Buffer returns the underlying []uint16 buffer.
+func (b *WString) Buffer() []uint16 {
+ if b.empty() {
+ return nil
+ }
+ return b.b
+}
+
+// Pointer returns a pointer to the first uint16 in the buffer.
+// If the [WString.Free] has already been called, the pointer will be nil.
+func (b *WString) Pointer() *uint16 {
+ if b.empty() {
+ return nil
+ }
+ return &b.b[0]
+}
+
+// String returns the returns the UTF-8 encoding of the UTF-16 string in the buffer.
+//
+// It assumes that the data is null-terminated.
+func (b *WString) String() string {
+ // Using [windows.UTF16ToString] would require importing "golang.org/x/sys/windows"
+ // and would make this code Windows-only, which makes no sense.
+ // So copy UTF16ToString code into here.
+ // If other windows-specific code is added, switch to [windows.UTF16ToString]
+
+ s := b.b
+ for i, v := range s {
+ if v == 0 {
+ s = s[:i]
+ break
+ }
+ }
+ return string(utf16.Decode(s))
+}
+
+// Cap returns the underlying buffer capacity.
+func (b *WString) Cap() uint32 {
+ if b.empty() {
+ return 0
+ }
+ return b.cap()
+}
+
+func (b *WString) cap() uint32 { return uint32(cap(b.b)) }
+func (b *WString) empty() bool { return b == nil || b.cap() == 0 }