chore: vendor

vendor/github.com/moby/term/windows/ansi_reader.go

@@ -0,0 +1,252 @@
+//go:build windows
+// +build windows
+
+package windowsconsole
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+	"unsafe"
+
+	ansiterm "github.com/Azure/go-ansiterm"
+	"github.com/Azure/go-ansiterm/winterm"
+)
+
+const (
+	escapeSequence = ansiterm.KEY_ESC_CSI
+)
+
+// ansiReader wraps a standard input file (e.g., os.Stdin) providing ANSI sequence translation.
+type ansiReader struct {
+	file     *os.File
+	fd       uintptr
+	buffer   []byte
+	cbBuffer int
+	command  []byte
+}
+
+// NewAnsiReader returns an io.ReadCloser that provides VT100 terminal emulation on top of a
+// Windows console input handle.
+func NewAnsiReader(nFile int) io.ReadCloser {
+	file, fd := winterm.GetStdFile(nFile)
+	return &ansiReader{
+		file:    file,
+		fd:      fd,
+		command: make([]byte, 0, ansiterm.ANSI_MAX_CMD_LENGTH),
+		buffer:  make([]byte, 0),
+	}
+}
+
+// Close closes the wrapped file.
+func (ar *ansiReader) Close() (err error) {
+	return ar.file.Close()
+}
+
+// Fd returns the file descriptor of the wrapped file.
+func (ar *ansiReader) Fd() uintptr {
+	return ar.fd
+}
+
+// Read reads up to len(p) bytes of translated input events into p.
+func (ar *ansiReader) Read(p []byte) (int, error) {
+	if len(p) == 0 {
+		return 0, nil
+	}
+
+	// Previously read bytes exist, read as much as we can and return
+	if len(ar.buffer) > 0 {
+		originalLength := len(ar.buffer)
+		copiedLength := copy(p, ar.buffer)
+
+		if copiedLength == originalLength {
+			ar.buffer = make([]byte, 0, len(p))
+		} else {
+			ar.buffer = ar.buffer[copiedLength:]
+		}
+
+		return copiedLength, nil
+	}
+
+	// Read and translate key events
+	events, err := readInputEvents(ar, len(p))
+	if err != nil {
+		return 0, err
+	} else if len(events) == 0 {
+		return 0, nil
+	}
+
+	keyBytes := translateKeyEvents(events, []byte(escapeSequence))
+
+	// Save excess bytes and right-size keyBytes
+	if len(keyBytes) > len(p) {
+		ar.buffer = keyBytes[len(p):]
+		keyBytes = keyBytes[:len(p)]
+	} else if len(keyBytes) == 0 {
+		return 0, nil
+	}
+
+	copiedLength := copy(p, keyBytes)
+	if copiedLength != len(keyBytes) {
+		return 0, errors.New("unexpected copy length encountered")
+	}
+
+	return copiedLength, nil
+}
+
+// readInputEvents polls until at least one event is available.
+func readInputEvents(ar *ansiReader, maxBytes int) ([]winterm.INPUT_RECORD, error) {
+	// Determine the maximum number of records to retrieve
+	// -- Cast around the type system to obtain the size of a single INPUT_RECORD.
+	//    unsafe.Sizeof requires an expression vs. a type-reference; the casting
+	//    tricks the type system into believing it has such an expression.
+	recordSize := int(unsafe.Sizeof(*((*winterm.INPUT_RECORD)(unsafe.Pointer(&maxBytes)))))
+	countRecords := maxBytes / recordSize
+	if countRecords > ansiterm.MAX_INPUT_EVENTS {
+		countRecords = ansiterm.MAX_INPUT_EVENTS
+	} else if countRecords == 0 {
+		countRecords = 1
+	}
+
+	// Wait for and read input events
+	events := make([]winterm.INPUT_RECORD, countRecords)
+	nEvents := uint32(0)
+	eventsExist, err := winterm.WaitForSingleObject(ar.fd, winterm.WAIT_INFINITE)
+	if err != nil {
+		return nil, err
+	}
+
+	if eventsExist {
+		err = winterm.ReadConsoleInput(ar.fd, events, &nEvents)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	// Return a slice restricted to the number of returned records
+	return events[:nEvents], nil
+}
+
+// KeyEvent Translation Helpers
+
+var arrowKeyMapPrefix = map[uint16]string{
+	winterm.VK_UP:    "%s%sA",
+	winterm.VK_DOWN:  "%s%sB",
+	winterm.VK_RIGHT: "%s%sC",
+	winterm.VK_LEFT:  "%s%sD",
+}
+
+var keyMapPrefix = map[uint16]string{
+	winterm.VK_UP:     "\x1B[%sA",
+	winterm.VK_DOWN:   "\x1B[%sB",
+	winterm.VK_RIGHT:  "\x1B[%sC",
+	winterm.VK_LEFT:   "\x1B[%sD",
+	winterm.VK_HOME:   "\x1B[1%s~", // showkey shows ^[[1
+	winterm.VK_END:    "\x1B[4%s~", // showkey shows ^[[4
+	winterm.VK_INSERT: "\x1B[2%s~",
+	winterm.VK_DELETE: "\x1B[3%s~",
+	winterm.VK_PRIOR:  "\x1B[5%s~",
+	winterm.VK_NEXT:   "\x1B[6%s~",
+	winterm.VK_F1:     "",
+	winterm.VK_F2:     "",
+	winterm.VK_F3:     "\x1B[13%s~",
+	winterm.VK_F4:     "\x1B[14%s~",
+	winterm.VK_F5:     "\x1B[15%s~",
+	winterm.VK_F6:     "\x1B[17%s~",
+	winterm.VK_F7:     "\x1B[18%s~",
+	winterm.VK_F8:     "\x1B[19%s~",
+	winterm.VK_F9:     "\x1B[20%s~",
+	winterm.VK_F10:    "\x1B[21%s~",
+	winterm.VK_F11:    "\x1B[23%s~",
+	winterm.VK_F12:    "\x1B[24%s~",
+}
+
+// translateKeyEvents converts the input events into the appropriate ANSI string.
+func translateKeyEvents(events []winterm.INPUT_RECORD, escapeSequence []byte) []byte {
+	var buffer bytes.Buffer
+	for _, event := range events {
+		if event.EventType == winterm.KEY_EVENT && event.KeyEvent.KeyDown != 0 {
+			buffer.WriteString(keyToString(&event.KeyEvent, escapeSequence))
+		}
+	}
+
+	return buffer.Bytes()
+}
+
+// keyToString maps the given input event record to the corresponding string.
+func keyToString(keyEvent *winterm.KEY_EVENT_RECORD, escapeSequence []byte) string {
+	if keyEvent.UnicodeChar == 0 {
+		return formatVirtualKey(keyEvent.VirtualKeyCode, keyEvent.ControlKeyState, escapeSequence)
+	}
+
+	_, alt, control := getControlKeys(keyEvent.ControlKeyState)
+	if control {
+		// TODO(azlinux): Implement following control sequences
+		// <Ctrl>-D  Signals the end of input from the keyboard; also exits current shell.
+		// <Ctrl>-H  Deletes the first character to the left of the cursor. Also called the ERASE key.
+		// <Ctrl>-Q  Restarts printing after it has been stopped with <Ctrl>-s.
+		// <Ctrl>-S  Suspends printing on the screen (does not stop the program).
+		// <Ctrl>-U  Deletes all characters on the current line. Also called the KILL key.
+		// <Ctrl>-E  Quits current command and creates a core
+	}
+
+	// <Alt>+Key generates ESC N Key
+	if !control && alt {
+		return ansiterm.KEY_ESC_N + strings.ToLower(string(rune(keyEvent.UnicodeChar)))
+	}
+
+	return string(rune(keyEvent.UnicodeChar))
+}
+
+// formatVirtualKey converts a virtual key (e.g., up arrow) into the appropriate ANSI string.
+func formatVirtualKey(key uint16, controlState uint32, escapeSequence []byte) string {
+	shift, alt, control := getControlKeys(controlState)
+	modifier := getControlKeysModifier(shift, alt, control)
+
+	if format, ok := arrowKeyMapPrefix[key]; ok {
+		return fmt.Sprintf(format, escapeSequence, modifier)
+	}
+
+	if format, ok := keyMapPrefix[key]; ok {
+		return fmt.Sprintf(format, modifier)
+	}
+
+	return ""
+}
+
+// getControlKeys extracts the shift, alt, and ctrl key states.
+func getControlKeys(controlState uint32) (shift, alt, control bool) {
+	shift = 0 != (controlState & winterm.SHIFT_PRESSED)
+	alt = 0 != (controlState & (winterm.LEFT_ALT_PRESSED | winterm.RIGHT_ALT_PRESSED))
+	control = 0 != (controlState & (winterm.LEFT_CTRL_PRESSED | winterm.RIGHT_CTRL_PRESSED))
+	return shift, alt, control
+}
+
+// getControlKeysModifier returns the ANSI modifier for the given combination of control keys.
+func getControlKeysModifier(shift, alt, control bool) string {
+	if shift && alt && control {
+		return ansiterm.KEY_CONTROL_PARAM_8
+	}
+	if alt && control {
+		return ansiterm.KEY_CONTROL_PARAM_7
+	}
+	if shift && control {
+		return ansiterm.KEY_CONTROL_PARAM_6
+	}
+	if control {
+		return ansiterm.KEY_CONTROL_PARAM_5
+	}
+	if shift && alt {
+		return ansiterm.KEY_CONTROL_PARAM_4
+	}
+	if alt {
+		return ansiterm.KEY_CONTROL_PARAM_3
+	}
+	if shift {
+		return ansiterm.KEY_CONTROL_PARAM_2
+	}
+	return ""
+}