src/net/parse.go - go - Git at Google

 // Copyright 2009 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.

 // Simple file i/o and string manipulation, to avoid
 // depending on strconv and bufio and strings.

 package net

 import (
 	"io"
 	"os"
 	"time"
 	_ "unsafe" // For go:linkname
 )

 type file struct {
 	file  *os.File
 	data  []byte
 	atEOF bool
 }

 func (f *file) close() { f.file.Close() }

 func (f *file) getLineFromData() (s string, ok bool) {
 	data := f.data
 	i := 0
 	for i = 0; i < len(data); i++ {
 		if data[i] == '\n' {
 			s = string(data[0:i])
 			ok = true
 			// move data
 			i++
 			n := len(data) - i
 			copy(data[0:], data[i:])
 			f.data = data[0:n]
 			return
 		}
 	}
 	if f.atEOF && len(f.data) > 0 {
 		// EOF, return all we have
 		s = string(data)
 		f.data = f.data[0:0]
 		ok = true
 	}
 	return
 }

 func (f *file) readLine() (s string, ok bool) {
 	if s, ok = f.getLineFromData(); ok {
 		return
 	}
 	if len(f.data) < cap(f.data) {
 		ln := len(f.data)
 		n, err := io.ReadFull(f.file, f.data[ln:cap(f.data)])
 		if n >= 0 {
 			f.data = f.data[0 : ln+n]
 		}
 		if err == io.EOF || err == io.ErrUnexpectedEOF {
 			f.atEOF = true
 		}
 	}
 	s, ok = f.getLineFromData()
 	return
 }

 func open(name string) (*file, error) {
 	fd, err := os.Open(name)
 	if err != nil {
 		return nil, err
 	}
 	return &file{fd, make([]byte, 0, os.Getpagesize()), false}, nil
 }

 func stat(name string) (mtime time.Time, size int64, err error) {
 	st, err := os.Stat(name)
 	if err != nil {
 		return time.Time{}, 0, err
 	}
 	return st.ModTime(), st.Size(), nil
 }

 // byteIndex is strings.IndexByte. It returns the index of the
 // first instance of c in s, or -1 if c is not present in s.
 // strings.IndexByte is implemented in  runtime/asm_$GOARCH.s
 //go:linkname byteIndex strings.IndexByte
 func byteIndex(s string, c byte) int

 // Count occurrences in s of any bytes in t.
 func countAnyByte(s string, t string) int {
 	n := 0
 	for i := 0; i < len(s); i++ {
 		if byteIndex(t, s[i]) >= 0 {
 			n++
 		}
 	}
 	return n
 }

 // Split s at any bytes in t.
 func splitAtBytes(s string, t string) []string {
 	a := make([]string, 1+countAnyByte(s, t))
 	n := 0
 	last := 0
 	for i := 0; i < len(s); i++ {
 		if byteIndex(t, s[i]) >= 0 {
 			if last < i {
 				a[n] = s[last:i]
 				n++
 			}
 			last = i + 1
 		}
 	}
 	if last < len(s) {
 		a[n] = s[last:]
 		n++
 	}
 	return a[0:n]
 }

 func getFields(s string) []string { return splitAtBytes(s, " \r\t\n") }

 // Bigger than we need, not too big to worry about overflow
 const big = 0xFFFFFF

 // Decimal to integer.
 // Returns number, characters consumed, success.
 func dtoi(s string) (n int, i int, ok bool) {
 	n = 0
 	for i = 0; i < len(s) && '0' <= s[i] && s[i] <= '9'; i++ {
 		n = n*10 + int(s[i]-'0')
 		if n >= big {
 			return big, i, false
 		}
 	}
 	if i == 0 {
 		return 0, 0, false
 	}
 	return n, i, true
 }

 // Hexadecimal to integer.
 // Returns number, characters consumed, success.
 func xtoi(s string) (n int, i int, ok bool) {
 	n = 0
 	for i = 0; i < len(s); i++ {
 		if '0' <= s[i] && s[i] <= '9' {
 			n *= 16
 			n += int(s[i] - '0')
 		} else if 'a' <= s[i] && s[i] <= 'f' {
 			n *= 16
 			n += int(s[i]-'a') + 10
 		} else if 'A' <= s[i] && s[i] <= 'F' {
 			n *= 16
 			n += int(s[i]-'A') + 10
 		} else {
 			break
 		}
 		if n >= big {
 			return 0, i, false
 		}
 	}
 	if i == 0 {
 		return 0, i, false
 	}
 	return n, i, true
 }

 // xtoi2 converts the next two hex digits of s into a byte.
 // If s is longer than 2 bytes then the third byte must be e.
 // If the first two bytes of s are not hex digits or the third byte
 // does not match e, false is returned.
 func xtoi2(s string, e byte) (byte, bool) {
 	if len(s) > 2 && s[2] != e {
 		return 0, false
 	}
 	n, ei, ok := xtoi(s[:2])
 	return byte(n), ok && ei == 2
 }

 // Convert integer to decimal string.
 func itoa(val int) string {
 	if val < 0 {
 		return "-" + uitoa(uint(-val))
 	}
 	return uitoa(uint(val))
 }

 // Convert unsigned integer to decimal string.
 func uitoa(val uint) string {
 	if val == 0 { // avoid string allocation
 		return "0"
 	}
 	var buf [20]byte // big enough for 64bit value base 10
 	i := len(buf) - 1
 	for val >= 10 {
 		q := val / 10
 		buf[i] = byte('0' + val - q*10)
 		i--
 		val = q
 	}
 	// val < 10
 	buf[i] = byte('0' + val)
 	return string(buf[i:])
 }

 // Convert i to a hexadecimal string. Leading zeros are not printed.
 func appendHex(dst []byte, i uint32) []byte {
 	if i == 0 {
 		return append(dst, '0')
 	}
 	for j := 7; j >= 0; j-- {
 		v := i >> uint(j*4)
 		if v > 0 {
 			dst = append(dst, hexDigit[v&0xf])
 		}
 	}
 	return dst
 }

 // Number of occurrences of b in s.
 func count(s string, b byte) int {
 	n := 0
 	for i := 0; i < len(s); i++ {
 		if s[i] == b {
 			n++
 		}
 	}
 	return n
 }

 // Index of rightmost occurrence of b in s.
 func last(s string, b byte) int {
 	i := len(s)
 	for i--; i >= 0; i-- {
 		if s[i] == b {
 			break
 		}
 	}
 	return i
 }

 // lowerASCIIBytes makes x ASCII lowercase in-place.
 func lowerASCIIBytes(x []byte) {
 	for i, b := range x {
 		if 'A' <= b && b <= 'Z' {
 			x[i] += 'a' - 'A'
 		}
 	}
 }

 // lowerASCII returns the ASCII lowercase version of b.
 func lowerASCII(b byte) byte {
 	if 'A' <= b && b <= 'Z' {
 		return b + ('a' - 'A')
 	}
 	return b
 }

 // trimSpace returns x without any leading or trailing ASCII whitespace.
 func trimSpace(x []byte) []byte {
 	for len(x) > 0 && isSpace(x[0]) {
 		x = x[1:]
 	}
 	for len(x) > 0 && isSpace(x[len(x)-1]) {
 		x = x[:len(x)-1]
 	}
 	return x
 }

 // isSpace reports whether b is an ASCII space character.
 func isSpace(b byte) bool {
 	return b == ' ' || b == '\t' || b == '\n' || b == '\r'
 }

 // removeComment returns line, removing any '#' byte and any following
 // bytes.
 func removeComment(line []byte) []byte {
 	if i := bytesIndexByte(line, '#'); i != -1 {
 		return line[:i]
 	}
 	return line
 }

 // foreachLine runs fn on each line of x.
 // Each line (except for possibly the last) ends in '\n'.
 // It returns the first non-nil error returned by fn.
 func foreachLine(x []byte, fn func(line []byte) error) error {
 	for len(x) > 0 {
 		nl := bytesIndexByte(x, '\n')
 		if nl == -1 {
 			return fn(x)
 		}
 		line := x[:nl+1]
 		x = x[nl+1:]
 		if err := fn(line); err != nil {
 			return err
 		}
 	}
 	return nil
 }

 // foreachField runs fn on each non-empty run of non-space bytes in x.
 // It returns the first non-nil error returned by fn.
 func foreachField(x []byte, fn func(field []byte) error) error {
 	x = trimSpace(x)
 	for len(x) > 0 {
 		sp := bytesIndexByte(x, ' ')
 		if sp == -1 {
 			return fn(x)
 		}
 		if field := trimSpace(x[:sp]); len(field) > 0 {
 			if err := fn(field); err != nil {
 				return err
 			}
 		}
 		x = trimSpace(x[sp+1:])
 	}
 	return nil
 }

 // bytesIndexByte is bytes.IndexByte. It returns the index of the
 // first instance of c in s, or -1 if c is not present in s.
 // bytes.IndexByte is implemented in  runtime/asm_$GOARCH.s
 //go:linkname bytesIndexByte bytes.IndexByte
 func bytesIndexByte(s []byte, c byte) int

 // stringsHasSuffix is strings.HasSuffix. It reports whether s ends in
 // suffix.
 func stringsHasSuffix(s, suffix string) bool {
 	return len(s) >= len(suffix) && s[len(s)-len(suffix):] == suffix
 }

 // stringsHasSuffixFold reports whether s ends in suffix,
 // ASCII-case-insensitively.
 func stringsHasSuffixFold(s, suffix string) bool {
 	if len(suffix) > len(s) {
 		return false
 	}
 	for i := 0; i < len(suffix); i++ {
 		if lowerASCII(suffix[i]) != lowerASCII(s[len(s)-len(suffix)+i]) {
 			return false
 		}
 	}
 	return true
 }

 // stringsHasPrefix is strings.HasPrefix. It reports whether s begins with prefix.
 func stringsHasPrefix(s, prefix string) bool {
 	return len(s) >= len(prefix) && s[:len(prefix)] == prefix
 }

 func readFull(r io.Reader) (all []byte, err error) {
 	buf := make([]byte, 1024)
 	for {
 		n, err := r.Read(buf)
 		all = append(all, buf[:n]...)
 		if err == io.EOF {
 			return all, nil
 		}
 		if err != nil {
 			return nil, err
 		}
 	}
 }

 // goDebugString returns the value of the named GODEBUG key.
 // GODEBUG is of the form "key=val,key2=val2"
 func goDebugString(key string) string {
 	s := os.Getenv("GODEBUG")
 	for i := 0; i < len(s)-len(key)-1; i++ {
 		if i > 0 && s[i-1] != ',' {
 			continue
 		}
 		afterKey := s[i+len(key):]
 		if afterKey[0] != '=' || s[i:i+len(key)] != key {
 			continue
 		}
 		val := afterKey[1:]
 		for i, b := range val {
 			if b == ',' {
 				return val[:i]
 			}
 		}
 		return val
 	}
 	return ""
 }
	// Copyright 2009 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.

	// Simple file i/o and string manipulation, to avoid
	// depending on strconv and bufio and strings.

	package net

	import (
	"io"
	"os"
	"time"
	_ "unsafe" // For go:linkname
	)

	type file struct {
	file *os.File
	data []byte
	atEOF bool
	}

	func (f *file) close() { f.file.Close() }

	func (f *file) getLineFromData() (s string, ok bool) {
	data := f.data
	i := 0
	for i = 0; i < len(data); i++ {
	if data[i] == '\n' {
	s = string(data[0:i])
	ok = true
	// move data
	i++
	n := len(data) - i
	copy(data[0:], data[i:])
	f.data = data[0:n]
	return
	}
	}
	if f.atEOF && len(f.data) > 0 {
	// EOF, return all we have
	s = string(data)
	f.data = f.data[0:0]
	ok = true
	}
	return
	}

	func (f *file) readLine() (s string, ok bool) {
	if s, ok = f.getLineFromData(); ok {
	return
	}
	if len(f.data) < cap(f.data) {
	ln := len(f.data)
	n, err := io.ReadFull(f.file, f.data[ln:cap(f.data)])
	if n >= 0 {
	f.data = f.data[0 : ln+n]
	}
	if err == io.EOF \|\| err == io.ErrUnexpectedEOF {
	f.atEOF = true
	}
	}
	s, ok = f.getLineFromData()
	return
	}

	func open(name string) (*file, error) {
	fd, err := os.Open(name)
	if err != nil {
	return nil, err
	}
	return &file{fd, make([]byte, 0, os.Getpagesize()), false}, nil
	}

	func stat(name string) (mtime time.Time, size int64, err error) {
	st, err := os.Stat(name)
	if err != nil {
	return time.Time{}, 0, err
	}
	return st.ModTime(), st.Size(), nil
	}

	// byteIndex is strings.IndexByte. It returns the index of the
	// first instance of c in s, or -1 if c is not present in s.
	// strings.IndexByte is implemented in runtime/asm_$GOARCH.s
	//go:linkname byteIndex strings.IndexByte
	func byteIndex(s string, c byte) int

	// Count occurrences in s of any bytes in t.
	func countAnyByte(s string, t string) int {
	n := 0
	for i := 0; i < len(s); i++ {
	if byteIndex(t, s[i]) >= 0 {
	n++
	}
	}
	return n
	}

	// Split s at any bytes in t.
	func splitAtBytes(s string, t string) []string {
	a := make([]string, 1+countAnyByte(s, t))
	n := 0
	last := 0
	for i := 0; i < len(s); i++ {
	if byteIndex(t, s[i]) >= 0 {
	if last < i {
	a[n] = s[last:i]
	n++
	}
	last = i + 1
	}
	}
	if last < len(s) {
	a[n] = s[last:]
	n++
	}
	return a[0:n]
	}

	func getFields(s string) []string { return splitAtBytes(s, " \r\t\n") }

	// Bigger than we need, not too big to worry about overflow
	const big = 0xFFFFFF

	// Decimal to integer.
	// Returns number, characters consumed, success.
	func dtoi(s string) (n int, i int, ok bool) {
	n = 0
	for i = 0; i < len(s) && '0' <= s[i] && s[i] <= '9'; i++ {
	n = n*10 + int(s[i]-'0')
	if n >= big {
	return big, i, false
	}
	}
	if i == 0 {
	return 0, 0, false
	}
	return n, i, true
	}

	// Hexadecimal to integer.
	// Returns number, characters consumed, success.
	func xtoi(s string) (n int, i int, ok bool) {
	n = 0
	for i = 0; i < len(s); i++ {
	if '0' <= s[i] && s[i] <= '9' {
	n *= 16
	n += int(s[i] - '0')
	} else if 'a' <= s[i] && s[i] <= 'f' {
	n *= 16
	n += int(s[i]-'a') + 10
	} else if 'A' <= s[i] && s[i] <= 'F' {
	n *= 16
	n += int(s[i]-'A') + 10
	} else {
	break
	}
	if n >= big {
	return 0, i, false
	}
	}
	if i == 0 {
	return 0, i, false
	}
	return n, i, true
	}

	// xtoi2 converts the next two hex digits of s into a byte.
	// If s is longer than 2 bytes then the third byte must be e.
	// If the first two bytes of s are not hex digits or the third byte
	// does not match e, false is returned.
	func xtoi2(s string, e byte) (byte, bool) {
	if len(s) > 2 && s[2] != e {
	return 0, false
	}
	n, ei, ok := xtoi(s[:2])
	return byte(n), ok && ei == 2
	}

	// Convert integer to decimal string.
	func itoa(val int) string {
	if val < 0 {
	return "-" + uitoa(uint(-val))
	}
	return uitoa(uint(val))
	}

	// Convert unsigned integer to decimal string.
	func uitoa(val uint) string {
	if val == 0 { // avoid string allocation
	return "0"
	}
	var buf [20]byte // big enough for 64bit value base 10
	i := len(buf) - 1
	for val >= 10 {
	q := val / 10
	buf[i] = byte('0' + val - q*10)
	i--
	val = q
	}
	// val < 10
	buf[i] = byte('0' + val)
	return string(buf[i:])
	}

	// Convert i to a hexadecimal string. Leading zeros are not printed.
	func appendHex(dst []byte, i uint32) []byte {
	if i == 0 {
	return append(dst, '0')
	}
	for j := 7; j >= 0; j-- {
	v := i >> uint(j*4)
	if v > 0 {
	dst = append(dst, hexDigit[v&0xf])
	}
	}
	return dst
	}

	// Number of occurrences of b in s.
	func count(s string, b byte) int {
	n := 0
	for i := 0; i < len(s); i++ {
	if s[i] == b {
	n++
	}
	}
	return n
	}

	// Index of rightmost occurrence of b in s.
	func last(s string, b byte) int {
	i := len(s)
	for i--; i >= 0; i-- {
	if s[i] == b {
	break
	}
	}
	return i
	}

	// lowerASCIIBytes makes x ASCII lowercase in-place.
	func lowerASCIIBytes(x []byte) {
	for i, b := range x {
	if 'A' <= b && b <= 'Z' {
	x[i] += 'a' - 'A'
	}
	}
	}

	// lowerASCII returns the ASCII lowercase version of b.
	func lowerASCII(b byte) byte {
	if 'A' <= b && b <= 'Z' {
	return b + ('a' - 'A')
	}
	return b
	}

	// trimSpace returns x without any leading or trailing ASCII whitespace.
	func trimSpace(x []byte) []byte {
	for len(x) > 0 && isSpace(x[0]) {
	x = x[1:]
	}
	for len(x) > 0 && isSpace(x[len(x)-1]) {
	x = x[:len(x)-1]
	}
	return x
	}

	// isSpace reports whether b is an ASCII space character.
	func isSpace(b byte) bool {
	return b == ' ' \|\| b == '\t' \|\| b == '\n' \|\| b == '\r'
	}

	// removeComment returns line, removing any '#' byte and any following
	// bytes.
	func removeComment(line []byte) []byte {
	if i := bytesIndexByte(line, '#'); i != -1 {
	return line[:i]
	}
	return line
	}

	// foreachLine runs fn on each line of x.
	// Each line (except for possibly the last) ends in '\n'.
	// It returns the first non-nil error returned by fn.
	func foreachLine(x []byte, fn func(line []byte) error) error {
	for len(x) > 0 {
	nl := bytesIndexByte(x, '\n')
	if nl == -1 {
	return fn(x)
	}
	line := x[:nl+1]
	x = x[nl+1:]
	if err := fn(line); err != nil {
	return err
	}
	}
	return nil
	}

	// foreachField runs fn on each non-empty run of non-space bytes in x.
	// It returns the first non-nil error returned by fn.
	func foreachField(x []byte, fn func(field []byte) error) error {
	x = trimSpace(x)
	for len(x) > 0 {
	sp := bytesIndexByte(x, ' ')
	if sp == -1 {
	return fn(x)
	}
	if field := trimSpace(x[:sp]); len(field) > 0 {
	if err := fn(field); err != nil {
	return err
	}
	}
	x = trimSpace(x[sp+1:])
	}
	return nil
	}

	// bytesIndexByte is bytes.IndexByte. It returns the index of the
	// first instance of c in s, or -1 if c is not present in s.
	// bytes.IndexByte is implemented in runtime/asm_$GOARCH.s
	//go:linkname bytesIndexByte bytes.IndexByte
	func bytesIndexByte(s []byte, c byte) int

	// stringsHasSuffix is strings.HasSuffix. It reports whether s ends in
	// suffix.
	func stringsHasSuffix(s, suffix string) bool {
	return len(s) >= len(suffix) && s[len(s)-len(suffix):] == suffix
	}

	// stringsHasSuffixFold reports whether s ends in suffix,
	// ASCII-case-insensitively.
	func stringsHasSuffixFold(s, suffix string) bool {
	if len(suffix) > len(s) {
	return false
	}
	for i := 0; i < len(suffix); i++ {
	if lowerASCII(suffix[i]) != lowerASCII(s[len(s)-len(suffix)+i]) {
	return false
	}
	}
	return true
	}

	// stringsHasPrefix is strings.HasPrefix. It reports whether s begins with prefix.
	func stringsHasPrefix(s, prefix string) bool {
	return len(s) >= len(prefix) && s[:len(prefix)] == prefix
	}

	func readFull(r io.Reader) (all []byte, err error) {
	buf := make([]byte, 1024)
	for {
	n, err := r.Read(buf)
	all = append(all, buf[:n]...)
	if err == io.EOF {
	return all, nil
	}
	if err != nil {
	return nil, err
	}
	}
	}

	// goDebugString returns the value of the named GODEBUG key.
	// GODEBUG is of the form "key=val,key2=val2"
	func goDebugString(key string) string {
	s := os.Getenv("GODEBUG")
	for i := 0; i < len(s)-len(key)-1; i++ {
	if i > 0 && s[i-1] != ',' {
	continue
	}
	afterKey := s[i+len(key):]
	if afterKey[0] != '=' \|\| s[i:i+len(key)] != key {
	continue
	}
	val := afterKey[1:]
	for i, b := range val {
	if b == ',' {
	return val[:i]
	}
	}
	return val
	}
	return ""
	}