func drain(r io.ByteReader, results chan int) {
var i int
for _, e := r.ReadByte(); e == nil; _, e = r.ReadByte() {
i++
}
results <- i
}
func unrolledUnPack4(buffer []int64, offset, len int, r io.ByteReader) error {
numHops := 2
remainder := len % numHops
endOffset := offset + len
endUnroll := endOffset - remainder
var val uint64
for i := offset; i < endUnroll; i = i + numHops {
byt, err := r.ReadByte()
if err != nil {
return err
}
val = uint64(byt)
buffer[i] = int64((val >> 4) & 15)
buffer[i+1] = int64(val & 15)
}
if remainder > 0 {
startShift := 4
byt, err := r.ReadByte()
if err != nil {
return err
}
val = uint64(byt)
for i := endUnroll; i < endOffset; i++ {
buffer[i] = int64((val >> uint64(startShift)) & 15)
startShift -= 4
}
}
return nil
}
// eats a single token returning:
// a bool, if it is an xml processing instruction
// a tag and optional default namespace, if an element
// and an error
func eatToken(in io.ByteReader) (bool, string, string, error) {
c, err := in.ReadByte()
if err != nil {
return false, "", "", ErrInvalid
}
switch c {
default:
valid, tag, ns := eatElement(in, c)
if valid {
return false, tag, ns, nil
}
case '!':
// can be a comment or a DOCTYPE
if eatComment(in) {
return false, "", "", nil
}
case '?':
valid, decl := eatPI(in)
if valid {
return decl, "", "", nil
}
case '<', '>', ' ', '\r', '\n', '\t':
}
return false, "", "", ErrInvalid
}
func (i InstReadFromInput) Eval(t Tape, in io.ByteReader, out io.ByteWriter) {
b, _ := in.ReadByte()
if b == byte(0) {
return
}
t.SetByte(b)
}
// Assumes that even partial matches may not overlap. Stops at match or newline.
func ScanUntil(r io.ByteReader, target string, ignorespace bool) (scanned string, pos int, err error) {
var i, j, k int
var b byte
buf := make([]byte, 0, len(target))
pos = -1
for {
b, err = r.ReadByte()
if err != nil {
return
} else if b == '\n' {
return
}
switch target[j] {
case b:
buf = append(buf, b)
j++
default:
if j > 0 && (b == ' ' || b == '\t') {
buf = append(buf, b)
k++
} else {
j = 0
}
}
if j >= len(target) {
scanned = string(buf)
pos = i - j - k + 1
return
}
i++
}
return
}
func eatDOCTYPE(in io.ByteReader) bool {
expect := make([]byte, 6)
for i := range expect {
c, err := in.ReadByte()
if err != nil {
return false
}
expect[i] = c
}
if string(expect) != "OCTYPE" {
return false
}
var depth int
for {
c, err := in.ReadByte()
if err != nil {
return false
}
switch c {
case '>':
if depth == 0 {
return true
}
depth--
case '<':
depth++
}
}
}
// eats an element returning:
// a bool to signfify if a valid element
// the tag name
// the default (xmlns=) namespace.
func eatElement(in io.ByteReader, c byte) (bool, string, string) {
buf := make([]byte, 32)
var (
err error
tag, ns string
idx int
)
for ; err == nil; c, err = in.ReadByte() {
switch c {
default:
if idx >= len(buf) {
cp := make([]byte, len(buf)*2)
copy(cp, buf)
buf = cp
}
buf[idx] = c
idx++
case '>', ' ', '\r', '\n', '\t':
if tag == "" {
tag = string(buf[:idx])
} else if ns == "" {
ns = extractNS(buf[:idx])
}
if c == '>' {
return true, tag, ns
}
idx = 0
}
}
return false, "", ""
}
func readBitPackedInts(buffer []int64, offset int, length int, bitSize int, r io.ByteReader) error {
var bitsLeft int
var current int
for i := offset; i < (offset + length); i++ {
var result int64
bitsLeftToRead := bitSize
for bitsLeftToRead > bitsLeft {
result <<= uint64(bitsLeft)
result |= int64(current & ((1 << uint64(bitsLeft)) - 1))
bitsLeftToRead -= bitsLeft
b, err := r.ReadByte()
if err != nil {
return err
}
current = int(b)
bitsLeft = 8
}
// handle the left over bits
if bitsLeftToRead > 0 {
result <<= uint64(bitsLeftToRead)
bitsLeft -= bitsLeftToRead
result |= int64((current >> uint64(bitsLeft)) & ((1 << uint64(bitsLeftToRead)) - 1))
}
buffer[i] = result
}
return nil
}
func (st *StringTable) Read(reader io.ByteReader) error {
var (
err error
currentString string = ""
currentIndex uint32 = 0
b byte
)
st.index = make(map[string]uint32)
st.length, err = readMultiByteUint32(reader)
if err == nil && st.length > 0 {
st.content = make([]byte, st.length)
var index uint32
for index = 0; index < st.length; index++ {
b, err = reader.ReadByte()
if err != nil {
break
}
st.content[index] = b
if b > 0 {
currentString += fmt.Sprintf("%c", b)
} else {
st.index[currentString] = currentIndex
currentString = ""
currentIndex = index + 1
}
}
}
return err
}
func readByte(r io.ByteReader) (byte, error) {
b, err := r.ReadByte()
if err == io.EOF {
err = io.ErrUnexpectedEOF
}
return b, err
}
// ReadBytes reads an encoded []byte from buf, returning the number of bytes
// read, and any read error encountered.
func ReadBytes(buf io.ByteReader) (ret []byte, n int, err error) {
tmpBuf := bytes.Buffer{}
acc := byte(0)
for i := 0; i < ReadByteLimit; i++ {
o := byte(0)
if o, err = buf.ReadByte(); err != nil {
return
}
n++
b := o & 0xfe // user data
m := uint(i % 8)
if m == 0 {
acc = b
} else {
// ignore err since bytes.Buffer.WriteByte can never return one.
_ = tmpBuf.WriteByte(acc | (b >> (8 - m)))
acc = (b << m)
}
if o&1 == 0 { // stop bit is 0
ret = tmpBuf.Bytes()
return
}
}
err = ErrByteLimitExceeded
return
}
func cmp(br1, br2 io.ByteReader, f1, f2 string) {
status := 0
char := int64(0)
line := int64(1)
for {
b1, e1 := br1.ReadByte()
b2, e2 := br2.ReadByte()
char++
if e1 != nil || e2 != nil {
if e1 == e2 {
break
}
if e1 == io.EOF {
fmt.Printf("EOF on %v\n", f1)
}
if e2 == io.EOF {
fmt.Printf("EOF on %v\n", f2)
}
break
}
if b1 == '\n' {
line++
}
if b1 != b2 {
printDiff(f1, f2, char, line, b1, b2)
status = 1
}
}
os.Exit(status)
}
func SkipLine(r io.ByteReader) error {
for {
if b, err := r.ReadByte(); err != nil || b == '\n' {
return err
}
}
return nil
}
// match implements the internal logic for running a single match, reading
// in each byte of the ByteReader and traversing the internal AC tree to look
// for matches.
func (t *acTree) match(reader io.ByteReader, output chan Match) {
m := t.Matcher()
for b, err := reader.ReadByte(); err != io.EOF; b, err = reader.ReadByte() {
for _, match := range m.Next(b) {
output <- match
}
}
close(output)
}
func more(r io.ByteReader, more byte) (x uint64, err error) {
x = 0
for more != 0 {
var b byte
if b, err = r.ReadByte(); err != nil {
return
}
more--
x += uint64(b) << (8 * more)
}
return
}
// Performs like io.ReadFull, but uses a ByteReader instead.
func ByteReadFull(rd io.ByteReader, buf []byte) (cnt int, err error) {
for cnt = 0; cnt < len(buf); cnt++ {
buf[cnt], err = rd.ReadByte()
if err == io.EOF && cnt > 0 {
err = io.ErrUnexpectedEOF
}
if err != nil {
return
}
}
return
}
func readInts(buffer []int64, offset, len, bitSize int, r io.ByteReader) error {
bitsLeft := 0
current := 0
switch bitSize {
case 1:
return unrolledUnPack1(buffer, offset, len, r)
case 2:
return unrolledUnPack2(buffer, offset, len, r)
case 4:
return unrolledUnPack4(buffer, offset, len, r)
case 8:
return unrolledUnPack8(buffer, offset, len, r)
case 16:
return unrolledUnPack16(buffer, offset, len, r)
case 24:
return unrolledUnPack24(buffer, offset, len, r)
case 32:
return unrolledUnPack32(buffer, offset, len, r)
case 40:
return unrolledUnPack40(buffer, offset, len, r)
case 48:
return unrolledUnPack48(buffer, offset, len, r)
case 56:
return unrolledUnPack56(buffer, offset, len, r)
case 64:
return unrolledUnPack64(buffer, offset, len, r)
}
for i := offset; i < (offset + len); i++ {
var result int64
bitsLeftToRead := bitSize
for bitsLeftToRead > bitsLeft {
result <<= uint64(bitsLeft)
result |= int64(current & ((1 << uint64(bitsLeft)) - 1))
bitsLeftToRead -= bitsLeft
byt, err := r.ReadByte()
if err != nil {
return err
}
current = int(byt)
bitsLeft = 8
}
// handle the left over bits
if bitsLeftToRead > 0 {
result <<= uint64(bitsLeftToRead)
bitsLeft -= bitsLeftToRead
result |= int64((current >> uint64(bitsLeft)) & ((1 << uint64(bitsLeftToRead)) - 1))
}
buffer[i] = result
}
return nil
}
func encodeSingle(input io.ByteReader, output io.ByteWriter) (noMoreInput bool,
err error) {
byteOne, err := input.ReadByte()
if err != nil {
// No more to read
return true, nil
}
if byteOne == 0x00 {
// Special cases
// Maybe special case
nextByte, err := input.ReadByte()
if err != nil {
err = output.WriteByte(0x00)
if err != nil {
return false, err
}
return true, nil
}
if nextByte == 0x00 || nextByte == 0x01 {
// Need to escape that
err = output.WriteByte(0x00)
if err != nil {
return false, err
}
err = output.WriteByte(0x01)
if err != nil {
return false, err
}
err = output.WriteByte(nextByte)
if err != nil {
return false, err
}
} else {
// Ah, no, no special case
err = output.WriteByte(0x00)
if err != nil {
return false, err
}
err = output.WriteByte(nextByte)
if err != nil {
return false, err
}
}
} else {
// Standard case
err = output.WriteByte(byteOne)
if err != nil {
return false, err
}
}
return false, nil
}
func readString(r io.ByteReader) string {
l := readUvarint(r)
var by []byte
for i := 0; i < int(l); i++ {
b, err := r.ReadByte()
if err != nil {
fmt.Println("Error reading string:", err)
os.Exit(1)
}
by = append(by, b)
}
return string(by)
}
func bytesToLongBE(r io.ByteReader, n int) (int64, error) {
var out int64
var val int64
for n > 0 {
n--
byt, err := r.ReadByte()
if err != nil {
return 0, err
}
val = int64(byt)
out |= val << uint64(n*8)
}
return out, nil
}
func readOffset(r io.ByteReader) (uint64, error) {
var offset uint64
for {
b, err := r.ReadByte()
if err != nil {
return 0, err
}
offset |= uint64(b & 0x7f)
if b&0x80 == 0 {
return offset, nil
}
offset = (offset + 1) << 7
}
}
func ByteCopyN(dst io.ByteWriter, src io.ByteReader, num int64) (cnt int64, err error) {
var val byte
for cnt = 0; cnt < num; cnt++ {
if val, err = src.ReadByte(); err != nil {
break
}
if err = dst.WriteByte(val); err != nil {
break
}
}
if cnt == num { // This is expected
err = nil
}
return
}
func ByteCopy(dst io.ByteWriter, src io.ByteReader) (cnt int64, err error) {
var val byte
for cnt = 0; true; cnt++ {
if val, err = src.ReadByte(); err != nil {
break
}
if err = dst.WriteByte(val); err != nil {
break
}
}
if err == io.EOF { // This is expected
err = nil
}
return
}
// ReadULeb128 reads and decodes an unsigned LEB128 value from a ByteReader to an unsigned int32 value. Returns the result as a uint32
func ReadULeb128(reader io.ByteReader) uint32 {
var result uint32
var ctr uint
var cur byte = 0x80
var err error
for (cur&0x80 == 0x80) && ctr < 5 {
cur, err = reader.ReadByte()
if err != nil {
panic(err)
}
result += uint32((cur & 0x7f)) << (ctr * 7)
ctr++
}
return result
}
func (h *Header) Read(reader io.ByteReader) error {
var err error
h.versionNumber, err = reader.ReadByte()
if err == nil {
h.publicIdentifier, err = readMultiByteUint32(reader)
if err == nil {
h.charSet, err = readMultiByteUint32(reader)
if err == nil {
h.charSetAsString, _ = GetCharsetStringByCode(h.charSet)
err = h.stringTable.Read(reader)
}
}
}
return err
}
// ReadUint reads an encoded unsigned integer from r and returns it as a uint64.
func ReadUint(r io.ByteReader) (uint64, error) {
var x uint64
for i := 0; ; i++ {
b, err := r.ReadByte()
if err != nil {
return x, err
}
x = (x << 7) | uint64(b&0x7f)
if b < 0x80 {
return x, nil
} else if i == 9 {
return 0, overflow
}
}
}
// interpret reads from r and writes to w. While reading any color escape codes detected
// are replaced by the result of calling subst with the escape code.
func interpret(r io.ByteReader, w io.Writer, subst func(s string) []byte) error {
inEscape := false
escape := &bytes.Buffer{}
for {
c, err := r.ReadByte()
if err != nil {
// EOF
break
}
if inEscape {
if rune(c) == '{' && escape.Len() == 0 {
// False alarm: this was the sequence {{ which means the user wanted to
// output {.
_, err = w.Write([]byte("{"))
escape.Reset()
inEscape = false
} else if rune(c) == '}' {
_, err = w.Write(subst(escape.String()))
escape.Reset()
inEscape = false
} else {
escape.WriteByte(c)
if MaxEscapeCodeLen > 0 && uint(escape.Len()) > MaxEscapeCodeLen {
// Escape code too long
w.Write([]byte("{"))
_, err = w.Write(escape.Bytes())
inEscape = false
}
}
} else {
if rune(c) == '{' {
inEscape = true
} else {
_, err = w.Write([]byte{c})
}
}
if err != nil {
// Write error occurred
return err
}
}
return nil
}
func readVulong(r io.ByteReader) (int64, error) {
var result int64
var offset int
b := int64(0x80)
for (b & 0x80) != 0 {
nb, err := r.ReadByte()
if err != nil {
return result, err
}
b = int64(nb)
if b == -1 {
return result, ErrEOFUnsignedVInt
}
result |= (b & 0x7f) << uint64(offset)
offset += 7
}
return result, nil
}
// ReadUvarint reads an encoded unsigned integer from r and returns it as a uint64.
func ReadUvarint(r io.ByteReader) (uint64, error) {
var x uint64
var s uint
for i := 0; ; i++ {
b, err := r.ReadByte()
if err != nil {
return x, err
}
if b < 0x80 {
if i > 9 || i == 9 && b > 1 {
return x, overflow
}
return x | uint64(b)<<s, nil
}
x |= uint64(b&0x7f) << s
s += 7
}
}
func decodeOffset(src io.ByteReader, steps int) (int, error) {
b, err := src.ReadByte()
if err != nil {
return 0, err
}
var offset = int(b & 0x7f)
for (b & 0x80) != 0 {
offset += 1 // WHY?
b, err = src.ReadByte()
if err != nil {
return 0, err
}
offset = (offset << 7) + int(b&0x7f)
}
// offset needs to be aware of the bytes we read for `o.typ` and `o.size`
offset += steps
return -offset, nil
}
