func unrolledBitPack1(input []int64, offset int, len int, w io.ByteWriter) error {
numHops := 8
remainder := len % numHops
endOffset := offset + len
endUnroll := endOffset - remainder
val := 0
for i := offset; i < endUnroll; i = i + numHops {
val = (val | (int(input[i]&1) << 7) |
(int(input[i+1]&1) << 6) |
(int(input[i+2]&1) << 5) |
(int(input[i+3]&1) << 4) |
(int(input[i+4]&1) << 3) |
(int(input[i+5]&1) << 2) |
(int(input[i+6]&1) << 1) |
int(input[i+7])&1)
err := w.WriteByte(byte(val))
if err != nil {
return err
}
val = 0
}
if remainder > 0 {
startShift := 7
for i := endUnroll; i < endOffset; i++ {
val = (val | int(input[i]&1)<<uint64(startShift))
startShift--
}
err := w.WriteByte(byte(val))
if err != nil {
return err
}
}
return nil
}
func unrolledBitPack4(input []int64, offset int, len int, w io.ByteWriter) error {
numHops := 2
remainder := len % numHops
endOffset := offset + len
endUnroll := endOffset - remainder
val := 0
for i := offset; i < endUnroll; i = i + numHops {
val = (val | (int(input[i]&15) << 4) | int(input[i+1])&15)
err := w.WriteByte(byte(val))
if err != nil {
return err
}
val = 0
}
if remainder > 0 {
startShift := 4
for i := endUnroll; i < endOffset; i++ {
val = (val | int(input[i]&15)<<uint64(startShift))
startShift -= 4
}
err := w.WriteByte(byte(val))
if err != nil {
return err
}
}
return nil
}
// WriteBytes writes an encoded []byte to buf, returning the number of bytes
// written, and any write error encountered.
func WriteBytes(buf io.ByteWriter, data []byte) (n int, err error) {
wb := func(b byte) (err error) {
if err = buf.WriteByte(b); err == nil {
n++
}
return
}
acc := byte(0)
for i := 0; i < len(data); i++ {
m := uint(i % 7)
b := data[i]
if err = wb(acc | 1 | ((b & (0xff << (m + 1))) >> m)); err != nil {
return
}
acc = (b << (7 - m))
if m == 6 {
if err = wb(acc | 1); err != nil {
return
}
acc = 0
}
}
err = wb(acc)
return
}
// Allows multiple bytes to be written to a buffer like io.Write.
func ByteWriteFull(wr io.ByteWriter, buf []byte) (cnt int, err error) {
for cnt = 0; cnt < len(buf); cnt++ {
err = wr.WriteByte(buf[cnt])
if err != nil {
return
}
}
return
}
// encodeInt writes an encoded int64 to the passed io.ByteWriter.
func encodeInt(v int64, w io.ByteWriter) {
if v < 0 {
v = ^(v << 1)
} else {
v <<= 1
}
for v >= 0x20 {
w.WriteByte((0x20 | (byte(v) & 0x1f)) + 63)
v >>= 5
}
w.WriteByte(byte(v) + 63)
}
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
}
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 writeVulong(w io.ByteWriter, value int64) error {
for {
if (value & ^0x7f) == 0 {
err := w.WriteByte(byte(value))
if err != nil {
return err
}
return nil
}
err := w.WriteByte(byte(0x80 | (value & 0x7f)))
if err != nil {
return err
}
value = int64(uint64(value) >> 7)
}
}
func writeRemainingLongs(w io.ByteWriter, offset int, input []int64, remainder int, numBytes int) error {
numHops := remainder
idx := 0
writeBuffer := make([]byte, 64, 64)
switch numBytes {
case 1:
for remainder > 0 {
writeBuffer[idx] = byte(input[offset+idx] & 255)
remainder--
idx++
}
case 2:
for remainder > 0 {
writeLongBE2(writeBuffer, input[offset+idx], idx*2)
remainder--
idx++
}
case 3:
for remainder > 0 {
writeLongBE3(writeBuffer, input[offset+idx], idx*3)
remainder--
idx++
}
case 4:
for remainder > 0 {
writeLongBE4(writeBuffer, input[offset+idx], idx*4)
remainder--
idx++
}
case 5:
for remainder > 0 {
writeLongBE5(writeBuffer, input[offset+idx], idx*5)
remainder--
idx++
}
case 6:
for remainder > 0 {
writeLongBE6(writeBuffer, input[offset+idx], idx*6)
remainder--
idx++
}
case 7:
for remainder > 0 {
writeLongBE7(writeBuffer, input[offset+idx], idx*7)
remainder--
idx++
}
case 8:
for remainder > 0 {
writeLongBE8(writeBuffer, input[offset+idx], idx*8)
remainder--
idx++
}
}
toWrite := numHops * numBytes
for j := 0; j < toWrite; j++ {
err := w.WriteByte(writeBuffer[j])
if err != nil {
return err
}
}
return nil
}
func writeLongBE(w io.ByteWriter, input []int64, offset int, numHops int, numBytes int) error {
writeBuffer := make([]byte, BufferSize, BufferSize)
switch numBytes {
case 1:
writeBuffer[0] = byte(input[offset+0] & 255)
writeBuffer[1] = byte(input[offset+1] & 255)
writeBuffer[2] = byte(input[offset+2] & 255)
writeBuffer[3] = byte(input[offset+3] & 255)
writeBuffer[4] = byte(input[offset+4] & 255)
writeBuffer[5] = byte(input[offset+5] & 255)
writeBuffer[6] = byte(input[offset+6] & 255)
writeBuffer[7] = byte(input[offset+7] & 255)
case 2:
writeLongBE2(writeBuffer, input[offset+0], 0)
writeLongBE2(writeBuffer, input[offset+1], 2)
writeLongBE2(writeBuffer, input[offset+2], 4)
writeLongBE2(writeBuffer, input[offset+3], 6)
writeLongBE2(writeBuffer, input[offset+4], 8)
writeLongBE2(writeBuffer, input[offset+5], 10)
writeLongBE2(writeBuffer, input[offset+6], 12)
writeLongBE2(writeBuffer, input[offset+7], 14)
case 3:
writeLongBE3(writeBuffer, input[offset+0], 0)
writeLongBE3(writeBuffer, input[offset+1], 3)
writeLongBE3(writeBuffer, input[offset+2], 6)
writeLongBE3(writeBuffer, input[offset+3], 9)
writeLongBE3(writeBuffer, input[offset+4], 12)
writeLongBE3(writeBuffer, input[offset+5], 15)
writeLongBE3(writeBuffer, input[offset+6], 18)
writeLongBE3(writeBuffer, input[offset+7], 21)
case 4:
writeLongBE4(writeBuffer, input[offset+0], 0)
writeLongBE4(writeBuffer, input[offset+1], 4)
writeLongBE4(writeBuffer, input[offset+2], 8)
writeLongBE4(writeBuffer, input[offset+3], 12)
writeLongBE4(writeBuffer, input[offset+4], 16)
writeLongBE4(writeBuffer, input[offset+5], 20)
writeLongBE4(writeBuffer, input[offset+6], 24)
writeLongBE4(writeBuffer, input[offset+7], 28)
case 5:
writeLongBE5(writeBuffer, input[offset+0], 0)
writeLongBE5(writeBuffer, input[offset+1], 5)
writeLongBE5(writeBuffer, input[offset+2], 10)
writeLongBE5(writeBuffer, input[offset+3], 15)
writeLongBE5(writeBuffer, input[offset+4], 20)
writeLongBE5(writeBuffer, input[offset+5], 25)
writeLongBE5(writeBuffer, input[offset+6], 30)
writeLongBE5(writeBuffer, input[offset+7], 35)
case 6:
writeLongBE6(writeBuffer, input[offset+0], 0)
writeLongBE6(writeBuffer, input[offset+1], 6)
writeLongBE6(writeBuffer, input[offset+2], 12)
writeLongBE6(writeBuffer, input[offset+3], 18)
writeLongBE6(writeBuffer, input[offset+4], 24)
writeLongBE6(writeBuffer, input[offset+5], 30)
writeLongBE6(writeBuffer, input[offset+6], 36)
writeLongBE6(writeBuffer, input[offset+7], 42)
case 7:
writeLongBE7(writeBuffer, input[offset+0], 0)
writeLongBE7(writeBuffer, input[offset+1], 7)
writeLongBE7(writeBuffer, input[offset+2], 14)
writeLongBE7(writeBuffer, input[offset+3], 21)
writeLongBE7(writeBuffer, input[offset+4], 28)
writeLongBE7(writeBuffer, input[offset+5], 35)
writeLongBE7(writeBuffer, input[offset+6], 42)
writeLongBE7(writeBuffer, input[offset+7], 49)
case 8:
writeLongBE8(writeBuffer, input[offset+0], 0)
writeLongBE8(writeBuffer, input[offset+1], 8)
writeLongBE8(writeBuffer, input[offset+2], 16)
writeLongBE8(writeBuffer, input[offset+3], 24)
writeLongBE8(writeBuffer, input[offset+4], 32)
writeLongBE8(writeBuffer, input[offset+5], 40)
writeLongBE8(writeBuffer, input[offset+6], 48)
writeLongBE8(writeBuffer, input[offset+7], 56)
}
toWrite := numHops * numBytes
for j := 0; j < toWrite; j++ {
err := w.WriteByte(writeBuffer[j])
if err != nil {
return err
}
}
return nil
}
func writeInts(input []int64, offset int, l int, bitSize int, w io.ByteWriter) error {
if input == nil || len(input) < 1 || offset < 0 || l < 1 || bitSize < 1 {
return nil
}
switch bitSize {
case 1:
return unrolledBitPack1(input, offset, l, w)
case 2:
return unrolledBitPack2(input, offset, l, w)
case 4:
return unrolledBitPack4(input, offset, l, w)
case 8:
return unrolledBitPack8(input, offset, l, w)
case 16:
return unrolledBitPack16(input, offset, l, w)
case 24:
return unrolledBitPack24(input, offset, l, w)
case 32:
return unrolledBitPack32(input, offset, l, w)
case 40:
return unrolledBitPack40(input, offset, l, w)
case 48:
return unrolledBitPack48(input, offset, l, w)
case 56:
return unrolledBitPack56(input, offset, l, w)
case 64:
return unrolledBitPack64(input, offset, l, w)
}
bitsLeft := 8
current := byte(0x00)
for i := offset; i < (offset + l); i++ {
value := input[i]
bitsToWrite := bitSize
for bitsToWrite > bitsLeft {
// add the bits to the bottom of the current word
current |= uint8(uint64(value) >> uint64(bitsToWrite-bitsLeft))
// subtract out the bits we just added
bitsToWrite -= bitsLeft
// zero out the bits above bitsToWrite
value &= (1 << uint64(bitsToWrite)) - 1
err := w.WriteByte(current)
if err != nil {
return err
}
current = 0
bitsLeft = 8
}
bitsLeft -= bitsToWrite
current |= uint8(value << uint64(bitsLeft))
if bitsLeft == 0 {
err := w.WriteByte(current)
if err != nil {
return err
}
current = 0
bitsLeft = 8
}
}
// flush
if bitsLeft != 8 {
err := w.WriteByte(current)
if err != nil {
return err
}
current = 0
bitsLeft = 8
}
return nil
}
func decodeSingle(input io.ByteReader, output io.ByteWriter) (noMoreInput bool,
endOfKey bool, err error) {
byteOne, err := input.ReadByte()
if err != nil {
// No more to read
return true, false, nil
}
if byteOne == 0x00 {
// Maybe special case
nextByte, err := input.ReadByte()
if err != nil {
// End reached, no special case
err = output.WriteByte(0x00)
if err != nil {
return false, false, err
}
return true, false, nil
}
if nextByte == 0x00 {
// End of key here, nothing to write
return false, true, nil
}
if nextByte == 0x01 {
// Escape, read the next byte
escapedByte, err := input.ReadByte()
if err != nil {
return true, false, nil //TODO: Is this error?
}
err = output.WriteByte(0x00)
if err != nil {
return false, false, err
}
if !(escapedByte == 0x00 || escapedByte == 0x01) {
// Error, wrong escaped byte
err = errors.New(fmt.Sprintf("Wrong escape sequence, expecting byte 0 or 1 "+
"but got %v", escapedByte))
return false, false, err
}
err = output.WriteByte(escapedByte)
if err != nil {
return false, false, err
}
// Done here with unescaping
return false, false, nil
}
// Nope, no special case
err = output.WriteByte(0x00)
if err != nil {
return false, false, err
}
err = output.WriteByte(nextByte)
if err != nil {
return false, false, err
}
} else {
// Standard case
err = output.WriteByte(byteOne)
if err != nil {
return false, false, err
}
}
return false, false, 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 (i InstWriteToOutput) Eval(t Tape, in io.ByteReader, out io.ByteWriter) {
b := t.GetByte()
out.WriteByte(b)
}
