mirror of
https://github.com/cwinfo/matterbridge.git
synced 2024-12-28 15:55:40 +00:00
2f33fe86f5
* Update dependencies and build to go1.22 * Fix api changes wrt to dependencies * Update golangci config
103 lines
3.0 KiB
Go
103 lines
3.0 KiB
Go
// Copyright 2018 Klaus Post. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
// Based on work Copyright (c) 2013, Yann Collet, released under BSD License.
|
|
|
|
package huff0
|
|
|
|
// bitWriter will write bits.
|
|
// First bit will be LSB of the first byte of output.
|
|
type bitWriter struct {
|
|
bitContainer uint64
|
|
nBits uint8
|
|
out []byte
|
|
}
|
|
|
|
// addBits16Clean will add up to 16 bits. value may not contain more set bits than indicated.
|
|
// It will not check if there is space for them, so the caller must ensure that it has flushed recently.
|
|
func (b *bitWriter) addBits16Clean(value uint16, bits uint8) {
|
|
b.bitContainer |= uint64(value) << (b.nBits & 63)
|
|
b.nBits += bits
|
|
}
|
|
|
|
// encSymbol will add up to 16 bits. value may not contain more set bits than indicated.
|
|
// It will not check if there is space for them, so the caller must ensure that it has flushed recently.
|
|
func (b *bitWriter) encSymbol(ct cTable, symbol byte) {
|
|
enc := ct[symbol]
|
|
b.bitContainer |= uint64(enc.val) << (b.nBits & 63)
|
|
if false {
|
|
if enc.nBits == 0 {
|
|
panic("nbits 0")
|
|
}
|
|
}
|
|
b.nBits += enc.nBits
|
|
}
|
|
|
|
// encTwoSymbols will add up to 32 bits. value may not contain more set bits than indicated.
|
|
// It will not check if there is space for them, so the caller must ensure that it has flushed recently.
|
|
func (b *bitWriter) encTwoSymbols(ct cTable, av, bv byte) {
|
|
encA := ct[av]
|
|
encB := ct[bv]
|
|
sh := b.nBits & 63
|
|
combined := uint64(encA.val) | (uint64(encB.val) << (encA.nBits & 63))
|
|
b.bitContainer |= combined << sh
|
|
if false {
|
|
if encA.nBits == 0 {
|
|
panic("nbitsA 0")
|
|
}
|
|
if encB.nBits == 0 {
|
|
panic("nbitsB 0")
|
|
}
|
|
}
|
|
b.nBits += encA.nBits + encB.nBits
|
|
}
|
|
|
|
// encFourSymbols adds up to 32 bits from four symbols.
|
|
// It will not check if there is space for them,
|
|
// so the caller must ensure that b has been flushed recently.
|
|
func (b *bitWriter) encFourSymbols(encA, encB, encC, encD cTableEntry) {
|
|
bitsA := encA.nBits
|
|
bitsB := bitsA + encB.nBits
|
|
bitsC := bitsB + encC.nBits
|
|
bitsD := bitsC + encD.nBits
|
|
combined := uint64(encA.val) |
|
|
(uint64(encB.val) << (bitsA & 63)) |
|
|
(uint64(encC.val) << (bitsB & 63)) |
|
|
(uint64(encD.val) << (bitsC & 63))
|
|
b.bitContainer |= combined << (b.nBits & 63)
|
|
b.nBits += bitsD
|
|
}
|
|
|
|
// flush32 will flush out, so there are at least 32 bits available for writing.
|
|
func (b *bitWriter) flush32() {
|
|
if b.nBits < 32 {
|
|
return
|
|
}
|
|
b.out = append(b.out,
|
|
byte(b.bitContainer),
|
|
byte(b.bitContainer>>8),
|
|
byte(b.bitContainer>>16),
|
|
byte(b.bitContainer>>24))
|
|
b.nBits -= 32
|
|
b.bitContainer >>= 32
|
|
}
|
|
|
|
// flushAlign will flush remaining full bytes and align to next byte boundary.
|
|
func (b *bitWriter) flushAlign() {
|
|
nbBytes := (b.nBits + 7) >> 3
|
|
for i := uint8(0); i < nbBytes; i++ {
|
|
b.out = append(b.out, byte(b.bitContainer>>(i*8)))
|
|
}
|
|
b.nBits = 0
|
|
b.bitContainer = 0
|
|
}
|
|
|
|
// close will write the alignment bit and write the final byte(s)
|
|
// to the output.
|
|
func (b *bitWriter) close() {
|
|
// End mark
|
|
b.addBits16Clean(1, 1)
|
|
// flush until next byte.
|
|
b.flushAlign()
|
|
}
|