986f076276
Add a new generic container registry client via a new `container` package. Use this to create a command line utility as well as a new upload target for container registries. The code uses the github.com/containers/* project and packages to interact with container registires that is also used by skopeo, podman et al. One if the dependencies is `proglottis/gpgme` that is using cgo to bind libgpgme, so we have to add the corresponding devel package to the BuildRequires as well as installing it on CI. Checks will follow later via an integration test.
122 lines
2.8 KiB
Go
122 lines
2.8 KiB
Go
package zstd
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import (
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"bytes"
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"encoding/binary"
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"errors"
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"fmt"
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"io"
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"github.com/klauspost/compress/huff0"
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)
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type dict struct {
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id uint32
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litEnc *huff0.Scratch
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llDec, ofDec, mlDec sequenceDec
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//llEnc, ofEnc, mlEnc []*fseEncoder
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offsets [3]int
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content []byte
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}
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var dictMagic = [4]byte{0x37, 0xa4, 0x30, 0xec}
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// ID returns the dictionary id or 0 if d is nil.
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func (d *dict) ID() uint32 {
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if d == nil {
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return 0
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}
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return d.id
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}
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// DictContentSize returns the dictionary content size or 0 if d is nil.
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func (d *dict) DictContentSize() int {
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if d == nil {
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return 0
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}
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return len(d.content)
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}
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// Load a dictionary as described in
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// https://github.com/facebook/zstd/blob/master/doc/zstd_compression_format.md#dictionary-format
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func loadDict(b []byte) (*dict, error) {
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// Check static field size.
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if len(b) <= 8+(3*4) {
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return nil, io.ErrUnexpectedEOF
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}
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d := dict{
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llDec: sequenceDec{fse: &fseDecoder{}},
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ofDec: sequenceDec{fse: &fseDecoder{}},
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mlDec: sequenceDec{fse: &fseDecoder{}},
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}
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if !bytes.Equal(b[:4], dictMagic[:]) {
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return nil, ErrMagicMismatch
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}
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d.id = binary.LittleEndian.Uint32(b[4:8])
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if d.id == 0 {
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return nil, errors.New("dictionaries cannot have ID 0")
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}
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// Read literal table
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var err error
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d.litEnc, b, err = huff0.ReadTable(b[8:], nil)
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if err != nil {
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return nil, err
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}
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d.litEnc.Reuse = huff0.ReusePolicyMust
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br := byteReader{
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b: b,
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off: 0,
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}
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readDec := func(i tableIndex, dec *fseDecoder) error {
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if err := dec.readNCount(&br, uint16(maxTableSymbol[i])); err != nil {
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return err
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}
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if br.overread() {
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return io.ErrUnexpectedEOF
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}
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err = dec.transform(symbolTableX[i])
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if err != nil {
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println("Transform table error:", err)
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return err
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}
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if debugDecoder || debugEncoder {
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println("Read table ok", "symbolLen:", dec.symbolLen)
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}
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// Set decoders as predefined so they aren't reused.
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dec.preDefined = true
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return nil
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}
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if err := readDec(tableOffsets, d.ofDec.fse); err != nil {
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return nil, err
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}
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if err := readDec(tableMatchLengths, d.mlDec.fse); err != nil {
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return nil, err
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}
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if err := readDec(tableLiteralLengths, d.llDec.fse); err != nil {
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return nil, err
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}
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if br.remain() < 12 {
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return nil, io.ErrUnexpectedEOF
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}
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d.offsets[0] = int(br.Uint32())
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br.advance(4)
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d.offsets[1] = int(br.Uint32())
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br.advance(4)
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d.offsets[2] = int(br.Uint32())
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br.advance(4)
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if d.offsets[0] <= 0 || d.offsets[1] <= 0 || d.offsets[2] <= 0 {
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return nil, errors.New("invalid offset in dictionary")
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}
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d.content = make([]byte, br.remain())
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copy(d.content, br.unread())
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if d.offsets[0] > len(d.content) || d.offsets[1] > len(d.content) || d.offsets[2] > len(d.content) {
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return nil, fmt.Errorf("initial offset bigger than dictionary content size %d, offsets: %v", len(d.content), d.offsets)
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}
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return &d, nil
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}
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