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author | Wim <wim@42.be> | 2022-08-13 16:14:26 +0200 |
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committer | GitHub <noreply@github.com> | 2022-08-13 16:14:26 +0200 |
commit | 6a3fc713978a0c1c9290a4afd08b47886b49b635 (patch) | |
tree | aa62cd85cf5671646c75ee38b3fc140ef7edcea8 /vendor/github.com/klauspost/compress/s2/index.go | |
parent | 3c4192ebf6a32e30cdd23a9644c2ceca72a006fa (diff) | |
download | matterbridge-msglm-6a3fc713978a0c1c9290a4afd08b47886b49b635.tar.gz matterbridge-msglm-6a3fc713978a0c1c9290a4afd08b47886b49b635.tar.bz2 matterbridge-msglm-6a3fc713978a0c1c9290a4afd08b47886b49b635.zip |
Update dependencies and go1.18 (#1873)
* Update dependencies and go1.18
* Exclude unnecessary linters and update build to go1.18
Diffstat (limited to 'vendor/github.com/klauspost/compress/s2/index.go')
-rw-r--r-- | vendor/github.com/klauspost/compress/s2/index.go | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/vendor/github.com/klauspost/compress/s2/index.go b/vendor/github.com/klauspost/compress/s2/index.go index 7b24a006..dd9ecfe7 100644 --- a/vendor/github.com/klauspost/compress/s2/index.go +++ b/vendor/github.com/klauspost/compress/s2/index.go @@ -533,3 +533,66 @@ func (i *Index) JSON() []byte { b, _ := json.MarshalIndent(x, "", " ") return b } + +// RemoveIndexHeaders will trim all headers and trailers from a given index. +// This is expected to save 20 bytes. +// These can be restored using RestoreIndexHeaders. +// This removes a layer of security, but is the most compact representation. +// Returns nil if headers contains errors. +// The returned slice references the provided slice. +func RemoveIndexHeaders(b []byte) []byte { + const save = 4 + len(S2IndexHeader) + len(S2IndexTrailer) + 4 + if len(b) <= save { + return nil + } + if b[0] != ChunkTypeIndex { + return nil + } + chunkLen := int(b[1]) | int(b[2])<<8 | int(b[3])<<16 + b = b[4:] + + // Validate we have enough... + if len(b) < chunkLen { + return nil + } + b = b[:chunkLen] + + if !bytes.Equal(b[:len(S2IndexHeader)], []byte(S2IndexHeader)) { + return nil + } + b = b[len(S2IndexHeader):] + if !bytes.HasSuffix(b, []byte(S2IndexTrailer)) { + return nil + } + b = bytes.TrimSuffix(b, []byte(S2IndexTrailer)) + + if len(b) < 4 { + return nil + } + return b[:len(b)-4] +} + +// RestoreIndexHeaders will index restore headers removed by RemoveIndexHeaders. +// No error checking is performed on the input. +// If a 0 length slice is sent, it is returned without modification. +func RestoreIndexHeaders(in []byte) []byte { + if len(in) == 0 { + return in + } + b := make([]byte, 0, 4+len(S2IndexHeader)+len(in)+len(S2IndexTrailer)+4) + b = append(b, ChunkTypeIndex, 0, 0, 0) + b = append(b, []byte(S2IndexHeader)...) + b = append(b, in...) + + var tmp [4]byte + binary.LittleEndian.PutUint32(tmp[:], uint32(len(b)+4+len(S2IndexTrailer))) + b = append(b, tmp[:4]...) + // Trailer + b = append(b, []byte(S2IndexTrailer)...) + + chunkLen := len(b) - skippableFrameHeader + b[1] = uint8(chunkLen >> 0) + b[2] = uint8(chunkLen >> 8) + b[3] = uint8(chunkLen >> 16) + return b +} |