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ceph-csi/vendor/github.com/pierrec/lz4/decode_other.go
Niels de Vos 91774fc936 rebase: vendor dependencies for Vault API
Uses github.com/libopenstorage/secrets to communicate with Vault. This
removes the need for maintaining our own limited Vault APIs.

By adding the new dependency, several other packages got updated in the
process. Unused indirect dependencies have been removed from go.mod.

Signed-off-by: Niels de Vos <ndevos@redhat.com>
2020-11-29 04:03:59 +00:00

99 lines
2.1 KiB
Go

// +build !amd64 appengine !gc noasm
package lz4
func decodeBlock(dst, src []byte) (ret int) {
const hasError = -2
defer func() {
if recover() != nil {
ret = hasError
}
}()
var si, di int
for {
// Literals and match lengths (token).
b := int(src[si])
si++
// Literals.
if lLen := b >> 4; lLen > 0 {
switch {
case lLen < 0xF && si+16 < len(src):
// Shortcut 1
// if we have enough room in src and dst, and the literals length
// is small enough (0..14) then copy all 16 bytes, even if not all
// are part of the literals.
copy(dst[di:], src[si:si+16])
si += lLen
di += lLen
if mLen := b & 0xF; mLen < 0xF {
// Shortcut 2
// if the match length (4..18) fits within the literals, then copy
// all 18 bytes, even if not all are part of the literals.
mLen += 4
if offset := int(src[si]) | int(src[si+1])<<8; mLen <= offset {
i := di - offset
end := i + 18
if end > len(dst) {
// The remaining buffer may not hold 18 bytes.
// See https://github.com/pierrec/lz4/issues/51.
end = len(dst)
}
copy(dst[di:], dst[i:end])
si += 2
di += mLen
continue
}
}
case lLen == 0xF:
for src[si] == 0xFF {
lLen += 0xFF
si++
}
lLen += int(src[si])
si++
fallthrough
default:
copy(dst[di:di+lLen], src[si:si+lLen])
si += lLen
di += lLen
}
}
if si >= len(src) {
return di
}
offset := int(src[si]) | int(src[si+1])<<8
if offset == 0 {
return hasError
}
si += 2
// Match.
mLen := b & 0xF
if mLen == 0xF {
for src[si] == 0xFF {
mLen += 0xFF
si++
}
mLen += int(src[si])
si++
}
mLen += minMatch
// Copy the match.
expanded := dst[di-offset:]
if mLen > offset {
// Efficiently copy the match dst[di-offset:di] into the dst slice.
bytesToCopy := offset * (mLen / offset)
for n := offset; n <= bytesToCopy+offset; n *= 2 {
copy(expanded[n:], expanded[:n])
}
di += bytesToCopy
mLen -= bytesToCopy
}
di += copy(dst[di:di+mLen], expanded[:mLen])
}
}