mirror of
https://codeberg.org/forgejo/forgejo
synced 2024-12-14 23:41:58 +01:00
56 lines
1.3 KiB
Go
56 lines
1.3 KiB
Go
|
// Copyright (c) 2017 Couchbase, Inc.
|
||
|
|
//
|
||
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
||
|
|
// you may not use this file except in compliance with the License.
|
||
|
|
// You may obtain a copy of the License at
|
||
|
|
//
|
||
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
||
|
|
//
|
||
|
|
// Unless required by applicable law or agreed to in writing, software
|
||
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
||
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||
|
|
// See the License for the specific language governing permissions and
|
||
|
|
// limitations under the License.
|
||
|
|
|
||
|
|
package vellum
|
||
|
|
|
||
|
|
func deltaAddr(base, trans uint64) uint64 {
|
||
|
|
// transition dest of 0 is special case
|
||
|
|
if trans == 0 {
|
||
|
|
return 0
|
||
|
|
}
|
||
|
|
return base - trans
|
||
|
|
}
|
||
|
|
|
||
|
|
const packOutMask = 1<<4 - 1
|
||
|
|
|
||
|
|
func encodePackSize(transSize, outSize int) byte {
|
||
|
|
var rv byte
|
||
|
|
rv = byte(transSize << 4)
|
||
|
|
rv |= byte(outSize)
|
||
|
|
return rv
|
||
|
|
}
|
||
|
|
|
||
|
|
func decodePackSize(pack byte) (transSize int, packSize int) {
|
||
|
|
transSize = int(pack >> 4)
|
||
|
|
packSize = int(pack & packOutMask)
|
||
|
|
return
|
||
|
|
}
|
||
|
|
|
||
|
|
const maxNumTrans = 1<<6 - 1
|
||
|
|
|
||
|
|
func encodeNumTrans(n int) byte {
|
||
|
|
if n <= maxNumTrans {
|
||
|
|
return byte(n)
|
||
|
|
}
|
||
|
|
return 0
|
||
|
|
}
|
||
|
|
|
||
|
|
func readPackedUint(data []byte) (rv uint64) {
|
||
|
|
for i := range data {
|
||
|
|
shifted := uint64(data[i]) << uint(i*8)
|
||
|
|
rv |= shifted
|
||
|
|
}
|
||
|
|
return
|
||
|
|
}
|