mirror of
https://codeberg.org/forgejo/forgejo.git
synced 2024-11-23 08:47:42 -05:00
94 lines
2.1 KiB
Go
Vendored
94 lines
2.1 KiB
Go
Vendored
// Copyright (c) 2020 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 zap
|
|
|
|
import (
|
|
"fmt"
|
|
)
|
|
|
|
type memUvarintReader struct {
|
|
C int // index of next byte to read from S
|
|
S []byte
|
|
}
|
|
|
|
func newMemUvarintReader(s []byte) *memUvarintReader {
|
|
return &memUvarintReader{S: s}
|
|
}
|
|
|
|
// Len returns the number of unread bytes.
|
|
func (r *memUvarintReader) Len() int {
|
|
n := len(r.S) - r.C
|
|
if n < 0 {
|
|
return 0
|
|
}
|
|
return n
|
|
}
|
|
|
|
// ReadUvarint reads an encoded uint64. The original code this was
|
|
// based on is at encoding/binary/ReadUvarint().
|
|
func (r *memUvarintReader) ReadUvarint() (uint64, error) {
|
|
var x uint64
|
|
var s uint
|
|
var C = r.C
|
|
var S = r.S
|
|
|
|
for {
|
|
b := S[C]
|
|
C++
|
|
|
|
if b < 0x80 {
|
|
r.C = C
|
|
|
|
// why 63? The original code had an 'i += 1' loop var and
|
|
// checked for i > 9 || i == 9 ...; but, we no longer
|
|
// check for the i var, but instead check here for s,
|
|
// which is incremented by 7. So, 7*9 == 63.
|
|
//
|
|
// why the "extra" >= check? The normal case is that s <
|
|
// 63, so we check this single >= guard first so that we
|
|
// hit the normal, nil-error return pathway sooner.
|
|
if s >= 63 && (s > 63 || s == 63 && b > 1) {
|
|
return 0, fmt.Errorf("memUvarintReader overflow")
|
|
}
|
|
|
|
return x | uint64(b)<<s, nil
|
|
}
|
|
|
|
x |= uint64(b&0x7f) << s
|
|
s += 7
|
|
}
|
|
}
|
|
|
|
// SkipUvarint skips ahead one encoded uint64.
|
|
func (r *memUvarintReader) SkipUvarint() {
|
|
for {
|
|
b := r.S[r.C]
|
|
r.C++
|
|
|
|
if b < 0x80 {
|
|
return
|
|
}
|
|
}
|
|
}
|
|
|
|
// SkipBytes skips a count number of bytes.
|
|
func (r *memUvarintReader) SkipBytes(count int) {
|
|
r.C = r.C + count
|
|
}
|
|
|
|
func (r *memUvarintReader) Reset(s []byte) {
|
|
r.C = 0
|
|
r.S = s
|
|
}
|