gitea/vendor/github.com/klauspost/compress/zstd/bytebuf.go
6543 86e2789960
Vendor Update (#16121)
* update github.com/PuerkitoBio/goquery

* update github.com/alecthomas/chroma

* update github.com/blevesearch/bleve/v2

* update github.com/caddyserver/certmagic

* update github.com/go-enry/go-enry/v2

* update github.com/go-git/go-billy/v5

* update github.com/go-git/go-git/v5

* update github.com/go-redis/redis/v8

* update github.com/go-testfixtures/testfixtures/v3

* update github.com/jaytaylor/html2text

* update github.com/json-iterator/go

* update github.com/klauspost/compress

* update github.com/markbates/goth

* update github.com/mattn/go-isatty

* update github.com/mholt/archiver/v3

* update github.com/microcosm-cc/bluemonday

* update github.com/minio/minio-go/v7

* update github.com/prometheus/client_golang

* update github.com/unrolled/render

* update github.com/xanzy/go-gitlab

* update github.com/yuin/goldmark

* update github.com/yuin/goldmark-highlighting

Co-authored-by: techknowlogick <techknowlogick@gitea.io>
2021-06-10 16:44:25 +02:00

131 lines
2.4 KiB
Go
Vendored

// Copyright 2019+ Klaus Post. All rights reserved.
// License information can be found in the LICENSE file.
// Based on work by Yann Collet, released under BSD License.
package zstd
import (
"fmt"
"io"
"io/ioutil"
)
type byteBuffer interface {
// Read up to 8 bytes.
// Returns io.ErrUnexpectedEOF if this cannot be satisfied.
readSmall(n int) ([]byte, error)
// Read >8 bytes.
// MAY use the destination slice.
readBig(n int, dst []byte) ([]byte, error)
// Read a single byte.
readByte() (byte, error)
// Skip n bytes.
skipN(n int) error
}
// in-memory buffer
type byteBuf []byte
func (b *byteBuf) readSmall(n int) ([]byte, error) {
if debugAsserts && n > 8 {
panic(fmt.Errorf("small read > 8 (%d). use readBig", n))
}
bb := *b
if len(bb) < n {
return nil, io.ErrUnexpectedEOF
}
r := bb[:n]
*b = bb[n:]
return r, nil
}
func (b *byteBuf) readBig(n int, dst []byte) ([]byte, error) {
bb := *b
if len(bb) < n {
return nil, io.ErrUnexpectedEOF
}
r := bb[:n]
*b = bb[n:]
return r, nil
}
func (b *byteBuf) remain() []byte {
return *b
}
func (b *byteBuf) readByte() (byte, error) {
bb := *b
if len(bb) < 1 {
return 0, nil
}
r := bb[0]
*b = bb[1:]
return r, nil
}
func (b *byteBuf) skipN(n int) error {
bb := *b
if len(bb) < n {
return io.ErrUnexpectedEOF
}
*b = bb[n:]
return nil
}
// wrapper around a reader.
type readerWrapper struct {
r io.Reader
tmp [8]byte
}
func (r *readerWrapper) readSmall(n int) ([]byte, error) {
if debugAsserts && n > 8 {
panic(fmt.Errorf("small read > 8 (%d). use readBig", n))
}
n2, err := io.ReadFull(r.r, r.tmp[:n])
// We only really care about the actual bytes read.
if err != nil {
if err == io.EOF {
return nil, io.ErrUnexpectedEOF
}
if debugDecoder {
println("readSmall: got", n2, "want", n, "err", err)
}
return nil, err
}
return r.tmp[:n], nil
}
func (r *readerWrapper) readBig(n int, dst []byte) ([]byte, error) {
if cap(dst) < n {
dst = make([]byte, n)
}
n2, err := io.ReadFull(r.r, dst[:n])
if err == io.EOF && n > 0 {
err = io.ErrUnexpectedEOF
}
return dst[:n2], err
}
func (r *readerWrapper) readByte() (byte, error) {
n2, err := r.r.Read(r.tmp[:1])
if err != nil {
return 0, err
}
if n2 != 1 {
return 0, io.ErrUnexpectedEOF
}
return r.tmp[0], nil
}
func (r *readerWrapper) skipN(n int) error {
n2, err := io.CopyN(ioutil.Discard, r.r, int64(n))
if n2 != int64(n) {
err = io.ErrUnexpectedEOF
}
return err
}