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authorFelix Lange <fjl@users.noreply.github.com>2018-04-09 19:47:06 +0800
committerGitHub <noreply@github.com>2018-04-09 19:47:06 +0800
commit0fac705ed0a2efcda4da9dce8971bbda73f299d5 (patch)
treee717d8a845bfd66c3882be23a6be21a4c40562b4 /compression/rle/read_write.go
parent315b9b18df7994d56f3570c509fc60ad6e3d570f (diff)
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compression/rle: delete RLE compression (#16468)
Diffstat (limited to 'compression/rle/read_write.go')
-rw-r--r--compression/rle/read_write.go101
1 files changed, 0 insertions, 101 deletions
diff --git a/compression/rle/read_write.go b/compression/rle/read_write.go
deleted file mode 100644
index 0e7ad90ae..000000000
--- a/compression/rle/read_write.go
+++ /dev/null
@@ -1,101 +0,0 @@
-// Copyright 2014 The go-ethereum Authors
-// This file is part of the go-ethereum library.
-//
-// The go-ethereum library is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Lesser General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// The go-ethereum library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public License
-// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
-
-// Package rle implements the run-length encoding used for Ethereum data.
-package rle
-
-import (
- "bytes"
- "errors"
-
- "github.com/ethereum/go-ethereum/crypto"
-)
-
-const (
- token byte = 0xfe
- emptyShaToken = 0xfd
- emptyListShaToken = 0xfe
- tokenToken = 0xff
-)
-
-var empty = crypto.Keccak256([]byte(""))
-var emptyList = crypto.Keccak256([]byte{0x80})
-
-func Decompress(dat []byte) ([]byte, error) {
- buf := new(bytes.Buffer)
-
- for i := 0; i < len(dat); i++ {
- if dat[i] == token {
- if i+1 < len(dat) {
- switch dat[i+1] {
- case emptyShaToken:
- buf.Write(empty)
- case emptyListShaToken:
- buf.Write(emptyList)
- case tokenToken:
- buf.WriteByte(token)
- default:
- buf.Write(make([]byte, int(dat[i+1]-2)))
- }
- i++
- } else {
- return nil, errors.New("error reading bytes. token encountered without proceeding bytes")
- }
- } else {
- buf.WriteByte(dat[i])
- }
- }
-
- return buf.Bytes(), nil
-}
-
-func compressChunk(dat []byte) (ret []byte, n int) {
- switch {
- case dat[0] == token:
- return []byte{token, tokenToken}, 1
- case len(dat) > 1 && dat[0] == 0x0 && dat[1] == 0x0:
- j := 0
- for j <= 254 && j < len(dat) {
- if dat[j] != 0 {
- break
- }
- j++
- }
- return []byte{token, byte(j + 2)}, j
- case len(dat) >= 32:
- if dat[0] == empty[0] && bytes.Equal(dat[:32], empty) {
- return []byte{token, emptyShaToken}, 32
- } else if dat[0] == emptyList[0] && bytes.Equal(dat[:32], emptyList) {
- return []byte{token, emptyListShaToken}, 32
- }
- fallthrough
- default:
- return dat[:1], 1
- }
-}
-
-func Compress(dat []byte) []byte {
- buf := new(bytes.Buffer)
-
- i := 0
- for i < len(dat) {
- b, n := compressChunk(dat[i:])
- buf.Write(b)
- i += n
- }
-
- return buf.Bytes()
-}