From 92c7aca817a78cc1b14a8d57a0be20b4772a1d69 Mon Sep 17 00:00:00 2001
From: obscuren <geffobscura@gmail.com>
Date: Mon, 3 Nov 2014 14:59:50 +0100
Subject: [PATCH] Refactored compress method into something more organised
---
compression/rle/read_write.go | 60 +++++++++++++++++------------------
1 file changed, 30 insertions(+), 30 deletions(-)
diff --git a/compression/rle/read_write.go b/compression/rle/read_write.go
index b4b73dab4..a5b80222c 100644
--- a/compression/rle/read_write.go
+++ b/compression/rle/read_write.go
@@ -45,39 +45,39 @@ func Decompress(dat []byte) ([]byte, error) {
return buf.Bytes(), nil
}
+func compressBlock(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.Compare(dat[:32], empty) == 0 {
+ return []byte{token, emptyShaToken}, 32
+ } else if dat[0] == emptyList[0] && bytes.Compare(dat[:32], emptyList) == 0 {
+ return []byte{token, emptyListShaToken}, 32
+ }
+ fallthrough
+ default:
+ return dat[:1], 1
+ }
+}
+
func Compress(dat []byte) []byte {
buf := new(bytes.Buffer)
- for i := 0; i < len(dat); i++ {
- if dat[i] == token {
- buf.Write([]byte{token, tokenToken})
- } else if i+1 < len(dat) {
- if dat[i] == 0x0 && dat[i+1] == 0x0 {
- j := 0
- for j <= 254 && i+j < len(dat) {
- if dat[i+j] != 0 {
- break
- }
- j++
- }
- buf.Write([]byte{token, byte(j + 2)})
- i += (j - 1)
- } else if len(dat[i:]) >= 32 {
- if dat[i] == empty[0] && bytes.Compare(dat[i:i+32], empty) == 0 {
- buf.Write([]byte{token, emptyShaToken})
- i += 31
- } else if dat[i] == emptyList[0] && bytes.Compare(dat[i:i+32], emptyList) == 0 {
- buf.Write([]byte{token, emptyListShaToken})
- i += 31
- } else {
- buf.WriteByte(dat[i])
- }
- } else {
- buf.WriteByte(dat[i])
- }
- } else {
- buf.WriteByte(dat[i])
- }
+ i := 0
+ for i < len(dat) {
+ b, n := compressBlock(dat[i:])
+ buf.Write(b)
+ i += n
}
return buf.Bytes()
--
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