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path: root/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/util/hash.go
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Diffstat (limited to 'Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/util/hash.go')
-rw-r--r--Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/util/hash.go28
1 files changed, 14 insertions, 14 deletions
diff --git a/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/util/hash.go b/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/util/hash.go
index 54903660f..7f3fa4e2c 100644
--- a/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/util/hash.go
+++ b/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/util/hash.go
@@ -7,38 +7,38 @@
package util
import (
- "bytes"
"encoding/binary"
)
// Hash return hash of the given data.
func Hash(data []byte, seed uint32) uint32 {
// Similar to murmur hash
- var m uint32 = 0xc6a4a793
- var r uint32 = 24
- h := seed ^ (uint32(len(data)) * m)
+ const (
+ m = uint32(0xc6a4a793)
+ r = uint32(24)
+ )
+ var (
+ h = seed ^ (uint32(len(data)) * m)
+ i int
+ )
- buf := bytes.NewBuffer(data)
- for buf.Len() >= 4 {
- var w uint32
- binary.Read(buf, binary.LittleEndian, &w)
- h += w
+ for n := len(data) - len(data)%4; i < n; i += 4 {
+ h += binary.LittleEndian.Uint32(data[i:])
h *= m
h ^= (h >> 16)
}
- rest := buf.Bytes()
- switch len(rest) {
+ switch len(data) - i {
default:
panic("not reached")
case 3:
- h += uint32(rest[2]) << 16
+ h += uint32(data[i+2]) << 16
fallthrough
case 2:
- h += uint32(rest[1]) << 8
+ h += uint32(data[i+1]) << 8
fallthrough
case 1:
- h += uint32(rest[0])
+ h += uint32(data[i])
h *= m
h ^= (h >> r)
case 0: