diff options
Diffstat (limited to 'vendor/github.com/gorilla/websocket/mask.go')
-rw-r--r-- | vendor/github.com/gorilla/websocket/mask.go | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/vendor/github.com/gorilla/websocket/mask.go b/vendor/github.com/gorilla/websocket/mask.go new file mode 100644 index 00000000..6a88bbc7 --- /dev/null +++ b/vendor/github.com/gorilla/websocket/mask.go @@ -0,0 +1,55 @@ +// Copyright 2016 The Gorilla WebSocket Authors. All rights reserved. Use of +// this source code is governed by a BSD-style license that can be found in the +// LICENSE file. + +// +build !appengine + +package websocket + +import "unsafe" + +const wordSize = int(unsafe.Sizeof(uintptr(0))) + +func maskBytes(key [4]byte, pos int, b []byte) int { + + // Mask one byte at a time for small buffers. + if len(b) < 2*wordSize { + for i := range b { + b[i] ^= key[pos&3] + pos++ + } + return pos & 3 + } + + // Mask one byte at a time to word boundary. + if n := int(uintptr(unsafe.Pointer(&b[0]))) % wordSize; n != 0 { + n = wordSize - n + for i := range b[:n] { + b[i] ^= key[pos&3] + pos++ + } + b = b[n:] + } + + // Create aligned word size key. + var k [wordSize]byte + for i := range k { + k[i] = key[(pos+i)&3] + } + kw := *(*uintptr)(unsafe.Pointer(&k)) + + // Mask one word at a time. + n := (len(b) / wordSize) * wordSize + for i := 0; i < n; i += wordSize { + *(*uintptr)(unsafe.Pointer(uintptr(unsafe.Pointer(&b[0])) + uintptr(i))) ^= kw + } + + // Mask one byte at a time for remaining bytes. + b = b[n:] + for i := range b { + b[i] ^= key[pos&3] + pos++ + } + + return pos & 3 +} |