bounds-checking elimination

hprose · Mar 18, 2022 · d29eadc · d29eadc
1 parent d4e3915
commit d29eadc
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Showing 3 changed files with 31 additions and 29 deletions.
diff --git a/rpc/socket/common.go b/rpc/socket/common.go
@@ -6,7 +6,7 @@
 |                                                          |
 | rpc/socket/common.go                                     |
 |                                                          |
-| LastModified: May 9, 2021                                |
+| LastModified: Mar 18, 2022                               |
 | Author: Ma Bingyao <[email protected]>                    |
 |                                                          |
 \*________________________________________________________*/
@@ -28,30 +28,31 @@ type data struct {
 }
 
 func makeHeader(length int, index int) (header [12]byte) {
-	header[4] = byte((length >> 24 & 0xff) | 0x80)
-	header[5] = byte(length >> 16 & 0xff)
-	header[6] = byte(length >> 8 & 0xff)
-	header[7] = byte(length & 0xff)
-	header[8] = byte(index >> 24 & 0xff)
-	header[9] = byte(index >> 16 & 0xff)
-	header[10] = byte(index >> 8 & 0xff)
 	header[11] = byte(index & 0xff)
+	header[10] = byte(index >> 8 & 0xff)
+	header[9] = byte(index >> 16 & 0xff)
+	header[8] = byte(index >> 24 & 0xff)
+	header[7] = byte(length & 0xff)
+	header[6] = byte(length >> 8 & 0xff)
+	header[5] = byte(length >> 16 & 0xff)
+	header[4] = byte((length >> 24 & 0xff) | 0x80)
 	crc := crc32.ChecksumIEEE(header[4:])
-	header[0] = byte(crc >> 24 & 0xff)
-	header[1] = byte(crc >> 16 & 0xff)
-	header[2] = byte(crc >> 8 & 0xff)
 	header[3] = byte(crc & 0xff)
+	header[2] = byte(crc >> 8 & 0xff)
+	header[1] = byte(crc >> 16 & 0xff)
+	header[0] = byte(crc >> 24 & 0xff)
 	return
 }
 
 func parseHeader(header [12]byte) (length int, index int, ok bool) {
-	crc := uint32(header[0])<<24 | uint32(header[1])<<16 | uint32(header[2])<<8 | uint32(header[3])
+	index = int(header[11]) | int(header[10])<<8 | int(header[9])<<16 | int(header[8])<<24
+	length = int(header[7]) | int(header[6])<<8 | int(header[5])<<16 | int(header[4]&0x7F)<<24
+	crc := uint32(header[3]) | uint32(header[2])<<8 | uint32(header[1])<<16 | uint32(header[0])<<24
 	if crc32.ChecksumIEEE(header[4:]) != crc {
 		index = -1
+		length = 0
 		return
 	}
-	length = int(header[4]&0x7F)<<24 | int(header[5])<<16 | int(header[6])<<8 | int(header[7])
-	index = int(header[8])<<24 | int(header[9])<<16 | int(header[10])<<8 | int(header[11])
 	if ok = (header[8]&0x80 == 0); !ok {
 		index &= 0x7fffffff
 	}

diff --git a/rpc/udp/common.go b/rpc/udp/common.go
@@ -6,7 +6,7 @@
 |                                                          |
 | rpc/udp/common.go                                        |
 |                                                          |
-| LastModified: May 5, 2021                                |
+| LastModified: May 18, 2022                               |
 | Author: Ma Bingyao <[email protected]>                    |
 |                                                          |
 \*________________________________________________________*/
@@ -26,26 +26,27 @@ type data struct {
 }
 
 func makeHeader(length int, index int) (header [8]byte) {
-	header[4] = byte(length >> 8 & 0xff)
-	header[5] = byte(length & 0xff)
-	header[6] = byte(index >> 8 & 0xff)
 	header[7] = byte(index & 0xff)
+	header[6] = byte(index >> 8 & 0xff)
+	header[5] = byte(length & 0xff)
+	header[4] = byte(length >> 8 & 0xff)
 	crc := crc32.ChecksumIEEE(header[4:])
-	header[0] = byte(crc >> 24 & 0xff)
-	header[1] = byte(crc >> 16 & 0xff)
-	header[2] = byte(crc >> 8 & 0xff)
 	header[3] = byte(crc & 0xff)
+	header[2] = byte(crc >> 8 & 0xff)
+	header[1] = byte(crc >> 16 & 0xff)
+	header[0] = byte(crc >> 24 & 0xff)
 	return
 }
 
 func parseHeader(header []byte) (length int, index int, ok bool) {
-	crc := uint32(header[0])<<24 | uint32(header[1])<<16 | uint32(header[2])<<8 | uint32(header[3])
+	index = int(header[7]) | int(header[6])<<8
+	length = int(header[5]) | int(header[4])<<8
+	crc := uint32(header[3]) | uint32(header[2])<<8 | uint32(header[1])<<16 | uint32(header[0])<<24
 	if crc32.ChecksumIEEE(header[4:]) != crc {
 		index = -1
+		length = 0
 		return
 	}
-	length = int(header[4])<<8 | int(header[5])
-	index = int(header[6])<<8 | int(header[7])
 	if ok = (header[6]&0x80 == 0); !ok {
 		index &= 0x7fff
 	}

diff --git a/rpc/websocket/common.go b/rpc/websocket/common.go
@@ -6,7 +6,7 @@
 |                                                          |
 | rpc/websocket/common.go                                  |
 |                                                          |
-| LastModified: May 5, 2021                                |
+| LastModified: Mar 18, 2022                               |
 | Author: Ma Bingyao <[email protected]>                    |
 |                                                          |
 \*________________________________________________________*/
@@ -20,15 +20,15 @@ type data struct {
 }
 
 func makeHeader(index int) (header [4]byte) {
-	header[0] = byte(index >> 24 & 0xff)
-	header[1] = byte(index >> 16 & 0xff)
-	header[2] = byte(index >> 8 & 0xff)
 	header[3] = byte(index & 0xff)
+	header[2] = byte(index >> 8 & 0xff)
+	header[1] = byte(index >> 16 & 0xff)
+	header[0] = byte(index >> 24 & 0xff)
 	return
 }
 
 func parseHeader(header []byte) (index int, ok bool) {
-	index = int(header[0])<<24 | int(header[1])<<16 | int(header[2])<<8 | int(header[3])
+	index = int(header[3]) | int(header[2])<<8 | int(header[1])<<16 | int(header[0])<<24
 	if ok = (header[0]&0x80 == 0); !ok {
 		index &= 0x7fffffff
 	}