first commit

util/bits/pio/reader.go

@@ -0,0 +1,121 @@
+package pio
+
+func U8(b []byte) (i uint8) {
+	return b[0]
+}
+
+func U16BE(b []byte) (i uint16) {
+	i = uint16(b[0])
+	i <<= 8
+	i |= uint16(b[1])
+	return
+}
+
+func I16BE(b []byte) (i int16) {
+	i = int16(b[0])
+	i <<= 8
+	i |= int16(b[1])
+	return
+}
+
+func I24BE(b []byte) (i int32) {
+	i = int32(int8(b[0]))
+	i <<= 8
+	i |= int32(b[1])
+	i <<= 8
+	i |= int32(b[2])
+	return
+}
+
+func U24BE(b []byte) (i uint32) {
+	i = uint32(b[0])
+	i <<= 8
+	i |= uint32(b[1])
+	i <<= 8
+	i |= uint32(b[2])
+	return
+}
+
+func I32BE(b []byte) (i int32) {
+	i = int32(int8(b[0]))
+	i <<= 8
+	i |= int32(b[1])
+	i <<= 8
+	i |= int32(b[2])
+	i <<= 8
+	i |= int32(b[3])
+	return
+}
+
+func U32LE(b []byte) (i uint32) {
+	i = uint32(b[3])
+	i <<= 8
+	i |= uint32(b[2])
+	i <<= 8
+	i |= uint32(b[1])
+	i <<= 8
+	i |= uint32(b[0])
+	return
+}
+
+func U32BE(b []byte) (i uint32) {
+	i = uint32(b[0])
+	i <<= 8
+	i |= uint32(b[1])
+	i <<= 8
+	i |= uint32(b[2])
+	i <<= 8
+	i |= uint32(b[3])
+	return
+}
+
+func U40BE(b []byte) (i uint64) {
+	i = uint64(b[0])
+	i <<= 8
+	i |= uint64(b[1])
+	i <<= 8
+	i |= uint64(b[2])
+	i <<= 8
+	i |= uint64(b[3])
+	i <<= 8
+	i |= uint64(b[4])
+	return
+}
+
+func U64BE(b []byte) (i uint64) {
+	i = uint64(b[0])
+	i <<= 8
+	i |= uint64(b[1])
+	i <<= 8
+	i |= uint64(b[2])
+	i <<= 8
+	i |= uint64(b[3])
+	i <<= 8
+	i |= uint64(b[4])
+	i <<= 8
+	i |= uint64(b[5])
+	i <<= 8
+	i |= uint64(b[6])
+	i <<= 8
+	i |= uint64(b[7])
+	return
+}
+
+func I64BE(b []byte) (i int64) {
+	i = int64(int8(b[0]))
+	i <<= 8
+	i |= int64(b[1])
+	i <<= 8
+	i |= int64(b[2])
+	i <<= 8
+	i |= int64(b[3])
+	i <<= 8
+	i |= int64(b[4])
+	i <<= 8
+	i |= int64(b[5])
+	i <<= 8
+	i |= int64(b[6])
+	i <<= 8
+	i |= int64(b[7])
+	return
+}