org.json4s.scalap.ByteCodecs.scala Maven / Gradle / Ivy
/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2007-2013, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
package org.json4s.scalap
object ByteCodecs {
def regenerateZero(src: Array[Byte]): Int = {
var i = 0
val srclen = src.length
var j = 0
while (i < srclen) {
val in: Int = src(i) & 0xff
if (in == 0xc0 && (src(i + 1) & 0xff) == 0x80) {
src(j) = 0x7f
i += 2
} else if (in == 0) {
src(j) = 0x7f
i += 1
} else {
src(j) = (in - 1).toByte
i += 1
}
j += 1
}
j
}
def decode7to8(src: Array[Byte], srclen: Int): Int = {
var i = 0
var j = 0
val dstlen = (srclen * 7 + 7) / 8
while (i + 7 < srclen) {
var out: Int = src(i).toInt
var in: Byte = src(i + 1)
src(j) = (out | (in & 0x01) << 7).toByte
out = in >>> 1
in = src(i + 2)
src(j + 1) = (out | (in & 0x03) << 6).toByte
out = in >>> 2
in = src(i + 3)
src(j + 2) = (out | (in & 0x07) << 5).toByte
out = in >>> 3
in = src(i + 4)
src(j + 3) = (out | (in & 0x0f) << 4).toByte
out = in >>> 4
in = src(i + 5)
src(j + 4) = (out | (in & 0x1f) << 3).toByte
out = in >>> 5
in = src(i + 6)
src(j + 5) = (out | (in & 0x3f) << 2).toByte
out = in >>> 6
in = src(i + 7)
src(j + 6) = (out | in << 1).toByte
i += 8
j += 7
}
if (i < srclen) {
var out: Int = src(i).toInt
if (i + 1 < srclen) {
var in: Byte = src(i + 1)
src(j) = (out | (in & 0x01) << 7).toByte; j += 1
out = in >>> 1
if (i + 2 < srclen) {
in = src(i + 2)
src(j) = (out | (in & 0x03) << 6).toByte; j += 1
out = in >>> 2
if (i + 3 < srclen) {
in = src(i + 3)
src(j) = (out | (in & 0x07) << 5).toByte; j += 1
out = in >>> 3
if (i + 4 < srclen) {
in = src(i + 4)
src(j) = (out | (in & 0x0f) << 4).toByte; j += 1
out = in >>> 4
if (i + 5 < srclen) {
in = src(i + 5)
src(j) = (out | (in & 0x1f) << 3).toByte; j += 1
out = in >>> 5
if (i + 6 < srclen) {
in = src(i + 6)
src(j) = (out | (in & 0x3f) << 2).toByte; j += 1
out = in >>> 6
}
}
}
}
}
}
if (j < dstlen) src(j) = out.toByte
}
dstlen
}
def decode(xs: Array[Byte]): Int = {
val len = regenerateZero(xs)
decode7to8(xs, len)
}
}