Many resources are needed to download a project. Please understand that we have to compensate our server costs. Thank you in advance.
Project price only 1 $
You can buy this project and download/modify it how often you want.
okhttp3.internal.http2.Huffman.kt Maven / Gradle / Ivy
/*
* Copyright 2013 Twitter, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package okhttp3.internal.http2
import java.io.IOException
import okhttp3.internal.and
import okio.BufferedSink
import okio.BufferedSource
import okio.ByteString
/**
* This class was originally composed from the following classes in
* [Twitter Hpack][twitter_hpack].
*
* * `com.twitter.hpack.HuffmanEncoder`
* * `com.twitter.hpack.HuffmanDecoder`
* * `com.twitter.hpack.HpackUtil`
*
* [twitter_hpack]: https://github.com/twitter/hpack
*/
object Huffman {
// Appendix C: Huffman Codes
// http://tools.ietf.org/html/draft-ietf-httpbis-header-compression-12#appendix-B
private val CODES =
intArrayOf(0x1ff8, 0x7fffd8, 0xfffffe2, 0xfffffe3, 0xfffffe4, 0xfffffe5, 0xfffffe6,
0xfffffe7, 0xfffffe8, 0xffffea, 0x3ffffffc, 0xfffffe9, 0xfffffea, 0x3ffffffd, 0xfffffeb,
0xfffffec, 0xfffffed, 0xfffffee, 0xfffffef, 0xffffff0, 0xffffff1, 0xffffff2, 0x3ffffffe,
0xffffff3, 0xffffff4, 0xffffff5, 0xffffff6, 0xffffff7, 0xffffff8, 0xffffff9, 0xffffffa,
0xffffffb, 0x14, 0x3f8, 0x3f9, 0xffa, 0x1ff9, 0x15, 0xf8, 0x7fa, 0x3fa, 0x3fb, 0xf9,
0x7fb, 0xfa, 0x16, 0x17, 0x18, 0x0, 0x1, 0x2, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
0x5c, 0xfb, 0x7ffc, 0x20, 0xffb, 0x3fc, 0x1ffa, 0x21, 0x5d, 0x5e, 0x5f, 0x60, 0x61,
0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
0x70, 0x71, 0x72, 0xfc, 0x73, 0xfd, 0x1ffb, 0x7fff0, 0x1ffc, 0x3ffc, 0x22, 0x7ffd, 0x3,
0x23, 0x4, 0x24, 0x5, 0x25, 0x26, 0x27, 0x6, 0x74, 0x75, 0x28, 0x29, 0x2a, 0x7, 0x2b,
0x76, 0x2c, 0x8, 0x9, 0x2d, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7ffe, 0x7fc, 0x3ffd, 0x1ffd,
0xffffffc, 0xfffe6, 0x3fffd2, 0xfffe7, 0xfffe8, 0x3fffd3, 0x3fffd4, 0x3fffd5, 0x7fffd9,
0x3fffd6, 0x7fffda, 0x7fffdb, 0x7fffdc, 0x7fffdd, 0x7fffde, 0xffffeb, 0x7fffdf,
0xffffec, 0xffffed, 0x3fffd7, 0x7fffe0, 0xffffee, 0x7fffe1, 0x7fffe2, 0x7fffe3,
0x7fffe4, 0x1fffdc, 0x3fffd8, 0x7fffe5, 0x3fffd9, 0x7fffe6, 0x7fffe7, 0xffffef,
0x3fffda, 0x1fffdd, 0xfffe9, 0x3fffdb, 0x3fffdc, 0x7fffe8, 0x7fffe9, 0x1fffde, 0x7fffea,
0x3fffdd, 0x3fffde, 0xfffff0, 0x1fffdf, 0x3fffdf, 0x7fffeb, 0x7fffec, 0x1fffe0,
0x1fffe1, 0x3fffe0, 0x1fffe2, 0x7fffed, 0x3fffe1, 0x7fffee, 0x7fffef, 0xfffea, 0x3fffe2,
0x3fffe3, 0x3fffe4, 0x7ffff0, 0x3fffe5, 0x3fffe6, 0x7ffff1, 0x3ffffe0, 0x3ffffe1,
0xfffeb, 0x7fff1, 0x3fffe7, 0x7ffff2, 0x3fffe8, 0x1ffffec, 0x3ffffe2, 0x3ffffe3,
0x3ffffe4, 0x7ffffde, 0x7ffffdf, 0x3ffffe5, 0xfffff1, 0x1ffffed, 0x7fff2, 0x1fffe3,
0x3ffffe6, 0x7ffffe0, 0x7ffffe1, 0x3ffffe7, 0x7ffffe2, 0xfffff2, 0x1fffe4, 0x1fffe5,
0x3ffffe8, 0x3ffffe9, 0xffffffd, 0x7ffffe3, 0x7ffffe4, 0x7ffffe5, 0xfffec, 0xfffff3,
0xfffed, 0x1fffe6, 0x3fffe9, 0x1fffe7, 0x1fffe8, 0x7ffff3, 0x3fffea, 0x3fffeb,
0x1ffffee, 0x1ffffef, 0xfffff4, 0xfffff5, 0x3ffffea, 0x7ffff4, 0x3ffffeb, 0x7ffffe6,
0x3ffffec, 0x3ffffed, 0x7ffffe7, 0x7ffffe8, 0x7ffffe9, 0x7ffffea, 0x7ffffeb, 0xffffffe,
0x7ffffec, 0x7ffffed, 0x7ffffee, 0x7ffffef, 0x7fffff0, 0x3ffffee)
private val CODE_BIT_COUNTS =
byteArrayOf(13, 23, 28, 28, 28, 28, 28, 28, 28, 24, 30, 28, 28, 30, 28, 28, 28, 28, 28, 28,
28, 28, 30, 28, 28, 28, 28, 28, 28, 28, 28, 28, 6, 10, 10, 12, 13, 6, 8, 11, 10, 10, 8,
11, 8, 6, 6, 6, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 7, 8, 15, 6, 12, 10, 13, 6, 7, 7, 7, 7, 7,
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 8, 7, 8, 13, 19, 13, 14, 6, 15, 5, 6,
5, 6, 5, 6, 6, 6, 5, 7, 7, 6, 6, 6, 5, 6, 7, 6, 5, 5, 6, 7, 7, 7, 7, 7, 15, 11, 14, 13,
28, 20, 22, 20, 20, 22, 22, 22, 23, 22, 23, 23, 23, 23, 23, 24, 23, 24, 24, 22, 23, 24,
23, 23, 23, 23, 21, 22, 23, 22, 23, 23, 24, 22, 21, 20, 22, 22, 23, 23, 21, 23, 22, 22,
24, 21, 22, 23, 23, 21, 21, 22, 21, 23, 22, 23, 23, 20, 22, 22, 22, 23, 22, 22, 23, 26,
26, 20, 19, 22, 23, 22, 25, 26, 26, 26, 27, 27, 26, 24, 25, 19, 21, 26, 27, 27, 26, 27,
24, 21, 21, 26, 26, 28, 27, 27, 27, 20, 24, 20, 21, 22, 21, 21, 23, 22, 22, 25, 25, 24,
24, 26, 23, 26, 27, 26, 26, 27, 27, 27, 27, 27, 28, 27, 27, 27, 27, 27, 26)
private val root = Node()
init {
for (i in CODE_BIT_COUNTS.indices) {
addCode(i, CODES[i], CODE_BIT_COUNTS[i].toInt())
}
}
@Throws(IOException::class)
fun encode(source: ByteString, sink: BufferedSink) {
var accumulator = 0L
var accumulatorBitCount = 0
for (i in 0 until source.size) {
val symbol = source[i] and 0xff
val code = CODES[symbol]
val codeBitCount = CODE_BIT_COUNTS[symbol].toInt()
accumulator = (accumulator shl codeBitCount) or code.toLong()
accumulatorBitCount += codeBitCount
while (accumulatorBitCount >= 8) {
accumulatorBitCount -= 8
sink.writeByte((accumulator shr accumulatorBitCount).toInt())
}
}
if (accumulatorBitCount > 0) {
accumulator = accumulator shl (8 - accumulatorBitCount)
accumulator = accumulator or (0xffL ushr accumulatorBitCount)
sink.writeByte(accumulator.toInt())
}
}
fun encodedLength(bytes: ByteString): Int {
var bitCount = 0L
for (i in 0 until bytes.size) {
val byteIn = bytes[i] and 0xff
bitCount += CODE_BIT_COUNTS[byteIn].toLong()
}
return ((bitCount + 7) shr 3).toInt() // Round up to an even byte.
}
fun decode(source: BufferedSource, byteCount: Long, sink: BufferedSink) {
var node = root
var accumulator = 0
var accumulatorBitCount = 0
for (i in 0 until byteCount) {
val byteIn = source.readByte() and 0xff
accumulator = accumulator shl 8 or byteIn
accumulatorBitCount += 8
while (accumulatorBitCount >= 8) {
val childIndex = (accumulator ushr (accumulatorBitCount - 8)) and 0xff
node = node.children!![childIndex]!!
if (node.children == null) {
// Terminal node.
sink.writeByte(node.symbol)
accumulatorBitCount -= node.terminalBitCount
node = root
} else {
// Non-terminal node.
accumulatorBitCount -= 8
}
}
}
while (accumulatorBitCount > 0) {
val childIndex = (accumulator shl (8 - accumulatorBitCount)) and 0xff
node = node.children!![childIndex]!!
if (node.children != null || node.terminalBitCount > accumulatorBitCount) {
break
}
sink.writeByte(node.symbol)
accumulatorBitCount -= node.terminalBitCount
node = root
}
}
private fun addCode(symbol: Int, code: Int, codeBitCount: Int) {
val terminal = Node(symbol, codeBitCount)
var accumulatorBitCount = codeBitCount
var node = root
while (accumulatorBitCount > 8) {
accumulatorBitCount -= 8
val childIndex = (code ushr accumulatorBitCount) and 0xff
val children = node.children!!
var child = children[childIndex]
if (child == null) {
child = Node()
children[childIndex] = child
}
node = child
}
val shift = 8 - accumulatorBitCount
val start = (code shl shift) and 0xff
val end = 1 shl shift
node.children!!.fill(terminal, start, start + end)
}
private class Node {
/** Null if terminal. */
val children: Array?
/** Terminal nodes have a symbol. */
val symbol: Int
/** Number of bits represented in the terminal node. */
val terminalBitCount: Int
/** Construct an internal node. */
constructor() {
this.children = arrayOfNulls(256)
this.symbol = 0 // Not read.
this.terminalBitCount = 0 // Not read.
}
/** Construct a terminal node. */
constructor(symbol: Int, bits: Int) {
this.children = null
this.symbol = symbol
val b = bits and 0x07
this.terminalBitCount = if (b == 0) 8 else b
}
}
}
