/*
* Copyright 2017 The Netty Project
*
* The Netty Project licenses this file to you 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 io.netty.handler.codec.http2;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.microbench.util.AbstractMicrobenchmark;
import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.BenchmarkMode;
import org.openjdk.jmh.annotations.Fork;
import org.openjdk.jmh.annotations.Measurement;
import org.openjdk.jmh.annotations.Mode;
import org.openjdk.jmh.annotations.OutputTimeUnit;
import org.openjdk.jmh.annotations.Scope;
import org.openjdk.jmh.annotations.Setup;
import org.openjdk.jmh.annotations.State;
import org.openjdk.jmh.annotations.Threads;
import org.openjdk.jmh.annotations.Warmup;
import java.util.concurrent.TimeUnit;
@Threads(1)
@State(Scope.Benchmark)
@Fork(1)
@Warmup(iterations = 5)
@Measurement(iterations = 10)
@OutputTimeUnit(TimeUnit.NANOSECONDS)
public class HpackDecoderULE128Benchmark extends AbstractMicrobenchmark {
private static final Http2Exception DECODE_ULE_128_TO_LONG_DECOMPRESSION_EXCEPTION =
new Http2Exception(Http2Error.COMPRESSION_ERROR);
private static final Http2Exception DECODE_ULE_128_TO_INT_DECOMPRESSION_EXCEPTION =
new Http2Exception(Http2Error.COMPRESSION_ERROR);
private static final Http2Exception DECODE_ULE_128_DECOMPRESSION_EXCEPTION =
new Http2Exception(Http2Error.COMPRESSION_ERROR);
private ByteBuf longMaxBuf;
private ByteBuf intMaxBuf;
@Setup
public void setup() {
byte[] longMax = {(byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF,
(byte) 0xFF, (byte) 0x7F};
longMaxBuf = Unpooled.wrappedBuffer(longMax);
byte[] intMax = {(byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0x07};
intMaxBuf = Unpooled.wrappedBuffer(intMax);
}
@Benchmark
@BenchmarkMode(Mode.AverageTime)
public long decodeMaxLong() throws Http2Exception {
long v = decodeULE128(longMaxBuf, 0L);
longMaxBuf.readerIndex(0);
return v;
}
@Benchmark
@BenchmarkMode(Mode.AverageTime)
public long decodeMaxIntWithLong() throws Http2Exception {
long v = decodeULE128(intMaxBuf, 0L);
intMaxBuf.readerIndex(0);
return v;
}
@Benchmark
@BenchmarkMode(Mode.AverageTime)
public int decodeMaxInt() throws Http2Exception {
int v = decodeULE128(intMaxBuf, 0);
intMaxBuf.readerIndex(0);
return v;
}
@Benchmark
@BenchmarkMode(Mode.AverageTime)
public int decodeMaxIntUsingLong() throws Http2Exception {
int v = decodeULE128UsingLong(intMaxBuf, 0);
intMaxBuf.readerIndex(0);
return v;
}
static int decodeULE128UsingLong(ByteBuf in, int result) throws Http2Exception {
final int readerIndex = in.readerIndex();
final long v = decodeULE128(in, (long) result);
if (v > Integer.MAX_VALUE) {
in.readerIndex(readerIndex);
throw DECODE_ULE_128_TO_INT_DECOMPRESSION_EXCEPTION;
}
return (int) v;
}
static long decodeULE128(ByteBuf in, long result) throws Http2Exception {
assert result <= 0x7f && result >= 0;
final boolean resultStartedAtZero = result == 0;
final int writerIndex = in.writerIndex();
for (int readerIndex = in.readerIndex(), shift = 0; readerIndex < writerIndex; ++readerIndex, shift += 7) {
byte b = in.getByte(readerIndex);
if (shift == 56 && ((b & 0x80) != 0 || b == 0x7F && !resultStartedAtZero)) {
// the maximum value that can be represented by a signed 64 bit number is:
// [0x01L, 0x7fL] + 0x7fL + (0x7fL << 7) + (0x7fL << 14) + (0x7fL << 21) + (0x7fL << 28) + (0x7fL << 35)
// + (0x7fL << 42) + (0x7fL << 49) + (0x7eL << 56)
// OR
// 0x0L + 0x7fL + (0x7fL << 7) + (0x7fL << 14) + (0x7fL << 21) + (0x7fL << 28) + (0x7fL << 35) +
// (0x7fL << 42) + (0x7fL << 49) + (0x7fL << 56)
// this means any more shifts will result longMaxBuf overflow so we should break out and throw an error.
throw DECODE_ULE_128_TO_LONG_DECOMPRESSION_EXCEPTION;
}
if ((b & 0x80) == 0) {
in.readerIndex(readerIndex + 1);
return result + ((b & 0x7FL) << shift);
}
result += (b & 0x7FL) << shift;
}
throw DECODE_ULE_128_DECOMPRESSION_EXCEPTION;
}
static int decodeULE128(ByteBuf in, int result) throws Http2Exception {
assert result <= 0x7f && result >= 0;
final boolean resultStartedAtZero = result == 0;
final int writerIndex = in.writerIndex();
for (int readerIndex = in.readerIndex(), shift = 0; readerIndex < writerIndex; ++readerIndex, shift += 7) {
byte b = in.getByte(readerIndex);
if (shift == 28 && ((b & 0x80) != 0 || !resultStartedAtZero && b > 6 || resultStartedAtZero && b > 7)) {
// the maximum value that can be represented by a signed 32 bit number is:
// [0x1,0x7f] + 0x7f + (0x7f << 7) + (0x7f << 14) + (0x7f << 21) + (0x6 << 28)
// OR
// 0x0 + 0x7f + (0x7f << 7) + (0x7f << 14) + (0x7f << 21) + (0x7 << 28)
// this means any more shifts will result longMaxBuf overflow so we should break out and throw an error.
throw DECODE_ULE_128_TO_INT_DECOMPRESSION_EXCEPTION;
}
if ((b & 0x80) == 0) {
in.readerIndex(readerIndex + 1);
return result + ((b & 0x7F) << shift);
}
result += (b & 0x7F) << shift;
}
throw DECODE_ULE_128_DECOMPRESSION_EXCEPTION;
}
}